The River Rouge facility built tanks, amphibious vehicles, tank engines, aircraft parts and engines, jeeps, and many other war materials, but not aircraft. Ford's B-24 production was accomplished at Willow Run, an entirely new plant built on farmland west of Detroit that was owned by Henry Ford. The story of the facility's construction and completion, with initial aircraft parts production beginning just eight months later with an assembly line over a half mile in length, is an amazing story in itself.
The B-24 was completely redesigned by Ford to facilitate mass production. Before their involvement in the program, the aircraft was essentially individually hand built with many parts fitted one by one. The factory and workforce were woefully inadequate to meet the demands of war production, and if Ford had not intervened, the final number built, in excess of 19,000, would never have been accomplished.
When Ford employees arrived at Consolidated Aircraft's Southern California plant in 1940 to gauge their interest in building the B-24, they found a disorganized hodgepodge that horrified their engineers. Ford was producing automobiles using, in some instances, measurements in millionths of an inch; Consolidated was continually modifying individual aircraft on the assembly line without making changes to drawings and records, and those drawings had little relationship with what was being made.
Parts made inside the factory were used to assemble aircraft outdoors on the ramp, and the temperature differences caused by sunshine and heat required individual parts to be cut and trimmed to fit.
Ford's director of engineering and the man most responsible for inaugurating the moving assembly line at Ford's Highland Park plant in 1910, Charles Sorensen, stayed up all night the same day he arrived in San Diego, and by morning had sketched out the design and flow of an assembly line over a half mile in length that would become the world's largest aircraft manufacturing facility, Willow Run.
One of Ford's first actions after signing a contract to build the bomber was to lease office space in downtown San Diego and import 200 engineers from Detroit. They spent several months cataloguing the myriad of drawings, notes, and even scraps of paper so a complete set of documents could be generated that had hard dimensions and numbers for each and every part.
Ford built a huge training center at Willow Run, and classes focused on all aspects of aircraft construction built a workforce that unerringly performed the tasks required to produce one of the most complex machines on Earth. It took unskilled men and women from all over America and turned them into dedicated workers that built the bomber with precision and speed that at its peak took just 63 minutes for a completed aircraft to roll out the doors of the cavernous factory.
Ford's experience in mass production was adapted to the construction of the huge bomber.
The aircraft was redesigned so separate prefabricated sections could be assembled and joined on the assembly line. A massive jig and machine tool was built by Cincinnati Milling Machine Company to mate, drill, and machine the B-24 wing center section; it saved millions of man hours over the production cycle. Among other functions, the fixture simultaneously drilled and tapped dozens of 5/8" holes used to bolt the four Pratt & Whitney R-1830 engines to the wings.
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