First-Hand:Legacy of NTDS - Chapter 9 of the Story of the Naval Tactical Data System

By David L.Boslaugh, Capt. USN, Retired

Digital Revolution in the Fleet

Spread of NTDS in the Fleet

It was the intent of the Chief of Naval Operations that all Navy combatant ships from guided missile frigate on up were to get the Naval,Tactical, Data System; provided they had enough years of useful service left to make the investment worthwhile. The first NTDS production equipment contract provided the equipage for nine guided missile frigates of the Belknap Class, for the two nuclear powered guided missile frigates Bainbridge and Truxton, two heavy missile cruisers, and three attack carriers that were fitted with guided missile systems. This was the first priority. Next, all existing attack carriers, not slated for near term decommissioning, were to get the system at their next regularly scheduled shipyard availability, and, in the mean time, all new construction heavy combatants would get the system during construction.

By the end of 1965, ten USN ships were at sea with NTDS, and 22 installations were underway as back fits or new construction. Also OPNAV had authorized installation in 33 more ships. By December 1966 there were 15 operational USN ships fitted with NTDS, and NTDS had been installed in allied navy ships of France, Italy, and Germany. Even if there might be a language barrier, the ships of six navies could share target and status information through the common language of NATO Link 11; the two additional participants being the Royal Navy and the Royal Canadian Navy who had devised their own Link-11 compatible tactical data systems.

NTDS data processing and display equipment was also being found useful by other project managers such as the Automatic Carrier Landing System that used radars, an NTDS computer, and data links to bring aircraft into hands-off carrier landings. Other uses of NTDS equipment were in: the National Emergency Command Post Afloat, the Attack Carrier Integrated Operational Intelligence Center, and the shipboard Message Processing and Distribution System. In addition, more than 15 shore based systems had incorporated NTDS equipment. These included the harsh environments of National Aeronautics and Space Administration remote tracking sites where the NTDS computers felt quite at home. [Bureau of Ships, internal memorandum from Code 607A to Code 22, Subject: NTDS Personnel requirements for CY 1966, Serial 607A-M104, 29 Nov. 1965] [Bureau of Ships, NTDS Project Office, NTDS Procurement Summary, 5 Dec. 1966]

Next in ship priority to have NTDS installed were eight guided missile frigates of the Coontz (DLG 6) Class and the nine guided missile frigates of the Leahy (DLG 16) Class. Although there were ten ships in the Coontz Class, DLG 10 and 11 (King and Mahan) already had service test NTDS installations. The project was called the Guided Missile Frigate Anti-Air Warfare Modernization Program, and included: NTDS with Weapons Direction System Mark 11, replacing the AN/SPS-39 air search radar with the AN/SPS-48 three dimensional radar, providing two-way communications between the underwater battery fire control system and NTDS, and upgrading the Terrier missile fire control system to a standard configuration. The first ships began the program in 1967, and the last would finish in 1975. [Cockell, Cdr. William A., Jr., USN, "The DLG Modernization Program," U.S. Naval Institute Proceedings, Vol. 98, No. 1/827, Jan 1972, pp. 101-104]

By late 1965 when the AAW Modernization Program was conceived, it was acknowledged that the two unit computers on the guided missile frigates were full to overflowing; and fleet officers were now comfortable with NTDS. The fleet wanted the system to do many more things. One solution to freeing up memory in the unit computers was to move the WDS Mark 11 function to an additional computer as part of the modernization program. Lcdr. Joe Randolph took on the task of conceptualizing the weapons direction system for the modernization program.

In addition to the original WDS Mk 11 functions, the Terrier missile system project office called for a greatly increased flow of signals between NTDS and the Terrier fire control system. These came from many points in the fire control system, and many were in the form of analog synchro signals to be converted by the new keyset central multiplexer. Many of these new signals were for the purpose of daily system tests of the missile system, wherein the missileers now had sufficient confidence in NTDS to use an off duty NTDS computer in a split system to run daily tests of the missile system. More about this later. Furthermore the connection between NTDS and the underwater battery fire control system called for the transmission and conversion of numerous synchro signals as well as on-off control and status signals.

In 1962 Univac management sensed the need for a militarized computer having about half the computing power of the NTDS unit computer, and began developing the 1218 computer with their own funds. It had an 18-bit word length and held from four thousand to 32 thousand words. The navy gave the machine the military designation CP-789. A version with expanded memory designated the AN/UYK-5 was also used by the USN in a shipboard material management system. Univac Division of Sperry Rand Corp. photo.

Randolph sized the new WDS MK 11 computing requirement and found it called for a computer having about half the computing power of the CP-642B unit computer. He recommended using a new machine Univac had developed on their own; sensing there would be need in the fleet for computers smaller than the unit computer. Univac called the new 18-bit-word 'minicomputer' the 1218, and BUSHIPS had already given it the military designation CP-789 when it had been put to work as the Beacon Video Processor computer. Randolph named the additional computer the 'control formatting unit.'   

Digitizing the Surface Missile System Computers

Digitizing Talos

In the beginning, the conventional wisdom in the naval weapons community was that digital computers were incapable of processing a weapons fire control solution. Their reasoning being that the fire control problem was made up of a large number of analog computations being done in real time in parallel. They knew that a digital computer executed instructions serially - one after the other, and they could not see how a digital computer could possibly jump fast enough among these many parallel computations to stay up with the fire control solution. What they didnít appreciate was the speed at which digital computers executed those serial instructions. But, finally in early 1962 the Talos missile system project manager, out of sheer frustration, decided to explore using a digital computer in the Talos fire control system.

The Talos system was the oldest of the '3Ts' surface missile systems and its fire control computer was the most complex. Component failures in the Talos computer were becoming a severe problem. The Talos program manager had been watching the progress of the Naval Tactical Data System and had become impressed with the reliability of the unit computer. He decided it was worth a try to see if a digital computer could handle the missile fire control solution. In his concept a digital computer would be combined with numerous analog to digital and digital to analog converters so that the rest of the missile system would interface with banks of converters that would appear to the radar director, the launch system, and other components as no different than the analog fire control computer. His hope was; first that a digital computer could handle the fire control computations in real time, and second that the combination of digital computer and converter banks would be much more reliable than the analog fire control computer. If successful he would replace the analog MK 111 Talos computers in the cruisers Long Beach, Albany, Chicago, and Columbus with the new system. The Talos project office issued a task to the Applied Physics Laboratory of Johns Hopkins University to investigate the idea.

Mr. Andrew Sheetz, a Talos servomechanisms engineer, in APLís Fleet Systems Department soon had the task in his hands. Other than he knew that digital computers existed, and that they needed a program, Sheetz confessed he knew nothing of digital computers. He went to APLís small group of computer programmers to learn what he could about the new machines, how they worked, and how programs were written. He drew diagrams of all the parallel elements in the fire control computations and how they worked together. It became apparent to him that some kind of direct digital simulation of the analog processes was going to be cumbersome and wasteful of computing resources. He realized he must start with the computer inputs and the the required end results and devise new ways of computing the solution After a few days of conceptualizing and calculating he satisfied himself that a digital computer with even less computing power than the NTDS unit computer could compute the fire control solution in real time.

Sheetz next worked out a general schematic of a digital computer, the required A/D and D/A converters, their conversion accuracy, and other peripheral equipment he would need. There were no A/D or D/A converters on the market in 1962, and Sheetz realized he would have to get the converters designed and built in-house at the Applied Physics Laboratory. To this point, the task had been a one-man effort until Sheetz brought in the APL Electronics Devices Design Group to take on the converters, and engineer Roger Higgins was assigned to design the converters. For the digital to analog converters, Higgins used large numbers of fast electromechanical relays in ladder arrangements. Sheetz noted that when the relays were tested with the digital computer they made a sound like thousands of unsynchronized ticking clocks. He found he could tell if they working OK by their sound. For the analog to digital converters Higgins designed new electronic circuits. These were so new that he obtained patents on many of them.

By 1963 Univac saw a market for an upgraded version of the 1218 computer having twice the speed and twice the memory capacity of their 1218. Their new 1219 used the same 18-bit instruction set architecture as the 1218. Among other uses the USN employed the 1219 when they converted their analog fire control computers to digital in the Talos. Tartar, and Terrier surface missile systems. It was given the military nomenclature CP-848. Univac Division of Sperry Rand Corp. photo

Sheetz used a commercial non-militarized digital computer to test his concept, and by early 1963 he had the computer running with the converters and simulated Talos system components, and he was able to come up with a realistic estimate of the processing power needed in a militarized shipboard computer. He selected the Univac-developed militarized 1218 machine having 32,000 18-bit memory words with four microsecond cycle time for his next round of tests which would be at the Mare Island Naval Schools Command. The school had a Talos fire control system complete with fire control radar and simulated launching system, and it was conveniently close to the BUSHIPS Weapons Direction System Mark 11 test site run by Lcdr. Jim Radja. With help from Radjaís team and APL engineer Jim Schneider, Sheetz had his equipment operating with the Talos radar and launching system simulator by early 1964. Testing lasted until the end of 1964 when the system was ready for disassembly and moving to a test ship: the heavy cruiser Albany.

Further testing aboard Albany with live missile shoots revealed that the 1218 computer (now designated CP-789) was stressed to the ragged edge of its performance, and the Bureau of Naval Weapons decided to upgrade to the newer Univac 1219 computer (designated CP-848), having twice the memory and twice the speed of the 1218. BUWEPS also designated the new computer with converters and peripherals as the Guided Missile Fire Control Computer Mark 152. Toward the end of 1966 BUWEPS began removing the Talos analog fire control computers from Long Beach, Albany, Chicago, and Columbus, and replacing them with the GMFCC Mark 152. [Sheetz, Andrew T., Interview with D. L. Boslaugh, 14 Nov. 1994]  [Schneider, James, Interview with D. L. Boslaugh, 3 Nov. 1994]

Digitizing Tartar

The Tartar and Terrier missile systems project managers had watched the Talos fire control computer digitization project with great interest, and when they saw the dramatic improvement in system reliability they wanted to do the same with their computers. The Tartar system project manager, Capt. Louis Stecker, was the first to approach his OPNAV sponsors with a proposal for funds for a computer digitization project. The sponsors checked their system reliability reports, and could not see enough of a reliability problem to warrant the expense. Captain Stecker continued to closely watch the reliability and performance of the new Talos digital computers and he discovered a new route to justify digitizing his fire control computer.

The surface missile systems were in a constant state of change: to correct problems, to add new features proposed by the fleet, to incorporate new technology, and to respond to perceived new threats. The Bureau of Naval Weapons called these changes ëordaltsí and they  were expensive and time consuming. For an electromechanical analog fire computer an ordalt could need two years or more from approval, to designing it, testing it, producing it , and installing in the fleet. In discussions with the Talos manager the Tartar director found that most of the ordalts to the new Talos computer were now computer program changes, and that they cost far less and took much less time to implement than analog system changes. This does not mean that computer program changes are trivial. They must be managed and recorded with great care and thoroughly tested, but nonetheless there were measurable cost and time benefits, and installation in the fleet only needed a new program load.

Capt. Stecker in early 1964 presented to his sponsors his analysis of cost and time savings of ordalts for a digital Tartar fire control computer. The conclusions were overwhelming. Cost savings of computer program changes more than justified the cost of computer conversion. Furthermore, Stecker could produce and install a program change in just a few months, rather than two years. Again, the Applied Physics Laboratory got the Tartar computer digitization task, and after analyzing the analog computerís equations of motion decided that the CP-848 (Univac 1219) militarized digital computer could handle the task. As in the Talos project, only the computer was to be digitized, and it would communicate with the rest of the Tartar system via A/D and D/A all-electronic converters designed at APL.  

The APL engineers shipped their equipment to the Bureau of Ships WDS Mark 11 test site at Mare Island Naval Schools Command, and with Lcdr. Jim Radjaís help embarked on a few months of system testing. As with Talos, the results were positive and won approval of the Naval Ordnance System Command for production. In 1971 the guided missile destroyer USS Joseph Strauss was the first to get a digital fire control computer for its Tartar missile system. [Applied Physics Laboratory, The Johns Hopkins University, "Survey of Digital Weapon Systems," estimated publication date 1975, p. 10-2]  [Walker, Clyde, Interview with D. L. Boslaugh, 13 Oct. 1994]

Digitizing Terrier

As early as 1966 Captain Wayne E. Meyer of the Terrier Missile System Project Office had started to show an interest in using digital computers; but not for fire control. Meyer was a strong advocate of running a Daily System Operability Test (DSOT) of the missile system, but it was a manually intensive, time consuming affair requiring hundreds of operator steps, measurement taking, and writing down results. We in the NTDS project office had told Meyer how a shipboard NTDS system could be split in two with one unit computer in charge of each half of the system. One of the system halves could continue normal CIC operations using a reduced capability NTDS operational program, and the other half could be used for training -  or testing programs could be loaded in the other computer.

Capt. Meyer had already supported the NTDS project by helping us bring a number of signals from the missile system into NTDS for our automated Ship System Operability Tests. One of these tests was the missile engagement test wherein the NTDS computer could make a time record of a number of critical events during missile firing, and it could record the tracks of target and missile during the engagement. Results could be printed out on the NTDS teletype and the tracks recreated at an NTDS console where a permanent record could be made with a Polaroid camera. With the advent of the new Keyset Central Multiplexer (KCMX) and the Dynamic Synchro Data Source (DSDS) many more analog, control, and status signals could be passed between the Terrier system and NTDS. All that was needed was missile switchboard changes, where most the signal voltages were available, and running of wiring to the KCMX and DSDS; and, of course, writing the necessary testing computer program, to automate the Terrier Daily System Operability Test.

In early 1967, the Terrier project office tasked Thomas R. Foard at the Applied Physics Laboratory to start working out the details of a ëDigital DSOTí. Foard first determined that the NTDS unit computer had more than enough computing power to solve the fire control equations of motion in real time.  Then he determined the points in the missile system where signal voltages, control and status signals would be tapped off and sent to the NTDS computer. Likewise, he determined points in the system that would receive stimuli in the form of synchro voltages and on-off control and status signals. He extended the concept even to the point of proposing sensors that would measure radiation from the fire control radar and send the measurement back to the NTDS computer. He called it 'end-around' testing. The Terrier project office approved his concept and in 1969 authorized installing the changes in the Terrier systems of the DLG-26 Class of guided missile frigates. [Foard, Thomas R., "Digital DSOT - A New Method of Operability Testing," U.S. Naval Institute Proceedings, Vol. 95, No. 793, Mar. 1969, pp.143-144]  [Foard, Thomas R., Letter to D. L. Boslaugh, 14 Sep. 1994]

Using the same logic as the Tartar system; that changing to digital fire control computers would more than pay for itself in reduced costs of ordalts, in 1969 the Terrier project manger convinced OPNAV to fund the rip out of analog fire control computers and installation of digital computers and converters. Again the Applied Physics Lab was tasked to design the system and write the Terrier fire control computer program for a CP-848 (Univac 1219) computer. Marion E. Oliver of APLís Fleet System Department undertook the task. The APL Silver Spring, MD, facility  had its own land based Terrier fire control system so Oliver was able to test the new system locally rather than use the Mare Island test site. Upon completion of land based testing, the prototype was installed in USS Belknap, where it completed successful at-sea testing in 1972. [Oliver, Marion E., Interview with D. L. Boslaugh, 9 Nov. 1994]

A Marriage of Digital Computers and Servomechanisms

In the digital fire control conversions described above the digital computer was controlling the bearing and elevation of the fire control radar director and the launcher only in the sense that it was sending position signals, in the form of digital numbers converted to analog synchro voltages, to these devices. Analog servo controllers then sensed the position of these devices and compared it with the commanded position sent from the computer; the difference between the commanded position and the actual position being called the error signal. The servo controller then sent the error signal to the drive mechanism causing the director or launcher to move until the error signal was zero. This is called ëopen loop controlí on the part of the digital computer.

As early as 1962, Commander Edmund Mahinske of the NTDS project office was questioning in his mind whether the NTDS unit computer could handle missile and gun fire control solutions. It boiled down to two questions: 1. did the unit computer have the processing power to do the job, and 2. could the servo loop be closed in the digital computer. That is, instead of sending an open loop position command to a launcher, director or gun mount, could the computer send an error signal to the drive mechanism based on the difference between commanded position and actual position as sent to the computer by a digital shaft position encoder? Could the computer take the place of the analog servo controller? This would eliminate complex, expensive, and sometimes unreliable, servo controllers, not to mention some analog to digital and digital to analog converters. One of the problems in Mahinskeís mind was the reality that the computer would not send a smooth continuous signal, but rather a jumpy stair step signal that could possibly excite resonant modes in the driven servomechanism.

In December 1962, during one of his periodic reviews of NTDS tasks at the Navy Electronics Laboratory in San Diego, Mahinske laid his questions before NEL engineer Robert McMannus, who in turn, introduced him to Dr. John B. Slaughter. Slaughter was an expert in the field of sampled data control system theory; which, in those days, consisted almost entirely of theory with almost no real practical demonstrations. Perhaps the only real application so far was one of Slaughterís experiments where he had successfully done closed loop control of a small analog device with a small digital computer. He had developed new digital servomechanism theory and new mathematical transform equations that he was itching to apply to a real-world problem.

A Three-inch/50 caliber Mark 33 twin gun mount aboard the aircraft carrier Wasp. U.S. Navy photo.

Mahinske and Slaughter laid out a task to apply his new theory to digitize a Navy antiaircraft gun fire control system. It would involve a standard 3-inch AA gun and its fire control radar. Mahinske would divert an NTDS unit computer for Slaughterís use, and the Lab would arrange to get the gun and radar. Slaughters task included not only implementing a radar directed fire control solution in the unit computer but also to to control the starting, stopping and direction of the gun and director drive mechanisms, as well as accurately positioning both. His fire control solution was even to control the motions of both to correct for the yawing, rolling, and pitching of an imaginary ship. By 1963 Slaughter was demonstrating precise, stable closed loop control of the gun and director, and positioning them with an accurate AA fire control solution. [Slaughter, John B. and Lackowski, Donald H., "Digital Control of a Tactical Weapon With a Shipboard G-P Digital Computer," Conference Proceedings - MIL-E-CON7 - National Convention on Military Electronics, pp. 1-5]   [Slaughter, John B., Interview with D. L. Boslaugh, 27 Oct. 1994]  [Mahinske, Capt. Edmund b., Letter to D. L. Boslaugh, 19 July 1994]

Slaughter was now ready to take on digital closed loop control of a real-life production shipboard servomechanism, and Lcdr. Joseph Randolph of the NTDS project office convinced Bureau of Naval Weapons representatives to sponsor an experiment to be done at the Northern Ordnance Corp. plant in Minneapolis, MN. Among other things, Northern Ordnance was the builder of the Tartar and Terrier launching systems, and the experiment would put an NTDS unit computer in closed loop control of a Tartar launcher. In July 1965 Dr. Slaughter arrived at the Northern Ordnance plant with a trailer holding a Unit computer and a number of analog to digital and digital analog converters. The computer was loaded with his sampled data servomechanism programs. The BUWEPS observers and Northern Ordnance engineers were astounded when they saw the quick, smooth responses and high accuracy with which the digital computer could control the launcherís powerful servo drives. The Tartar project office soon ordered production digital servo drives for the new Mark 13 launching system for the Tartar-D surface missile system. [Navy Electronics Laboratory, San Diego, CA, "Advanced Control Systems Research and Development" - Long Range Program FY 67-FY71, 1 July 1966, p. 4]

An Anti-submarine Rocket (ASROC) launcher aboard the heavy cruiser Columbus, 1962. U.S. Navy photo.

By 1966,Captain Robert P. Foreman, who had been Terrier missile system project officer during the days of the developing the original Weapons Direction System Mark 11 for ships of the Belknap Class, was back in the Bureau of Naval Weapons in charge of the Antisubmarine Rocket (ASROC) project. The new ASROC system was to have a digital fire control computer, and Foreman wanted the ASROC launcher to be controlled by digital servo drives. Again Dr. Slaughter received a task to take his trailer back to Northern Ordnance and work out digital drives for the new launcher. [Foreman, Capt. Robert P., Interview with D. L. Boslaugh, 8 Sept. 1944] [Slaughter interview]

Tartar surface-to-air missile launcher. U.S. Navy photo.

The new Tartar Mark 13 launcher, with digital servo drives, was being installed in guided missile destroyers as of July 1966, and at the same time, at Northern Ordnance, Dr. Slaughter had almost finished testing the new digital servo drives for the ASROC launcher. Furthermore, the Bureau of Ships Radar Branch was evaluating a digital servo drive for mechanically stabilizing the antenna of the AN/SPS-48 three dimensional search radar, and Dr. Slaughter was also working on an upgrade to the Tartar D missile system radar director that would give it digital angle and range tracking. Digital computers were even going below into the engineering spaces where BUSHIPS was experimenting with a digitally controlled main propulsion steam plant. The twilight of the analogs was starting.  [Navy Electronics Laboratory, San Diego, CA, "Advanced Control Systems Research and Development - Long Range Program FY 67-FY71," 1 July 1966, pp. 4,5,9]

Too Many Computers

New Computer Types for New Applications

A depiction of the Marine Tactical Data System AN/UYK-8 computer used in the upgraded Beach Relay Link-11 communication system. The original Beach Relay computer was an air cooled version of the CP-642 NTDS Unit computer, and the UYK-8 used the same 30-bit architecture but was brought down to approximately one fourth the volume of its predecessor CP-808 computer using first generation integrated circuits instead of discrete transistors. Image from a Univac Division of Sperry Rand Corp. brochure, provided by Mr. John H. Westergren.

At first other projects and programs bought and used NTDS CP-642B unit computers as-is for many different applications such as the Automated Carrier Landing System and for processors at remote NASA tracking sites.  Then in 1963 the Bureau of Naval Weapons procured an airborne version of the CP-642B, designated CP-823U for use in the Orion land based submarine hunting aircraft. This computer was built with first generation microelectronics technology to shrink it in weight and size, but it retained the unit computers architecture. In a previous chapter we related how the Marine Tactical Data System used an air cooled version of the CP-642B unit computer, designated CP-808, in their Beach Relay communication system. In 1967 the Marines asked for an improved successor to the CP-808 with the same 30-bit word length and instruction set architecture as the CP-808 but higher speed, dual processing capability, and using first generation microelectronics circuitry. The resulting Univac AN/UYK-8 computer occupied about one fourth the volume of its predecessor machine. 

Components of the Univac 1830, CP-823/U airborne computer used in the engineering prototype computing system of the P-3 maritime patrol ASW aircraft system automation project called A-New. The machine used the NTDS CP-642 unit computer 30-bit architecture but was brought down in size and weight with first generation integrated circuit technology. From left, four airborne input/output units, ground input/output unit, memory unit, processor unit, airborne power supply, and control console. This is the prototype Univac 1830, CP-823U computer at its end state. After years of development with the cooperation of Univac and navy civilian and military personnel, four hundred ninety-nine production units, designated CP-901 were delivered to the Navy. Photo courtesy Mr. Todd J. Thomas of Note: Mr. Thomas has stored and preserved this machine for the past 40 years.

But, technology was not standing still and potential computer users were asking for machines with greater processing power than the unit computers. Some new users also had compelling reasons for computers with longer word lengths than the CP-642Bís 30 bits. The rapid progress of technology, combined with increased processing power demands stimulated a spate of designing and building a new computer for each new application in the fleet.

In late 1964 the Bureau of Ships began acquiring a new computer for NASA remote tracking sites to process telemetry data for the Apollo program. The resultant Univac 1230 computer was housed in a CP-642B cabinet and used CP-642B logic cards, but had a number of additional features including an external memory cabinet with additional 30-bit magnetic core memory. Thirty nine of the machines were delivered to NASA, and an additional 24 were built for Navy use, with the designation CP-855. Univac Division of Sperry Rand Corp. photo.
A Univac CP-667 computer built for the Navy’s Mobile Operational Control Center project which was cancelled at the DOD level. It used first generation integrated circuits technology, and in its time it was the most powerful computer in Navy inventory, but only prototypes were built. There is some question whether one or three prototypes were built. Univac Division of Sperry Rand Corp. photo.

Some users wanted a more powerful machine with a 36-bit word length, and in 1962 Don Ream of the NTDS project office wrote a specification for a 36-bit machine that could hold a magnetic core memory of anywhere from 32,000 to 131 thousand words. BUSHIPS designated it the CP-667 and issued a competitive request for bids. Univac won the competition and delivered the prototype in March 1964. At the time, the Department of Defense was championing a computer standardization program among all the services and cancelled the CP-667 project after only prototypes had been built. The DOD standardization program never came to fruition, but the CP-667 remained its victim. [Ream, Donald L., Letter to D. L. Boslaugh, 24 Mar. 1993] In 1965 the National Aeronautics and Space Administration asked BUSHIPS to develop a new computer for their remote tracking sites for the APOLLO moon missions. The resultant CP-855 computer was based on the CP-642B unit computer architecture but had twice the speed and in addition to the 32,000 30-bit word memory in the computer cabinet, it had another 115 thousand words of magnetic core memory in an external cabinet. The CP-855 would also be used in some Navy shipboard systems. [Hoskins, Paul H., Letter to D. L. Boslaugh, 1 Mar. 1004]

The Univac CP-890 computer built for the Trident ballistic missile program as a navigation computer was generally based on NASA’s Univac 1230 telemetry processing computer, but used a combination of discrete transistors and integrated circuits. This allowed the machine to be slimmed down enough to fit through a standard 25-inch diameter submarine hatch. It was a little over six feet tall. Univac Division of Sperry Rand Corp. photo.

The Trident ballistic missile project in 1966 asked for a miniaturized version of NASA's CP-855 for use aboard ballistic missile subs. The reason for the miniaturization request was the requirement that the computer had to fit through a standard 25-inch diameter submarine deck hatch. Univac slimmed down the CP-855 by a combination of discrete transistor components and second generation microelectronics technology to achieve a cabinet six feet tall but only 18 inches deep, and 22 inches wide and weighing 700 pounds. The new machine, designated CP-890, used 32 thousand words of 30-bit magnetic core memory. One can see that the forward march of technology as well as the demand for new,  more powerful computers by more and more shipboard systems was beginning to cause a proliferation of computer types in the fleet. [Univac Division of Sperry Rand Corporation, Military Computer Genealogy Chart, Undated, Estimated 1968]  [Joyce, Lcdr. Robert Richardson, USN, "History of the AN/UYK-20(V) Data Processing System and its Impact on Tactical Systems Development," Thesis, Naval Postgraduate School, Monterey, CA Sep. 1976, p. 96]

Finally 32-Bits

Don Ream continually emphasized to us junior NTDS project officers the utility of the NTDS general purpose, stored program unit computers as opposed to special purpose fixed program computers. In reality, however, the unit computers were not truly general purpose. Their architecture was optimized to the NTDS tactical computing load. As the many new uses for digital computers multiplied in the U.S. Navy, Ream was continually asked for new machines with more flexibility, and even the NTDS processors could do with more flexibility. One of the ground rules in NTDS system design was the requirement for at least two computers in each system for casualty backup in case of failure of one of the computers. In case of computer failure the remaining computers would be reloaded with reduced capability programs until the ailing computer was repaired. This meant the systems analysts had to the best job they could in assigning tactical processing functions to each computer to even out the computing load in each machine, However, even with the best attempt at load leveling, there would be times when one or more computers might be hard at work while others were loafing.

By 1966 it could be seen that a new computing architecture where multiple processors could share a common memory to continually execute highest priority functions, with an even load on each processor, would be very desirable not only for NTDS, but also for the many other users of NTDS computers. There were other desirable changes. For example, the unit computer's central processing unit not only executed the tactical program, but also controlled the timing and actions of all other parts of the computer such as memory transfers and input/output actions. This took central processor time away from the tactical program, and sometimes other sections were made to wait too long before their turn came for CPU servicing. Such an architecture had been necessary when logic was expensive and dedicated processors to control specific internal functions would have been prohibitively expensive, not to mention reliability problems that such additional logic could engender.

The original 1957 NTDS project office specification for the prototype AN/USQ-17 unit computers called for a word length of 32 bits because the number 32 is an even power of two and thus an ideal word length for a computer using binary arithmetic. The transistors of 1957 however lacked the power output to support a 32-bit word length no matter how hard Seymour Cray tried, and the project had to accept a 30-bit word length. A decade later the 30-bit architecture had been propagated through more than seven more models of Navy and Marine Corps computers. It was clearly time for a more modern NTDS computer architecture with a 32-bit word length, multiprocessing capability, and separate control processors for individual computer sections. Furthermore, all this would not be hard to do, or prohibitively expensive with rapidly progressing integrated circuit technology. [Remington Rand Univac, Federal Systems Division brochure, "AN/UYK-7 - The Next Generation," undated, p. 3]

AN/UYK-7 computer modules. Univac Division of Sperry Rand Corp. photo.
Two banks of four each AN/UYK-7 computers in a land based programming/test site. Univac Division of Sperry Rand Corp. photo.

In late 1966, engineer Paul Hoskins transferred from the Bureau of Ships Technical Representative office in St. Paul to the NTDS project office where Don Ream soon had him at work writing a specification for a new NTDS computer; bearing in mind that many other projects would also be using the new machine. He and Ream came up with a new building block architecture for the 32-bit machine wherein a number of CPUs would share not only a common memory, but also a common input output unit. That way the CPUs could reallocate their processing load to undertake the highest priority functions at any given time. Furthermore each other computer section would have its own dedicated control processor. The original unit computers had a repertoire of 62 instructions, however the new machine would have greatly increased instruction versatility with a 131 instruction repertoire. [Hoskins, Paul H., Letter to D. L. Boslaugh, 1 Mar, 1994]

AN/UYK-7 computer memory module. Univac Division of Sperry Rand Corp. photo.

By January 1968 the Bureau of Ships had been renamed the Naval Ship Systems Command, and in that month NAVSHIPS contracted with Univac to build a prototype computer to the Ream/Hoskins specifications. The machine was to be designated AN/UYK-7. Even though there was now some solid state microelectronics memory on the market, the machine was still specified to use magnetic core memory; the reason being tactical computers had to retain their memory settings in case of power failure, and solid state memories could not yet do that. The magnetic cores were, however, of a new technology allowing a 1.5 microsecond cycle time. This gave a two-and-one-half times speed advantage over the CP-642-B unit computer, and enabled it to execute a tactical program instruction mix at 500,000 instructions per second. A fast computer for its day.

Thanks to new integrated circuit technology the UYK-7ís enclosure was only about one fourth the volume of the unit computer. Furthermore, the UYK-7 cabinet could accommodate various arrangement of standard sized building block modules, and if more memory was needed an additional cabinet could be fitted with more memory modules up to a total of 262 thousand 32-bit words per computer. In April 1969 the Navy took delivery of the UYK-7 prototype for testing, and in late 1970 Univac began deliveries. By January 1974, in addition to NTDS, 32 other Navy projects and programs were using AN/UYK-7 computers. [Naval Ship Systems Command, Procurement Plan No. 69-5 - AN/UYK-7, 25 Sep-1968, pp. 1-5]  [Remington Rand Univac, Federal Systems Division brochure, "AN/UYK-7 - The Next Generation," undated, p. 4]  [Secretary of the Navy, Management Information Center Report, "AN/UYK-7 Tactical Computer System," 21 Oct. 1971, pp. 1-3]

OPNAV Directs Fleet Computer Standardization

By 1969, in the U.S. Navy, there were eleven attack carriers, three heavy cruisers, 14 guided missile frigates, and two destroyer escorts fitted with the Naval Tactical Data System. (The two destroyer escorts were carrying an experimental antisubmarine warfare version of NTDS) In addition, NTDS computers, as well as other computer types were being used in many other shipboard systems; and problems were starting to arise. In June 1969 Admiral B. A. Clarey, the Vice Chief of Naval Operations, dispatched a letter to the Chief of Naval Material (CNM) complaining that each different type of digital equipment needed its own maintenance and operator training schools, technical manuals, spare parts kits, supplies in the Navy Supply System, its own planned maintenance system, as well as computer programming support tools.

Clarey went on to note that Naval Material Command project managers appeared to be making no attempt to incorporate newly automated functions into existing automated systems, but instead seemed to acquire new and different computer types for each newly automated application. In order to help alleviate the rapidly rising costs of supporting these new automated systems he  recommended that the CNM require project managers to first show that the new function could not be incorporated into an existing system. If that was not possible, they should be required to prove they could not use a computer type already in Navy inventory.

Clarey noted further that there seemed to be no central management of the rapidly growing aggregate of tactical computer resources in the Navy. And, he was right. The NTDS project office was providing NTDS computers, peripherals and display systems to many other users, and a number of automation projects were buying their digital resources directly from manufacturers. But it was far beyond the NTDS project's charter to try to exercise some kind of standardization control over shipboard automation projects. Lastly, the VCNO recommended, but did not direct, that the CNM set up a central organization for 'coordinating' the acquisition of digital equipment and supporting computer programs for shipboard automation projects. Furthermore, he proposed that this organization should be a central source of technical support and should enforce the policies he had enumerated in his letter. There seemed to be no immediate Naval Material Command action in response to these recommendations. [Office of the Chief of Naval Operations, Letter to Chief of Naval Material, Subject: Management of Automatic Data Processing Equipment in Ships, Serial OP-911F/)P-353/msa Ser 244P91, dated 29 June 1969]

One of the jobs of an under secretary of the Navy is reviewing shipbuilding programs presented to the Defense System Acquisition Review Council. In 1971 Under Secretary of the Navy John W. Warner began noticing a disturbing trend in ship construction projects having systems using digital computers - in particular the new AN/UYK-7 computer. Computer programs seemed to be at the heart of the problem. In some cases late computer program deliveries were actually delaying ship construction schedules, and in many cases the cost of computer programs had grown far beyond original coast estimates. Warner tasked a Secretarial special assistant to investigate the problem and determine its extent, find out how shipboard computer programs were developed and managed, find out how computer programs were supported after ship delivery, and find out what , if any organization had any form of overview management of the many tactical computer programs. [Warner, John W., Under Secretary of the Navy, Memorandum to the Special Assistant to the Secretary of the Navy, Subject: Computer Software Impact on Ship Acquisitions, dated 3 Apr. 1971]

The special assistant's report verified that many projects other than the Naval Tactical Data System were using UYK-7 computers, as well as other computer types. He also found that even though the NTDS project had budgeted for a computer program development support system including a compiler, library management system, and other support programs for the UYK-7 computer, they had been deleted by budget review authorities during the many steps of the budget review process. This resulted in each project using the UYK-7, as well as the other machine types, having to pay contractors to develop their own set of supporting computer programs, thus causing cost escalation and resulting schedule delay of tactical computer programs. Another finding was that in many cases projects had not budgeted for maintaining their tactical computer programs after delivery. The report recommended that the Navy should use only one type of 'standardized' digital computer in all shipboard tactical systems with one set of standard supporting computer programs. Furthermore, project managers should be required to arrange for lifetime support of their computer programs.

After reading the report, the Secretary of the Navy took two actions; 1. he forwarded the report to the Chief of Naval Operations with directions to have the recommendations carried out, and 2. to get a better understanding of the UYK-7 programming support problem he asked the General Accounting Office to investigate why the UYK-7's support software package had been deleted in the budget review process. The CNO in-turn directed the Chief of Naval Material to designate, or acquire, a standard Navy digital computer with one package of supporting computer programs to be used in all shipboard tactical systems. The resultant General Accounting Office report on what went wrong with the UYK-7 computer programming support system budget is reproduced below.

"Dear Mr. Secretary:

The General Accounting Office has reviewed the practices of the Naval Ship Systems Command related to the procurement of the AN/UYK-7(V) computer system We wanted to find out whether the Navy was  effective in managing the development and procurement of this multipurpose computer system. 

Computers are an integral and important part of modern weapon systems. As a part of these systems, computers help to aim guns at oncoming targets, guide missiles, locate enemy ships and planes, and perform a host of other similar functions.

AN/UYK-7(V) is such a computer. It is described as a general-purpose, high-performance, third-generation digital computer system. According to the Navy the computer will provide greater reliability, faster processing speeds, and greater data processing capabilities than any other military computer presently in service.

AN/UYK-7(V) had its beginning in mid-1967 when discussions took place between the Navy and a contractor for the development of a new computer. Cognizant Navy officials said that the AN/UYK-7(V) development had been given approval on the basis of plans for its use in a single shipboard system. Plans for multiapplication of the computer followed only a short time later.

By the time the development contract was awarded late in 1967, the AN/UYK-7(V) effort had been directed toward meeting the needs of four new major programs: (1) a program for the procurement of an advanced surface-missile system called AEGIS, (2) a program for the Landing Helicopter Assault (LHA) ship, (3) a program for a conventionally powered destroyer, and (4) a program for a nuclear-guided-missile frigate. Later, in mid-1968, the development contract was modified to include the computer needs of still another program--the Junior Participating Tactical Data System.

Since its conception, potential application of this computer system has continued to grow. Navy planning documents indicated that the computer would be a significant component of more than 40 different Navy systems or programs, including most of the Navy's new ships and submarines. 

Our review of the procurement of the AN/UYK-7(V) computer system revealed problems concerning the acquisition of its associated programming equipment and the planning for the 

acquisition of computers for training purposes. Inadequate financial planning for these requirements was the source for both of these problems, There was no meaningful overall plan to provide for financing of the AN/UYK-7(V) computer program as a whole.

The costs for developing the AN/UYK-7(V) computer and its associated programming equipment were funded, in part, under a tactical data system development program and under several different weapon systems programs which would make use of this computer. The time required to accumulate funds from different programs to finance the development of the associated programming equipment delayed its availability. This, in turn, resulted in a delay and cost increase to at least one weapon system program. Also adequate funds had not been provided for AN/UYK-7(V) computer training programs. Details concerning these matters are set forth below.

Delayed Development of Computer Programming Equipment

Programming of computers with machine instructions needed to accomplish a given task can be both time consuming and costly. Equipment to assist in the programming of the AN/UYK-7(V) computer systems consists of a compiler which was to have been developed concurrently with the computer. The compiler converts instructions into the type of electrical impulses which the computer hardware can use to perform the desired processing operations.

In its financial planning, the Navy planned separately for the funds needed for development of the AN/UYK-7(V) computer and the compiler. The Navy proceeded with the hardware development without interruption. However, funds for the compiler were requested under a number of activities or programs which subsequently were reduced or eliminated during the budgetary process.

For example, funds to be used for compiler development apparently were included for the fiscal year 1968 budget under a request for operating the Navy Electronics Laboratory Center but were subsequently eliminated when the congressional budget request was prepared. According to a Navy official, funds for the compiler were then included in the fiscal year 1969 budget request for the DXGN ship program; but the amount requested for the compiler was cut during the budget appropriation process.

Funds for the development of the compiler were ultimately accumulated from five data systems and weapon or ship programs and were provided in November 1969, about 2 years after the development of the hardware was funded. To effectively utilize the AN/UYK-7(V) computer, the sub- system compiler must be available with the computer; however, the contract for the development of the compiler was not awarded until after the initial production models of the AN/UYK-7(V) computer had been delivered.

This out-of-phase development and procurement of the computer and compiler has affected the LHA ship program. The Navy was committed under the LHA contract to furnish its contractor with the compiler for use in conjunction with contractor-furnished AN/UYK-7(V) computers. The compiler was not available when needed, and the LHA contractor had to use other means to satisfy the need which the compiler was intended to fulfill. This work-around may add about $2.3 mil- lion to the cost of the LHA program.

We believe that the development of the AN/UYK-7(V) computer and its associated programming equipment should have been treated as an integral program because of their interdependence.

Computer for Training Purposes Not Available

The Navy cannot make effective use of new equipment un- less it has personnel trained to operate, maintain, and repair that equipment. Such personnel must be available simultaneously with the introduction of the equipment into operating use; otherwise the readiness of the weapon systems that employ the new equipment will be affected.

As of December 1970 adequate funds had not been provided for AN/UYK-7(V) computer training programs. The Navy scheduled training programs to begin in fiscal year 1972 but did not provide for the acquisition of the computers needed to conduct the training. According to a Navy official, the cognizant training facility will have to supply its own funds for the purchase of AN/UYK-7(V) computers. We were advised by a Navy official that, due to the cost of the AN/UYK-7(V) computer, training facility funds could not support the acquisition of the number of AN/UYK-7(V) computers needed for training. As a result, unless appropriate changes are made,those designated to undergo such training will have to use textbooks to learn how to operate and maintain an AN/UYK-7(V) 

computer and will have no opportunity to practice on one. Since the computers are to be installed on the LHA and DD-963 ships in fiscal year 1973, it is important to Navy readiness that proper training be provided to those who will be required to operate and maintain the AN/UYK-7(V) computer systems aboard these ships.


Meaningful financial management of all aspects of an acquisition program is essential to ensure economical development and efficient usage of new equipment. In the case of the AN/UYK-7(V) computer, funding for all aspects was not provided. As a result of the fragmented funding, important aspects were delayed with consequent impairment in the planned use of the computer.

We believe that acquisitions of important general-usage equipment, such as the AN/UYK-7(V) computer, should be managed as individual programs just as the Navy manages its weapon systems acquisitions, This concept of acquisition management provides the means for managing and controlling all aspects of an acquisition program as a whole and for ensuring timely availability and effective introduction of new equipment into the fleet.


We recommend that the Navy manage its acquisitions of tactical computer systems intended for multishipboard usage as individual programs using a management concept similar to that used by the Navy to manage its weapon systems acquisitions.

If you desire, we shall be glad to discuss this matter in greater detail with you or with your staff.

Sincerely yours,

Director, Procurement and Systems

Acquisition Division

The Honorable

The Secretary of the Navy"

[United States General Accounting Office, Procurement and Systems Acquisition Division, Letter B-163074, May 22 1972]

In August 1971 the Chief of Naval Material responded to the CNO letter, as well as Admiral Claryís June 1969 letter, by establishing the Tactical Automated Data Systems Office (TADSO) at Naval Material Command Headquarters, and assigning Rear Admiral Joseph E. Rice as first director. Radm. Rice, an engineering duty officer, had formerly been Commander of the Naval Electronic Systems Command. Responsibilities of the new office included overview management of developing and producing the standards, preparing an annual master plan for Navy embedded computer resources - including five-year requirements projections, preparing an annual budget for standard equipment and support computer programs development, preparing a NAVMAT Instruction on required tactical computer programming standards, and conducting a waiver review process. The waiver review was for projects who claimed they had needs for tactical computing resources that could not be met by the standards. TADSO's function was to review waiver requests and recommend approval or disapproval. Only the CNM could approve a waiver.

The other part of the Chief of Naval Material's response to the CNO computer standardization directive was designating, in November 1971, the AN/UYK-7 and its CMS-2 computer programming support system as Navy standards. Furthermore he directed that all shipboard tactical automation programs would use the NTDS display and communications subsystems, as well as NTDS data processing peripheral equipment as standards. [Joyce, pp. 14-15]  [Naval Ship Systems Command, Memorandum to Distribution, Subject: AN/UYK-7 General Purpose Operating System Requirements, Serial 012:RLN:jc 5230 Ser 849-012, dated 6 Dec. 1971]  For future standard computer requirements beyond the AN/UYK-7, the CNM authorized the Naval Air Systems Command to set up a project to develop a new line of computers called the All Applications Digital Computer (AADC). They were to be a family of computers of differing processing power but all having the same architecture and instruction set. They were to be modular, building block in construction and to be produced either with shipboard enclosures or airborne enclosures.

The Need for a Standard Minicomputer

The TADSO office had no sooner been set up, when they started getting waiver requests for computers with processing power less than the AN/UYK-7. The UYK-7 was considered a 'mainframe' computer and was obvious overkill for many projects needs. It became clear that there should be a Navy standard shipboard minicomputer. The AADC project would include minicomputers of varying processing power, but their availability was to be four years hence, whereas there was immediate need for a standard mini, or the Navy was going to see more computer proliferation. As an interim measure, until the AADC was ready, TADSO elected to competitively acquire a militarized version of an existing minicomputer. The idea was to use off-the-shelf, low risk, low lead time components in a fully militarized package having a mean time between failure of 2000 hours.  [Joyce, p 21]  [Hager, Capt. Charles, USN, Naval Electronic Systems Command, AN/UYK-20 project manager, Project Managerís presentation on AN/UYK-20 computer]

By August 1972, TADSO had completed a specification for the standard minicomputer, and sent it to the Office of the CNO in company with an urgent request for a relatively small $1.8 million to fund militarizing an existing commercial computer. OPNAV responded by reprogramming small amounts from a number of projects they thought would be potential users of the computer. By September 1972 TADSO had received the designation AN/UYK-20 for the new minicomputer and assigned development to the Naval Electronic Systems Command (NAVELEX). Commander  Charles F. Hager was assigned responsibility for the development. He had been operations officer of the Guided Missile Frigate Belknap, the first new-construction ship to receive production NTDS equipment, and he had developed a fascination for the new technology; so much so that he requested redesignation as an engineering duty officer to keep working in the new technology. In October, TADSO received a waiver request from the Mark 68 Gunfire Control System project office to use a computer smaller than the AN/UYK-7 mainframe computer. Instead of approving the waiver, the CNM directed that the Mark 68 project would be the first AN/UYK-20 user.  [Joyce, p. 21]  [Naval Material Command Headquarters, Letter to Distribution List, Subject; Standard Navy Mini Digital Processor (AN/UYK-20); use of in development programs, Serial MAT 09Y:JER Ser 112, dated 7 June 1973]

In December 1972, Cdr Hager sent the UYK-20 request for proposals to the computer industry and set up a proposal review team. The selection concept was simple. The review team would review all proposals to find out if they technically met the specifications. Of those that met the specification requirements, the contract would be awarded to the contractor with lowest unit cost. Four of the returned proposals from: Control Data Corporation, General Electric, Raytheon, and Univac met the specifications, even though in each case the proposed commercial minicomputer would need some reengineering. There was no off-the-shelf machine that exactly complied with the specifications without some modifications (not counting the changes required to militarize the units). [Joyce, p. 37]

Univac had proposed the lowest unit cost, and was awarded the contract in April 1973. The contract was to cover the coming three years, after which NAVAIR's All Applications Digital Computer was expected to be in production. In May Radm. Rice designated the AN/UYK-20 minicomputer the Navy standard computer for all shipboard tactical computing applications where the smallest packaging of the AN/UYK-7 computer was too much for the job. To give users a leg up on developing programs for the new computer, commercially packaged versions were to be available to users within three months after signing the contract. Production deliveries of militarized versions were to start in May 1974.  [Naval Material Command Headquarters, Tactical Digital Standard (TADSTAND) 1 (Revision 1), Standard Shipboard Tactical Digital Processors and Program Language, Serial MAT 09Y:JER Ser 130, dated 29 May 1973] 

Univac had no apparent trouble in meeting the tight production schedule, and furthermore kept the price to the promised level; $24,324.00 per machine as long as the production run was 150 machines, or more. The users and the rest of the computer industry could not believe the price. It was less than the price of equivalent non-militarized off-the-shelf machines offered by other manufacturers. TADSO and OPNAV thought they had a great success on their hands in taking an existing minicomputer (with some engineering changes) and militarizing it. But, things started to go wrong as more of the machines accumulated in programming centers and laboratories. The AN/UYK-20s showed nowhere near their specified 2,000 hours mean time between failures. Sometimes they ran only a few days before failure, and users desperate to stay with their computer program development schedules sometimes had to resort to buying two machines when they only needed one; the extra machine being their spare parts box to keep one machine running.

At first TADSO and NAVELEX thought it was just early production growing pains that would soon be overcome. But the failure curve stayed steady, and by mid 1975 Chuck Hager, (by then Captain) began to realize that the advanced technology integrated circuits embodied in the new machine had a serious reliability problem and drastic damage control measures were in order. Hager had a number of UYK-20s delivered to the Naval Weapons Center at Dahlgren, VA, where they ran them day and night in an accelerated testing program. They repaired them immediately when they failed and put them back on the line again, al the while keeping thorough repair and MTBF records. Dahlgren engineers confirmed that on average, the machines were failing every 500 to 600 hours - far from their specified 2,000 hour MTBF.

An AN/UYK-20 minicomputer, center with red nameplate, in a reproduction of the Battleship Missouri’s Naval Modular Automated Communication System (NAVMACS). Taken aboard the museum battleship Missouri. Photo by Bruce C. Murray, Battleship Missouri Amateur Radio Club.
Close up of an AN/UYK-20 16-bit Navy standard minicomputer with door open. Photo by Bruce C. Murray, Battleship Missouri Amateur Radio Club.

The Dahlgren engineers also noted that after about 12,000 of operation, MTBF went up to 1,500 hours. They realized what they were doing was eliminating components having 'infant mortality' problems and replacing them with more reliable components. Furthermore, they found that most of the unreliable components were associated with the engineering changes Univac had made to their basic commercial minicomputer to meet the UYK-20 specifications. These were new, relatively untried integrated circuit components, and Univac's demanding schedule had not allowed the kind of reliability testing they would have gotten in a normal development. Univac and NAVELEX set up a UYK-20 component reliability improvement program, and by 1978 the aggregation of over 1,000 AN/UYK-20s in the fleet was showing an average of 2,865 hours between failures. Furthermore thr UYK-20 had become the world's most widely used militarized computer. In March 1981 the Navy made a fleet-wide assessment of tactical computer reliability with the following mean time between failure results:

CP-642    4,128 hours

AN/UYK-7    2,528 hours

AN/UYK-20  12,096 hours

[Joyce, pp 50-78]  [Berry, F. Clifton, Jr., "Turning Problems into Success - The Saga of the Navy's Standard Computer," Armed Forces Journal International, Apr, 1978, p. 9]  [Secretary of the Navy, Office of the Assistant Secretary for Research, Engineering, and Systems, Report of the Navy Embedded Computer Logistics Working Group, Mar. 1981]

The AN/UYK-20 project taught NAVELEX and TADSO some valuable lessons about acquiring standard computers. The first being that militarizing an existing off-the shelf computer, that was supposedly built of well proven components, was far from the simple process they thought it would be. They also realized that even seemingly minor changes in a computer will require that the entire machine be given a thorough requalification testing program, as if it were a new computer - before requiring multiple projects to use it. The last lesson was that, even though giving a contract to the the lowest bidder is the politically correct easy way out, it is not always the best selection criteria in the long run. [Joyce, p. 82]

Digitizing the Guns

The surface missile system analog fire control computers were larger and more complex than analog gunfire control computers and were thus the first targets for digitization. However, in the late 1960s the Naval Ordnance System command embarked on project to build a general purpose digitized gun fire control system that could be used by a variety of gunnery systems ranging from 30 mm fast firing cannon mounts to eight-inch turrets. For good measure, it was even specified that it should be able to control Tartar missile batteries. The system was to be built around a Navy standard AN/UYK-7 computer and was to be able to handle anti-ship surface gun fire, anti-ship surface missile fire, anti-air defense, and indirect shore bombardment (where the target can not be seen by radar or optics). It was also to allow anti-surface fire to be either radar or optically directed. The project resulted in the Mark 86 Gun Fire Control System which was service approved in December 1972. [Vinci, Vin, Lockheed Electronics Co., "Mk 86 Gunfire Control System" U.S. Naval Institute Proceedings, Vol. 103/8/894, Aug 1977. pp. 92-94]

We have already mentioned in passing that the first directed user of the AN/UYK-20 standard minicomputer came to be the Mark 68 Gun Fire Control System improvement program. The Mark 68 fire control computer was originally an analog device used to control the Mark 42 five-inch gun mount. This gun mount had been designed in the early 1950s for the first new class of destroyers to be built following World War II, the Forrest Sherman (DD 931) Class. Vietnam War experience with the fire control computer revealed that it had reliability, accuracy, and reaction time problems that did not seem to be amenable to cure by the normal ëordaltí process. In 1972 the Naval Ordnance Systems Command, noting the success of replacing analog missile fire control computers with a combination of a digital computer and A/D and D/A converters, decided to do the same with the GFCS Mark 68 analog computer.

NAVORD selected a CP-848 (Univac 1219) digital computer, but as already related, the Chief of Naval Material in the waiver review process, directed that the project would use the new standard UYK-20 instead. The upgraded fire control system was tested live with a five-inch gun mount by the Surface Gun Systems Subgroup of the new Naval Sea Systems Command at Navy Surface Weapons Center, Dahlgren, VA, in June 1975. Their target was a small high speed radio controlled boat that was maneuvering near the extreme range of the Mark 42 gun. The first few rounds destroyed the boat. Next NAVSEA arranged for the upgraded GFCS Mark 68 to be installed in the destroyer Charles F. Adams for at-sea operational evaluation, with the following improved performance as compared to the original analog fire control computer:

2.2-to-one improvement in performance against surface targets

8-to-one improvement in performance against air targets

6-to-one improvement in system reaction time

2-to-one improvement in system reliability

The operational Test and Evaluation Force also reported that the digital computer allowed almost instant computer program replacement, or changes, to ballistic programs to accommodate upgraded projectiles. Previously, such changes had required expensive and time consuming hardware modifications. [Schlegmilch, R. O., "A Systems Approach to Gun Weapon Systems," NAVSEA Journal, Vol. 24, NO. 10, Oct. 1975, pp. 45, 50, 52-53]



In the mid 1950s the perceived airborne threat to the fleet never stood still. Soviet air attack capabilities, in particular, were constantly improved with faster, longer range bombers, and air launched standoff missiles were becoming more potent, and with longer standoff ranges. Furthermore the Navyís potential adversaryís electronic warfare capabilities were always getting better, with new devices to fool or jam USN shipboard radars. There were two schools of thought on how to best respond to the ever-increasing threat. The surface missile system managers in the Bureau of Naval Weapons were generally in favor of evolutionary improvements to the Talos, Terrier, and Tartar systems, which they felt could keep the their systems competitive for perhaps two more decades. The other line of thought favored a radical new system development with a new very powerful and capable shipboard radar and potent new missiles. This was the thinking of senior engineers in the civilian organizations, such as the Applied Physics Laboratory of the Johns Hopkins University, who provided technical support to the 3-T project managers. Furthermore they were influential and had the ears of decision makers in high places.  [Klingman, William K., APL - Fifty Years of Service to the Nation - A History of the Johns Hopkins University Applied Physics Laboratory, The Johns Hopkins University Applied Physics Laboratory, 1993, ISBN 0-12-912-04-2, pp. 139-140]

The advanced technology experts prevailed, and by the late 1950s the Applied Physics Laboratory had a BUWEPS task to formulate a new highly advanced shipboard surface missile system. It would would be named Typhon. They conceived a new electronically steered ëagile beamí radar that combined long range search, three dimensional search, precision fire control tracking, target illumination, and missile guidance in one device. Two new missiles were also to be developed, the largest of which they called a Super Talos, that would have a range of 200 miles, and would be capable of shooting down a Soviet bomber before it could launch an anti-ship standoff missile. The second missile they called Super Tartar. It would have a medium range of perhaps 60 miles and would be capable of bringing down anti-ship missiles as well as attacking aircraft.

The Typhon designers also conceived a nuclear powered 'Typhon' frigate that would be fitted with a twin rail launcher for the long range Super Talos missiles and two single rail launchers for the medium range Super Tartar missiles. The Typhon frigate would have a displacement of about 9,700 tons, making it larger than the DLG 26 Class frigates, and it would be very expensive. The high expense, however, they believed would be offset by the Typhon missile systemís capabilities because the conceptualizers believed that only one Typhon frigate would be capable of providing air defense for an entire task force. [Polmar, Norman, "USS Norton Sound: the Newest Old Ship,"  U.S. Naval Institute Proceedings, Vol. 105/4/914, Apr. 1979, p. 76]

The existing Talos, Terrier, and Tartar missiles required a shipboard pointing illuminating radar to bounce radar energy off the target to a seeker head in the missile. While the missile was still on the launcher, the seeker head would acquire the illuminatorís reflected signal, and the missile would 'home all the way' to the target. The problem with such an arrangement was the need to assign an illuminating radar to the target from before launch to time of intercept. There were normally only two illuminating radars for each twin-arm launcher, and thus each launcher could only have two missiles in the air simultaneously, even though the launcher could be loaded and fired much more rapidly had it not the illuminator constraint.

The guidance concept for Typhon was to be considerably different than the '3-Ts.'  The agile beam Typhon radar would be able to accurately track a large number of targets simultaneously, as well as a number of missiles in the air, thus the Typhon fire control computer would constantly know the positions of the intended target and its assigned missile. The system would feature a digital fire control computer that computed missile guidance commands to be beamed to the missile as coded radar signals. The end result would be many missiles in the air simultaneously.  [Inman, Capt. Bryce D., USN, "From Typhon to Aegis - The Issues and Their Resolution," Naval Engineerís Journal, Vol. 100, No. 3, May 1988, ISSN 0028-1425, p. 62]

An optical Luneberg lens had been a theoretical scientific concept for many years, and Dr. John Garrison of the Applied Physics Laboratory could see an application of this optical theory to build a powerful, highly accurate, agile beam radar. In concept, a Luneberg optical lens is a transparent sphere having an index of refraction that varies linearly from the outer edge to the center. Mathematically the lens has the property that a point source of light placed at a point on the edge will be focused into an extremely narrow light beam beam emanating from the sphere exactly opposite the location of the light source. In Dr. Garrisonís concept, Typhon would use a large dielectric sphere having index of refraction properties like a Luneberg lens. Then a point source of radar energy would be focused into a narrow radar beam emanating opposite the source.

To elaborate on Garrisonís idea, thousands of radar transmitting elements would be placed around the sphere, and they would be under control of a digital computer that could switch the sources on and off at great speed. Narrow radar beams could be rapidly generated and flicked around in three dimensions at high speed. There was one limitation in the concept. The radar point sources could not emit energy at the power needed for real life radar transmissions because to do so would melt the dielectric sphere in short order. The energy of the emitted beams was too small for practical radar use, but, the emitted beams did have the correct pattern of phases and amplitudes across the surface of the sphere to generate a narrow directional beam.

The next step in Garrisonís concept was to place thousands of powerful amplifiers around the spherical surface, interspersed with the small transmitting elements. The amplifiers would feed thousands of transmitter elements correspondingly located on an external transmitting sphere that would then replicate the phases and amplitudes of the low powered signals on the outgoing surface of the Luneberg lens, but greatly amplified so that the transmitting sphere sent a powerful finely focused radar beam in the direction opposite the small exciter signal on the lens. The digital computer could switch exciters on an off at electronic speeds, resulting in powerful amplified beams sent out in the commanded directions. Garrison calculated that the large guided missile frigate radar version would use 10,800 exciter elements, 2,700 power amplifiers and 10,200 radiating elements on the spherical transmitting antenna. Three smaller receiving antennas covered by thousands of receiving elements would be spaced equidistant around the base of the transmitting antenna. Banks of radar receivers would send target bearing, elevation and range directly to the digital computer. There would be no live video showing on the radar scopes, only computer generated signals. [Inman, p. 64]  [Inman, Capt. Bryce D.,  Letter to D. L. Boslaugh, 15 Aug. 1995]

Westinghouse Electric Corporation won the contract for the AN/SPG-59 radar which was to be built in two versions: a small-ship configuration having 3,400 radiating elements, and larger ship model with 10,000 radiating elements. The two versions would have input power requirements of two point five and five megawatts, which were considerably greater than the power required for search radars. The small-ship version of the radar was to be an equivalent to the AN/SPS-32 and 33  electronically scanned billboard radars that had been installed in the nuclear powered cruiser Long Beach and the attack carrier Enterprise, but had been too heavy for destroyer and frigate ship classes. The larger radar would go aboard guided missile frigate sized ships, and the small version would go aboard destroyer sized ships.  [Polmar, pp 76-77]  [Inman, p. 62]

Reducing the Typhon radar to real life engineering was a different story. APL and Westinghouse engineers found that they could indeed construct dielectric spheres having the refraction characteristics of a Luneberg lens, but even the low power of the exciters caused the spheres to melt. The best they could do was come up with a large sandstone sphere as the Luneberg lens. It could withstand the heat but was not a good approximation of the required lens, and this is where an elegant theory started to go wrong. They found that the sandstone sphere could send out a fairly focused main beam, but much of the emanated radar energy was transmitted in undesired side lobes. [Inman letter]

Other engineering problems reared their heads. The cabling and wave guides needed for the thousands of amplifiers and transmitting elements were very demanding of tight tolerances that were difficult to meet in construction practice. The amplifiers and other power handling electronics also grew in weight and volume to the point that the small-ship version not only could not be carried by destroyer type ships, but could not even be fitted aboard a guided missile frigate. This caused cancellation of a planned class of seven Typhon frigates. The larger system was now suitable only for heavy cruisers, but concerns were arising in BUWEPS that even the larger system was going to have marginal performance, particularly in its jamming resistance. [Fahey, James C., The Ships and Aircraft of the United States Fleet, 8th ed, U.S. Naval Institute, Annapolis, MD, 1965, ISBN 0-87021-637-6, p. 11] [Inman, p. 64]

Close-up of the Typhon radar installed in USS Norton Sound. U.S. Navy photo.
The guided missile test ship USS Norton Sound (AVM 1) fitted with the small-ship version of the Typhon AN/SPG-59 radar, 1964. U.S. Navy photo.

The prototype small-ship Typhon system was to be tested aboard the guided missile test ship USS Norton Sound (AVM 1), a former World War II seaplane tender converted to test missile systems.  Norton Sound would first be fitted with the Typhon radar - that required a shipboard generating capability of 3,300 horsepower. After testing the radar, the missile magazines and launchers would be installed. While the small ship version of the SPG-59 was being installed in Norton Sound, Robert S. McNamara, the secretary of defense, cancelled the Typhon program on 7 January 1964, but did allow radar installation to continue so that the novel concept could be tested. Norton Sound was placed back in commission on 20 June 1964, and conducted Typhon radar tests until mid 1966. [Polmar, p. 77]  In at-sea testing, Norton Sound's operators found that the Typhon radar could not detect a small jet airplane even at the minimum operating range of the radar. [Inman, p. 64]

The Advanced Surface Missile System

With the demise of Typhon, the surface missile system project managers thought they could resume improving the 3-Ts with evolutionary upgrades, however Secretary McNamara had other ideas. In the same directive that abolished Typhon, McNamara told the Navy to start a new project to eventually replace Talos, Tarrier and Tartar, he called it the Advanced Surface Missile System (ASMS). Rear Admiral Eli T. Reich, Director of the Surface Missile Systems Project Office, responded by inviting a number of companies to prepare funded contract definition proposals. Seven industry proposals were received. In general their concepts were similar to Typhon featuring a powerful computer-directed multifunction radar, but most of the contractors proposed electronically steered flat array antennas similar to the Long Beach and Enterprise planar array radars. [Inman, pp. 64-65]

Captain Bryce D. Inman, an engineering duty officer, had been associated with radar research and development for most of his Navy career. It started in World War II when Ensign Inman was assigned as special assistant to Dr. Robert M. Page, the inventor of American naval radar at the Naval Research laboratory. Inman had stayed involved with radar for the following two decades and in 1964 received orders to take charge of the Radar Design Branch in the Bureau of Ships. Inman quickly found out that running the Radar Branch was not his only job; he was also search radar manager for the Surface Missile Systems Project Office under an additional duty assignment arrangement, and Radm. Reich expected a lot of his time. His first assignment from Reich was to evaluate the search radar portions of the ASMS proposals. [Inman, Capt. Bryce D., USN, NTDS Comments, Oral history tape, 4 May 1993]

Radm. Reich wanted to give the contract definition proposals a thorough and wide ranging technical review, and to do this, in January 1965 set up an ASMS Assessment Group. Reich asked former Chief of the Bureau of Ordnance, retired Rear Admiral F. S. Withington to chair the group; which also became known as the 'Withington Committee.' Representatives were assigned from the Navy's material bureaus, the SMS project, contractor and Navy laboratories, OPNAV, and, interestingly, the competing contractors. In the case of the latter, specific named individuals were requested, and the contractor was not allowed to be represented if that named individual was not provided. The committee was divided into subgroups concentrating on: defining the operational requirement, assessing overall system effectiveness, the ship system concept, the missile, the launching system, logistics, system reliability, shipboard installation, and cost. [Inman, p. 65]

The ship system subgroup was further divided into teams that addressed: radar, command and control, fire control, and equipment items such as computers, and operator display subsystems. Capt. Inman was put in charge of both the command and control and radar groups. The NTDS project officer, Cdr. Glyde B. Hannah served as next in charge of the command and control team, and he assigned his assistant NTDS project officers to work in their specialty areas. This writer spent most of his time on the ship system concept. The Assessment Group was quartered at a site in Silver Spring, MD, and met from January to mid May 1965. Some worked full time on the contract evaluations, and others were brought in as needed for specific tasks.

The Group found that they were not only evaluating contractor proposals, but at the same time were better defining and firming up the ASMS concept. The group kept the Typhon multi function, agile beam radar concept but agreed with most of the contractors that it should be flat arrays. They retained most of the Typhon missile guidance ideas, but decided that individual small radar dish antennas, under control of the digital fire control computer, should illuminate the target for missile terminal homing guidance. Capt. Inman noted that the Typhon radar was not intended to support air interceptor control, and that a separate shipboard 3-D radar would be needed for interceptor control if the requirement were not incorporated in the ASMS multifunction radar. The main change needed would be an increase in range from 200 to 250 miles; the same maximum range as the AN/SPS-48 3-D radar. The Assessment Group accepted Inman's recommendation as well as his  recommendation that the Naval Tactical Data System should be used to do the ASMS command and decision function as weapons direction and interceptor control were already being done in NTDS. The group also decided to use NTDS AN/UYK-7 computers as the standard ASMS digital computer, and to equip the system with the forthcoming generation of NTDS operator displays.  [Inman, p. 66]

In mid 1965 Radm. Reich sent the ASMS study report to the Office of the Secretary of Defense, and OSD staffers observed that the Army was just beginning the definition phase of their new Surface to Air Missile System-D (SAM-D), and that SAM-D and ASMS seemed to have a lot of the same functional requirements. Secretary McNamara had come from the auto industry where he was a champion of commonality of parts and components among various auto models of the same manufacturer. The practice could save a lot of money, and he could not see why ASMS and SAM-D could not share many components in common such as the missiles, radars, and computers. He therefore directed the Army and Navy to show him why the two projects could not be merged into a joint Army/Navy missile system. This was to be done by an Army/Navy study group, and Capt. Bryce Inman was subsequently assigned as Navy Technical Director of the group. The group's study report listed a number of differences in the operational requirements of the two systems, and furthermore they built a case that differences in environmental requirements would make a common system unacceptably expensive. They recommended against commonality. McNamara felt they were being parochial and was displeased and unconvinced. He then directed that the Army, in their soon to be released SAM-D request for industry proposals, should call for a separate proposal on a common Army/Navy missile system in addition to their proposal for the Armyís SAM-D system.

By late summer 1966, Commander Erick Swenson was back in the Bureau of Ships as the NTDS project officer, and was reading another request from Capt. Inman to provide more NTDS office support to the seemingly never ending job of defining the Advanced Surface Missile System. This time to work on the Army SAM-D missile source selection board; specifically to help evaluate the Army/Navy commonality proposals. The selection board was to meet for four months, and rather than meet in the Washington D.C. area it was going to meet on the Army's own turf at the Redstone Arsenal at Huntsville, Alabama. Most of the NTDS staff would come down to Huntsville intermittently as needed in their specialty areas, but since I had worked in the Withington Committee ship system concept group, Capt Inman requested my presence for the full four months.

Because of the possible magnitude of a subsequent contract, the Army was going to do the source selection evaluation in secrecy, and the NTDS secretary was instructed to tell callers only that we were on travel. We were not to discuss our assignment with any one, and we were to tell our wives only that we were going to Huntsville. They were not to reveal our location to any one. I was allowed to tell my daily working contacts in the Surface Missile Systems Project Office that I would be gone for four months, and to give them the names of laboratory engineers who were being brought in to the NTDS office to cover our work while we were gone. Capt Wayne Meyer who was now the Terrier system project manager guessed my assignment immediately because he had been 'threatened' to work on the selection board too, and had prevailed on Radm. Reich to get him off the hook.

Meyer enumerated a number of NTDS/Terrier system tasks I was working on and queried who was going to do my work while I was gone. I told him how laboratory engineers had been tasked to cover the work, but he responded that with one phone call to Radm. Reich he could get me released from the assignment - if I wished. I replied that I was sort of looking forward to the work because it was a chance to get the ASMS concept better defined. He shot back that he thought ASMS was going to be a colossal waste of time; that it was again going to go too far beyond what could be accomplished with todayís engineering capability and technology, and was going to be another flop like Typhon. He was convinced that evolutionary improvements to the existing surface missile systems was the only viable approach. My rejoinder was that the Navy had learned a lot from Typhon and how to avoid its mistakes. Furthermore ASMS was going to build on a lot of existing technology such as the AN/SPS 32/33 agile beam radars, and that it was going to use proven NTDS computers and display subsystems. Capt Meyer was far from convinced, and his last words on the subject were, "Well I hope you enjoy your vacation."

We settled in to the first week of proposal evaluations at Hunsville in October 1966, and after the first week some of us in the Navy group went to Sunday services at a local church. During the coffee hour after the service the rector queried what we Navy people were doing in Huntsville. Our stock answer was 'Navy business at Redstone Arsenal.' The ministerís face showed instant recognition; "Oh yes, its got to be the SAM-D source selection board." Apparently the local Army reviewers were marching to a different set of security drums than we were.

As we went through the proposals it became clearer and clearer to both Army and Navy personnel who had spent years developing systems and equipment conforming to their unique environmental requirements that building a system with components that embodied a full set of both service's environmental requirements was going to levy a huge cost burden. For example, the Navy does not have a blowing sand requirement, or a jungle fungus resistance requirement, or a mud or dirt protection requirement. The Army, in turn, does not have to build its equipment to survive being surrounded by salt laden moist air. Though both services had shock and vibration resistance requirements, they were technically quite different. The Navy has hull borne and air borne equipment noise suppression requirements that the Army does not have to worry about because the possibility of an enemy submarine homing in on their emanations is not very likely. The lists of differences went on and on.

We also found that operational performance requirements would levy features and capabilities that the sister service just did not need, and to build in all these capabilities into a common system would put unneeded logistics and operational costs on both services. The Navy senior representatives sent their report back to the office of the Secretary of the Navy, recommending strongly against the common system. The Army managers were also against commonality, but were concerned that if some token amount of commonality were not recommended it might go hard on the SAM-D project, so they came up with a possible area of commonality - computers. At the working level the Army was looking forward to developing their own tactical computer, and it did not endear me to my Army coworkers when I told them we had built an air cooled version of our shipboard CP-642B unit computer for the Marine Tactical Data System helicopter huts. But, again we found that fielding a computer that incorporated all Army and Navy environmental requirements in one box would be expensive. We presented our analysis to our seniors, and they dropped the token commonality offering.

The Army/Navy missile system commonality study did have its benefits. In the sequestered environment of Huntsville the Navy group was able to think through a number of unresolved aspects of the Advanced Surface Missile System. Furthermore, there was a fertile exchange of ideas between the Army and Navy workers, and probably a little bit of sister service thinking and concepts rubbed off into each system development. The AN/SPS-32 and 33 planar array agile beam radars on the nuclear propelled ships Long Beach and Enterprise performed very well when they worked, but their technology had been too far ahead of its time, and the radars did not work all the time. The radars were eventually removed from the two ships and replaced with AN/SPS-48 three dimensional and AN/SPS-49 long range search radars, however they had proven that the agile beam concept would work if supported by the right technologies and engineering design. It is interesting to recall that the most asked question asked by the Navy working group when firming up the ASMS concept was, "How did they do it in the SPS-32/33?."

Secretary McNamara eventually let the Army and Navy go their separate ways. The Armyís SAM-D later became the Patriot missile system that gave a good accounting of itself in the Gulf War, and the Advanced Surface Missile System began its slow, and sometimes painful, progress toward eventually emerging as the Aegis combat system.

Building Aegis

On 1 May 1966 the Bureau of Ships and the Bureau of Naval Weapons were disestablished and the headquarters components of each, minus their engineering organizations, were transformed into the Naval Ship Systems Command and the Naval Ordnance Systems Command respectively. In early 1967 the newly formed NAVORD set up a fourth missile system project in the Surface Missile Systems Project Office - the Advanced Surface Missile System Project. The ASMS project proceeded at a modestly low level of effort doing more system definition work, assessing technologies, and writing contract specifications. The specifications were packaged into a request for contract definition proposals, and on 10 October 1968 the Boeing Company, General Dynamics, and RCA were awarded about six million dollars each to prepare contract definitions for ASMS. [Inman, Capt. Bryce D., USN, Letter to D. L. Boslaugh, 15 Aug. 1959]

The Talos, Terrier, and Tartar systems had been developed under stress and a sense of urgency because of the threat of new Soviet high speed jet airplanes and standoff missiles, but ASMS did not seem to have that same environment of urgency. On 21 October 1967 the project got an infusion of urgency when the Israeli destroyer Eilat was sunk by two Soviet -built Styx anti-ship missiles fired from Egyptian torpedo boats. This made it clear to the U.S. Navy that anti-ship missiles were a definite threat to the USN surface fleet and that the Navy needed a surface missile system with extraordinary short detection, processing, and reaction time, and that system needed a high probability of success in bringing down a hostile anti-ship missile. [HMS Zealous (R39), From Wikipedia, the free encyclopedia]

The shot of adrenaline to the ASMS project had some effect, but was not as stimulating as it could have been. There were still many senior officers in the Naval Ordnance Systems Command who still believed the route to surface missile system improvement was through evolution of existing systems, and they were less than enthusiastic about accelerating ASMS. Furthermore there were high ranking officers in OPNAV and in the fleet who had experienced first hand, or had seen, the troubles with the Enterprise and Long Beach electronically scanned planar array radars, especially their problems with passing targets around the corners of the arrays in heavy seas. To them the phrases 'electronically scanned' and 'planar array' were dirty words and they were not interested in perpetuating the technology.  [Inman letter]

The ASMS project proceeded at a moderate pace undergoing continuous definition and review cycles. At the end of each cycle the system seemed to have grown in features and capabilities, but at the expense of increased complexity, size, and corresponding weight. Many of these new 'nice to have features' were added in order to humor officials in the review cycle who kept coming up with innovative ideas. The innovation that finally 'broke the camels back' was the modular ship concept. The idea was to pre install all ASMS subsystems, except the launcher and missile magazine, in two large deck houses that could be built in a factory environment and then placed as finished units on the shipís superstructure late in construction.

The penalty of all these refinements was a growth in high topside weight and resultant overturning moment that made the system unacceptable for its original target ships - large destroyers and guided missile frigates. The original ships were to have full load displacements in the range of 5,000 to 7000 tons, but now ASMS needed a ship having about twice that displacement. In mid 1969 the only planned ship class that could carry ASMS were the 23 ships of the DLGN 38 nuclear powered guided missile frigate class. Accordingly, the Secretary of the Navy directed the ASMS project to direct its design for that class, and for the DLGN 38 program manager to design the ships to receive ASMS [Inman letter]

The DLGN 38 Class shipbuilding specifications were signed out by the Commander, Naval Ship Systems Command on 21 November 1969. The Class was to have a highly integrated, all digital combat system, with each of the subsystems, including the centerpiece ASMS, using the new AN/UYK-7 Navy standard computer. The combat system was expected to achieve new heights in improved intersystem data flow and reduced detection-to-engagement reaction times. [Nunneley, Cdr. James K., USN, "The DLGN- 38  is Born," U.S. Naval Institute Proceedings, Vol. 96, No. 10/812, Oct. 1970, pp 95-96]  

Neither the name 'Advanced Surface Missile System' nor its acronym was a very catchy name compared to Talos, Terrier, or Tartar. Furthermore NAVORD wanted its surface missile system's names to be short and dramatic. The ASMS project set up a contest to give the new system a fitting name, and Captain Louis J. Stecher emerged as the winner. He had formerly commanded the Talos/Tartar cruiser Columbus, and had later been the Tartar system project officer where, among other things, he digitized the Tartar fire control computer. His entry was 'Aegis' the name of the shield of the Greek god Zeus, the ruler of the heavens. The new missile system would be the 'shield of the fleet.' Capt. Stecher also came up with a longer name, perhaps jokingly, for which 'AEGIS' could be an acronym; Advanced Electronic Guided Interceptor System. The long name never stuck. [Aegis Combat System, From Wikipedia, the free encyclopedia]

The ASMS project office and RCA entered into a weapon system engineering contract on 1 December 1969 . The contract specified that the new system was to be called 'Aegis.'  Also, the ASMS project was renamed Aegis project office on that date. The contract further specified that the primary system radar, designated AN/SPY-1 would be an electronically steered, multi function, planar array, and it would be controlled by AN/UYK-7 Navy standard computers. The missile guidance would use the Typhon concept whereby the SPY-1 would steer the missile to the terminal guidance point with coded radar signals. In a break from the Typhon concept, small pointing terminal guidance illuminating radar dishes, derived from the Tartar system, would bounce signals off the target to guide a seeker head in the missile. The missile would be the standard Terrier/Tartar missile; with improvements, and the command and decision, radar control, weapons control, and data link subsystems would use standard NTDS AN/UYK-7 computers and AN/UYA-4 operator consoles. [Inman Naval Institute article, p. 71]

The Vietnam War combined with the expensive process of converting 31 fleet ballistic missile submarines to be fitted with Poseidon missiles in the early 1970s put a huge strain on the Navy budget. The end result was cutting back on shipbuilding funds, and reducing the planned DLGN 38 class from 23 ships to only four. Furthermore, SECNAV decided to arm these four with twin-rail Tartar missile systems instead of Aegis. No more cruisers of the size needed to carry Aegis were authorized during the first half of the 1970s, and as a result, the Aegis project did not have a target shipbuilding program. In early 1970 Captain Louis Stecker, who had named Aegis, was now a staff officer in the Office of the Secretary of Defense. He had been following the Aegis project, and realized that with the present weight and volume of the Aegis system, it might never get a target ship. The system needed reduction and simplification, and he managed to push through a modification to the RCA Aegis contract calling for a simplification study. [King, Radm. Randolph W., USN, and Palmer, Lcdr. Prescott, USN, eds, Naval Engineering and American Seapower, Nautical and Aviation Publishing Company of America, Baltimore, MD, ISBN 0-933852-73-8, pp. 356-357]  [Inman letter]

Captain Bryce Inman retired from the Navy in 1970 and went to work for RCA in the Aegis program office, where his first job was to take charge of the Aegis simplification study. Inman could not believe how much the system had grown in features, weight, and volume since he had worked on the Withington Committee. He could see many areas in the system that could be deleted or simplified, but first he needed to find out how much the system needed to be shrunk to fit into a feasible target shipbuilding project. He picked the new Spruance destroyer class as his target because if Aegis could not be shoehorned into the Spruance class it probably would not see enough new receiving ships to make Aegis project continuation worth while, in his estimation.

USS Spruance, the lead ship of a class of 31 destroyers, was the first USN gas turbine propelled ship. Spruance class hull and propulsion plant also formed the basis for the 27 ships of the Ticonderoga Aegis cruiser class. U.S. Navy photo.

Inman got the Spruance booklet of general plans to use as a target to determine how much weight and volume would have to be removed from the Aegis components. His resultant study showed ways to cut the SPY-1 radar transmitter and signal processor weight in half and to cut the fire control equipment weight by one third. Furthermore, his team identified a number of nice-to-have features and equipment that did not seem vital to the Aegis mission. If all recommendations were taken, Aegis could be installed in Spruance class destroyers. The Aegis project office sent the study report to the Naval Ship Engineering Center at Hyattsville, MD, where engineers confirmed the results, but also found that Aegis, in that form, would use up all the Spruance lifetime weight and overturning moment allowance. The culprit was the modular deck house concept that so many senior reviewers thought was such a neat idea and still insisted upon it. [Inman letter]

In 1967 Captain Wayne Meyer had received orders to leave the Terrier System project office and report to the Naval Ship Missile Systems Engineering Station at Port Hueneme, California, as Director of Engineering. Three years later he received orders to return to the Naval Ordnance Systems Command as Director of the Aegis Project Office. As we have already related,  Meyer was no stranger to either the technicalities of shipboard guided missile systems, or the ins and outs of project management in the Washington, D.C. environment.

When this writer studied servomechanisms there was an adage we were taught; "If you can't measure something, you can't control it." Capt. Meyer believed in firm project control, thorough testing of each system increment, and measuring the product. For his measurements he set up five 'operational cornerstones' that defined overall system performance; 1. reaction time, 2. firepower, 3. immunity to electronic countermeasures and the environment, 4. continuous availability, and 5. area coverage. Each had a numerical measure, or set of measures, and any new feature or change to the system was assessed by its calculated impact on these measures. [Aegis Combat System, From Wikipedia, the free encyclopedia]

On 1 July 1970 Admiral Elmo R. Zumwalt became the new Chief of Naval Operations, and by early 1972 his staff had prepared a new operational requirement for a single purpose battle group anti-air protection ship. It was to have high firepower, but it had to be affordable so that it could be built in large numbers. Zumwalt called in the commanders of the Naval Ordnance Systems Command and the Naval Ship Systems Command and gave them an ultimatum. He said he wanted a production run of small ships carrying the Aegis missile system, to have a displacement of 5,000 tons, and to cost no more than $100 million each. If they could do it, he would move the Aegis system project to the highest priority, but if they couldnít do it, he intended to cancel Aegis. Capt. Meyer told the system commanders he could get Aegis into such a small ship if he could eliminate the modular deck house and some other nice-to- have features identified by the simplification study - and they bought it.

Admiral James L. Holloway III became Chief of Naval Operations on 1 July 1974, and one of his first actions was to cancel the single purpose Aegis AAW escort project. Instead, he said he wanted a conventional multi purpose destroyer equipped with Aegis. Things were falling into place for Aegis. The first of the new Spruance (DD 963) destroyer class had been laid down on the building ways in November 1972 and its full load displacement was 7,800 tons. Aegis was now able to be fitted into a small 5,000 ton warship, and the DD 963 hull was a natural candidate. The Chief of Naval Operations approved of the idea, and and his Fiscal Year 1978 shipbuilding program budget to Congress included an Aegis ship (DDG 47) to be built on a Spruance Class hull.  [Inman Letter]

[Moore, Capt. John N., RN, Editor, Janes American Fighting Ships of the 20th Century, Mallard Press, New York, 1991, ISBN 0-7924-5626-2, p. 172]

One of the main reasons the AN/SPS-32/33 planar array radars on Long Beach and Enterprise had been operationally unsuitable was their structural bending and resultant beam misalignment in heavy seas. Bryce Inman at RCA remembered that and other 'billboard radar' ship installation related problems, and prevailed on his RCA bosses to form a Ship Integration Engineering Group that would make sure every aspect of Aegis design would fit the realities of ship construction and operation. The group was made organizationally separate from the normal RCA Aegis system engineering team and rather reported directly to the RCA Aegis program manager. The Ship Integration Engineering Group often recommended disapproval of design approaches and new features when they did not conform with the real life requirements of ship construction and operation. They were, at times, just as irritating to Capt. Meyer as they were to RCA management, but the realists usually prevailed. [Inman oral history tape]

The Naval Sea Systems Command and the Naval Ordnance Systems Command were both intimately involved in shipbuilding and sometimes their prerogatives and responsibilities got in each other's way. There was usually just an uneasy peace between the two. The relationships and responsibilities as to who did what when building and equipping a ship were governed by a list of agreements. For example NAVSEA was responsible for installing the deck studs that held down a missile launcher, but NAVORD was responsible for supplying the nuts and washers that went on the studs. Even with the agreements, representatives of the two commands often failed to see-eye-to-eye. In 1974 the squabbles got so bad that the Secretary of the Navy, on 1 July, abolished the two commands and merged them into the Naval Sea Systems Command. Things got a little better, but a reorganization can't change the way people think about what they perceive as their functions and responsibilities. [King, p. 447] [Inman, letter]

One of the unresolved differences in thinking was between the Naval Tactical Data System project officer and the Aegis project manager. NTDS had the function of processing all targets through a threat evaluation and weapons assignment (TEWA) computerized function before assigning targets to a weapon system or airborne interceptor. The Aegis project, however, was concerned about fast moving, low flying aircraft or missiles that might hit a target ship only seconds after detection. They felt that such obvious high treat targets should be fed directly to the fire control computer upon detection. The NTDS project contended that TEWA processing only took milliseconds and that all targets should go through TEWA analysis before passing to fire control. The disagreement was magnified even more because the two different groups were using and controlling the same SPY-1 radar on the part of one side for search and air intercept control, and on the part of the other side for fire control and missile guidance. The disagreement was resolved by pulling the NTDS functions into the Aegis system. The NTDS boundary with Aegis was moved out to the data link equipment, and the NTDS function became known as the Aegis command and decision subsystem. It can be seen that, even though NTDS had become fully accepted by the Navy, it was starting to lose its identity. [Inman letter and oral history tape]    

The cruiser in a cornfield. The Aegis Combat System engineering test site near Moorestown, NJ, is a commissioned Navy activity. A SPY-1 planar antenna array can be seen at the forward edge of the superstructure. Lockheed Martin Corp. photo.

USS Norton Sound, in 1974, was fitted with the prototype Aegis system including a one-face array of the AN/SPY-1 radar, a Mark 26 missile magazine and launcher for the new Standard Missile, and a small pointing target illuminating radar dish. The working SPY-1 planar antenna array was installed to starboard on a deck house above the bridge at a 45 degree angle to the shipís centerline, the other side of the deckhouse featured a dummy array to give the installation some symmetry. The prototype Aegis installation was completed in May 1964, and soon after Norton Sound began system tests. In the first live firings, two Standard-MR missiles having inert warheads were fired at a remotely controlled Ryan Firebee target drone. The first missile came close enough to the Firebee to down it if it had an explosive warhead. The second missile made skin contact with the target and destroyed it. [Polmar, pp. 78-81]

The missile test ship USS Norton Sound with prototype Aegis missile system installed, 1980. Only one array of the SPY-1 radar was installed - on the starboard side of the deckhouse. The array on the port side is a dummy to give the ship some symmetry. U.S. Navy photo.

In further Aegis firing tests during 1975, Norton Sound made eleven successful Standard-MR (SM-1) kills in a row.  The victims included more Firebee drones as well as remotely controlled QF-86 North American Sabre fighters,  QT-33 Lockheed jet trainers, a Talos missile, and a Bomarc anti-aircraft missile. In 1976 Norton Sound's Aegis system, in a test of the anti-surface mode, sank a remotely controlled Septar target boat in a demonstration that the system could handle enemy anti-ship missile boats. [Polmar, p 82]

In 1967 OPNAV had sponsored a research and development project called 'Seahawk' to build an all digital ship. All subsystems in the combat system were to use digital computers, and the subsystems would be highly integrated so that the combat system would truly work as one system with information in one subsystem flowing freely to all the others. Systems such as NTDS, search radars, sonar, missile fire control, gun fire control, underwater battery fire control, inertial navigation, electronic warfare, electronic countermeasures, IFF, and external communications were to be tightly linked together by inter computer data channels. Project Seahawk never came to fruition, probably for two reasons; 1. it did not enjoy the same vigorous OPNAV sponsor support that NTDS had, and 2. the individual project managers and sponsors of the participating systems seemed to be less than enthusiastic or cooperative about being pulled into orbit around a 'super' project manager. It took more than a strong project manger in the Naval Ship Systems Command; it also needed a very strong OPNAV sponsor who could knock heads and exercise a certain amount of coercion. It will be remembered in the case of NTDS that the Chief of Naval Operations, Admiral Arleigh Burke himself, exercised that function when needed.

The DLGN 38 (Virginia) class guided missile frigates had all digital computers in their combat subsystems, as well as did the later Spruance (DD 963) Class destroyers, the Kidd (DDG-93) Class destroyers, and the Oliver Hazard Perry (FFG 7) Class frigates. Each succeeding class had a little higher level of combat system integration, but not even the FFG-7 Class had the level of system integration envisioned by the Seahawk project. The  Spruance and Kidd Class destroyers in particular suffered from system coordination, data transfer, and interface problems as reported in Board of Inspection and Survey reports [Meyer, Radm. Wayne E., USN, "The Combat Systems of Warships," U.S. Naval Institute Proceedings, Vol. 103, No. 891, May 1977, p 119]  The problems of Project Seahawk were still being manifested. Individual sponsors and project managers representing the many 'special interest' communities in the Navy were still loath to come under the influence of a single integrating super project manager.

The lead ships of two ship classes built on the same hull and using the same gas turbine main propulsion plant. The destroyer Spruance is at left and the Aegis cruiser Ticonderoga is at right. U.S. Navy photo.

In June 1977 the Naval Sea Systems Command took a dramatic step to ensure the many systems that had to be integrated with the Aegis system in the DDG 47 (Ticonderoga) Class would be truly integrated. This they did by placing the Ticonderoga Class shipbuilding program and the Aegis project under one project manager - Rear Admiral Wayne E. Meyer. It was to be called the Aegis Shipbuilding Project. NAVSEA and Ingalls Shipbuilding Division of Litton Industries, on 22 September 1978, signed a contract for construction of Ticonderoga which was commissioned on 22 January 1983. It had taken 12 years since Wayne Meyer took over the Aegis project in 1970, but Aegis at sea was finally a reality. Twelve years of powerful critics attacking the project, solving seemingly overwhelming engineering problems,bringing various Navy special interest groups in line, and yearly defending his project funds before Congress. He had built the Navy's first truly integrated shipboard combat system. [Blades, Cdr. Todd R., USN, "Aegis On Its Way to Sea," U.S. Naval Institute Proceedings, Vol. 105/1/911, Jan 1979, p. 101, p. 104]

Inspecting the 100th bay of four AN/UYK-7 computers delivered to the AEGIS Combat System project. From left: Richard Seaberg, Univac Defense Systems Division president, Rear Admiral Wayne Meyer, Robert Faust (Univac), Donald Ream (Navsea), unknown navy captain. Photo courtesy of VIP Club Legacy Committee
Radm Meyer prepares to cut the celebratory cake (in the form of an AEGIS cruiser) with his naval officer’s sword. From left: Emmit Johnson (Univac), Seaburg, Meyer, unknown army officer, Ream. Photo courtesy of VIP Club Legacy Committee

The Aegis guided missile destroyer USS Wayne E. Meyer in San Diego Bay, February 2011. U.S. Navy photo.
Retired Rear Admiral Wayne E. Meyer at a ceremony marking the 100th Aegis Combat System delivered to the U.S. Navy, 27 November 2006. U.S. Navy photo.

In the year 2012 the Aegis Combat System is still the premier combat system in not only the U.S. Navy, but is installed in combatant ships of Japan, Republic of Korea, Norway, Spain, and Australia. At present there are 82 Aegis ships in the U.S. Navy, and 21 in foreign navies; and more are on the way. The system has undergone numerous upgrades over the years, including getting powerful new Navy standard computers. The one most significant upgrade is probably the vertical launching system wherein the standard missiles are stowed vertically in magazines just below quick acting doors in the main deck, allowing the missiles to be launched directly from their magazine. Today the Aegis Combat System controls not only standard anti-air missiles, but also the close-in weapon system, the underwater antisubmarine battery, anti surface ship weapons, and most recently anti-ballistic missile defense. The latest capability is attested to by an incident that happened in February 2008.   [Aegis Combat System, From Wikipedia, the free encyclopedia]

A view of the Mark 41 vertical launch system doors aboard a Ticonderoga Class cruiser, March 2003. The VLS magazine requires far less volume for a given number of Aegis standard missiles than the preceding pointing launcher systems, and gave the Ticonderoga class considerably more firepower. U.S. Navy photo.
A SM-3 standard missile emerging from the vertical launch system magazine aboard the Aegis cruiser USS Lake Erie in a test flight against a ballistic missile launched from the pacific missile range, November 2005. It knocked down the ballistic missile. U.S. navy photo.

On 14 December 2006 the United States launched a surveillance satellite designated USA 193. Soon after reaching orbit the control station lost contact with the satellite, and it was later determined that it was in a deteriorating orbit that would eventually bring it back into the atmosphere. The problem being, the satellite was fueled with hydrazine a hazardous substance that could cause a toxic cloud upon reentry, with bad consequences if it came down in an inhabited area. Knowing that Aegis had the capability to bring down short and medium range ballistic missiles, the Department of Defense asked the Navy if an Aegis system could bring down the errant satellite. Lockheed Martin engineers worked out the needed changes, tested them, and installed them on three Aegis ships, where the crews were trained for the shoot-down. On 20 February 2008 USS Lake Erie launched an SM-3 missile while tracking the satellite with the AN/SPY-1 radar and simultaneously sending guidance commands to the missile until in the vicinity of the satellite; where the missile's own homing guidance took over. The final result was a direct hit. [From Naval web site, 13 November 2008]

The USA 193 National Reconnaissance Office satellite is launched atop a Delta II rocket at Vandenberg Air Force Base, CA, 14 December 2006. Not long after, the ground control station lost contact with the satellite, U.S. Air Force photo.
Aboard the Aegis cruiser Lake Erie (CG 70) off Hawaii, 20 February 2008. Fire Controlman 2nd Class Andrew Jackson reaches to launch an SM-3 missile to bring down the failed USA 193 surveillance satellite. He is manning a Navy standard AN/UYQ-21 operator console. U.S. Navy photo.
The Aegis missile on its way toward a direct hit on the USA 193 satellite 130 miles above the Pacific. U.S. Navy photo.
The two classes of Aegis ships moored together at Norfolk, VA, 1 April 1996. The Aegis cruiser Ticonderoga is at left. At right is USS Laboon (DDG 58) an Arleigh Burke Class Aegis destroyer. Except for the Fletcher and Gearing Classes of destroyers, the Arleigh Burke Class will have the largest production run of any USN surface combatant. Today they are the only active class of destroyer in the U.S. Navy. U.S. Navy photo.

The Last of the Navy Mainframes

Software Rules!

We have related how the AN/UYK-20 standard minicomputer was intended as a three-year gapfiller until the Naval Air Systems Commandís All Applications Digital Computer (AADC) became available. We have also told how the AADC project had to be reoriented to airborne applications only; resulting in a line of airborne computers designated AN/AYK-14(V) having the same 16-bit architecture as the AN/UYK-20 minicomputer. The (V) in the nomenclature signifies that the new airborne computer came in various sizes with differing computing power and memory to match numerous applications. But, this left the Naval Sea Systems Command in the embarrassing position of having no new competitive source for standard minicomputers; for which there was in the mid 1970s a large projected demands. NAVSEA now had to acquire both the AN/UYK-7 shipboard mainframe computer and the AN/UYK-20 minicomputer on a sole source basis from Univac. [Joyce, p. 22] The rest of the computer industry besieged their congressmen with complaints about NAVSEA's noncompetitive sole source relationship with Univac.

An AN/AYK-14 Navy standard airborne computer and its modules. The AN/AYK-14 is packaged in a number of configurations having differing computing power. It has an expanded instruction set of the Navy standard AN/UYK-20 minicomputer. Image from a Control Data Corporation brochure.
After a long and useful life, this smaller version of the Control Data Corporation AN/AYK-14 standard airborne computer now resides in The Computer History Museum at Mountain View, CA. Photo courtesy of The Computer History Museum.
Ships of the NTDS fleet, December 1976. Original source unknown, updated by the author.

By mid 1977 NAVSEA and the Naval Material Command (NAVMAT) felt the time, and the state of new computer technology, was ripe for competitively acquiring replacements for both standard computers. NAVMAT, NAVSEA, and NAVELEX representatives, in late 1977, briefed the Assistant Secretary of the Navy for Research, Engineering, and Systems, Dr. David Mann, on their proposed approach for competitively acquiring the next generation of standard computers. What they planned was a joint development with the Army to be called the Military Computer Family Architecture (MCFA). This would involve selecting a popular, well used commercial computer architecture and embody it in a family of militarized machines ranging from mainframes to microprocessors, all of which could execute the same computer programs. Their favored architecture was the PDP-11 computer built by the Digital Equipment Corporation. [Secretary of the Navy, Office of the Assistant Secretary for Research, Engineering, and Systems, Final Report of the Navy Embedded Computer Review Panel, Oct. 1978 p. 1]

Industry complaints about the Navyís sole source relationship with Univac was well known to Dr. Mann, but he questioned the feasibility of using the PDP-11 architecture in real-tine military systems. Instead of approving NAVMAT's approach, Mann felt it would be better to have a group of acknowledged industry experts study the problem in depth. He intended to form a Navy Embedded Computer Review Panel to review the state of the art in the computer industry as well as the Navyís tactical computer stance and  recommend alternative approaches to the NAVMAT if warranted. Mann asked for panel representatives from the computer industry, laboratories including the Applied Physics Lab and Lincoln Labs at MIT, information technology consultants, and Navy organizations such as OPNAV and SECNAV. Mr. Joseph M. Fox, a former IBM vice president was asked to chair the panel. In order to maintain the panel's objectivity, NAVMAT, systems command, and Navy laboratory representatives were not put on the panel, but participated by providing briefings, written material, and numerical information. Mann also sent questionnaires out to all Navy project and program offices asking not only about their future needs for tactical computers, but also their present holdings of computer programs that ran in the standard computers and their future computer program development plans. The panel had its first meeting in January 1978 and provided a final report in October of that year.

From 1961 to 1977, The number of U.S. Navy ships equipped with NTDS grew from three to 73 as shown above. {Final Report of the Navy Embedded Computer Review Panel, Oct. 1978, p E-5.

The panel dug deeply and came up with some results that Navy computer managers had not realized. The report showed that by 1977 the Navy had fielded 380 CP-642 unit computers, 930 bays of AN/UYK-7 computers, and 1,638 AN/UYK-20 minicomputers, giving a total of 2,948 machines. Furthermore projections showed that in six years this number was going to quadruple. This was not too much of a surprise, but what came next was a revelation. The panel noted that by 1985 the total of of fielded Navy standard computers would be valued at hundreds of millions of dollars, but more significantly the value of tactical computer programs would be in the billions of dollars. Clearly, computer programs were going to be the dominant cost in Navy embedded computer systems. The panel noted that if the Navy adopted a new computer architecture, much of this investment in programs would have to be rewritten to run in the new machines; and rewriting programs was not trivial because a rewritten program needs full retesting. Furthermore, the panel said because of the cost of new programs, existing programs, or segments thereof, should be reused wherever possible in new applications.

The panel recommended that the Navy should develop a new family of computers, embracing the latest in computer technology, but should retain the instruction set architectures of the UYK-7 and UYK-20 computers so that the large investment in computer programs could be reused. The panel also noted that the new computers could also have additional new instructions and features, as long as they could execute the existing computer programs.

The panel also expressed its concern that, in spite of the establishment of the Tactical Digital Systems Office (TADSO) at Naval Material Command Headquarters, the day-to-day management of standard computer acquisition was fragmented among the systems commands and there seemed to be little collaboration or mutual support among Navy computer developments. For example, NAVSEA was in charge of the AN/UYK-7 computer and standard operator display subsystems, whereas NAVELEX had developed the AN/UYK-20 minicomputer, and NAVAIR was in charge of the AN/AYK-14 airborne computer and standard signal processors. The panel recommended that the Navy consolidate all tactical computer developments under a single program manager. That program manager should also be responsible for standard computer peripherals and operator displays, computer programming support tools, tactical computer programming standards, centralized life cycle logistics support of all tactical embedded computer products, long range computer requirements planning, and managing related research and development projects. [Final Report of the Navy Embedded Computer Review Panel, pp. 6-11, 18-19]

The report on the Fiscal Year 1979 Appropriations Bill from the House Appropriations Committee had a statement saying the Committee was pleased to find the Navy was going to competitively acquire its next generation of standard shipboard computers, and that these computers would be able to reuse the Navy's large investment in existing computer programs. The report further agreed that the Navy should not try to competitively buy more of the existing UYK-7 and UYK-20 computers, but should press ahead with developing new computers using the latest in technology. To provide an incentive for the new developments, the Committee noted it had reprogrammed Navy funds marked for upgrades to the existing machines into the new development. It also forbade any further improvements to the UYK-7 and UYK-20 computers. [U.S. House of Representatives, Appropriation Committee Report on FY 1979 Appropriation Bill, Backup to PL 95-485, 20 Oct. 1978, pp 340-341]

In December 1978 Capt. Eugene Reiher, who had relieved Radm. Joseph Rice as head of TADSO, retired from active duty and Capt Charles Hager, who had been in charge of AN/UYK-20 minicomputer development in NAVELEX, was assigned as director of the newly established Navy Tactical Embedded Computer Program Office (TECPO) which replaced TADSO.  ["Navy Taps Chief for TADSO Command," Electronic News, Monday, December 25, 1978]  The implementing directive also assigned the new office responsibility for managing research and development of: the two new standard computers, standard signal processors, peripheral equipment, operator displays, and computer programming support tools. The actual developments were to be done by project offices in the systems commands under the technical direction and fiscal control of the TECPO office.

Building Two New Computers

In late 1978 the NAVSEA NTDS project officer, Capt. Carl C. Drenkard, assisted by computer engineer Paul H. Hoskins, started work on the plan for developing the directed successor to the AN/UYK-7 computer. Then in late 1979 NAVSEA set up a new project office, the Navy Shipboard Tactical Embedded Computer Resources Office (PMS 408), to be headed up by engineering duty officer Capt. James P. O'Donovan, to develop both of the new shipboard computers.  The new project also absorbed the responsibilities and resources for remaining UYK-7 and UYK-20 production and life cycle support, as well as for standard display subsystems, the AN/UYS-2 enhanced modular signal processor, and standard computer programming support software. The standard airborne computer remained in NAVAIR because of safety of flight considerations. NTDS data link equipment development was moved to the Naval Electronic Systems Command. The NTDS project office was no longer in the computer, display, or data link development business, but would rather be one of the many users of PMS 408's standard tactical digital equipment. [Grant, Lt. Peter M., USN, "Getting the Big Picture into our CICs," U.S. Naval Institute Proceedings, Vol. 110/1/971, Jan. 1984, p. 110] [Drenkard, Capt. Carl C., USN, Letter to D. L. Boslaugh, 21 Nov. 1994]

As one of his last acts before retiring from government service, engineer Paul Hoskins wrote a general description of the requirements for the new mainframe computer. Then he set up a navy-wide design review group of engineers from Navy laboratories, systems commands, and project offices to work out the requirements in detail. NAVSEA engineer Joseph Mallonnee in the newly formed PMS-408 took over the DRG upon Hoskins retirement, and later served as project engineer for the new AN/UYK-43 mainframe computer. Capt. O'Donovan set up a similar DRG for the new AN/UYK-44 minicomputer.

The two new computers were to be built of the latest solid state integrated circuit technology, and both machines were to be able to execute computer programs written for their predecessor computers. The mainframe was specified to be able to execute a tactical program instruction mix at a rate of 4.5 million instructions per second on average, and it was to have a memory of at least ten million 32 bit words, with a future memory expansion capability of four billion words. It was to have 64 input/output channels so that one AN/UYK-43 computer could take the place of four AN/UYK-7 computers. Furthermore, it was to fit the same mounting bolts and accept the same signal and power cables as the AN/UYK-7. The machine was to be designed so that it could be fitted with denser memory, faster processors, and other new technologies as they came available. Submarines did not participate in NTDS, but were starting to use digital computers in their weapon systems. Two of the requirements thus placed on the new mainframe were the ability to fit through a standard 25-inch diameter submarine deck hatch without disassembly, and a strict restriction on generating structural and airborne noise.

The new standard AN/UYK-44 minicomputer was to have two million 16-bit memory words, whereas the preceding AN/UYK-20 minicomputer had 65 thousand words, and it was to be about twice as fast as its predecessor, executing a tactical instruction mix at 900 thousand instructions per second. The new mini was to have the same size and shape as the UYK-20 and it was to be able to fit on the same mounting bolts, as well as accept its predecessor's input/output and power cables.

The two design review groups completed their detailed specifications in March 1980, and representatives of seventeen contractors attended the May bidders conference.  Right up to the time of of NAVSEA's release of request for bids, seven contractors said they intended to compete. Capt. O'Donovan was feeling pretty good. But in July, when the competitive bidding closed, NAVMAT and NAVSEA officials were distressed because only two bids had been submitted on each machine; two each from IBM and Univac. O'Donovan had hoped to have at least four different contractors build engineering development models of each machine, from which two production contractors would be selected for each computer. In September 1980 NAVSEA awarded engineering development contracts to IBM and Univac for each of them to develop both computers. Later there would be a competitive evaluation of engineering development models to pick a production supplier for each machine.

In October 1980 when this writer relieved Capt. Charles Hager as director of the Tactical Embedded Computer Program Office in NAVMAT, Capt. O'Donovan and I visited some of the contractors who had, at the last minute, declined to submit bids on the two standard computers. We wanted to find out why they had backed off. In most cases they were relatively small firms who specialized in putting an already-developed commercial machine in a militarized package. As we got deeper into the conversations they usually noted that the particular machine they offered did not meet the Navy specifications without considerable reengineering. In particular, the requirement to be able to run existing AN/UYK-7 or AN/UYK-20 computer programs meant they would have to rework their instruction set architectures. In most cases they would have had to start out from scratch designing a new machine. Some said that they did not feel confident enough about beating Univac to tie up most of their engineering resources for a couple of years, and others honestly said they did not have the engineering capability to design a new machine.

The AN/UYK-44 Navy standard minicomputer, the successor to the AN/UYK-20. Lockheed Martin Corp. photo.

IBM and Univac both delivered AN/UYK-44 engineering development models one week ahead of schedule in September 1982. When Capt. O'Donovan's engineers ran the first Navy acceptance tests they perversely loaded the Univac computer with the IBM testing programs and vice versa. To the credit of both contractors, both machines worked even with the other's test programs. After five months of technical and production cost evaluations, NAVSEA, in February 1983, awarded a five-year firm fixed unit price UYK-44 production contract to Univac.

A few months after start of preparations for production, Univac made a proposal to cut the new minicomputer's production cost by making what both Univac and the Navy adjudged to be a minor change in the mini's new high-tech multilayer silicon substrate circuit boards. The change would replace the gold interconnection wiring 'printed' on each layer of the seven layer boards with copper. The expected cost savings were appreciable, and we expeditiously gave approval. Part of the enthusiasm may have been due to the abhorrence of Navy program managers of the term 'gold plated,' that the critics of military specifications love to levy against military projects. Nobody as much as dreamed that we were virtually plunging the computer into a new research and development program.

The UYK-44 was one of the first electronic devices ever to use the new multi layer silicon substrate circuit boards. They allowed a high density of printed circuit chips and at the same time give better component cooling. Univac engineers, physicists, and chemists had perfected the gold printed wiring process which called for many chemical treating steps and baking in vacuum ovens at precise temperatures, and they did not see any particular problem in changing the process to copper lands. The first new boards came out of the ovens and ran fine in their initial tests, but after a few days failures occurred. The copper lands were separating inside the layers of the boards.

After a few months of tries with the copper conductors we were starting to realize that what we thought was deterministic science was in reality a combination of alchemy and black arts. What was supposed to work in theory was not working in practice. Eleven different project mangers had placed orders for advance production UYK-44 models , and they were counting on delivery by December 1983, which was now only a month away. Univac was making little headway in perfecting the copper wiring process, and we began to think seriously about going back to the gold wiring. But, after some deliberation, the highest levels of NAVMAT and NAVSEA supported a position that the potential cost savings over the production life of the computer was worth possible user project delays. We would not go back to the gold wiring, and one of the top items on the Chief of Naval Material's daily problem list was the status of the UYK-44 circuit boards.

One of the AN/UYK-44 standard minicomputer’s multilayer silicon substrate printed circuit cards. The silicon layers were very effective in conducting heat out to the metal edge rim, and allowed a high density of integrated circuit packaging. This card was from an early test production run, and one can see some hard wires near the center that were added to correct circuit errors. Photo by the author.

Fortunately their were some ameliorating factors. Most future UYK-44 users were in the computer program development phase and could use AN/UYK-20 computers to develop most of their programs. For those who absolutely had to have a working UYK-44, Jim O'Donovan located every engineering development model Univac had built and parceled them out to project managers. When that wasnít enough, he went back to IBM and found they still had their engineering development models in storage. IBM pulled them out, made sure they ran and shipped them off to designated project mangers.

The UYK-44 project was starting to look a lot like the early days of the AN/UYK-20 minicomputer project, but with the significant difference that Capt. O'Donovan would not release a production machine until it had passed extended reliability tests. This writer made daily rounds of phone calls to project managers to get a measure of their pain level, and Capt. O'Donovan directed his few remaining engineering development machines to where the pain was worst. Finally, a few months into 1984, we were able to take the UYK-44 off the CNM's problem list. Univac scientists had found the right combination in their alchemy, and the new copper wired circuit boards began passing extended reliability tests. UYK-44 production was cranked up to supply all the promised machines.

The Univac AN/UYK-43 engineering development computer also started running in to technical problems of a much different nature than electronic circuit boards; in this case what the uninitiated might consider a prosaic design problem - cooling of the electronics. The UYK-43 computer consumed about as much power as an electric stove with the oven and all burners on, and all that heat had to be removed by a cooling system. Heat is the main enemy of solid state electronics, and the UYK-43 contract specification required that no single transistor junction temperature could be above a specified temperature in normal operation. A single overheated transistor would become the most likely computer failure point. The specification emphasized that average junction temperatures didn't count; all junctions had to meet the temperature requirement.

The design of the cooling system in a high performance computer has always been a severe engineering problem, and both IBM and Univac considered it one of their most critical design areas. Capt. O'Donovan's engineers witnessed the cooling system tests of both contractorís computers, and noted that IBM had pursued a very sophisticated cooling design that met all specifications. At Univac, however, they saw that even though the average junction temperature was within bounds, there were hot spots. They warned Univac engineers that, so far, the Univac UYK-43 was not in compliance, and that if the hot spots could not be corrected, IBM was probably going to win by default. Univac tried fixes, but nothing worked.

Univac engineers came to the belated realization that a new UYK-43 cabinet design was going to be needed; and there was not much time left. The Univac cabinet was a complex built-up welded device that would take too long to rework. In desperation Univac engineers designed a new cabinet out of solid aluminum slabs, and took their plans to a local Minneapolis company who fabricated complex things out of aluminum slabs with computer controlled milling machines. In a few weeks Univac had assembled the first aluminum enclosure and installed the internals. Cooling system tests showed they met all junction temperature requirements. A few days later a Univac manager called Capt. O'Donovan to tell him that the new cabinet not only met all temperature, shock, and vibration specs, but also in production quantities was going to cost about a third less than the old cabinet.

The dual processor version of the Univac AN/UYK-43 Navy standard shipboard mainframe computer. The tall, slender form factor allows the machine to fit through a standard 25-inch diameter submarine deck hatch. Lockheed Martin Corp. photo.
Artist’s depiction of the IBM single processor and dual processor versions of the AN/UYK-43 computer. Image from an IBM brochure.

Government testing of both contractorís computers started in March 1982, and it was found that the Univac machine slightly exceeded all specification requirements, whereas the IBM entry exceeded specifications by about 3% on average. Both contractors fixed price unit production prices were gratifyingly low, however IBM price exceeded Univac by about 15%. The contract did not require that the Navy give the contract to the lowest bidder; it was up to the selection board's overall assessment and discretion. As the tests and evaluations were being wrapped up, this writer started getting phone calls from congressional staffers, SECNAV officials, and DOD officials. The general thrust of the calls was trying to feel me out on who was going to win the production contract. I was not allowed to tell them anything, not even my private thoughts. The other thrust of the calls was the assumption on the part of the callers that since Univac had won the large UYK-44 minicomputer contract, the Navy was going to give the mainframe contract to IBM. Congressional staffers even suggested this might be appropriate as a way to give the Navy another supplier of standard computers.

Univac's significantly lower unit production costs, won out however, and in March 1983 NAVSEA awarded the AN/UYK-43 production contract to Univac. The day after the award was announced this writer got a phone call from the Assistant SECNAV office for Research Engineering and Systems. I was to go see the senior staffer of the House Armed Services Committee the following day. When I entered his office he said, "We just can't believe the Navy gave the UYK-43 production contract to Univac, wasn't the IBM entry three percent better?" I replied, "Yes sir, but the IBM unit production costs were 15 % higher." The staffer then asked, "Wasn't either machine considered a good bargain, and wouldn't it have been good to get another supplier of your standard computers?" "Yes sir, but our projection for total life time production of the 43 is over one billion dollars, and 15% of that is 150 million. That, to us, is a lot of money the Navy could use to buy other things." There were no more questions.

It has been conventional thinking that military 'spec' hardware of any kind, and, even more so for sophisticated hardware like computers, that they must cost considerably more than  commercial items that do the same thing. The UYK-43 price was so low that we began wondering how it compared with commercial machines of equivalent computing power. One of Capt. O'Donovan's engineers did an industry survey that confirmed our suspicions. The UYK-43 price came out lower than the average price of equivalent commercial machines. The price was so low that innovative project mangers began planning to use them in applications where military hardened machines were not needed, such as shore computing sites. They even planned to use the new mainframes as automated digital switchboards in shipboard systems because the machines cost less than a conventional digital switchboard.

Also, a submarine weapon system project that had planned to use numerous minicomputers and microprocessors in a distributed architecture ran into unresolvable data distribution and time lag problems that forced the project to fall back on using a large number of UYK-43 computers. By early 1984 Capt. O'Donovan had accumulated more orders for the new mainframe than his early projections, and his planners were showing a very large future orders projection. A projection that Univac managers apparently just could not believe. Univac had not geared up to produce the new machine at the ordered rate and they started coming off the production line much too slowly. There was also some conjecture in Navy circles, that Univac, like many others, had assumed that IBM was going to be given the UYK-43 contract, and had not put much planning into gearing up for large scale production. Univac managers remained silent when that subject was brought up. Univac officials were invited to various Washington D.C. admiral's offices for some not-too-friendly chats to convince them the Navy was serious about the large projection of orders, and by mid 1985 the new mainframes were coming off the production line in the needed numbers.

The following is one example of how the UYK-43 was pulled into work where 'milspec' computers were not really needed. It happened in May 1984, when I looked up to see Barbara Henderson, the Tactical Embedded Computer Program Office secretary standing in my office doorway, a sheet of paper in her hand, and a puzzled look on her face. "You had better look at this captain." It was a letter, and at the bottom was written in red felt marker strokes, "What the Hell?" and under that query, the initials of the Chief of Naval Material, Admiral Steven A. White. It was a personal letter from the CEO of a large corporation complaining that the Aegis project had initially committed to using their supermini computers in five shore based computer programming sites as Aegis combat system simulators. But now they had changed their mind and were going to use AN/UYK-43 militarized machines in place of their computers. The CEO wanted to make sure Adm. White knew of this inexplicable and very expensive decision to use costly 'milspec' machines in place of their much less expensive commercial minicomputers.

I made a quick phone call to the Aegis Shipbuilding Program Office and asked for Captain John J. Donegan. I asked, "Why are you doing this Jack ?, you don't have to use Navy standard computers in shore simulation applications." The reply, "Because its cheaper." He said his engineers had done a cost comparison study of using the company's minicomputers versus using UYK-43s, and had found using the 43 would cost about half as much, giving a cost reduction of around $8 million. The analysis ran as follows. The five shore sites needed a total of either 17 of the companyís supermini computers that cost $316K each for a total of $5.37 million, or 20 UYK-43 machines at unit cost of $275K each for a total of $5.5 million. So far this gave the commercial machines a slight edge. But, fifteen of the commercial machines needed to appear to the rest of the system like Navy standard computers, meaning they would each need modifications to give them Navy standard input/output channels at a cost of $248.7K each, giving a total cost of commercial machines of $9.1 million; as opposed to a total of $5.5 million for the UYK-43s. The comparison did not stop there, however.

Capt. Doneganís engineers had also worked out a 15-year life cycle comparative cost of ownership. First, the unique commercial machines needed their own set of repair parts at each site, whereas there were to be other UYK-43 computers at each site, so the additional UYK-43s could use the basic kit of onsite spares without additional stocking. Repair parts are sort of an insurance item that requires one or two each of critical parts even though there is very little chance of that part failing. The commercial machines would also need specially trained maintenance technicians, most likely supplied under contract by the computer maker, whereas Navy technicians already on site could maintain the additional UYK-43s. Then there was the matter of power consumption. The Navy machines were designed to put the lightest possible load on shipboard generators, and over 15 years would consume about a half million dollars less worth of electric power.

The 15-year cost ownership came out at $7.5 million for the commercial, machines as compared to $2.25 million for the additional UYK-43s. Total acquisition and life cycle cost for commercial machines was thus $16.6 million for the commercial machines and $7.75 million for the Navy standards; a savings of $.8.85 million.  There was also another benefit to using the UYK-43s. The Navy computers needed only one fourth the floor space as the commercial machines; this being due to the requirement to be able to lower the UYK-43 through a 25-inch diameter submarine hatch.

[Naval Material Command Headquarters, Embedded Computer Program Office. Point paper, Aegis Combat System Interface Simulator, Comparison of System Costs, 2 May 1984]

Jack Donegan told me that the company managers refused to believe him when he showed them the cost analysis, and that they left his office in a rage, dropping the threat that they were going to put a full page add in The Washington Post exposing the Aegis projectís unbelievable action. But first, their CEO decided to try his letter of complaint to the Chief of Naval Material. We sent the cost analysis to the CNM and that was the last we heard of it. Capt. Donegan was looking forward to the full page add in The Washington Post so he could frame it on his wall; but it never materialized. 

A bank of AN/UYK-43 computers at the Aegis Ballistic Missile Defense laboratory, Naval Space and Warfare Systems Center-Pacific, San Diego, CA. After more than three decades since their fleet introduction, UYK-43 computers were still on active duty in November 2015. Photo courtesy of the U.S. Navy

Captain Jim O'Donovan served as program manager of the Shipboard Tactical Embedded Computer Resources Office until October 1984 when he took command of the Naval Research Laboratory. O'Donovan was relieved as PMS-408 by Captain Donald L. Leichtweiss who, as an Ensign, had been the junior member of the original Naval Tactical Data System project office.

The AN/UYK-43 computer door latches could be a little quirky. The Royal Australian Navy used a number of UYK-43s, and this is their unofficial depiction of the latches. From “Memories of CDSC (Royal Australian Navy Combat Data Systems Center)” Royal Australian Navy Publication, May 2009

The AN/UYK-43 would be the last of the Navy standard mainframe computers. As computer technology moved forward to microprocessors having the computing power of early mainframes much of the shipboard information processing workload was moved to microprocessors embedded directly into operator consoles, communications equipment, and other host equipment. When central mainframe processing power was needed, this was gradually taken over by military hardened commercial off-the-shelf (COTS) processors and the ability to reliably translate 'legacy' computer programs to run in the COTS processors. The evolution of processors in the Aegis combat system over the years is an illustrative case.

  • 1980, Build 1/2/3, Ships CG 47-64, Computers - AN/UYK-7, AN/UYK-20
  • 1990, Build 4/5, Ships DDG 61-78, CG 65-73, Computers - AN/UYK-43, AN/UYK-44
  • 1994-1998/1999, Build 6 phase I, Ships DDG 79-84, CG 66 & 69, - AN/UYK-43/44 + Adjunct COTS
  • 1997-2001, Build 6, Phase III, Ships DDG 85-90, Computers - AN/UYK-43/44 + Adjunct COTS
  • 1999-2002, Build 7, Phase I, Ships DDG 91-112, Computers - All COTS
  • 2004-2006, Build 7 Phase III, Aegis Open Architecture, Computers - A scaleable pool of interchangeable processors

[Aegis Combat System "AWS Computer Architecture Evolution Path After POM-04" web site]

As of November 2015, there are still about 47 USN ships equipped with AN/UYK-43 computers, as well as a number of the machines serving at shore sites.

Evolution of NTDS Display and Communication Systems

Navy Standard Display Subsystems

The AN/UYA-4 Display Subsystem

By 1964 Vice Admiral Charles B. Martell was Chief of Anti-Submarine Warfare in the Office of the Chief of Naval Oprtations. He had been watching the progress of the Naval Tactical Data System project for some time, and had decided time was ripe to build a variant of NTDS to equip ships that specialized in anti-submarine warfare. The project was titled the Anti-Submarine Warfare Ship Command and Control System (ASWSC&CS), and two versions were to be built for research and development purposes. One version would go aboard two destroyer escorts, and the second aboard an ASW carrier - designated a CVS. Lieutenant Commander Carl Drenkard, in the NTDS project office was assigned additional duty as ASWSC&CS technical director reporting to the ASW Project Office at Naval Material Command Headquartres. [Drenkard, Capt. Carl C., USN, "History of the Anti-Submarine Warfare Ship Command and Control System," Oct. 1993, p 1]  To read a history of the Anti-submarine Warfare Ship Command and Control System, the reader can click on this link.

Vice Admiral Charles B. Martell, with corncob pipe, OPNAV’S Chief of Anti-Submarine Warfare visits the NTDS engineering test site at the Navy Electronics Laboratory, 22 July 1960. He soon began formulating ideas for using NTDS in an anti-submarine role. Capt. Parker Folsom the OPNAV NTDS project sponsor is at right in civilian attire.

The time was ripe to develop a new generation of NTDS display subsystem, and furthermore, in addition to the existing NTDS displays, the ASW project needed a new display console with a larger 22-inch cathode ray tube specifically designed to support anti-submarine warfare. It was to be a horizontal faced scope that could display submarine track histories, and allow viewers to stand around the sides of the display. It was to contain enough of its own memory to recall and show up to 60 submarine, aircraft, or surface ship target tracks. Vadm Martell agreed that the ASW project would fund developing a new NTDS display subsystem - to be designated AN/UYA-4.

The evolution of NTDS operator consoles from 1956 to 1975. At far top right to left are engineering test SSA-23, service test SYA-1, first production SYA-4, and UYA-4 consoles. The inset shows SYA-4 consoles in the combat information center of the destroyer USS John Young (DD-973). Photo courtesy of Raytheon Systems Co.
An AN/UYA-4 NTDS operator’s console aboard an Aegis cruiser.

LCDR Drenkard became NTDS project office manager of the new display development and Mr. Fred Russell in the Radar Branch, who had already developed three generations of NTDS display subsystems became project engineer. Hughes Aircraft was awarded a research and development contract to provide a set of three service test display systems for the three ASWSC&CS test ships. This time Russell and Hughes were able to combine the data input console and user console into one universal console. The two other console types would be the height/size console and the new horizontal screen ASW console which they decided to call the operations summary console. The new subsystem would be the first NTDS displays to use integrated circuit chips instead of discrete components. This resulted in a decrease by two thirds in the number of circuit cards, and a resultant decrease in electronics volume that allowed mounting the auxiliary readout indicators in the top of the console rather than the previous freestanding auxiliary readout cabinet.

A view of the combat information center of the USS Estocin (FFG 15). Two NTDS AN/UYA-4 operator consoles can be seen at right center. An operations summary console is at far right. April 1980. U.S. Navy photo
Detail of the Operations Summary Console Face. From a U.S. Navy training manual

The UYA-4 specification called for the new subsystem to support not only anti-air and anti-submarine warfare but also all other conceivable ship warfare areas. To accommodate the expanded use, Hughes increased the number of operator selectable console modes. Other improvements included adding ASW related symbols to the symbol repertoire and the ability to write alphabetic messages (in addition to numbers) on the face of the radar scope. The anti-submarine warfare support requirement called for automatically bringing sonar submarine position data into the NTDS computer, rather than the previous manual entry requirement. This called for a new sonar azimuth converter and expanding the NTDS radar switchboard to accommodate 11 different sensor inputs. A later refinement would be a television converter that permitted showing TV pictures on the radar scopes.

Following completion of ASWC&CS operational evaluation in 1968, the AN/UYA-4 display subsystem was approved for service use, and Hughes Aircraft Co. subsequently won a competitive production contract to produce the subsystem for new NTDS ships as well as other users.  [Hughes Aircraft Company, Fullerton, CA, "Navy Tactical Displays," undated publication, pp 2,3,8,9] [Grant, Lt. Peter M., USN, "Getting the Big Picture into Our CICs," U.S. Naval Institute Proceedings, Vol 110/1/971, Jan 1984, p. 109]

At Last, a Large Screen Display

One of the collateral duties of NTDS project officers, including junior officer assistants, was briefing flag officers on the progress of NTDS. A number of times in these briefings we would get a comment from one of the admirals along the line of, "NTDS was developed by lieutenant commanders for lieutenant commanders! when are you going to do something for us admirals?" When we asked what they wanted, a large screen display was almost always at the top of their list. Heretofore they had been provided with their own NTDS command consoles, just dedicated user consoles at which they had to sit. But they did not like to sit at a console while exercising command. What they wanted was something that could show the NTDS picture on a large vertical screen so they could move around the CIC and discuss the situation with others face-to-face, rather than having someone looking over their shoulder at their console, or vice versa. Even the larger screen AN/UYA-4 operations summary console did not satisfy their need.

As early as 1962 OPNAV had written an operational requirement for a computer driven large screen tactical display, but technology was the problem. First of all, it had to stand up to the shock, vibration, salt air, heat, and humidity of the shipboard environment. The shock of one near miss in battle could not put it out of action when it was needed the most. It had to be simple to adjust and maintain, and it had to be as reliable as the rest of the NTDS equipment. It could not be the weak link. Furthermore the picture could not lag real-time events, and it had to be crisp and clear. In addition to being the ASW Ship Command and Control System project officer, Lcdr. Carl Drenkard had other collateral duties, one of which was exploratory development projects manager for the Director of the BUSHIPS Command and Control Systems Management Office, to which the NTDS project office reported. [Grant, p. 109]

In this part-time R&D management job, Drenkard had looked at a lot of large screen display ideas and even funded some promising looking ones, but with unhappy results. One of the first was a large grid with thousands of holes, and illuminated from behind. Each small hole was covered by a small flap that could be opened or closed on computer command. The opened holes would show an image, but he found the many thousands of flap mechanisms were subject to high mechanical failure rates, and the scheme took too much computer processing power. He looked at banks of projectors where servo controlled styli scraped images on smoked glass slides, but the stylus servomechanisms were no more reliable than the little door flaps, and it took a lot of projectors to realistically show a tactical situation.

Next Drenkard and Fred Russell of the Radar Branch funded a contractor who said he could do the job with photochromic film. This film had the properties of a black and white photo negative, but without the need to develop it. An image was created on the film by banks of servo pointed projectors that projected images of symbols onto the film. Once the completed image was prepared, it persisted for a few minutes and could be projected on a screen. Unfortunately, the banks of computer controlled pointing servos were just as unreliable as the multiple servos in the other schemes. The next contractor said he could generate the image on photochromic film another way, without the many servos. He exposed it directly to the image on a PPI scope, and did get projectable images, but they were too fuzzy to be of practical use. [Bureau of Ships, "Technical Development Plan for the Naval Tactical Data System (NTDS) - SS 191," 1 Apr. 1964, p 2-2]

What Lcdr. Drenkard and Fred Russell really wanted was an all-electronic device that could write images at electronic speeds and be controlled by a computer. You would think cathode ray tubes used in radar scopes and television screens would have been the answer, but it must be remembered that in the mid 60s a two-foot cathode ray tube was barely within the state of the art, but what was needed was a screen that could be read from anywhere in the CIC, meaning it had to be about five feet across. They finally found their all-electronic breakthrough in 1965 when Navy Electronic Laboratory scientists showed them an idea they had been working on. They showed Drenkard and Russell how they could use a small, but highly precise, cathode ray tube to project a sharp image on photochromic film through a bundle of fine fiber optics tubes. The image on the film could then be projected by shining a light down on to the film and reflecting it back by a one-way (dichrotic) optical film put between the small cathode ray tube and the fiber optics bundle.

NEL engineers built a working model of the device which Hughes Aircraft Co. then engineered into a milspec shipboard large screen display projector. It could project the same tactical picture as could be seen on an NTDS operatorís scope. The device was designated OA-8393 large screen display and was installed in the two amphibious force flagships (Mount Whitney and Blue Ridge) command areas as well as the command areas of some NTDS equipped heavy cruisers and attack carriers. The OA-8393 worked but was not a great success. The nature of the photochromic film caused it to have a 10-to 15 second delay in projecting the tactical picture, and it was not installed in other ships. [Hughes Aircraft Company, Ground Systems Group, Fullerton, CA, "Summary of AN/UYA-4 Display Equipment Characteristics, for PMS 408.41, Naval Ship Systems Command," July 1981]  [Grant, p. 109]

Our, now familiar, liquid crystal diode was the final step needed to develop a fully useable NTDS large screen display. This time Navy Electronics Lab scientists found if they laid a thin liquid crystal film over the face of a small precision CRT, the charges on the face of the CRT could make corresponding points in the film transparent while the rest remained opaque. By substituting the photochromic film in the large screen display projector with a liquid crystal diode film they had a projector that could show the tactical situation in real time and with clarity. In 1982 Hughes Aircraft delivered the prototype liquid crystal light valve large screen display to the Aegis Combat System Engineering Development Site at Moorestown, NJ, for evaluation. [Grant, pp. 110] [Drenkard, Capt. Carl. C., USN, Letter to D. L. Boslaugh, Oct. 1993]

Early Navy standard large screen displays aboard an Aegis cruiser, circa 1988. U.S. Navy photo
Navy standard large Screen displays aboard the Aegis destroyer USS John S. McCain, March 1998. One can see the progress of technology in ten years, U.S. Navy photo.

The AN/UYQ-21 Display Subsystem

In the summer of 1969 Cdr. Carl Drenkard received orders from the NTDS project to become the Fleet Electronics Material Officer on Commander In Chief Atlantic Fleet's staff, but by 1975 Capt. Drenkard was back in the NTDS project office. This time he relieved Capt. Erick Swenson, who had been NTDS project officer for the preceding nine years. Soon after taking over the project, Drenkard realized the existing production AN/UYA-4 display subsystem was not only becoming technically obsolescent, but also fleet users were asking for numerous new display capabilities. Furthermore the Naval Sea Systems Command research and development organization had developed a number of new display technologies under the umbrella of a prototype next generation NTDS display subsystem project. Drenkard felt the time was ripe to move the prototype into a service test configuration for at-sea evaluation, and in early 1976 had management of the project moved into the NTDS project office where LCDR Donald L. Leichtweiss was assigned manager of the new AN/UYQ-21 display subsystem development, and engineer Cliff Bedore of Fred Russell's radar display systems group became project engineer. The Radar Branch sent out a competitive request for quotations for an engineering development system in January 1972, and Hughes Aircraft Company won the industrywide competition in early 1973.

The new display subsystem featured not only combined raw sensor video, computer generated symbols and digital television pictures on the operator scopes, but also the symbols and television displays were to be in multiple colors. The displays were modular and could be put together in numerous form factors, providing whatever capabilities a particular operator station needed. TV monitors could be worked into the operator station or put at other locations, and up to eight external TV cameras could feed the monitors and the display scopes. For example a weapons control station could now visually see the missile launcher or gun mount they were controlling, or underwater battery fire control could see the anti-submarine rocket (ASROC) launcher and a TV camera could be remotely pointed to see the spot in the ocean where the ASROC missile was supposed to enter the water.

Other features were an external hard copy plotter that could print out an instant snapshot of what an operator was seeing on his console, and a liquid crystal light valve large screen display projector that could project a picture of the display being shown on a particular console. A new console was devised to show underwater acoustics scans. Graphics capabilities and symbology in general was considerably expanded over previous display subsystems. A typewriter keyboard was a standard feature in most consoles, allowing yet another way for an operator to communicate with the computer, another operator station, or to update information on automated status boards.

A Navy Standard AN/UYQ-21 operator console aboard the Attack carrier USS Carl Vinson. U.S. Navy photo.
Detail of an AN/UYQ-21 operator console. From a U.S. Navy training manual.

The prototype of the new display subsystem started Navy technical evaluation at the Naval Ocean Systems Center (formerly the Navy Electronics Laboratory) in May 1978 after which it was installed aboard the Fast Frigate USS Fanning for further technical evaluation and then operational evaluation. At-sea technical evaluation was completed in January 1979, and successful operational evaluation completed later that year. It was approved for service use in 1981. [Sanchez, John M., Letter to D. L. Boslaugh 15 Jan. 2012]

The AN/UYQ-70 Display Subsystem

The Congressional Fiscal year 1993 budget contained language requiring he U. S. Navy to initiate an advanced tactical display system program taking advantage of the strides the commercial world had been making in display technology and work stations. The new standard display system was to make maximum use of commercial off the shelf items not requiring government research and development, and using commercial communication protocols and bus standards. It was to have an 'open' architecture allowing easy insertion of new commercially developed items and computer programs, as well as existing Navy 'legacy' computer programs.

This family of compatible operator displays and work stations was given the name Advanced Display System, and Congress directed initial application was to be in the Theater Air Defense and Aegis Combat Systems. The Advanced Display System was to be used in multiple environments ranging from surface combatant ships, to submarines, to aircraft, to  'mission critical' shore based systems. The primary difference in the various platform uses would be external packaging ruggedized as necessary to protect the commercially developed internal components. The display systems would be either air or water cooled depending on the environment and application.

In response to the Congressional direction, the Naval Sea Systems Command set up the AN/UYQ-70 Advanced Display System Program Office in 1993. NAVSEA awarded a competitive ADS contract to a team made up of Lockheed Martin, DRS Technologies, and Raytheon. The baseline system was designed around the industry standard VERSA Module Eurocard (VMI) backplane. Industry standard communication protocols such as Fiber Distributed Data Interface (FDDI), ETHERNET, and Transmission Control Protocol/Internet Protocol (TCP/IP), as well as some existing Navy standard 'legacy' interfaces were selected for internal and external communication. The Hewlett Packard 743 family of microprocessors was selected for internal system processing. System operating manuals and maintenance manuals were no longer paper volumes, but stored internally in the display unit's hard drives.

The family of Navy standard AN/UYQ-70 Navy Standard display subsystem components. Lockheed Martin Corp. image.

The Advanced Display System approval for production was received in September 1995 following successful technical and operational evaluations. It is notable that the ADS R&D program went from project authorization, through development, and through test in just two years. The project showed how the military could make use of computer resources already developed by private industry and could field embedded computer systems at far less development cost and in considerably less time than traditionally developed military specification systems. As of June 2009 AN/UYQ-70 display subsystems were in use in more than 20 Navy weapon systems. Time will tell if, and how well, the concept stands up in battle.  [Naval Sea Systems Command, AN/UYQ-70 Advanced Display System Program Office, Procurement of the AN/UYQ-70(V) Advanced Display System, From web site] [Commander, Naval Inventory Control Point, Mechanicsburgh, PA, Letter to Assistant Deputy Under Secretary of Defense (Materiel Readiness and Maintenance Policy, Subj: NOMINATION FOR THE 2009 SECRETARY OF DEFENSE PERFORMANCE BASED LOGISTICS AWARDS PROGRAM, 16 Jun. 2009]

Evolution of Link 11 Equipment

The original NTDS Link 11 equipment, comprised of the AN/SSQ-29 data terminal set and the AN/SRC-16 HF radio, worked, but they were big, and required considerable maintenance attention, especially the banks of tuned resonators in the data terminal set. By late 1964, OPNAV queried the NTDS project office if they could develop more reliable, easier maintained, and smaller next generation versions of these devices, and this became the work of communications engineer Lieutenant Commander George A. Friese when he was assigned to the NTDS project in mid 1964. The first user of the new Link 11 equipment would be the Anti-Submarine Warfare Ship Command and Control System (ASWC&CS) R&D project of which Lcdr. Carl Drenkard was serving in collateral duty as technical director.

Since Drenkard was, in effect, paying for the upgraded Link 11 development he also had another request to Lcdr. Friese. The existing AN/SRC-16 radio used a brute force 5,000 watt power amplifier to ensure a solid 300 mile propagation of its HF ground wave. There were even stories of aircraft armorers drawing huge sparks between bomb and airplane when arming airplanes aboard attack carriers when the NTDS Link 11 was in operation. (The SRC-16 was supposed to be shut down during armament loading on the flight deck, but sometimes people forgot - with alarming results.) Drenkard had studied the problem in his spare moments, and concluded the new Link 11 radio could get by well with a 1,000 watt transmitter if a new shipboard wide-band wire antenna and a new antenna coupler could be developed in conjunction with the new radio. Friese incorporated the new requirements in his project.

Collins Radio was awarded the development contract for both items, and in late 1965 delivered new AN/SRC-23 HF radios and AN/USQ-36 data terminal sets for the three experimental ASWC&CS ships. At sea operational evaluation showed that the new radio with new antenna and coupler did indeed perform as well as its predeceding, five times more powerful, radio set. Both units also proved to be smaller, more reliable and easier to maintain. Upon service approval in January 1970, the AN/SRC-23 radio set and AN/USQ-36 data terminal set became the new standard NTDS Link 11 equipment. A number of foreign navies also bought the units. 

The second generation AN/SRC-23 NTDS Link 11 high frequency radio. Photo courtesy of Rockwell International Corp.
The second generation AN/USQ-36 NTDS Link 11 data terminal set. Photo courtesy of Rockwell International Corp.
The third generation NTDS Link 11 equipment combined the data terminal set (left) and the high frequency radio (right) under one nomenclature - the AN/USC-30 Data Communication System. Photo courtesy of Rockwell International Corp.

By 1975, Link 11 again had new equipment, this time the AN/USC-30 data communication system which was even smaller and more reliable than its immediate predecessor.  [Drenkard, p. 5]  [Office of the Chief of Naval Operations, Letter to the Chief of Naval Material, Subject: AN/SRC-23, AN/SRA-34, and AN/USQ-36; service approval of, Serial OP-414/mgm Ser944p4, 1 Jan 1970]

As of 1988 Link 11 had been in use for almost three decades, and their were clues that Link 11 data transmission capacity might not be adequate to support a modern wide-area tactical conflict. Although BUSHIPS and its successors had brought the Link 11 equipment through five generations of improvement the data communications capacity had remained about the same. Even though short range wide bandwidth UHF Link 11 was now a reality, and Link 11 could be transmitted over satellites, the constraints of the long range high frequency radio medium still allowed a transmission limit of about 2,500 digital bits per second. This bandwidth allowed passing data on about 200 tracks per second, but Navy analysts estimated that in an all-out conflict with the Soviet Union, Link 11 might have to handle perhaps 3000 tracks per second to support modern tactical coordination requirements.

The reason was, by now there were many new dimensions to the use of Link 11 that placed demands on Link 11 far beyond those required by a naval task force of the 1960s. For example there was the large E-3A land based Airborne Warning and Control System (AWACS) aircraft used by the U. S. Air Force and many NATO nations. The AWACS airplane, as well as other units of the Air Force Tactical Air Control System (TACS) used Link 11 as its primary means of communicating with naval ships , shore installations, and other TACS units. Another example of the new burden s on Link 11 was its use as the connection between naval units and the NATO Air Defense Ground Environment (NADGE) that had control and reporting centers throughout Europe. [Van Domselaar, Bert, "Tactical Data Link Interoperability in Maritime Operations," NATO's Sixteen Nations, Feb-Mar, 1988, p. 73]

Even though the new Joint Tactical Information Distribution System (JTIDS) was expected to handle perhaps half of the 3000 tracks, it was essential that the Navy upgrade Link 11 capacity. In response, the Advanced Tactical Data Link Office of the Navy's Space and Naval Warfare Systems Command (formerly the Naval Electronic Systems Command) devised a four pronged Link 11 improvement program including the following:

  • Use of a wider selection of higher bandwidth communications media such as more short range UHF radios, more UHF satellites for longer ranges, even use of extremely high frequency (EHF) satellites.
  • Modifying the computer programs in the many tactical systems now interconnected by Link 11 to transmit higher priority information first.
  • Changing the data link protocols to lower the overhead data bits per transmission to allow more tactical data per frame.
  • Additional training of fleet operators to get the most out of Link 11.

It is significant that in all the above improvements there were no basic changes to the principles of Link 11; principles that had been devised by Lieutenant Commander Edmund Mahinske and his team some thirty years before.  [Marcus, Daniel J., "Navy Eyes Upgrade to Battlefield Tracking Network," Defense News, Mon. Feb. 20 1989, p. 43]

For Rear Admiral Thomas F. Marfiak's First-hand account of the use of Link 11 during the 1990-1991 Desert Shield/Storm campaign the reader can click on this link.


The old Workhorse Gets Overloaded

By 1980 the U.S. Navy had 93 ships carrying the Naval Tactical Data System, and by 1998 the total number of NTDS and Aegis ships was projected to number more than 170, meaning that more than half of all USN ships would be fitted with either NTDS or Aegis. The newer ships were equipped with computers having unimaginably more power than the NTDS service test ships, had far more capable display subsystems, and featured thorough integration with other computerized systems. There remained, however, more than 50 ships still equipped with the early NTDS CP-642 unit computers. Even though a third unit computer had been added to these ships, and they had extended memory units, the combat direction systems in these ships were becoming overloaded. 

In these ships the computers could no longer process their workload within the required response times. This appeared as delayed responses to data requests, lagging updating of track symbols, blinking symbols, and the ball tab responding too slowly to the track ball. On some ships the systems started showing these symptoms when processing only half of the designed track capacity. Even on some ships equipped with the newer AN/UYK-7 computers these troubles were showing up.

In September 1980 the Secretary of the Navy’s Computer Logistics Working Group determined that the above inventory of major digital computer types was installed aboard USN ships. (The AN/UYK-5 was a non-tactical version of the Univac CP-789 used in the shipboard Material Maintenance Management data processing system.)

To illustrate the proliferation of automated systems in the fleet, it is instructive to follow the career of one guided missile frigate, in this case USS Wainwright (DLG 28, and later CG 28). When Wainwright was commissioned in 1966 she had two digital CP-642A NTDS unit computers, and in  1972 she got an additional NTDS CP-642B computer. Soon after two CP-789 computers were installed, one serving the Beacon Video Processor and the other functioning as the upgraded Weapons Direction System Mark 11 control formatting unit. In 1974 the ship's Terrier missile systems were converted from analog computers to two CP-848 digital computers, and by the end of 1976 three AN/UYK-20 computers were part of the equipage. One of the UYK-20s served the AN/SPS-48 three dimensional radar's automatic detection and tracking subsystem, and another was the processor for the new Weapons Direction System Mark 14 in which the weapons direction function had been moved out of the heavily loaded NTDS computers. The third UYK-20 was part of the AN/SYR-1 communications tracking set that handled data sent down from an upgraded terrier missile. Thus in eight years the count of general purpose stored program digital computers in Wainwright had gone from two to ten.  [Applied Physics Laboratory, The Johns Hopkins University, "Survey of Digital Weapon Systems", estimated publication date 1975, pp. 9-3, 9-5]

To get a handle on the problem of the growing load on the older NTDS computers, the Office of the Chief of Naval Operations in 1980 directed an NTDS Functional Allocation Study that found over the preceding 20 years many new functions had been added to NTDS in these ships, and NTDS had been increasingly interconnected with other systems, without any kind of a master plan or even keeping track of the computers' loading. It had been too easy to add functions by adding memory and loading in new program patches. The older computers had simply run out of processing speed needed to handle all the new demands.

The study group noted that NTDS in the older ships had been primarily designed to support anti-air warfare, but now was providing automated support to anti-submarine warfare, electronic warfare, and anti surface operations. In 1962 NTDS computers processed 15 functions, interfaced with three data links and a missile system, but by 1980 they were processing 27 functional areas and were connected to four data links as well as six other automated shipboard systems. Furthermore NTDS was now not only required to show the anti air picture but was expected to show a current picture of the ships entire tactical environment. The study report also noted that there were even more new systems under development that would go aboard these older ships with the expectation that NTDS would integrate them into the ship's combat system. NTDS in these ships was seriously overloaded, and it was only going to get worse. [Albrecht, Capt. Carl J., USN, Project Officer, "NTDS Functional Allocation Study, Draft Final Report of the NTDS Functional,Allocation Study   (Intra Ship)", Office of the Chief of Naval Operations, Op-351, 5 Mar. 1981, pp. 3-4, 6]

In the older NTDS ships, the study group concluded there had been very little management or planning of how new functions had been added to NTDS under the pressures of the Vietnam War and the additions of many new weapon systems. The report recommended that an NTDS master plan be mapped out showing forthcoming system support requirements, that a priority be assigned to each projected requirement, and that an office be established to review and screen new requirements, and set their priorities. The study also acknowledged that the Naval Sea Systems Command, for some time, been trying to set up an activity to do the above, and to map out and fund system improvements in the older ships. But the funds needed for this top-down planning and improvement effort, called the Combat System Improvement Plan, had been consistently turned down by senior SECNAV and OPNAV budget review officials. The study group recommended the plan be authorized and funded as soon as possible. [Albrecht, p. 7]

The Combat System Improvement Plan proposed a ripout of the older NTDS computers and replacing them with the new AN/UYK-43 standard computers, having 46 times the speed and 312 times the memory capacity of the original unit computers. The older AN/SYA-4 operator displays would be replaced with the new AN/UYQ-21 display subsystem. The upgraded systems would be called the Advanced Combat Direction System (ACDS) rather than the Naval Tactical Data System. [Goodman, Glenn W.,  Jr., "New Threat Upgrade Modernizes AAW Capabilities of Pre-Aegis Ships," Armed Forces Journal International, Apr. 1987, p 91]

Rejuvenating Some Grand Old Ladies With New Threat Upgrade

By mid 1980 navy analysts realized that new Soviet short range anti-ship missiles that could be launched from submarines, surface ships, and even small patrol boats were becoming a serious threat to the U.S. fleet. They were called 'pop-up' missiles, and a targeted ship had only seconds to detect them and get defensive missiles in the air. The newer Aegis ships could handle the new threat pretty well but the older Tartar and Terrier equipped ships did not have the rapid detection capability or the needed quick system reaction time. It was clear that their combat direction and missile systems needed an upgrade to better match Aegis capabilities. OPNAV approved a plan to upgrade most Tartar and Terrier ships with missile system improvements and also approved the Combat Direction System Improvement Program for these ships. The guided missile frigates in the Leahy and Belknap Classes would get the new Block IV extended range SM-2 Standard missile having a range of 200 nautical miles.

Thirty five of the 50 NTDS ships having CP-642 unit computers would be given the Advanced Combat Direction System. The 15 older ships were (supposedly) so close to the end of their operational lives that they would retain their original NTDS suites. These were: ten ships of the DLG-6 Class, the attack carrier Coral Sea, the fast frigates Voge and Koelsch that carried the Anti-submarine Warfare Ship Command and Control System, and the two amphibious command ships Blue Ridge and Mount Whitney. As we have previously documented, the two amphibious command ships would live on as fleet command ships and are still serving today with vastly improved automated systems.  [Meinig, Capt. G. R. Jr., USN, Assistant Deputy Commander for AAW and Surface Warfare Systems, Naval Sea Systems Command; Ailes, Radm. R. H., USN, Director Surface Combat Systems Division, Office of the Chief of Naval Operations, "Combat Direction Systems (CDS) Improvement Plan, 30 June 1986", p. 2-2]  [Goodman, p. 91]

The two air search radars, the AN/SPS-48 and 49, that Commander Irvin McNally had described in specification language in 1956 were still in the fleet in 1980; in their fifth incarnations. The latest versions of both featured automatic target detection and tracking. In the case of the latest SPS-48, it now had a digital receiver and signal processor that could automatically detect and track very small targets, even in the face of heavy jamming. It also had improved positional accuracy and higher elevation coverage, and sent its track information to a central track processor with no operator intervention. Responses to jamming and other operator control functions were also automated. The latest versions of these radars were to be included in New Treat Upgrade. Even existing AN/SPS-48 radars would be removed and replaced by the E version, and in ships having the older SPS-40 long range search radar the SPS-40 would be replaced by the AN/SPS-49 radar. The three CP-642 unit computers and their extended memory unit would be replaced by one AN/UYK-43 computer, and a space reservation would be left for an additional future UYK-43. [Goodman, p. 91]

By 1980, most target data input to NTDS in the newer ships was fully automatic, and manual target detection and updating was no longer needed. Raw video was still supplied to the operator consoles so that operators could monitor the performance of the automated systems and intervene only if it seemed the system was having a problem. In New Threat Upgrade a new device, the Norden AN/SYS-2 Integrated Automatic Detection and Tracking System, would receive  inputs from all tracking sensors including radars, sonars, electronic countermeasures, and other passive detection devices. It would combine these inputs, correlate them among sensors, and build one master tracking file which it fed to the central ACDS processors. [Goodman, p. 91]

The purpose of ‘cooperative engagement capability’ was to allow an Aegis ship to engage a ‘pop-up’ or sea skimming anti-surface missile while it was still below the ship’s radar horizon. In the original CEC experiments a P-3 ASW airplane equipped with radar of fire control accuracy passed the pop-up missile coordinates to the Aegis ship which was able to engage the ‘attacking’ missile without ever ‘seeing’ it. The original experiments were code named ‘Mountain Top.’ U.S. Navy diagram

By 1980 a new targeting capability called Remote Track Launch on Search (RTLOS) had been perfected and would be included in New Treat Upgrade. This would allow an Aegis ship to pass target information over Link 11 to an NTU ship so that the NTU ship could be in search radar silence and still pass target data to its missile fire control systems. The firing ships fire control radar would be automatically pointed at the target but did not need to be turned on until just before intercept to illuminate the target for terminal guidance. Another capability that was in experimental phase, but would eventually incorporated in the NTU ships was called Cooperative Engagement Capability (CEC). CEC depended on precise navigational systems such as ships inertial navigation system (SINS). It passed target data with fire control accuracy among aircraft, ships, and shore systems and it provided the means for fire control computers to develop fire control solutions and fire at targets without turning on either search or fire control radars.

The guided missile frigate Biddle, originally DLG 34 but later redesignated a cruiser (CG 34), was the first ship to get production New Threat Upgrade. In May 1988 Biddle entered the Puerto Rican Operating Area for a month of combat system tests. In his book Hard Charger! author James A. Treadway writes:

Biddle also performed a Remote Track Launch On Search (RTLOS) test with the USS Valley Forge. Valley Forge tracked and processed the data, and Biddle in EMCON A, was in Receive Only mode on Link 11. We fired an SM-2 ER at a QF-4 target aircraft and destroyed the target at over 100 miles away. We actually had a target kill painted on the Link 11 Terminal set in the computer room.  [Treadway, James A., Hard Charger! - The Story of the USS Biddle (DLG-34), iUniverse, Inc., New York, 2005, ISBN -13: 978-0-595-67313-1, pp. 233-236]

There were occasions in missile shoots where the NTU ships actually performed better than older Aegis ships, but they could not equal Aegis in defending against a saturation missile attack. [New Threat Upgrade, From Wikipedia, the free encyclopedia]  [O'Driscoll, Michael J. and Krill, Jerry A., "Cooperative Engagement Capability," Naval Engineer's Journal, Vol. 109, No. 2, Mar. 1977, pp. 43-57]

Can Old Computers Last Forever?

The CP-642B NTDS unit computer production line was in operation until 1975 even though the newer AN/UYK-7 computer started production in 1971; the reason for the overlap being to fill all CP-642 orders and to install a third unit computer on the DLG-16 and 26 Class guided missile frigates. The grand total of CP-642 production for the U.S. Navy was 380, with 230 installed in ships, 43 in fleet computer programming centers, and 107 at other shore activities. The NTDS project officers assumed that after ten to 15 years of use, the electronics in the machines would probably begin to degrade, and the CP-642s would either be replaced by newer machines or they would devise a way to refurbish them with new electronics drawers.

But, something strange happened. As the old workhorses aged their reliability only got better. The mean time between failure measured during service test had been over 1,500 hours instead of the specified 300 hours, but the project officers did not think this unexpectedly good reliability was going to last. However, by March 1981 CP-642 reliability had increased to 4,128 hours, and laboratory studies showed no signs that it was going to get worse. The studies also showed that, by then, the unit computers had a large repertoire of stable well debugged computer programs that were constantly being reused. Navy planners concluded that it would be best to keep the old computers on their ships for the remainder of the shipís lifetimes, and if their combat systems needed new functions, the new functions would be executed in newer computers. The exception to the rule being the 35 New Threat Upgrade ships. Also, the ships Long Beach and Enterprise that had been fitted with the slower service test CP-642A computers had them replaced by AN/UYK-7 standard computers. In the late 1980s, the UYK-7s in Long Beach and Enterprise were replaced by AN/UYK-43 computers as part of the New Treat Upgrade program. [Report of the Navy Embedded Computer Logistics Working Group, p. 49]  [Meinig, p. D-12]

The count of USN ships equipped with CP-642 computers maxed out at 54 in the late 1970s and then the count began to decrease as older ships were decommissioned, replacement by UYK-7 computers in some ships, and then the replacements under the NTU project. As the old unit computers came off the ships, NAVSEA had all printed circuit cards removed for use as spares in the surviving CP-642s. Foreign navies even inquired if they could purchase the old unit computers, but it did not seem to be a good idea to perpetuate logistic support for these obsolete machines.

After 27 years of service as of 1989, about 180 unit computers remained in fleet inventory, but the removal rate increased dramatically under the twin pressures of replacing them with UYK-43 computers in the missile ship NTU program and in aircraft carriers. In the next five years, ship decommissionings took more CP-642s out of the fleet until in December 1994 only two ships still had original CP-642 unit computers. These were the amphibious command ships Blue Ridge and Mount Whitney, which in 1998 had their extensive NTDS-based information processing systems replaced by the Joint Maritime Command Information System (JMCIS) which used commercial off the shelf computers and work stations. Their combat information centers were upgraded to the AN/UYK-43-based Advanced Combat Direction System. After 36 years of fleet service the Naval Tactical Data System was no more. [Commanding Officer USS Mount Whitney (LCC/JCG 20), Letter to Director of Naval History, Subj: Command History Report, Ser 00/213, 9 Apr. 1999]  

Navy standard computers delivered and on order as of Feb. 1989.
The first forty years of Navy tactical computers. Original source unknown, updated by the author.

Against All Odds

When this writer was assigned to the NTDS project office in 1962, I noticed a strange attitude on the part of some senior engineering duty commanders and captains. They did not seem to be interested when I talked about NTDS, in fact they seemed to shy away, and trying to get them involved with the project was hopeless. I talked about this phenomena with some of the 'old time' NTDS project staff, and they would say, "Oh yea, there are some EDs who are convinced that the project is going to be a colossal failure and they don't want their careers caught in the undertow when the ship goes down." There were many who believed that NTDS could not possibly succeed because of its dependence on the infant technologies of digital computers and transistors, not to mention resistance on the part of 19 out of 20 naval officers.

When NTDS was eventually acclaimed not only a success, but also one of the most successful projects in the Navy; it amazed people. Especially because it had stayed within budget and scheule. A number of studies were commissioned to analyze the NTDS project to find why it had been so successful in spite of the odds against it. Sometimes it seems there was as much money spent on studying NTDS than was spent on NTDS development.

President John F. Kennedy in 1962 was concerned about military projects, especially the failure rates, and cost and schedule overruns, and he set up a commission to study the problem. He wanted the commission to look at every large development project in the Department of Defense, and to nominate the two most successful undertaken by each service. They were to examine these two in great detail to identify the factors of success. For the Navy they picked the Polaris fleet ballistic missile project and NTDS as most successful of the era.  [Mahinske, Capt. Edmund B., USN, Letter to D. L. Boslaugh, 5 April 1993]

In 1963 the National Academy of Sciences (NAS) was tasked to review successful major DOD projects and pick two for an in-depth analysis of how their use of scientific and engineering manpower contributed to their success. NAS picked the Naval Tactical Data System and U. S. Air Force's TITAN II intercontinental ballistic missile project. NAS representatives did extensive interviews at both government and contractor organizations involved with the project, and they noted that the contractors felt that the high technical competence of the Navy Electronics Laboratory and Bureau of Ship personnel had contributed greatly to project success. In particular the four engineering duty officers in the NTDS project office were singled out both for their technical grasp of the project and for their broad banded management ability.

The NAS study noted that the project officers not only managed and led the project, but also on many occasions got deeply involved in technical problems and made final engineering decisions themselves. The study also reported that most of the project officers had masters degrees in electrical engineering or electronics, that all had previously served in Navy engineering activities such as shipyards and manufacturing plants, and perhaps most importantly all had served at sea in jobs involving radar systems and electronics. In addition to the project officers: Capt. Svendsen, Cdr. Mahinske, Lcdr. Swenson, and Cdr. Stoutenburgh, the study singled out the important contributions of Cdr. Alfred M. Bettis, Donald L. Ream, and Frederick A. Russell. [Graf, R. W., "Case Study of the development of the Naval Tactical Data System" National Academy of Sciences, Committee on the Utilization of Scientific and Engineering Manpower, p VII-3]

The Chief of Naval Development in 1966, set up a working group to review navy research and development projects of the previous decade and nominate the ten projects considered most successful. Harbridge House of Cambridge, Mass., was tasked to analyze the ten in depth to identify the planning, organization, management procedures, manager's backgrounds, scheduling and review procedures that tended to make the projects successful. Four of the ten selected projects were Bureau of Ships projects; the AN/SPS-48 radar, the AN/BQQ-8 under-ice sonar, the Naval Tactical Data System, and the AN/BQQ-2 sonar. [Chief of Naval Development, Letter to Commander Naval Ship Systems Command, Subject: Case Studies of Selected Navy Developments, Serial MAT 0321:GHG Seroo1903, 12 Sept. 1966]

Review of the three above mentioned studies shows some common factors in each study that tended to move the NTDS project toward success. It would only be subjective, and very difficult, to try to list them in order of importance, and no attempt to do so is made here. However, if any of these factors had been missing, the project probably would have foundered.

A real, validated, and supported operational requirement.   The operational requirement for some sort of automated processing and display of radar data had been articulated by the Chief of Naval Operations himself soon after the end of World War II. Many attempts to satisfy this requirement with electromechanical and electronic analog computing systems were tried without success.

Strong support from the highest levels of the Navy. Even though 19 out of 20 naval officers were opposed to the new system, mainly out of their concerns that they were going to be taking orders from some sort of electronic brain, the Secretary of the Navy and the Chief of Naval Operations were solidly behind NTDS, even to the point of publicly forbidding interference or attempts at micromanagement by anybody.

A parallel OPNAV sponsor project office manned by technically competent, dedicated project officers. The NTDS sponsor's office in OPNAV took on much of the administrative burden of running the project. In particular, the Bureau of Ships project office only had to work up a budget and present it to OPNAV once a year. From that point the OPNAV project officers took on the burdensome task of constantly justifying and defending project funds. This left the BUSHIPS project managers the time to concentrate on management and technical issues. The OPNAV project officers also stayed abreast of the project by daily interaction with the BUSHIPS managers rather than requiring time consuming periodic formal project reviews.

Strong, technically competent support from a Navy laboratory. Instead of establishing a prime contractor to serve as system integration and test agent, the Navy Electronics Laboratory took on this role and executed it very well. NEL also provided expert technical and engineering support to the BUSHIPS project officers in many areas, and undertook many studies and investigations in support of the project. Furthermore NEL, and its NTDS test and integration facilities, served as the ideal place to train the officers and men who would man the NTDS installations in the service test ships.

Hand picked naval officers and enlisted men to man NTDS in the service test ships. The Bureau of Naval Personnel went out of its way to select and assign the 'cream of the crop' to the NEL test site and then to the service test ships. There was also a reverse benefit in these assignments, in that the officers and senior enlisted men who had converted to the new enlisted rating of Data System Technician were able to factor the benefits of their considerable at-sea operational experience into system development and in devising the first NTDS computer programs. Once at sea with the new system, this cadre of officers and men were able to take on NTDS operation and maintenance in a totally professional manner with no need for technical guidance or help from outside activities. They had become the experts.

Competent support and technical contributions from three principal contractors, each in the area of their expertise. Univac, Hughes Aircraft, and Collins Radio rose to the challenge of doing seemingly impossible technical things, and seemed to be more interested in making NTDS a success than they were in just making money. There are many examples of their contributions, as typified by Arthur Collins, president of Collins Radio, who, at his own expense built an extra NTDS Link 11 data terminal set and had it installed in his personal yacht for at-sea testing. There was the 'value engineering' response of Hughes Aircraft in lowering the cost of the prototype display subsystem when told its cost was going to break the NTDS bank and might cause project termination. Then there is the technical expertise of Univac's transistor genius Seymour Cray in devising the first militarized transistor-based digital computer from his experience in working on the design of one of the Navy's first vacuum-tube codebreaking computers.

NTDS project officers in the Bureau of Ships who had a firm technical grasp of what they were trying to build, and the technical and management competence to do it. The basic ideas for the Naval Tactical Data System did not come from the outside, they came from the operational and technical experience of Commanders McNally and Svendsen. This was especially from their WW II radar experience, and the fantastic coincidence that Svendsen had not only been in charge of building the Navy's first vacuum-tube codebreaking computers, but also had just finished building a transistorized codebreaking computer. Both officers also had a creative bent, knew how to exercise strong, but supportive, leadership, and knew how to manage complex technical projects. Svendsen also went on to select three of the very best assistant project officers who were also not only technically competent but were also leaders, detailists and excellent managers of complex technical tasks.

The Freedom to Fail. McNally and Svendsen had an agreement with their seniors in the Bureau of Ships and in OPNAV that, if they wanted them to do in five years what normally took 14, they would have to forego the time consuming rounds of formal project reviews and just let them keep on working. This was reasonable because the two commanders were the ones who had defined the the new system and they knew better than any senior reviewing official whether they were on the right track or not. It was agreed, when the project officers needed help, they would ask for it, otherwise the seniors would stand clear and settle for informal progress briefings.

Captain Joseph Stoutenburgh later summarized Capt. Svendsen's contribution to NTDS management in a letter to this writer:

Believe me, the entire operation was driven by his superb technical breadth, his understanding of the Navy's operational needs, his knowledge of pertinent academic and industry/Navy research, design and manufacturing talent; combined with his firm, positive leadership style. The top levels of the Navy granted Captain Svendsen the authority to match the responsibility assigned, and they did not second guess him. Score one for the Navy Brass! It was my assessment that he did the same with all those who served the NTDS office.

We had no reason to believe that we would succeed with the NTDS program. Time and again we were ripe for defeat. We were too far beyond that 'edge' of technology. The equipment we needed - indeed the very electrical components - were nonexistent. They had to be brought into being. We proceeded on faith. Capt. Edmund Mahinske, 15 April 1993

Every time that I remember we would approach 'the end' of our capability, knowledge, funding, or time to do the next job - suddenly someone would reach down and say "let me help here!" It was tremendously exciting,. Capt Erick Swenson, 5 May 1988