The B-24 Liberator was produced in larger numbers than any other American military aircraft. This was achieved through the creation of the Liberator Production Pool which saw the aircraft produced at five factories run by three different companies, amongst them the massive Ford plant at Willow Run.
The pool was created by the Air Corps in the autumn of 1940. Three new factories were built to produce an extra 100 B-24s per month. Work on each aircraft began at a new Ford plant at Willow Run, which would produce 100 “knock down” B-24 assemblies each month. These partially completed aircraft would then be split equally between a new Consolidated plant at Fort Worth and a new Douglas plant at Tulsa where they would be completed. These aircraft would be given the designation B-24E to indicate that they came from the Ford Plant. Later aircraft were designated as B-24H. Contracts to built these new factories were not signed until February-March 1941.
In the spring of 1941 this plan was modified to increase production from 100 aircraft per month to 350 per month. Douglas, Tulsa and Consolidated, Fort Worth would both expand so they could assemble 75 planes per month, while Ford, Willow Run would more than double in size, producing the 150 “knock-down” kits for Tulsa and Fort Worth and 200 complete aircraft in their own right.
Finally in January 1942 after the Japanese attack on Pearl Harbor a fifth plant was added to the pool, built by North American at Dallas. Aircraft produced at Dallas were designated as the B-24G-NT.
The designation system was simplified with the appearance of the B-24J, which was produced by all three main manufacturers and both sub-assembly plants.
The Ford plant at Willow Run became the most famous American aircraft factory of the Second World War. Here Ford attempted to apply automotive mass production methods to the production of heavy bombers. However this was a complex process and early progress was very slow. Consolidated had to sent “knock-down” B-24s from San Diego to Forth Worth and Tulsa, where they were assembled as B-24Ds while production levels at Willow Run were improved. In September 1943 the situation was so serious that Material Command of the USAAF suggested that the government should take over the factory. By the end of 1943 Willow Run had only produced 1,315 complete aircraft.
Ford’s gamble paid off fully in 1944. In the last two years of the war Willow Run produced 5,467 complete aircraft, for a total production of 6,791. The factory also produced 1,893 “knock-down” units that were completed at Fort Worth and Tulsa, for a total of 8,684 aircraft. The plant reached its peak in August 1944 when it produced 428 B-24s. In airframe poundage this was half of the peak monthly output of the entire German aircraft industry!
Consolidated also increased their efficiently greatly during 1943. At the start of the year it took 24,800 man hours to build one B-24 at San Diego, while by January 1944 that time had fallen to 14,500 hours! The cost per aircraft also fell dramatically, from $304,391 in 1942 to $124,516 in 1944.
The final two letters of the full designation of a B-24 indicated which factory had completed the aircraft:
CO – Consolidated, San Diego
CF – Consolidated, Fort Worth
DT – Douglas, Tulsa
NT – North American, Dallas
FO – Ford Motor Company, Willow Run