ASME-Landmark:Pit-Cast Jib Crane


Jib cranes were used to lift molten iron to pit-like molds where it was cast into pipe (the "pit-cast" method). When the American Cast Iron Pipe Company constructed its plant facilities at Birmingham, Alabama, in 1905-06, six jib cranes were installed. These cranes were purchased from the Alliance Machine Company and the Cleveland Crane and Car Co., Ohio, and were among the first to employ electric motors to power this type of equipment. ACIPCO used D.C. electric motors to mechanize the hoisting, booming, and swing actions of these jib cranes. The brakes, however, that controlled those actions were originally mechanical. Later, air brakes were installed, and still later electric brakes were used.

The cranes were operated in pairs, back to back, each serving a pit about twenty-five feet in depth. Pipe molds were placed vertically in the pits, lined with sand, and fitted with a core to form the interior of the pipe. After the pipe had been poured the mold was opened and the pipe extracted and removed from the pit, and the process repeated. The jib crane was the workhorse and key piece of machinery that made this process possible.

When pit casting was replaced by centrifugal casting in the 1920s, many pits were filled and the cranes were used to produce cast iron fittings or general maintenance work. Only one jib crane remained fully operational, with very few modifications from the day it was built, for 80 years at the American Cast Iron Pipe Company. It was probably the last pit-cast jib crane to operate, which it did until it was given to the Sloss Furnace Museum in early 1986. See ASME website for more information