The truck plant at war: the M-5-6 and the Lend-Lease line

1941 – 1945

Fort Wayne's war truck: When the Army standardised its 2½-ton 6×6 cargo truck designs in 1940–41, International Harvester's design — the M-5-6 — was put into production at Fort Wayne in 1941. Five hundred M-5-6s and 3,000 M-5-6x4s, wearing a commercial K-model cab, were complete by 1942 and were exported to the Soviet Union. The Wisconsin Historical Society's International Harvester photographs show the trade in progress: M-5-6 trucks on an assembly line the captions locate as possibly the Fort Wayne Works, crated for shipment with the original caption noting the trucks were "originally sold to the United States Army" and "diverted under the Lease-Lend Program to Russia."

The Navy's standard: The design was then upgraded — larger engine, larger tires, military open cab — and standardised as the M-5H-6, which became the U.S. Navy's and Marine Corps' standard 2½-ton truck, the only truck of its class with locking differentials. More than 30,000 of the M-5 family were built between 1941 and 1945. A compiled count of the industry's war production credits the Fort Wayne plant with more than 115,000 military vehicles of all types across the war years; the figure is printed as its source gives it, a compilation, not a plant ledger. The city's ordnance depot appears in the same photographic record staging massed Army ambulances for shipment to Europe in March 1944 — Detroit-built ambulances, staged here but not built here, a distinction this section keeps. The war's effect on the dealers who sold the cars the factories stopped making is told in the dealer-trade entry below; the home front as a whole is the war sections' subject.

Sources:

1. The 2½-ton 6×6 truck record (Ordnance Corps standardisation history) — the M-5-6's production at Fort Wayne from 1941, the 500 and 3,000 export figures by 1942, the M-5H-6 standardisation for the Navy and Marines, and the family's total above 30,000, 1941–45.
2. Wisconsin Historical Society, International Harvester Company photo albums — the M-5-6 assembly-line and crating photographs and their Lend-Lease captions.
3. Jim Allen's International Harvester war-production account, in Farm Show's reporting on the U.S. auto industry in World War II — Harvester's 244,000 military vehicles across its plants and more than 115,000 built in Fort Wayne.
4. ACGSI, International Harvester in Allen County — the March 1944 Ordnance Depot ambulance photograph, captioned as Detroit-made vehicles.