Studebaker US6 2½-ton 6×6 truck

{{Short description|American exported military cargo vehicle}} {{Redirect|US6|the road|U.S. Route 6}} {{Infobox weapon |name=Studebaker US6 |image=Studebaker US.jpg |image_size=300 |caption=Studebaker US6 U4 Cargo truck |origin=[[Studebaker#Studebaker Factories|Studebaker Automotive Plant]], [[South Bend, Indiana]], US [[Studebaker#Chippewa Factory|Studebaker Chippewa Ave. Assembly]], [[South Bend, Indiana]], US |type={{frac|2|1|2}}-ton 6×6 trucks and 5-ton 6×4 trucks  |is_vehicle=yes  |designer=Studebaker |design_date=Before 1940 |manufacturer=[[Studebaker]] and [[REO Motor Car Company|REO]] |production_date=1941–1945 |number=219,882, almost 90% by Studebaker |variants=  |spec_label=U1 Cargo{{sfnp|TM 9-807|1943|pp=14–16, 138}} |weight={{cvt|9875|lb}} empty |length={{cvt|20|ft|11|in|m|2}} |width={{cvt|7|ft|4|in|m|2}} |height={{cvt|7|ft|3|in|m|2}} top of cab {{cvt|8|ft|10|in|m|2}} overall  |engine=Hercules JXD inline-6 gasoline motor |engine_power={{cvt|86|hp}} |transmission=5 speed × 2 range transfer case |suspension=Beam axles on leaf springs |vehicle_range={{cvt|236|mi}} |speed={{cvt|45|mph}} }}

The '''Studebaker US6''' [[List of U.S. military vehicles by supply catalog designation#G500 to G599|(G630)]] was a series of [[2 1/2-ton 6×6 truck|{{frac|2|1|2}}-ton 6×6]] and 5-ton 6×4 trucks manufactured by the [[Studebaker|Studebaker Corporation]] and [[REO Motor Car Company]] during [[World War II]]. The basic cargo version was designed to transport a {{cvt|2+1/2|ST|lb kg|adj=on}} cargo load over any type of terrain in any weather. Most of these were exported to the [[Soviet Union]] under [[Lend-Lease]] by the US during World War II, since the competing [[GMC CCKW 2½-ton 6×6 truck|GMC 6×6 CCKW]] design proved to be more suitable for [[Western Front (World War II)|Western Front]] conditions.

==History== ===Design and development=== In 1939–1940, the [[United States Army Ordnance Corps|US Army Ordnance Corps]] was developing {{cvt|2+1/2|ST|kg|adj=on}} tactical [[Six-wheel drive|6×6]] trucks that could operate off-road in all weather. Studebaker, [[Yellow Coach Manufacturing Company|Yellow Coach]] (a [[General Motors|GM]] company) and [[International Harvester]] all submitted designs that were accepted and went into production in 1941.

More than 200,000 {{frac|2|1|2}}-ton 6×6 trucks and similar {{cvt|5|ST|kg|adj=on}} 6×4 versions in 13 variations were built. Studebaker was the primary manufacturer, which built 197,678 of them at its South Bend, Indiana plant, while REO produced 22,204 more at its Lansing, Michigan plant from 1944 under a sub-contract. Reo trucks are identical to Studebakers, but Reo built only cargo-model trucks with the long wheelbase and without the front-mounted winch, more specifically referred to as the US6 U9. All production by both manufacturers ended in 1945.{{sfnp|Crismon|2001|p=184, 328-329}}{{sfnp|Doyle|2003|pp=122–124}}

===Service=== The US6 was manufactured primarily for export under [[Lend-Lease]]. The Soviet Union would become the largest foreign operator. The first Studebaker US6 trucks arrived in the USSR in the autumn of 1941. The [[Red Army]] organized a test of eleven 6×6 US6 trucks which took place between July 1942 and May 1943. The results were used to direct the enlargement of the payload from {{cvt|2+1/2|to|4|ST|kg}}.{{sfnp|Jeghers|2000|pp=18-19}} In 1945, it was lowered to {{cvt|3+1/2|ST|kg}}, although on improved roads they could carry up to a maximum of {{cvt|5|ST|kg}}.

Large numbers of Studebaker US6 trucks were supplied to the Soviet Union via the [[Persian Corridor]] in Iran under the US's [[Lend-Lease]] program.{{cn|date=April 2024}} The truck fulfilled many important roles in service with Soviet military forces during the war, such as towing artillery pieces and anti-tank guns and transporting troops over long distances. It was renowned for its overall ruggedness and reliability, including its ability to run on poor-quality fuel. The Soviet [[Red Army]] also found them to be a suitable platform for conversion into [[Katyusha rocket launcher]]s, although this was not their main purpose. The truck became affectionately known as the ''Studer'' by Soviet troops and was even recognized of its importance (to the Soviet war effort) by [[Joseph Stalin]], who sent a personal letter of appreciation to Studebaker, in which he thanked it for the superb quality of the US6 for Soviet service.{{cn|date=April 2024}}

Studebaker US6 trucks were also used by the US military in the construction of the [[Ledo Road]] in Burma, and the [[Alaska Highway|Alcan Highway]] in North America, during WWII.{{cn|date=April 2024}}

==Specifications== ===Engine and driveline=== [[File:Hercules_JXD_engine_right.jpg|thumb|right|Hercules JXD engine]] [[File:Stude US6 shift patterns.jpg|thumb|Dump truck w/winch shift patterns]] [[File:Stude US6 frame.jpg|thumb|Long wheelbase frame]] The US6 used a Hercules JXD engine, with a {{cvt|320|cuin|L|1}} [[Flathead engine|L-head]] [[Straight six engine|inline 6 cylinder]] [[Petrol engine|gasoline engine]] developing {{cvt|86|hp}} at 2,800 rpm and {{convert|200|lbft|0|abbr=on}} of [[torque]] at 1,150 rpm. A conservative-type and highly-reliable engine with a compression ratio of only 5.82:1, it could use 68-octane gasoline. This same engine was also used in the M3 Scout Car and, later, [[M8 Greyhound]] and M20 armoured cars (the latter was a variant (lacking the gun turret) of the M8 Greyhound).{{sfnp|TM 9-807|1943|pp=138–139}}{{sfnp|Crismon|2001|p=184, 328-329}}{{sfnp|Doyle|2003|pp=122–124}}{{sfnp|TM 9-2800|1947}}

The [[BorgWarner|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.{{efn|More specifically, the U10/U11 and U12/U13 dump truck models.}}{{sfnp|TM 9-1807|1944|pp=22-23}}

The [[Timken Company|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 6×4 trucks) and two to the rear, with one for each rear axle.{{sfnp|TM 9-1807|1944|pp=43–44}}

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.{{sfnp|TM 9-1807|1944|pp=84–87, 127–129}}

===Chassis=== The US6 had a [[Vehicle frame#Ladder Frame|ladder frame]] with three [[beam axle]]s, the front on semi elliptical [[leaf spring]]s, the rear tandem on quarter elliptical leaf springs with locating arms.{{sfnp|TM 9-807|1943|pp=289-290}}{{sfnp|TM 9-1807|1944|pp=177-179}}

There were two wheelbases, the short {{convert|148|in|m|2}}, used in semi tractors, dump trucks, and short cargo models, and the long {{convert|162|in|m|2}}, used in tankers, long cargo models, and the U9 chassis cab.{{efn|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. 6×4 models, intended for on-road use only, were rated at {{convert|5|ST|kg}}, twice the 6×6's off-road rating.{{sfnp|Doyle|2003|pp=122–124}}{{sfnp|TM 9-807|1943|p=14}}

===Cab=== The US6 carried the design of Studebaker's [[Studebaker M-series truck|M series]] civilian truck cab, although it was modified for military use. Studebaker trucks were different from other {{frac|2|1|2}} 6×6 trucks built for the war effort of the UA because [[Quarter glass|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.{{sfnp|Doyle|2003|pp=122–124}}

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 {{cvt|9|ft|m|2}} long. These "prime mover"-style bodies were not a success as the US6 was to be mainly used for transporting cargo.{{sfnp|Crismon|2001|p=184, 328-329}}

The '''U3/U4''' and the 6×4 '''U7/U8''' cargo trucks had a longer wheelbase, which allowed the spare tire to be mounted under the {{cvt|12|ft|m|2}} truck-bed. 197,000 trucks with the {{cvt|12|ft|m|2}} truck-bed were built.{{sfnp|Crismon|2001|p=184, 328-329}}

The '''U5''' tank truck had a long wheelbase and a two-compartment {{cvt|750|u.s.gal|L}} tank mounted on the truck-bed. Tanker trucks were not equipped with winches.{{sfnp|Crismon|2001|p=184, 328-329}}

The 6×4 '''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 {{cn span|date=April 2024|(most of the US6 trucks in 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.{{sfnp|TM 9-1807|1944|pp=211-216}}

==Dimensions== {| class="wikitable" |- ! style="width: 110px;"|Model{{sfnp|TM 9-807|1943|p=14}} !! style="width: 60px;"|Wheelbase !! style="width: 70px;"|Length{{refn|group=lower-alpha|name=lww|With winch, add {{cvt|1|ft|3|in|m|2}}.}} !! style="width: 60px;"|Width !! style="width: 70px;"|Height !! Weight empty{{refn|group=lower-alpha|name=www|With winch, add {{cvt|610|lb}}.}} |- | U1 Cargo (U2 with winch) || Short || {{cvt|20|ft|11|in|m|2}} || {{cvt|7|ft|4|in|m|2}} || {{cvt|8|ft|10|in|m|2}}{{refn|group=lower-alpha|name=bow|To cargo area tarpaulin bows.}} || {{cvt|9875|lb}} |- | U3 Cargo (long) (U4 with winch) || Long || {{cvt|27|ft|11|in|m|2}} || {{cvt|7|ft|4|in|m|2}} || {{cvt|8|ft|10|in|m|2}}{{refn|group=lower-alpha|name=bow}} || |- | U5 Tank {{sfnp|TM 9-2800|1947|p=280}} || Long || {{cvt|20|ft|11|in|m|2}} || {{cvt|7|ft|4|in|m|2}} || {{cvt|7|ft|3|in|m|2}} {{refn|group=lower-alpha|name=cab|To top of cab.}} || {{cvt|10585|lb}} |- | U6 Tractor || Short (6×4) || {{cvt|17|ft|3|in|m|2}} || {{cvt|7|ft|3|in|m|2}} || {{cvt|7|ft|2|in|m|2}}{{refn|group=lower-alpha|name=cab}} || {{cvt|8190|lb}} |- | U7 Cargo (long) (U8 with winch) || Long (6×4) || {{cvt|27|ft|11|in|m|2}} || {{cvt|7|ft|4|in|m|2}} || {{cvt|8|ft|10|in|m|2}}{{refn|group=lower-alpha|name=bow}} || |- | U9 Cab/chassis || Long || || {{cvt|7|ft|3|in|m|2}} || {{cvt|7|ft|3|in|m|2}}{{refn|group=lower-alpha|name=cab}} || |- | U10 End dump (U11 with winch) || Short || {{cvt|18|ft|9|in|m|2}} || {{cvt|7|ft|4|in|m|2}} || {{cvt|7|ft|7|in|m|2}}{{refn|group=lower-alpha|name=shield|To top of dump body cab shield.}} || {{cvt|10150|lb}} |- | U12 Side dump (U13 with winch) || Short || {{cvt|18|ft|11|in|m|2}} || {{cvt|7|ft|4|in|m|2}} || {{cvt|7|ft|7|in|m|2}}{{refn|group=lower-alpha|name=shield}} || {{cvt|10150|lb}} |} {{reflist|group=lower-alpha|2}}

<gallery mode="packed"> File:Military Vehicles (2621947332).jpg|Cargo truck (Privately owned and fully restored) File:Bundesarchiv Bild 204-018, Berlin, Henryk Gorovits neben russischem LKW.jpg|Cargo truck (in Berlin, May 1945) File:Studebaker US6 in Techical museum Togliatti.JPG|Cargo truck (Museum exhibit) File:G-630 Tractor Studebaker US6-U6 H-384605 pic1.JPG|Tractor-semitrailer (Museum exhibit) File:Near East Iran - truck convoy of US supplies for USSR - NARA - 195340.jpg|Tractor-semitrailers (along the Persian Corridor, some time in 1943) File:Verkhnyaya Pyshma Tank Museum 2011 029.jpg|Katyusha mobile-type multiple rocket launcher (Museum exhibit) File:RIAN archive 303890 A battery of Katyusha during the 1941-1945 Great Patriotic War.jpg|A battery of Katyusha MRLS firing (at Stalingrad, some time in 1942) </gallery>

==Legacy== [[File:GAZ-51 during the VII Aircraft Picnic in Kraków.jpg|right|thumb|A GAZ-51 truck]] Some Studebaker US6 trucks that were shipped to the [[Soviet Union]] during WWII were used by [[GAZ]] to study and built their own new post-war model based on it, the [[GAZ-51]] truck, which would use the cab and front end of the Studebaker model, albeit in a slightly modified form.<ref name="[41]">{{cite web|title=drakony-s-zdanovich-a-m-gaz-51-osobennosti-raboty-dvigatelya|url=https://marshalinstrument.ru/en/kpp/drakony-s-zdanovich-a-m-gaz-51-osobennosti-raboty-dvigatelya/|access-date=2021-08-19}}</ref> This truck would eventually undergo [[mass production]] in 1946. The construction of the Studebaker US6 also strongly influenced the construction of the postwar [[ZIS-151]] truck, which then evolved into the [[ZIL-157]] truck and remained in production up until 1994.

The Studebaker US6 truck became a legendary vehicle with its Soviet operators at the time and was called the "King of Roads" by soldiers<ref name="[48]">{{cite web|title=Studebaker US6, US6x4. REO co-produced U3 modification in 1944–1945.|url=http://www.autogallery.org.ru/gstuder.htm|access-date=2021-08-19}}</ref> due to their reliability and dependability, and is still popular in Russian vehicle-collector circles and clubs. In the [[United States]], these trucks are seen as the symbol for the [[Lend-Lease]] program to the USSR.<ref name="[69]">{{cite web |title=Studebaker US6|url=https://icm.com.ua/technique/studebaker-us6/|access-date=2021-08-19}}</ref> <!--''Dubious utility for a wiki article''

It is estimated that an unrestored US6 truck would cost around $11,000, while a restored one would cost around $24,000.<ref name="[82]">{{cite web|title=Buyer's Guide: WWII Studebaker & Reo US6 Trucks|date=2020-07-13|url=https://www.militarytrader.com/military-vehicles/hmv-buyers-guide-studebaker-reo-us6-trucks|access-date=2021-08-19}}</ref>

''The source only says that approximately 20,000 units were built by Reo, not that they are the "most sought-after US6 trucks".''

The most sought-after US6 trucks are the ones that were produced by [[REO Motor Car Company|REO Motors]] (U9 version), since only slightly over 20,000 units were built by them.<ref name="[98]">{{cite web|title=Studebaker US6: The Lend-Lease 'Deuce and a Half'|date=March 2012|url=https://www.historynet.com/studebaker-us6-the-lend-lease-deuce-and-a-half.htm|access-date=2021-08-19}}</ref>-->

==See also== *[[List of the United States military vehicles by supply catalog designation]] *[[List of the United States military vehicles by model number]] *[[GMC CCKW 2½-ton 6×6 truck|GMC CCKW {{frac|2|1|2}}-ton 6×6 truck]]

==Notes== {{reflist|2}}

==References== *{{cite book|last=Crismon|first=Fred W|title=US Military Wheeled Vehicles|edition=3|year=2001|publisher=Victory WWII Pub.|isbn=0-970056-71-0}} *{{cite book|last=Doyle|first=David|title=Standard catalog of U.S. Military Vehicles|year=2003|publisher=[[Krause Publications]]|isbn=0-87349-508-X}} *{{cite book|last=Jeghers|title=EV Cars Lend-Lease|year=2000|publisher=Tornado}} *{{cite web|url=https://archive.org/details/TM9-807|title=TM 9-807 2 1/2-ton 6×6 Truck and 2 1/2 to 5-ton 6×4 truck (Studebaker US6 and US6×4)|publisher=US War Dept.|date=1943|access-date=2016-02-24|ref={{harvid|TM 9-807|1943}} }} *{{cite web|url=https://sd3624203692.files.wordpress.com/2019/06/tm9-1807-stude-us6-maint.pdf|title=TM 9-1807 Power Train, Chassis, and Body for 2 1/2 ton 6×6 Truck and 2 1/2 to 5-ton 6×4 Truck (Studebaker US6 and US6×4)|publisher=US War Dept.|date=1944|access-date=2019-09-25|ref={{harvid|TM 9-1807|1944}} }} *{{cite web|url=https://sd3624203692.files.wordpress.com/2019/06/tm9-2800-veh-47.pdf|title=TM 9-2800 Military Vehicles|publisher=US Dept. of the Army|date=1947|access-date=2019-09-25|ref={{harvid|TM 9-2800|1947}} }}

==External links== {{commons|Studebaker US6}} *{{cite web|url=http://www.oldcmp.net/us6.html|title=Studebaker US6|website=oldcmp.net|url-status=dead|archive-url=https://web.archive.org/web/20120522004931/http://www.oldcmp.net/us6.html|archive-date=2012-05-22}} *{{cite web|url=http://www.o5m6.de/ForeignTrucks.html#SoftUS_2_5|title=Engines of the Red Army in WW2|website=o5m5.de|archive-url=https://web.archive.org/web/20161220201818/http://www.o5m6.de/ForeignTrucks.html#SoftUS_2_5|archive-date=2016-12-20}} *{{cite web|url=http://www.olive-drab.com/idphoto/id_photos_us6.php|title=Studebaker / Reo US6 2 1/2 Ton Cargo Truck|website=olive-drab.com|archive-url=https://web.archive.org/web/20160329200909/http://www.olive-drab.com/idphoto/id_photos_us6.php|archive-date=2016-03-29}}

{{DEFAULTSORT:Studebaker US6 2½-ton 6x6 truck}} [[Category:Studebaker vehicles|US6]] [[Category:Military trucks of the United States]] [[Category:World War II vehicles of the United States]] [[Category:World War II vehicles of the Soviet Union]] [[Category:World War II vehicles]] [[Category:Military vehicles introduced from 1940 to 1944]] [[Category:Lend-Lease in the Soviet Union]]