Studebaker US6

"US6" redirects here. For the road, see U.S. Route 6.

The Studebaker US6 (G630) was a family of ​2 ¹⁄₂-ton 6x6 and 5 ton 6x4 trucks manufactured by the Studebaker Corporation and REO Motor Car Company during World War II. Most were exported to the Soviet Union.

History

In 1940 the US Army set a requirement for a 6x6 truck with a ​2 ¹⁄₂-ton (2,268 kg) off-road payload. Studebaker, Yellow Coach (a GM company), and International Harvester submitted designs. All three were accepted and in production by 1941.

A total of 219, 882 ​2 ¹⁄₂-ton (2,268 kg) 6x6 and 5-ton (4,536 kg) 6x4 trucks in thirteen variations were built. Studebaker was the primary manufacturer, building 197,678, while REO sub-contracted 22,204 more. Most were exported to the Soviet Union.

Specifications

Engine and driveline

The US6 used a Hercules JXD engine, a 320 cu in (5.2 L) L-head inline 6 cylinder gasoline engine developing 86 hp (64 kW) at 2800 rpm and 200 lbf⋅ft (271 N⋅m) of torque at 1150 rpm. A conservative and reliable engine with a compression ratio of only 6:1, it could use very low octane gasoline. This engine was also used in the M3 and later M8/M20 armored cars.

The transmission was a Warner T 93 5 speed with a direct 4th gear and overdrive 5th gear. The transfer case had high and low gears, and engaged the front axle. In 6x4 models it was blocked in high and did not drive the front axle. Both front and rear axles were a Timken split type. The transmission was also used by CCKWs, as were many transfer cases and axles.

Chassis

The US6 had a ladder frame with three beam axles, the front on semi elliptical leaf springs, the rear tandem on quarter elliptical leaf springs with locating arms. There were two wheelbases, the 13 feet 1 inch (3.99 m) long wheelbase (LWB) used in most models, and the 12 feet 4 inches (3.76 m) short wheelbase (SWB), used in semi tractors and dump trucks (measurements are from the centerline of the front axle to the centerline of rear bogie). All models had 7.50-20” tires and dual rear tires. 6x4 models, intended for on road use only, were rated at 5 tons (4536 kg), twice the 6x6’s off road rating.

Body

The US6 used Studebaker’s civilian truck cab, modified for military use. Studebaker trucks were unique from other ​2 ¹⁄₂ trucks built for the war effort because vent windows were included in each door. These windows were separate from the window that rolled down into the door and could be rotated out to help with ventilation.

Studebaker designed the open military cab also used by the CCKW, but their major customer, the U.S.S.R, preferred the closed cab for their climate. While Studebaker's open cab became the US standard, the US6 returned to the closed cab after only 10,000 units.

Models

• US6 Cargo U2.jpg

  Cargo U2

• US6 Tanker U5.jpg

  Tanker U5

• US6 Tractor U6.jpg

  Tractor U6

• US6 Dump U11.jpg

  Dump U11

• US6 Dump U13.jpg

  Dump U13

Dimensions

Model Body	Wheelbase Drive	Length	Width	Height (overall)	Weight (empty)
Cargo U1 12 feet (3.7 m) bed	Short 6x6	20 feet 11 inches (6.38 m)	7 feet 4 inches (2.24 m)	8 feet 10 inches (2.69 m)	9,875 lb (4,479 kg)
Cargo U2 with winch	Short 6x6	22 feet 1 inch (6.73 m)		8 feet 10 inches (2.69 m)	10,485 lb (4,756 kg)
Cargo U3 17 ft (5.2 m) bed	Long 6x4	27 feet 11 inches (8.51 m)	7 feet 4 inches (2.24 m)	8 feet 10 inches (2.69 m)
Cargo U4 with winch	Long 6x4	29 feet 10 inches (9.09 m)	7 feet 2 inches (2.18 m)	8 feet 6 inches (2.59 m)
Tanker U5 750 US gal (2,800 L)	Long 6x6	20 feet 11 inches (6.38 m)	7 feet 4 inches (2.24 m)	7 feet 3 inches (2.21 m)	10,585 lb (4,801 kg)
Tractor U6	Short 6x4	17 feet 6 inches (5.33 m)	7 feet 2 inches (2.18 m)	7 feet 3 inches (2.21 m)	8,190 lb (3,710 kg)
Cargo U7 17 ft (5.2 m) bed	Long 6x4	27 feet 11 inches (8.51 m)	7 feet 4 inches (2.24 m)	8 feet 10 inches (2.69 m)
Cargo U8 with winch	Long 6x4	29 feet 10 inches (9.09 m)	7 feet 4 inches (2.24 m)	8 feet 10 inches (2.69 m)
Cab/chassis U9	Long 6x6		7 feet 3 inches (2.21 m)	7 feet 3 inches (2.21 m)
Dump U10 End dump	Short 6x6	18 feet 9 inches (5.72 m)	7 feet 4 inches (2.24 m)	7 feet 7 inches (2.31 m)	10,150 lb (4,600 kg)
Dump U11 with winch	Short 6x6	20 feet (6.10 m)	7 feet 4 inches (2.24 m)	7 feet 7 inches (2.31 m)	10,760 lb (4,880 kg)
Dump U12 Side dump	Short 6x6	18 feet 11 inches (5.77 m)	7 feet 4 inches (2.24 m)	7 feet 7 inches (2.31 m)	10,150 lb (4,600 kg)
Dump U13 with winch	Short 6x6	240 in (610 cm)	7 feet 4 inches (2.24 m)	7 feet 7 inches (2.31 m)	10,760 lb (4,880 kg)

Combat use

Large numbers of Lend-Lease Studebaker trucks were sent into the Soviet Union via the Persian Corridor. The Soviets found them a good platform for "Stalin Organ" Katyusha rocket launchers, although it was not their prime use in the Soviet Union. It fulfilled many roles in the Red Army, such as pulling artillery and was renowned for its ruggedness and reliability. The truck was affectionately known as the Studer by Soviet troops.

Studebaker US6 trucks were also used in the construction of the Burma Road as well as the Alcan Highway in North America.

Gallery

• Military Vehicles (2621947332).jpg

  Cargo with long bed
  (Privately restored)

• Bundesarchiv Bild 204-018, Berlin, Henryk Gorovits neben russischem LKW.jpg

  Cargo with short bed
  (Berlin, 1945)

• G-630 Tractor Studebaker US6-U6 H-384605 pic1.JPG

  Semi tractor-trailer
  (Museum exhibit)

• 

  Semi tractor-trailers
  (Persian Corridor, 1943)

• BM-13 RB2.jpg

  Katyusha launcher
  (Museum exhibit)

• 

  Katyusha battery firing
  (Stalingrad, 1942)

See also

• G-numbers
• List of U.S. military vehicles by supply catalog designation
• List of U.S. military vehicles by model number
• GMC CCKW

External links

• Studebaker/Reo US6 2.5 Ton Cargo Truck images and details
• Australian Studebakers US6
• US 2.5-ton 6x6 Trucks in World War II
• Studebaker/Reo US6 at The-Bluprints.com