Studebaker US6

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

Studebaker US6
Type  2 1⁄2-ton 6x6 trucks and
5-ton 6x4 trucks
Place of origin United States of America
Production history
Designer Studebaker
Manufacturer Studebaker and REO
Produced 1941 to 1945
Number built More than 200,000
Specifications (U1 Cargo[1])
Weight 9,875 lb (4,479 kg) empty
Length 20 ft 11 in (6.38 m)
Width 7 ft 4 in (2.24 m)
Height 7 ft 3 in (2.21 m) top of cab
8 ft 10 in (2.69 m) overall
Engine Hercules JXD
Transmission 5 spd. x 2 range trf. case
Suspension Beam axles on leaf springs
Operational
range
 236 mi (379.8 km)
Speed 45 mph (72 km/h)

The Studebaker US6 (G630) was a series of 2½-ton 6x6 and 5-ton 6x4 trucks manufactured by the Studebaker Corporation and REO Motor Car Company during World War II. The basic cargo version was designed to transport a 5,000 lb (2,300 kg) cargo load (12 ft (3.7 m) long) over all types of terrain in all kinds of weather. Most of these were exported to the Soviet Union under Lend-Lease by the USA during World War II.

History

In 1939, the US Army Ordnance Corps created a set of standards for a 6×6 truck with a  2 1⁄2-ton (2,238kg) off-road payload. Studebaker, Yellow Coach (a GM company) and International Harvester all submitted designs that were accepted shortly afterwards and in went into production by 1941.

The US6 was manufactured primarily for export under Lend-Lease, of which the Soviet Union would become the largest foreign operator. Production first began at Studebaker's plant in South Bend, Indiana, in June 1941, and in 1944, REO's plant in Lansing, Michigan, would also begin producing them.

The first Studebaker US6 trucks arrived in USSR in the autumn of 1941. The Soviet Red Army organized a test of eleven 6x6 "Studebekkers" (as they become referred to in the USSR) which took place between July 1942 and May 1943. The results were used to direct the enlargement of the payload from  2 1⁄2 tons (2,300kg) to 4 tons (3,600kg).[2] In 1945, it was lowered to  3 1⁄2 tons (3,200kg, although on improved roads they could carry up to a maximum of 5 tons (4,500kg).

A total of 219,882  2 1⁄2-ton (2,268 kg) 6x6 trucks and similar 5-ton (4,536 kg) 6x4 versions in thirteen variations were built. Studebaker was the primary manufacturer, which built 197,678 of them, while REO produced 22,204 more under a sub-contract. REO trucks are identical to Studebakers, but REO only built US6 cargo-model trucks with the long wheelbase and without the frontally-mounted winch, more specifically referred to as the US6 U9.[3][4]

Specifications

Engine and driveline

Hercules JXD engine
Dump truck w/winch shift patterns
Long wheelbase frame

The US6 used a Hercules JXD engine, with an 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-type and highly-reliable engine with a compression ratio of only 5.82:1, it could use 72-octane gasoline. This same engine was also used in the M3 half-tracks and, later, M8 Greyhound and M20 armoured cars (the latter was a variant (lacking the gun turret) of the M8 Greyhound).[5][3][4][6]

The Warner T 93 5 speed transmission had a very low first, a direct fourth and an overdrive fifth gear. A power take-off could be fitted to operate a winch (mounted just below in front of the radiator) and/or the hydraulic hoist on dump trucks (the U10/U11 and U12/U13 dump truck models).[7]

The Timken T-79 transfer case had high and low ranges, a neutral position and could either engage or disengage the front axle. There was one output shaft mounted forward to the front axle (not used in 6x4 trucks) and two to the rear, with one for each rear axle.[8]

Both front and rear axles were of the Timken split-type with a ratio of 6.6:1. The front axle had ball-type constant-velocity joints while the two at the rear were full-floating.[9]

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.[10][11]

There were two wheelbases, the short 148 inches (3.76 m), used in semi tractors, dump trucks, and short cargo models, and the long 162 inches (4.11 m), used in tankers, long cargo models, and the U9 chassis cab (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.[4] [12]

Cab

The US6 carried the design of Studebaker’s civilian truck cab, although it was modified for military use. Studebaker trucks were unique from other  2 1⁄2 6x6 trucks built for the war effort of the USA because vent windows were included in each door. These vent windows were separate from the main window that rolled down into the door-frame and could be swung out to help with the truck cab's ventilation.

Studebaker also designed the open-type military truck cab which was featured on the GMC CCKW (later models), but their major customer, the USSR, preferred the closed cab for their generally harsh (cold-weather) climate. While Studebaker's open-type truck cab became the American standard, production of the US6 with the closed-type truck cab was restarted after only 10,000 units of the former.[4]

Models

The U1 and the U2 cargo trucks (which had a frontally-mounted winch) had a short wheelbase and the spare tire was mounted behind the cab, thus allowing a truck-bed measuring only 9 ft (2.74 m) long. These “prime mover”-style bodies were not a success as the US6 was to be mainly used for transporting cargo.[3]

The U3/U4 and the 6x4 U7/U8 cargo trucks had a longer wheelbase, which allowed the spare tire to be mounted under the12 ft (3.66 m) truck-bed. 197,000 trucks with the 12 ft (3.66 m) truck-bed were built.[3]

The U5 tanker truck had a long wheelbase and a two-compartment 750 U.S. gal (2,800 l) tank mounted on the truck-bed. Tanker trucks were not equipped with winches.[3]

The 6x4 U6 semi-tractor was the only semi-tractor version in the entire US6 truck series. Semi-tractors have limited off-road performance and, therefore, the U6 was rated for a 5-ton load on improved roads. For this same reason, they had no frontally-mounted winch.

The U9 cargo truck had a long wheelbase and lacked a frontally-mounted winch. The Soviet Katyusha multiple rocket launcher could be mounted on their truck-beds (most of the US6 trucks in Soviet Red Army service were of the U9 model).

The U10/U11 (end-type) and the U12/U13 (side-type) dump trucks had a short wheelbase. Both types had the dump-body mounted on a sub-frame at the rear of the truck, with the end-type dump having a hydraulic cylinder attached to the chassis with a lever arrangement while the side-type dump had the hydraulic cylinder mounted directly to the truck body.[13]

Dimensions

Model[12] Wheelbase Length[lower-alpha 1] Width Height Weight empty[lower-alpha 2]
U1 Cargo
(U2 with winch)		 Short 20 ft 11 in (6.38 m) 7 ft 4 in (2.24 m) 8 ft 10 in (2.69 m)[lower-alpha 3] 9,875 lb (4,479 kg)
U3 Cargo (long)
(U4 with winch) 		Long 27 ft 11 in (8.51 m) 7 ft 4 in (2.24 m) 8 ft 10 in (2.69 m)[lower-alpha 3]
U5 Tanker [14] Long 20 ft 11 in (6.38 m) 7 ft 4 in (2.24 m) 7 ft 3 in (2.21 m) [lower-alpha 4] 10,585 lb (4,801 kg)
U6 Tractor Short
(6x4) 		17 ft 3 in (5.26 m) 7 ft 3 in (2.21 m) 7 ft 2 in (2.18 m)[lower-alpha 4] 8,190 lb (3,710 kg)
U7 Cargo (long)
(U8 with winch) 		Long
(6x4) 		27 ft 11 in (8.51 m) 7 ft 4 in (2.24 m) 8 ft 10 in (2.69 m)[lower-alpha 3]
U9 Cab/chassis Long 7 ft 3 in (2.21 m) 7 ft 3 in (2.21 m)[lower-alpha 4]
U10 End dump
(U11 with winch) 		Short 18 ft 9 in (5.72 m) 7 ft 4 in (2.24 m) 7 ft 7 in (2.31 m)[lower-alpha 5] 10,150 lb (4,600 kg)
U12 Side dump
(U13 with winch) 		Short 18 ft 11 in (5.77 m) 7 ft 4 in (2.24 m) 7 ft 7 in (2.31 m)[lower-alpha 5] 10,150 lb (4,600 kg)
  1. ↑ With winch add 1 ft 3 in (0.38 m).
  2. ↑ With winch add 610 lb (280 kg).
  3. 1 2 3 To cargo area tarpaulin bows.
  4. 1 2 3 To top of cab.
  5. 1 2 To top of dump body cab shield.

Combat use

Large numbers of Studebaker US6 trucks were supplied to the Soviet Union via the Persian Corridor in Iran under the USA's Lend-Lease programme. The Soviet Red Army found them to be a suitable mobile-type platform for conversion into Katyusha rocket launchers (more popularly known as "Stalin's Organ") but this was not intended to be their main use in the USSR. Instead, the truck fulfilled many more strategic and important roles for the Soviet Red Army, such as towing artillery pieces and anti-tank guns and transporting troops over long distances and was renowned for its overall ruggedness and reliability (such as being able to run on poor-quality fuel that was available to the Soviet Red Army, which did not have great access to much higher-quality fuels). The truck became affectionately known as the Studer by Soviet troops and was even recognised by Joseph Stalin (the leader of the Soviet Union at that time), who sent a letter of appreciation to Studebaker, in which he thanked them for the superb quality of the US6 for Soviet service. Later on, after WWII, the USSR also copied the design of the Studebaker US6 into the ZiL-151, which, in turn, was replaced by the ZiL-157.

Studebaker US6 trucks were also used by the US military in the construction of the Burma Road (being used for logistics transport on the Burma Road too) as well as on the Alcan Highway in North America.

See also

Notes

References

External links

Wikimedia Commons has media related to Studebaker US6.
This article is issued from Wikipedia - version of the 12/5/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.