The Diamond T Company was an American automobile and truck manufacturer. They produced commercial and military trucks.

History

The Diamond T Motor Car Company was founded in Chicago in 1905 by C. A. Tilt. Reportedly, the company name was created when Tilt’s shoe-making father fashioned a logo featuring a big “T” (for Tilt) framed by a diamond, which signified high quality. The company's hood emblem on trucks was a sled dog in harness. From its beginnings manufacturing touring cars, the company later became known for its trucks. By 1967, as a subsidiary of White Motor Corporation, it was merged with Reo Motor Company to become Diamond Reo Trucks, Inc.

During World War II, Diamond T produced a prototype of a heavy truck in the 980/981, a prime mover which was adapted and quickly acquired by the British Purchasing Commission for duty as a tank transporter tractor. Coupled with a Rogers trailer, the truck gave sterling service with the British Army in North Africa Campaign, where its power and rugged construction allowed the rescue of damaged tanks in the most demanding of conditions. In addition Diamond T built the entire range of the G509 series 4 ton 6X6s, including cargo, dump, semi tractor, and wrecker trucks, as well as some lighter trucks, and even G7102 half tracks. Diamond T ranked 47th among United States corporations in the value of World War II military production contracts.Peck, Merton J. & Scherer, Frederic M. The Weapons Acquisition Process: An Economic Analysis (1962) Harvard Business School p.619 Diamond T manufactured three pickup trucks: The Model 80,201 and the Model 202. The pickups were powered by the Hercules QX-series 6-cylinder engines. The model 80 was produced from 1936 to 1938 and the Model 201 was produced from 1938 to 1949.

Cars Diamond T produced automobiles in Chicago from 1905 to 1911. The models produced were powerful touring cars of up to 70 hp.

Model and Year Engine HP Wheelbase Diamond T (1907) Four-cylinder 40 114″ Diamond T (1908) Four-cylinder 50 114″ Diamond T (1909) Four-cylinder 50 114″ Model D (1910) Four-cylinder 35 108″ Model E (1910) Four-cylinder 45 124″ Diamond T (1911) Four-cylinder 45 124"

Trucks

Commercial models 1928–1929 brought major mechanical improvements across the entire range. A closed cab with doors was introduced. All-wheel hydraulic drum brakes were used. Six-cylinder engines were available from Continental and Hercules for heavy trucks and a four-cylinder Buda powered light trucks. All trucks had geared-differential rear axles. By 1929 there were chassis load ratings (the weight of the body and payload) up to 12 tons (10,900 kg) on three axles.

1933–1935 In 1933 a new all-steel covered cab with doors and roll-up windows was introduced. In a 1935 model year style change it had been improved with a "streamlined" V-style windshield. This cab would be used on commercial and military trucks until replaced in 1951. In 1935 the trucks were also improved mechanically and new models were introduced. They developed through the rest of the 1930s. In 1935, Diamond T sold 6454 units and in 1936 it increased to 8750 trucks. In 1938, Diamond T sold 4393 units and in 1939 it increased to 5412 trucks. In 1940 Hercules six-cylinder gasoline and diesel engines up to were used and Cummins diesels up to were introduced in 1940.

1940–1942 In 1940 Hercules six-cylinder gasoline and diesel engines up to were used and Cummins diesels up to were introduced. In 1942 improved models went into production and then stopped after only 530 units for military production of tactical trucks and half-tracks.

1946–1947 Production of commercial trucks was stopped for military production in 1942. A small number of commercial trucks began to be built in 1944 and more in 1945. In 1946, the first year of full commercial production, there were five models, in 1947 there were fourteen. After World War II heavy trucks were measured by Gross Vehicle Weight Rating (GVWR), the total weight of the chassis, body, and payload. In 1947 there were chassis rated from to with conventional, sleeper, and COE models. Annual model changes were discontinued and many models continued unchanged until 1950. Gasoline and diesel engines were offered by Continental, Cummins, and Hercules. Single and tandem rear axles were available in many wheelbases.

Military models Model 980/981 12-ton 6x4 trucks (G159) were ballast tractors used as tank transporters. Designed for the British military they were also used by the US Army. Powered by a Hercules DFXE diesel engine developing and geared very low, it could pull a trailer of up to and proved capable of the task of moving the heaviest tanks then in service. Early trucks used a standard Diamond T commercial cab (also used by the 4-ton G509 trucks). In August 1943 it was replaced with an open military cab. A long butterfly hood had vertical louvers along both sides.

A short ballast body was mounted behind a mid-mounted winch. There were closed tool compartments along both sides, two open containers in the front, and a bottom-hinged tailgate. The box could hold of ballast to increase traction on the rear tandem axles. When paired with the M9 Rogers trailer, the combination was designated the M19 tank transporter. A number of cars were delivered to the USSR under Lend-Lease during WWII.

Model 968 4-ton 6x6 truck (G509) Prime mover cargo trucks entered production as the standard 4-ton 6x6 chassis in 1941. It was produced with both a closed steel commercial-style cab and later an open military cab. It was designed to tow the 155 mm howitzer and carry its crew and ammunition. The chassis was used for different bodies, but the majority of 4-tons were Model 968s.

Standard models were powered by the 6 cyl., Hercules RXC engine that developed mated to a five speed manual transmission and two speed transfer case. The truck weighed and could tow .

Model 967 was a pre-standard prime mover cargo truck (21 were built as wreckers). Produced in early 1941, it was fitted with Hercules RXB inline six cylinder engine. Distinguishable by one piece brush guard on the front.

Model 969 Wrecker was the US Army's standard medium wrecker during World War II. It was equipped with the Holmes W-45 heavy-duty military wrecker bed with its twin boom and two 5-ton winches at the front of the bed as well as a front-mounted winch. A variety of other recovery equipment was carried, along with its own air compressor. It weighed and could tow .

Model 970 Cargo truck was designed to carry bridging pontoons. The bed is longer than the 968.

Model 972 dump truck was the largest dump truck the US Army had during World War II. Originally they were not fitted with front winches in order to reduce front axle loading. After a Corps of Engineers request, winches were fitted from June 1944 onwards.

Model 975 was a bridge truck built for Canada.

Production models The pre-assigned serial numbers only indicate the maximum possible production quantity.

Year Production figures Model Load capacity Serial number 1916 73 JA 0,75 to1001 to 1073 76JB 1 to3001 to 3076 J5 1 to J21,5 to 849J4 1,5 to1151 to 1999 J3 2 to 78 L3,5 to801 to 878 250LB 3,5 to901 to 1150 R 5 to Sum ~ 1,000 1917 J5 1 to3501 to 4999 ↑ (s. 1916) J4 1,5 to1151 to 1999 J3 2 to ↑ (s. 1916) LB3,5 to901 to 1150 R 5 to Sum 1918 ↑ (s. 1917) J5 1 to3501 to 4999 ↑ (s. 1917) J4 1,5 to1151 to 1999 500 J3 2 to2501 to 3000 ↑ (s. 1916) LB3,5 to901 to 1150 64 R 5 to751 to 814 1,501S 5 to10500 to 12000 7,999 T 1.5 to12001 to 19999 ↑FS 1,5 to 12001 to 19999 Sum 1919 ↑ (s. 1917) J5 1 to3501 to 4999 ↑ (s. 1917) J4 1,5 to1151 to 1999 ↑ (s. 1918) T 1.5 to12001 to 19999 ↑ FS 1,5 to 12001 to 19999 ↑ (s. 1918) J3 2 to2501 to 3000 ↑ (s. 1916) LB 3,5 to901 to 1150 R 5 to10001 to ↑ (s. 1918) S 5 to10500 to 12900 Sum 1920 T 1,5 to 374 Farm Special 1,5 to12261 to 12634 388 U2 to20000 to 20387 196 LB3,5 to5687 to 5882 2 R 5 to10145 to 10146 15S 5 to10542 to 10556 172 J3 2 to8595 to 8766 Sum> 900 1921 O3 1 to 50000 to ↑( s. 1920) T 1,5 to12261 to 12634 ↑ Farm Special 1,5 to 169 U2 to20388 to 20556 33 K3,5 to30111 to 30143 7 EL 5 to40021 to 40027 79 S 5 to10558 to 10636 Sum > 400 1922 93 O3 1 to 60011 to 60103 113 T 1,5 to12636 to 12748 ↑ Farm Special 1,5 to12636 to 12748 562 U2 to20556 to 21117 189 K3,5 to30144 to 30332 11 EL 5 to40028 to 40038 135S 5 to10542 to 10676 Sum 1,103 1923 170 O3 1,25 to 60104 to 60273 215 T1,5 to12749 to 12963 591 U2 2,5 to90001 to 90591 263 K3,5 to30333 to 30595 25 EL 5 to40039 to 40063 42 S5 to10677 to 10718 76 75 0,75-1 to81001 to 81076Sum 1,382 1924419 75 1 to 81077 to 81495 7 O4 1,25 to50201 to 50207 25 T21,5 to13201 to 13224 509U2 2,5 to90592 to 91100 165K 3,5 to30596 to 30760 37 S 5 to10719 to 10755Sum 1,161 1925 to to toSum 1926 to to toSum 1927 to to toSum 1928 to to toSum 2,308 1929 151 1 to 33601 to 290 1,5 to51501 to 302 2 to42976 to 550 2,5 to61001 to 400 2 to74113 to 502 2,5 to95196 to 5052,5 to95196 to U56SP3 to23282 to 700 3,5to32058 to 800 4 to63045 to 600 3 to23701 to 601 3 to23801 to 602 3 to24001 to 605 3 to19551 to 10005 to40201 to 1600 8 to31301 to 2500 10-12 to11101 toSum 3,590 1930 to to toSum 2,888 1931 to to toSum 2,483 1932 to to toSum 2,250 1933 to 6 Diamond T Doodlebug to 4,139 toSum 1934 to to toSum 5,440 1935 to to toSum 6,454 1936 to to toSum 8,750 1937 to to toSum 8,118 1938 to to toSum 4,393 1939 to to toSum 5,412 1940 to to toSum 6,354 1941 M20 8 to 968 4 to toSum 6,077

See also List of automobile manufacturers Diamond T tank transporter Diamond T Doodlebug

Notes

References

External links Diamond T (and REO) Trucks (Hank's Truck Pictures)