Oral-History:Henry B. Abajian
About Henry B. Abajian
Abajian got an Electrical Engineering degree in 1938 from Rhode Island State and a Masters of Engineering from Yale in 1940. He came to work at the Rad Lab in September 1941. His first assignment was to design power-generating equipment and motor controls as a member of Group 56. At the Rad Lab he mainly worked on the SCR-584 (an anti-aircraft radar system), from production design, to testing on military bases, to acceptance by the military for production in early 1943 to production by Westinghouse and GE. He then went to England in February 1944 to provide systems support and training for the SCR-584; later that year he left for the Pacific Theater to do similar work. He performed project engineering of the SCR-584's MTI (moving target indication) from March to August of 1945. He was assigned to field service in England from February to April of 1944 and in the Pacific from May 1944 to March 1945. He would have been part of the invasion of Japan if that had gone forward. After the war he went to work at the Airborne Instruments Laboratory.
In this interview, Abajian discusses his responsibilities for the XT-1 power system and explains how the XT-1 evolved into the system adopted by the military as the SCR-584. He recalls his working relationships with other members of the SCR-584 group including Lee Davenport, George Harris, and Leo Sullivan and describes the project support rendered by other Rad Lab groups and outside contractors. Abajian discusses cooperative efforts with General Electric and Westinghouse in the production of the SCR-584 and describes modifications made to improve its efficiency in field use. He recounts his two personnel training and systems support assignments as technical representative for the SCR-584 in England and in the Pacific. He concludes by reflecting on his later experiences at Airborne Instruments Laboratory.
About the Interview
HENRY B. ABAJIAN: An Interview Conducted by Frederik Nebeker, IEEE History Center, 11 June 1991
Interview # 074 for the IEEE History Center, The Institute of Electrical and Electronics Engineers, Inc.
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It is recommended that this oral history be cited as follows:
Henry B. Abajian, an oral history conducted in 1991 by Frederik Nebeker, IEEE History Center, Piscataway, NJ, USA.
Interview
Interview: Henry B. Abajian Interviewer: Frederik Nebeker Date: 11 June 1991 Location: Boston, Massachusetts
Educational Background
Nebeker:
This is an interview with Henry Abajian on the 11th of June 1991 in Boston. The interviewer is Rik Nebeker. Before we talk about Rad Lab, could you tell me briefly about your education and experience before Rad Lab?
Abajian:
In 1938 I graduated with an electrical engineering degree from University of Rhode Island which, at that time was Rhode Island State. I got my Master of Engineering from Yale University in 1940, where Ernie Pollard was on the physics staff.
Nebeker:
What were you particularly interested in at that time?
Radiation Lab
Recruitment
Abajian:
It was all power engineering, and the electronics was a hobby. I was a ham radio operator, and electronics was just one of those off-on sciences. After Yale I went to United States Steel in Pittsburgh in their electrical engineering department. September of '41 is when I came to Radiation Lab.
Nebeker:
That first year of operation.
Abajian:
Yes. How I got there was interesting. The head of the small department of electrical engineering at Rhode Island State College was a Navy Reserve officer and was being called to active duty. He contacted me and said, "How about you coming to RI and teaching the electrical engineering?" In those days there were only six electrical engineers in my class. It was a small department. I said, "Yes." I was actually appointed to the staff at Rhode Island State College. In that first month there Prof. Wes Hall got a telegram from the Navy that said they thought they could do without him and he didn't have to leave. There they were with the two of us on the staff. At that time, Prof. Hall knew about Radiation Laboratory at MIT, so he brought me to MIT; and that's how I joined it. I had only one paycheck [Chuckling] from the State of Rhode Island.
Nebeker:
In those days radar was highly classified. Did you know what was going on at Rad Lab?
Abajian:
No. Not a bit. Wes Hall didn't know too much about it, but he knew that there was some secret research being done there. I think he knew Wheeler Loomis, and that's why he brought me and personally introduced me. Beyond that I didn't know anything about it.
Nebeker:
Did you arrive and then get briefed in what was going on there? How did you learn about the operation of it?
Abajian:
After I got in was when I first learned about it.
Introduction to Work
Nebeker:
So as far as you knew, was this just some electronics work that made use of your training?
Abajian:
Exactly. That is all. The first week or so was primarily introductory to brief me on the various things. I'll tell you! My eyes popped on some of the things that I was shown and things I was told. I never would have dreamed that those things could be done. But when someone showed me a 10-centimeter dipole an inch or so across as an antenna, I just couldn't believe it! In all of my prior experience in ham radio if we got to 2-1/2 meters, which at that time was ham radio, that was really high-frequency signal. Initially, I worked in the engineering group at Radiation Laboratory preparing some power-generating equipment facilities for the Division 8 gang that was developing what became the SCR 584. When I first saw the experimental work that they were doing with the old XT-1, it didn't take me long to say, "Hey, I want that." I was then transferred to the SCR 584 development program.
Nebeker:
Were you with the power-generating equipment, and then switched to the SCR 584 in June?
Abajian:
Yes. That's it exactly.
Nebeker:
Were there dangers of your being drafted at that time when you accepted the job at Rad Lab?
Abajian:
No, not at all. In fact, I had a deferment because of my University of Rhode Island assignment. That was before I came to Rad Lab. While we were in Rad Lab and well along in the XT-1 (Engineering model of SCR 584) development, two or three of us who were working on it thought that we were shirking our duty and suggested to the good Colonel McGraw at Camp Davis that we probably could do a lot of good if we enlisted and got into the military. Jimmy McGraw said, "No way!" As long as you fellows are where you are, I have control over you," but the minute you get into the military, I have no idea where you're going to be, and you'll probably get misassigned anyway. You are more valuable to us there at Rad Lab than in the military." So that was the end of it.
Nebeker:
You learned about the work going on at Rad Lab, once you got there?
Abajian:
Yes.
Work Environment
Nebeker:
Was it fairly open? Could you talk to people and learn about all the different projects?
Abajian:
Oh, yes.
Nebeker:
Was everyone there within Rad Lab open about it?
Abajian:
Yes. We used to have weekly seminars at that time. One night every week there was a seminar, and a speaker was usually someone from the inside — occasionally some guests from outside — speaking on the work that they were doing. It was quite open within the laboratory.
Nebeker:
Did you learn about the earlier work that the Army and Navy had done just prior to the war on radar? I know at Fort Monmouth there had been some work.
Abajian:
No. Not at that time.
Nebeker:
Did people from Army or Navy ever present a seminar or come to talk to you about work that they were doing?
Abajian:
Not to my recollection. These were usually technical types. One outside visitor was William Hansen who was at Sperry at the time. He was one of the speakers. The Varian Brothers were from outside, and they spoke. But none, to my recollection, were from the military.
Nebeker:
To what extent did the Rad Lab draw on the earlier work that the Army and Navy had done?
Abajian:
I'd be a poor one to answer that. Ivan Getting got around so much more, and his contacts with the military were more frequent and more in depth than any of ours. We on the development of the system had all of our contacts with the people responsible for the testing and the approving of it. There were different agencies that were responsible for that. Ivan was well up there.
Power Generation
Nebeker:
The power-generating equipment that you worked on originally — what was that for specifically?
Abajian:
I keep referring to SCR 584, but at that time it was the XT-1. The system had to work off a power plant. They needed one for the XT-1 to be taken out in the field. The original concept was to have the power generator for the radar system driven by coupling to the radar truck engine. It proved to be impractical. It was then decided that what was needed was a second truck that would hold a separate gasoline-driven motor generator set and, at the same time, provide a maintenance facility to support the radar system. That task was assigned to me.
Nebeker:
Were you in charge of that?
Abajian:
Yes. But it was no major thing at all.
Nebeker:
Was this in line with your training?
Abajian:
Yes. In a much smaller way. Having come from a steel mill where small motors were 10,000 horsepower, this was just a small engine generator set in a truck. But that is what introduced me to the XT-1 and Lee Davenport.
Nebeker:
Was this power system for the XT-1 made to fit into an existing Army vehicle?
Abajian:
No. The trucks that we were using at the time were bought here in the Boston area from the White Truck Company. Since the XT-1 and some of the other motorized, mobile systems used the White trucks, we just bought another truck from White. I had a body outfit build the special body, and got the MG set from an outfit somewhere in Minnesota. The body fabricators put it all together, wired it on the inside, and provided for the connections to the system. It was all straightforward, very simple, nothing complicated.
Nebeker:
Didn't you worry that since this was going to be used by the Army that you had to do things a certain way for them?
Abajian:
No. The whole system at that time was experimental, just to prove the concept. There was no concern — and rightly so — for meeting any military specifications or any special environmental conditions. It was just to build an experimental set and to demonstrate its feasibility.
XT-1/SCR 584 Group
Nebeker:
When you switched to the SCR 584 group, what did you do then?
Abajian:
Well, then I joined with Lee Davenport and George Harris. Leo Sullivan came in a little bit later. We worked on the system putting all of the components that we got from the components people together into a working system. Then we would test it and refine it. There was always something new coming up. For instance we started out with a bead-supported transmission line, and then later on came the stub-supported transmission line. There was a steady stream of upgrading the system until it finally got accepted by the military for production.
Nebeker:
When did they finally accept the system?
Abajian:
Ivan will give you that information specifically. It was early in 1943. In fact, Lee Davenport will probably be able to nail that down closer than I can. Ivan was responsible for the business of splitting it between General Electric and Westinghouse, the two companies that produced the SCR 584, with General Electric being the lead contractor.
Nebeker:
Can you describe that SCR 584 group for me?
Abajian:
Lee Davenport was the group leader. He was the head of the project. George Harris and Leo Sullivan and I were the other three that were with him. We were supported by all of the components people in Rad Lab — the magnetron people, Division 6 (the range group designed the range system), the display group, the receiver group, etc. They would join us for their particular part of the system and would be with us for our testing programs at Deer Island near the Winthrop area. We had an engineer, Sidney Godet, on loan to us from General Electric Company well before General Electric was picked as one of the two contractors. He was a specialist in servo systems. In those days the amplidynes were new, and he knew all about them. He also was a member of the XT-1 group.
Nebeker:
Were you able to call on these different groups within Rad Lab? As you needed them?
Abajian:
Exactly.
Nebeker:
Did you have to call them back because of changes in display or whatever?
Abajian:
Yes. They would join us in the testing. If there was some shortcoming, they would troubleshoot it and see what changes had to be made to overcome those shortcomings.
Nebeker:
Did this project have pretty high priority in that sense of being able to call on the resources?
Abajian:
I'd have to say yes because we were never wanting for the lack of support. It wasn't that the SCR 584 group (at that time, the XT-1 group) would say we need such and such; therefore, drop whatever you're doing and come do it. There was no such thing at all. I don't recall anything of that nature. But we were never wanting for supplies or support. All those component people gave excellent support to all of the systems.
Work Ethic
Nebeker:
Of course you were trying to move as rapidly as possible. What was the atmosphere in that group during that development?
Abajian:
The esprit de corps — you'll never see it again in your lifetime, in my opinion. None of us ever looked at a clock. It didn't mean a thing. We loved what we were doing — all of us. Almost to the point where we were ignoring other family obligations.
Nebeker:
What would be a typical work week in that period for you?
Abajian:
It would be hard to pin a number on it. If we had to work until midnight, we did. And we felt that this was fine. When everything was pretty good and we could wait until tomorrow to do the next step, then we'd quit. If it happened to come at nine o'clock, we'd quit. If there was no such problem, we'd be home at five o'clock.
Nebeker:
Did you ever work weekends?
Abajian:
Oh, all the time.
Nebeker:
Did you work Sundays as well?
Abajian:
We did that, too. There was no resentment, either. At that time most of us were not married. We were all single individuals. Leo got married towards the end. I got married in October of '42, a year after I joined the Lab. My wife came to work as a secretary at Rad Lab. Even then, there was no problem with doing the work as required.
Nebeker:
Didn't your wife resent the long hours?
Abajian:
Not even when we went away on the testing phases. We traveled to Fort Monroe in Virginia near Norfolk. Then when the Anti-aircraft Board moved to North Carolina, near Wilmington, our testing work was done there. We'd be there for weeks at a time. There was never a problem.
Selling the XT-1
Nebeker:
Can you describe how the SCR 584 was sold to the military? How was their acceptance of it?
Abajian:
High performance. They had the measurements. They did all of the measuring.
Nebeker:
Where did this take place mainly?
Abajian:
Initially at Fort Monroe; but the final testing was done when they moved to Camp Davis at North Carolina. There the Board had its own instrumentation people. It was set up to record all the data and to determine the accuracy of our system tracking an airplane in addition to measuring the performance during actual live shooting; but since that involved a computer between us and the guns, the end result was only as good as the accuracy of our system putting good present-position data into the computer.
Nebeker:
Did they compare your system with another in those tests?
Abajian:
Yes. Bell Laboratories had a development contract for what became designated the SCR-545. We were the SCR-584. The Army ran the same tests on the Bell system. In fact, for a while, both their prototype and our XT-1 were at Camp Davis at the same time. The rivalry, of course, was very, very friendly.
Nebeker:
Was it clear that it was one system or the other?
Abajian:
Yes. Bell Labs also did a great job; however, their system was quite big because it had a combined search/track antenna system. The system combined an early warning search antenna array with a parabolic reflector used for the automatic tracking part of the system. All of us, including their own people, used to make some jokes about their van because it looked like a freight car. Some wiseacre would hang out the door waving, his lantern and calling, "Whooo whooo! Whooo whooo!" The SCR-584 had only that smaller, 6-foot parabolic antenna, and that was a neater package.
Nebeker:
In the development of that radar, were you trying to meet certain military needs?
Abajian:
Oh, yes.
Nebeker:
Were you trying to keep the size down?
Abajian:
Keeping the size down, to my knowledge, was not laid on us at the start as a requirement. The whole effort was towards the accuracy of the system. We were supposed to prove that it could obtain present-position data on an aircraft at least as good as what they were able to get by the optical tracking systems. We proved that. Ultimately the military went on record as saying that the automatic data that they got from an SCR-584 was superior to what they were able to derive by optical means.
Nebeker:
Was that what you were aiming at in the development of the system?
Abajian:
Oh, yes.
Nebeker:
So what happened when you sold the military on it?
Abajian:
Once the Anti-Aircraft Board came up with the decision, the report on the performance of the system it made its decision to recommend the XT-1 to be the anti-aircraft radar system. It then got designated as the SCR-584. The board also gave Bell Labs a small contract for a modest quantity of SCR-545s, because of the work that Bell Labs did. From that point on, Ivan and the upper military echelons were all in on this business of who to do it, how to do it, and so on. Our job on the XT-1 was done when we showed that this system could really do the job and do it well.
Production of SCR 584
Nebeker:
So what did you do after that?
Abajian:
Once the SCR-584 went into production, the General Electric Company and Westinghouse needed all of the support information they could get from Radiation Lab; so we in the SCR-584 group made several trips to the Westinghouse Company and the General Electric Company to assist them during the production design and testing of the SCR-584.
Nebeker:
Did the production design take place entirely at those companies?
Abajian:
Yes. They knew a lot more about that aspect than any of us. Remember, they were well-established in product design as producers. We were just a bunch of young squirts who never gave too much thought to some detailed military specs or any of that. We were there for the engineering system design part of it.
Nebeker:
What changes were made in the design in that phase?
Abajian:
A good example would be the antenna system. What we had on the XT-1 was a machine gun mount that we modified to put a servo system and synchros on it; then we mounted the antenna on it. That was our antenna mount. Chrysler had the contract to design and produce an antenna mount that would meet all of the military's environmental and performance characteristics, and they did a great job. There was no resemblance between the great job that they did and our breadboard system of the machine gun mount. There were several other things that their electronics people did that were of no concern to us during the development. Remember, we were breadboarding.
Nebeker:
How much of your design was taken over directly for the production design?
Abajian:
The transmission line system, for example, was entirely what Radiation Lab had done. In one of the speeches today by Pound, he was describing the 7/8-inch stub-supported transmission line. It all went from MIT, and their lines for EW and Westinghouse were all produced in a small company in New York City.
Nebeker:
What about the logical design of the system?
Abajian:
The component for component was exactly as we had laid it out.
Nebeker:
Weren't there changes made in that?
Abajian:
No. The contractors just took every one of the designs of these components — the receiver unit, the servo amplifiers, the commutator unit, the display unit, etc. and did an excellent product-design job for mass production. The Army laid on the two contractors the requirement that whatever was made by GE had to be interchangeable with Westinghouse and vice versa. Those two outfits did a great job of handling that.
Nebeker:
Did they also know about the military specifications?
Abajian:
Oh yes. They were heavily involved in all of that. And Chrysler was too. Chrysler was making tanks at that time. They designed an antenna system from scratch with a gearing system and a automatic lubrication system that was based heavily on their automotive experience. When the antenna had to be produced they just designed a punch, a hole press, or whatever, and in one day they could punch out enough of those antennas to take care of GE & Westinghouse for months.
Nebeker:
During this period were you and some of the others on the XT-1 team working with the engineers in these companies?
Abajian:
Yes. Whenever they needed any kind of support or were going to start on any kind of a testing system — either a subsystem or when the first full systems came together — we would go to them. I went to Syracuse, New York, and spent quite a bit of time up there when their first systems were coming together. We joined the contractors during debugging. At GE, we took the system out on a road test to see how this thing would travel over the roads. Well, we brought it back after about ten miles. (I can't remember the exact distance; but it was a fair ride over secondary roads). When we opened the van to check for damage, several of those major components which were on drawers that slid into a rack with screws to hold them in place were dangling. The screws had come loose, and those drawers were hanging from the cables. Immediately there became a requirement that the screws that held this equipment into the racks were all going to be made much longer than would ordinarily be necessary, as well as with locking devices.
Nebeker:
Did this team stay together and work full time on the project throughout this entire period?
Abajian:
Oh, sure. We still were working on the old XT-1 back at Rad Lab putting more refinements in it. Other system modifications were developed. For example, the N2 Gate was developed as a counter-measure. The MTI came up later. There were any number of little things that we would continue to do. We were running tests with the XT-1 for shell velocity measurements. From our group Leo Sullivan and George Harris were at Dahlgren at the Ordnance Department. We had previously told them that we could see the echo from the shell (after the gun was fired) on our scope. We could track it and actually could lock on it. When it burst, we could see the effect of the burst. We said, "Gee, maybe there's a way to measure muzzle velocity in a gun." I say "we." Actually it was Leo and George. They went down to Dahlgren with the equipment and made some measurements. They took the radar data (with the physicists there) and checked it against their firing tables.
The physicists said our radar data was not accurate enough, that they were way off. Our fellows asked, "way off relative to what"? The reply was that our data was substantially at variance with the firing tables. Leo asked, "Well, what makes you think that the firing tables are correct?" Well, you couldn't have insulted them more than that. But they said, "Well, we'll show you." They then did the mathematical calculations used to generate those firing tables. Lo and behold, they discovered that what they had used in their calculations for the tables was the drag function for the old 3-inch anti-aircraft shell instead of for the 90-millimeter shell. They were quite embarrassed over the whole thing. Then and there was born an engineering change to modify the M7 mechanical computer and the Bell Labs M9 computer. They were modified to take into account the correct drag function. That was one of the things that came out of our continuing work at Rad Lab.
Mission to Britain
Abajian:
This was all done while the work was going on at General Electric and Westinghouse. When the time came for the buzz bombs expected over England, we had to rush some of these SCR-584s through production to get them to England in preparation for the buzz bombs. Westinghouse was fairly well along, and the military was leaning on them to put on a real effort. Sullivan, Harris, and I went to Westinghouse at Lansdowne, Maryland. We worked right around the clock. They had their crews working also. We stayed right with them. It was just a wonderful thing to see that effort. I remember one humorous thing. We were dressed in nice new clothes since we were traveling. I was not about to get mine dirty. I took all my outer clothes off, and I worked all that night there in my underwear. But we came through! We got those ten systems out. That was their goal at the moment.
Nebeker:
Were they shipped off to England?
Abajian:
Yes. That was the objective: To get as many out of Westinghouse and GE as possible. Then I went to England in February, 1944, to provide systems support and assist with personnel training.
Nebeker:
Tell me about that. What were your reasons for going to England then?
Abajian:
One of the proposals to combat the expected buzz bombs was to use the SCR-584, the Bell Labs M9 computer, the 90-millimeter guns, and the proximity fuses. The AA people came to Rad Lab and said, "We want some of your people to support the shipment of SCR-584's to England."
Nebeker:
Where were these AA people from?
Abajian:
They were from Camp Davis, from the Anti-Aircraft Board. The order obviously came from above them. So they took Army instructors from the AA school at Davis, and they took instructors from the Signal Corps where there was a maintenance school. They got an M9 man from Army Ordnance, and Westinghouse sent one of its men. I went from Rad Lab. All were under the overall command of Colonel McGraw from the Anti-Aircraft Board. Colonel McGraw and I were the first two to get across, and these other people came right behind us.
Nebeker:
How did you get across?
Abajian:
We flew in a C-54 from Washington via Newfoundland and then across to Prestwick in Scotland.
Nebeker:
What happened during that time in England?
Abajian:
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Colonel McGraw and I were quite close. In Washington he told me in detail why we were being sent over there. He spoke about the buzz bombs, knowing that they were all going to be coming from the Continent across the Channel to England. The SCR-584 design included a search mode; but in that mode it would revolve continuously. That seemed to me to be a waste during the time it would be looking back towards London. I suggested to Jimmy that what we ought to be doing is to put another modification in the SCR-584 for a sector scan so that we can look only across the channel because we knew from where the buzz bombs were coming. Jimmy said, "Well, I don't know. Let's forget it for now." Well, in one of the big open meetings in London with the British, Jimmy got up and said, "How would you feel about putting a sector scan on the 584?" They all joined in: "That's great!" Jimmy turned around to me and said, "Get on the phone and call the Rad Lab." At the time, we had a British branch of Radiation Lab; so the call went via our British branch back to MIT.
Nebeker:
It's obviously important to have somebody who knows the system to be able to judge how troublesome a modification like that would be.
Abajian:
Well, yes. In fact, the word I sent back was "Get a synchro and rig it with a variable-speed motor with an adjustable crank arm, so that now the motor with this adjustable crank arm would rock the synchro back and forth. We would then couple that synchro into the positioning system so that that in turn would cause the antenna to sector scan." I said, "There's no fancy electronics. It is just a little motor of variable speed and a very rugged device like a synchro." Well, what we got was a wholly electronic package, and it didn't take them very many days to design that and produce it. I've got the date in my diary when I sent the word back to them to come up with it, and DuBridge himself brought it with him. I looked at that thing and I said, "Hell! all electronics, that's not what I asked for." But they were absolutely right in the way Rad Lab did it because it had much greater flexibility than the thing I was suggesting. Not only that, the synchros and other rotating stuff like those motors were in very short supply in the military hardware. They came up with just resistors, capacitors, gas tubes, etc. They did a great job! And it worked. It got incorporated in later versions of the SCR-584 radar.
Nebeker:
When you went over there, were some of the SCR-584s already in use?
Abajian:
No, they were just getting over there. This was new equipment. Our primary mission was to train the AA troops that were there in the use of it. Jimmy came up with the whole business of how to deploy them. He had to fight for this plan. He wanted to deploy one group down along the coast so that they would get the earliest possible acquisition, and then support them by another belt of SCR-584s further back inland so that whatever got through the first gang was then tackled by the much greater number of SCR-584s and 90-millimeter guns that backed them up. We were there to train. IFF equipment had also just arrived there; but that had never been previously integrated with the 584. That was one of the tasks that was put on me, to now look at that IFF equipment, integrate it with the SCR-584, and give some instruction in it. The Army didn't have anyone there at that time for the RC-184 IFF.
Nebeker:
What was your status exactly? You were part of the military mission, but as a civilian?
Abajian:
Yes, I participated as a civilian. Our official title was "Technical Representative."
Nebeker:
So you were training the crews in handling the SCR-584s?
Abajian:
Right. We conducted schools. We went to the big depot area where the SCR-584 equipments were located. The various AA units sent their personnel there so that we were able to conduct the schools. We also had to marry the IFF equipments with the SCR-584. It sounds snobbish, but I've got to say it. The IFF, in my opinion, at that time was not a very good piece of equipment. Because of the super secrecy that was assigned and attached to the IFF there was little or no coordination with the SCR-584 development people. The Signal Corps handled that one separately all the way. There were any number of things that could have been done to have integrated that system with the SCR-584 properly.
Nebeker:
Was that something foreseen — that those two systems would be integrated?
Abajian:
It was foreseen that they would have to be used together because we had to identify at whom we were shooting. But the concept of integrating it properly with the SCR-584 seemed to have become lost in the shuffle. If there were any discussion of how to integrate it in any other echelons I had no way of knowing it. There'd be no reason at all why the IFF antenna could not have been locked electrically to the SCR-584. The IFF doesn't detect. The SCR-584 would do the detection and the tracking. Then once a target is detected, the next thing to do would be to identify it - is that friend or foe? If it were foe, then, of course, the data would move the guns in to shoot. So it seemed logical that the antenna of the IFF should have been locked electrically to the SCR-584 so that whenever the SCR-584 was tracking something, it then asks, "Hey, friend or enemy?" As it was, the IFF crew had to turn cranks and ask, "what's your azimuth." and "What's your range?" And so on.
Nebeker:
Do you think that was mainly a result of secrecy during the war? Or was it more a problem of a civilian operation and this military operation?
Abajian:
I have only an opinion. I believe it was a product of the super secrecy that was attached to the IFF development. They believed a lot of us had no need to know, or something like that. That's my guess. But I have no way of knowing.
Nebeker:
Was there a pattern when larger systems were put together, that participants often felt there was a lack of coordination at a higher level?
Abajian:
I wasn't that close to the IFF program except for this one system. It was called the RC-184, designed and produced by Belmont Radio. We never had any contact with them. Not at our level, anyway.
Nebeker:
How did the training go there in England?
Abajian:
It went quite well. And the troops responded just fine. They were all so eager to learn. Here was some new fancy equipment coming that was going to be a lot better than what they had. The old low-frequency SCR-268s were fine, but not even a poor second to this microwave equipment that we were bringing to the AA people; so they were quite eager to learn.
Nebeker:
Were there any major problems in the training?
Abajian:
No. There were a few isolated instances where some young officer would kick up a heel about our equipment being no good, and believed he knew a better way to do it. In other words, "don't tell me how to learn the system." But nothing major. It went quite well.
Mission to Pacific
Nebeker:
How long were you in England?
Abajian:
I was there for just about two months. Then came the message that they needed Radiation Lab support on the SCR-584 in the Pacific. I got called back from England, and I guess I was home about a month. From there I went to the Pacific Theater.
Nebeker:
Where in the Pacific?
Abajian:
Initially, I flew right to Noumea, New Caledonia, to check in.
Nebeker:
That must have been quite a flight in those days.
Abajian:
Yes, it was. I went over there in a B-24 from Hamilton Field in California. First stop Hawaii, next stop Canton Island, next stop Suva, Fiji, and then from Suva, Fiji, into New Caledonia. The action in the Solomon Islands had all but stopped. Our troops were there, island after island, and they all had SCR-584s by now; there had been a sizeable shipment. So until they arranged for me to go north, I got sent back to Fiji because they had a battalion there. I had contact with them, servicing their problems, answering questions, some little training, and then back to New Cal. From there I went to Guadalcanal. Then it was Bougainville, and clear up to Emirau on the Equator, including Green Islands, Munda, and then back to Guadalcanal. At the end of that tour, I got the call to go to the 14th Anti-Aircraft Command in Australia. I went from Brisbane north to New Guinea — Port Moresby — across to the other side to Finchaven where the 14th Anti-Aircraft Headquarters was located. I worked out of there for quite a while. Next I went to Hollandia, then to Leyte in the Philippines. There was the first real action that I actually saw, where we were shooting at aircraft and they were shooting back at us. From Leyte I got on the Mindoro operation on an LST, and that course went down around Bohol Island on up to Mindoro. I had quite a time in Mindoro.
Mindoro was a fun experience. The SCR-268's that had been previously assigned to the 90mm AA Batteries, and replaced by the SCR-584's, were re-assigned to the searchlight units. The function of the SCR-268 was to direct the searchlights onto close-and-low flying targets so that the 40mm automatic weapons could fire at night; however, the accuracy of the SCR-268 was not adequate for directing a 3o-4o search light beam onto such targets. I suggested to the AA Battalion Commander that a searchlight be connected to the spare SCR-584 that was used for general search duty until such time as it would be needed for a gun battery. The accuracy of the SCR-584 was such that it was not possible to miss - every time the light got turned on there would be a target in its beam. GE remotely controlled light and crew was delivered to us; and I connected the light to the SCR-584. Night after night, every time the light was turned on the target was brightly illuminated and the 40 mm guns had a great time. The prize performance, however, was the show when a high-flying target came over the area. The light was not needed for firing the 90 mm guns connected to the SCR-584 Radar and M-9 Computer; therefore, the procedure was to wait until the first salvo of 90 mm busts appeared in the target area. Then the light was turned on, and the target was always in the beam. On one night the sequence was (a) the first bursts appeared, (b) the light was turned on, (c) the second salvo of burst appeared right on the target, and (d) the target came tumbling down to earth, brightly illuminated all the way down. The cheers were heard all across the valley. The next day a group of fighter pilots visited the AA headquarters and said it was the first time they ever felt safe on the ground. You can bet enemy aircraft activity over Mindoro all but disappeared.
Nebeker:
Did you find it generally without difficulty working with the military commanders?
Abajian:
Absolutely no difficulty at all. They were great. There was one instance — and I won't forget this because of how it wound up — when I checked the radars in the battalion. The main bang of the radar when it fires normally would appear (because of pre-firing) at a range of about -80 to -100 yards from zero. It didn't vary much from that, unit to unit; but in this one battalion, it was at -200 or more yards for that pre-zero main bang. When I mentioned that to the battalion commander, I said, "You know, there's something wrong because these things should all be set up in that range of between -80 and -100 yards. I've never seen anything like that." "No, no," he said, "this is right. We had that determined by trial shot, and the baseline for the trial shot was laid out by the Coast & Geodetic Survey." "So," he said, "I'll rely on the Coast & Geodetic Survey." "Well, Colonel, it's your battalion. What can I say?" I left them shortly thereafter since I was going from unit to unit. I happened to be there at Mindoro in battalion head quarters (where we hooked the light up) one day when the battalion commander came over and said, "Hank, we just got a message from the Colonel where you were once before. He wanted me to tell you that you were right. The Coast & Geodetic Survey got out and rechecked their baseline, and they found an error in it." But the good colonel saw fit to send that message all the way up through channels to get it to me.
Nebeker:
Well, that was nice.
Abajian:
He could have kept his mouth shut.
Nebeker:
Were you traveling the Pacific alone generally?
Abajian:
Yes. There was no one with me from Radiation Lab. But when I got there, they assigned an anti-aircraft officer to travel with me.
Nebeker:
Did your mission include training at that time?
Abajian:
Yes, it included training. I conducted a school back in Guadalcanal. We had instruction manuals that I wrote. I made copies of diagrams out of the tech manual in the equipment. The instructions in annuals were printed in Australia and flown back to us. The school was where all the batteries sent their maintenance men — not their operators; it was maintenance instruction where we learned all about the general theory of all of the components of the system and keeping it going. We taught in lay terms that these hard-working GIs could understand, and they were good. Considering their backgrounds, you've got to admire them. I made a list of the various civilian pursuits that these SCR-584 maintenance men had before they were inducted, and some of them would just amaze you. One that I won't forget was a guy who worked in a fishhook factory before induction. The one with the best training in electronics used to operate a sound truck on the West Coast; but they all did a great job.
Nebeker:
Were you also involved in the maintenance of these units on your travels?
Abajian:
Oh, yes. I would check every one that I visited, to see whether or not it was performing to its fullest capabilities. I would look into the history of what they reported as problems because that was information that I would send back to O.C. Sig. O. in Washington. In Washington, they were collecting all of this data from all over the world to see what had to be done.
Nebeker:
You've given a couple of examples already where some modification was made in the field. Did that happen often?
Abajian:
Do you mean like putting in the sector scan? No.
Nebeker:
Weren't there many production modifications?
Abajian:
No. There were some new gadgets that we knew we were going to put in, e.g. you may hear people mention something called the N2 gate. When the German business of chaff was rearing its ugly head, we wondered how to combat the chaff. Harvard had that countermeasures responsibility. Al Grass devised what we called the N2 gate. The SCR-584 would track everything out to 32,000 yards. But when you were going to shoot, you didn't want all of the extraneous signals in the tracking channel; so a tracking channel in the receiver was gated on at just exactly the right time so that the echo from the target that you wanted would come into the receiver. That gating was called a narrow gate. That gate, which turned the receiver on, was fairly wide; in fact, somewhat wider than the signal that we got from the airplane. That meant that the signal from the chaff around the airplane would interfere with the tracking of the aircraft. Al Grass came up with an extra-narrow gate so that it would pick up only a small part of the signal from the aircraft. Naturally, that one had to be called a "narrow narrow" gate, and that led to the N2 gate designation. The N2 gate kit got into production; but no kits had arrived at the Pacific Theater while I was there.
Nebeker:
I was wondering, if you would learn about parts that were often breaking down, would changes be made?
Abajian:
There was little or nothing done because of the time constraints. For example, the drive motor in the pedestal would fail fairly frequently. The failure occurred in the field winding because it was very poorly inpregnated. The motors were sent to Australia, where a motor-winding organization would determine by taking apart the motor how many turns and what size wire was required, and would then rewind those fields. Then they would impregnate them properly and send them back. But to make a change back in the States, you couldn't do it. Ultimately that motor did get redesigned to have a permanent magnet field. The Chief Signal Officer put out a big volume of reports from all over the world on the SCR-584 problems in the field.
Nebeker:
Well, I'm sure it affected maintenance, that people knew that certain things were likely to break down.
Abajian:
Oh, yes.
Nebeker:
According to this you were in the Pacific until March of '45.
Abajian:
After Mindoro I flew back to Leyte and got on another convoy for the Luzon landing. I went all the way, right around through the same straits, up past Mindoro, going farther north and then into Lingayen Gulf. That was early in January.
Dangers of Pacific Duty
Nebeker:
Were there dangers of Japanese subs in that period?
Abajian:
Not subs, but kamikazes. In fact, on the Mindoro operation while the AA major, who was my escort, and I were on the deck one afternoon we saw a plane coming our way. The cruiser "Nashville" was up ahead and to the right of us. The plane was coming down and straight at us. The major looking at it, said: "Hey, that guy'd better pull out pretty soon," because our sky was just filled with our own airplanes. They were all over us. Well, the plane continued coming down; and when he banked we saw those red meatballs on him. He came right around, picked his spot on the cruiser "Nashville" and went right into it. That was the first explosion. All the radars on every ship were in operation; but the bogey got through undetected.
Nebeker:
Didn't they recognize him as a foe?
Abajian:
I suspect that with the IFF equipment being what it was, there was no way of separating him from all of the other friendlies that were in the sky. There was one other bogey up there. They found him; but that guy got away. On another occasion I almost got killed at Lingayen Gulf.
Nebeker:
How was that?
Abajian:
A Japanese raiding party came down one night and attacked our SCR-584 where I had been working. I was working on the radar out in an open field. A short distance away was a coconut grove where the command post for the battalion was located. That radar was the one and only radar that gave me any kind of trouble trying to bring it up to snuff. The radar had come from the Central Pacific. Remember, I was in the South Pacific. For that Luzon operation, they brought troops from everywhere. To get ready for the Luzon operation the troops were told to button up and be ready to move. They emptied all of their sandbags wherever they were. This particular crew, when they emptied the sandbags, folded them up (because they knew they were going to need them) and put them inside the radar. Then they sealed up the radar because if they ever had to drive off into deep water, the SCR-584 would float and could be pulled ashore. So that radar was sealed with wet sandbags inside. You never saw such fungus as when they opened that radar. The crew had cleared up quite a bit of it when I got to it. The transmission lines particularly were heavily infested. But there was more and more fungus. I brought the performance back up substantially; but I knew it was capable of even better performance. I tell you, it was driving me bats. Well, I was staying there with them, and I slept every night on the tailgate. The crew had dug a revetment for the radar. All I had to do was walk out and just step on the tailgate, and I would bunk down there and sleep. Well, this one night, I was heading out to sleep on the tailgate when one of the fellows who was on watch, said, "Hey, we put up that tarpaulin out in front of the radar as a tent." He said, "You can have my cot. I've got my cot there."
An invitation like that I couldn't turn down; so there I was asleep in front of the radar instead of on the tailgate. That was the night those Japanese came down. They set up a machine gun off the tailgate of that radar, and they let blast. I tell you, if I had been there, I'd have been all full of holes. Well, the shooting woke me up. There were a couple of other fellows there with me. They also woke up, and they said, "Hey, let's get out of here!" So in my modesty I put on my pants and I was going to put on shoes. Suddenly there was a blast right outside our tarpaulin. I think it was a grenade that they threw over there, nowhere near us, but well within our earshot. When that thing went off it sounded like a Big Bertha. I dropped the shoes, and these other guys dropped everything, and we just took off across the field. Now barefoot, I stepped on a piece of barbed wire on my way back towards the command post. I got into the command post ok; and of course they were all awake by this time. Our troops were exchanging fire with the Japanese. The Japanese rolled a drum of gasoline down into the revetment under the radar and set it on fire. That whole radar just went right up in flames. We knew we had three boys in there, but there was a front door to the radar. When the Japanese began shooting there at the back, our boys took off via the front. One of the fellows was hit badly enough that he couldn't travel much. When he got out in front of the radar, he fell down and played dead. We picked him up, and he was okay the next day.
Anyway, I got back to the command post. I was a civilian, not authorized to carry weapons. The executive officer, a major, had come from the dugout to a position behind a coconut tree where I was hiding. There I was with the major who had raised his carbine and was shooting out from behind the tree. I commented to him., "Gee, I don't know what I'm doing here, major. I don't have a gun." As I said, we weren't allowed any as civilians. That was one of the no-no's. He looked at me and said, "You don't have a gun?!" "No, I don't have a gun." He said, "Here!" And he took his .45 out of his holster and he put it in my hand. I said, "What do I do with it?" He gave me instructions then and there on how to release the safety and cock it. He resumed firing toward the Japanese at the radar location. I turned around. Remember! The radar's on fire. I looked down the road to the rear of our location; and in that direction I saw several figures dart across the road and come in behind our command area.
"Major!" I said, "Look at them! Look at them out back there!" He turned around; and, sure enough. there were these figures just jumping across the road, illuminated by the burning radar. "Yeah, I see 'em," he said, and he turned right around and resumed shooting back toward the radar. He didn't get excited about the figures behind us. I turned around again and I saw another one coming across toward us. I lowered that .45, took careful aim, and waited I for the next one. The next figure darted out across the road. I fired and what a BANG! Oh, that .45 had a kick in it like a mule. I think I must have hit a star in the sky... or something like that. About that time a voice behind us said, "It's Sergeant Mitchell. Let me in the area." The only round I ever fired — and I had to fire at one of our own boys." Well, he got in, and at that point the Japanese fired one of those "D" mortars toward us. It landed in that coconut tree right above the major and me. Down came the coconuts and the coconut fronds. I didn't get hit. Nothing hit me, but the fronds came down on us. At that point, with my toe hurting from the barbed wire, I said, "Major, I'm going back in the command post."
And I started crawling back. I had to go behind a GI who was standing behind a coconut tree and also firing out there at the Japanese. I remembered about trigger-happy men and I said, "Hold your fire, soldier. I'm making my way into the CP." He quickly turned around, aimed his rifle down at me, said, "Who are you?" I said, "Mr. Abajian." He said, "Whooo!!??" All of a sudden I got to remembering that I was in a unit maybe two or three days at a time, sometimes a little longer I didn't get to know many people, and they didn't get to know me. Quickly at that point I said, "It's the civilian radar technician." "Oh," he said, and he lowered the rifle, and I went into the dugout. Well, the next morning that guy came over to me and said, "You don't know how close you came to getting it last night." He said, "You know, whatever you said, that was the best Japanese-sounding name that I've heard." Then about that time along came the Inspector General, a colonel from IG, who said to the battalion commander, "Colonel, I'm making my usual rounds to check on last night's action to see if there was any promiscuous or uncontrolled fire." The battalion colonel said, "No. Everything was all under control." The IG left, and I said, "Colonel, you're forgetting when I turned around and fired at one of our boys." "Ah," he said, "I didn't forget, Hank." He said, "Uncontrolled maybe, promiscuous, no." But that was the closest I came. Boy, was I glad to see that radar go up in smoke. I was just so happy to see that thing go up. I really tried and couldn't bring it up to full performance.
Nebeker:
And that was near the end of your Pacific tour?
Abajian:
Yes. Manila had already fallen at that time, and General French, brigade commander, said when I asked him if I could go home since I had been there almost a full year, as far as he was concerned he'd approve it. So I went back from there to New Guinea, Finchaven and waited for orders to go home. General Marquat, the 14th Anti-Aircraft commander, had to okay it, too. I got home sometime in April. I said, I've done my duty. My wife and I decided that we would raise a family. She was pregnant shortly thereafter. It was in early July when the cable came from General Marquat that he wanted Abajian back. He wanted me back for an operation on the Japanese mainland. DuBridge asked if I would go back. My wife was expecting, and here was Marquat calling for me to go back. It was a toss-up; but after discussion between me and my wife, we decided that the right thing to do was to go back because she was home with her family and there'd be no problem for her. So orders were drawn up sending me back to the Pacific. I was on vacation in Vermont that August. When I came back from that vacation, I was supposed to go; but that's when the A-bombs were dropped. I got saved. I didn't have to go back.
Work Environment and Security
Nebeker:
When did your Rad Lab assignment end?
Abajian:
The end was in November of '45. Then I went to Airborne Instruments Laboratory with Bert Fowler. Bert was on GCA. Mike Chaffee, who was on the MEW system, also went there. There were several of us from Rad Lab. Incidentally, one of the things we tried to use the XT-1 for while all this production work was being handled by contractors, was to use the SCR-584 in the GCA concept. That was the original plan for GCA. The plan was to follow in good weather an airplane down the ideal path along which it would want to come in if the visibility were poor. That flight path was then recorded. Then in the actual case where one wanted to come in with poor visibility, the radar would track him down and compare his position with the ideal path. Then by voice communication, the controller would give him correction information to put him on the ideal path. That was fine until he got down fairly close to the ground or particularly if he was coming in over water. What happened was that the reflected signal from the aircraft not only was coming directly, but it was also coming down onto the water and reflected off the surface back up to the radar and the radar would get confused. Instead of tracking the real one, it would track its mirror image below the water. We were tracking submarines. The GCA people then knew that that approach wouldn't work. So they changed the whole concept of the GCA system. That was Bert's and Luis Alvarez's program and Bert was part of the GCA team.
Nebeker:
Let me just ask a general question about military-Rad Lab communications. I guess you've given a lot of examples of good communications, and a few examples of where there might have been more. What's your general view of how it worked?
Abajian:
I have nothing but fine words to say about it. Initially there was a lot of suspicion and looking down their noses at these scientists there at MIT that were going to tell the military how to do things or what to do. But it didn't take long before the effort by Ed Bowles and Vannevar Bush, plus some early results, paid off. The military said, "Hey, there's something there." And all of my experiences directly with the military were fine. They were great. We were accepted. In fact, we were in demand. There was a great relationship, no matter which gang we worked with whether it was overseas or here in the States throughout the testing phase. If there was any kind of politicking or ill will anywhere, it had to be way above me because I saw none of it.
Nebeker:
Did you feel hampered in any of your activities by security regulations?
Abajian:
No. We were quite careful to observe then. The only security bad fallout that I could identify was the way the IFF program went. Just that. Aside from that there was none that I know about. We were accepted and respected, and we respected them for what they knew and how they did things, the way they measured a system to make sure that it was going to be what they wanted, all of it.
Nebeker:
Well, thank you very much.
