GMC CCKW

This article is about the original World War II "Deuce-and-a-half". For its successor, see M35 2½-ton cargo truck.

CCKW
300px CCKW 353 cargo truck with winch
Type	​2 1⁄2 ton (2,268kg) 6×6 Cargo truck
Place of origin	United States
Production history
Manufacturer	Yellow Coach/GM Truck and Coach
Produced	1941-1945
Number built	562,750
Variants	See text
Specifications (353 Cargo w/winch)
Weight	8,800 lb (4,000 kg) empty 16,400 lb (7,400 kg) loaded
Length
Width	88 in (2.24 m)
Height	93 in (2.36 m) to cab overall
Engine	GMC 270 91 hp (68 kW)
Transmission	5 spd. x 2 range trf. case
Suspension	Beam axles on leaf springs
Fuel capacity	40 US gal (150 L)
Operational range	300 mi (482.8 km)
Speed	45 mph (72 km/h)

Thе GMC CCKW was 2½-ton 6x6 U.S. Army cargo truck that saw heavy service in both World War II and the Korean War. The original "Deuce and a Half", it formed the backbone of the famed Red Ball Express that kept Allied armies supplied as they pushed eastward after the Normandy invasion.

The CCKW came in many variants, including open or closed cab, long wheel base (LWB 353) and short (SWB 352), and over a score of specialized models. It began to be phased out with the deployment of the 6×6 M35 in 1950, but remained in active U.S. service until the mid-1960s.

History

File:GMC CCKW SWB 6x6 Truck.jpg

CCKW 352 prime mover

File:Convoy Red Ball Express.jpg

CCKWs in a Red Ball Express convoy, 1944

Development

In 1940, the US Army set a requirement for a 6×6 truck with a 12 ft (3.7 m) cargo area and a 2½ ton (2,268 kg) off-road payload. General Motors, already supplying modified commercial trucks to the Army, modified the 1939 ACKWX-built for the French Army-into the CCKW. The General Motors design was chosen by the Army and went into production at GM'S Yellow Truck and Coach division's Pontiac, Michigan plant alongside 6×4 CCWs. Later they were also manufactured at GM's St. Louis, Missouri Chevrolet plant.

The name CCKW comes from GMC model nomenclature:

• "C", designed in 1941
• "C", conventional cab
• "K", all-wheel drive
• "W", dual rear axles

By the end of production in 1945, 562,750 CCKWs in all variants had been built, a total second only to the “Jeep”.

Specifications

Engine and driveline

The CCKW was equipped with the GMC 270 engine, an overhead valve I6 with 91 hp (68 kW) at 2750rpm and 216 lbf⋅ft (293 N⋅m) at 1400rpm. A bore by 4 in (102 mm) stroke gave a 269.5 cu in (4.4 L) displacement. This engine was designed for commercial trucks, and proved reliable in service.

The transmission was a Warner T93 5-speed with a direct 4th gear and overdrive 5th gear. The transfer case had high and low gears, and engaged the front axle. Originally all axles were a Timken split type, later trucks also used GM "banjo" types.

Chassis

The CCKW had a ladder frame chassis with three driven 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 short Model 352 and the long Model 353. The short, 145 in (368 cm) / 167 in (424 cm), was used with a short cargo bed as an artillery prime mover for 75mm and 105mm howitzers. All other models used the long, 164 in (417 cm) / 186 in (472 cm). Tires were 7.50-20, brakes were hydraulic with vacuum assist.

Some were fitted with 10,000 lb (4,500 kg) front-mounted winches. These used longer frame rails, and could be installed only at the factory, rather than in the field.

Some open cab chassis were cut in half behind the cab for air transport. Each half was a load, at the vehicle's destination, the halves were bolted back together.

Versions

File:GMC CCKW 750 Gal Tanker.jpg

Gasoline tanker (750 US gal (2,800 L))

File:G-508 GMC CCKW-353-B2 with m55 Machine-gun mount pic3.JPG

CCKW-353-B2 guntruck with M45 Quadmount on M20 trailer in bed, loading ramps attached to side

Initially, all versions used a modified commercial closed cab design having a metal roof and doors. By 1944 an open cab version, with a canvas roof and doors, was used. This was easier to build, and the roof could be removed to lower the shipping height. 1 in 4 open cabs had a machine gun mounting ring above the co-driver's position.

The CCKW provided a platform for the widest range of bodies on any U.S. military vehicle, with the 12 ft (3.7 m) cargo version being the most common. As steel was more heavily rationed during the course of the war, the steel cargo bed was replaced by a wooden one. Wooden beds proved unsatisfactory and a 'composite' bed with steel sides, framing, and wooden bottom slats was developed. However, the composite bed was still unsatisfactory and the bed design returned to all steel.

A rectangular van configuration was used in communications, medical, workshop, and many other specialty roles.

Specialized variants

Many specialized variants of the basic 6×6 CCKW were made, some in small numbers, including those converted in the field. These include:

• Short-wheelbase/long-wheelbase 2½-ton cargo truck
• Bomb Service
• Chemical decontaminating
• Chemical handling
• Dental Operating Van
• Dump
• Fire Engine
• Flatbed
• Fuel tanker (750 US gal (2,800 L))
• High lift
• K-53 Van
• K-60 Van
• Ordnance Maintenance Van
• Pipeline equipment
• Pontoon bolster
• Surgical Van
• Water purification truck
• Water tanker (700 US gal (2,600 L))
• Welder

CCW

The CCW, an on-road, 5-ton 6×4 truck version of the CCKW that lacked only its front wheel drive. A beam front axle was used, with the transfer case locked in high range.

AFKWX

GMC AFKWX-353 C.O.E. from WWII

The AFKWX 353, a cab over cargo bed version of the CCKW, went into production alongside it in 1942 at Yellow’s Pontiac plant and Chevrolet’s in St. Louis. Otherwise mechanically identical, its compact cabin design allowed a 15 ft (4.6 m), and later 17 ft (5.2 m) cargo bed to be fitted. The first 50 produced had closed cabs, all others were open. The cab over design made engine maintenance difficult. As a result, only 7235 were built, none with a front-mounted winch.

DUKW

DUKW in use by American troops in France

Main article: DUKW

The DUKW (“Duck”) was an amphibious truck that shared the CCKW's driveline. First produced at Yellow’s Pontiac plant, as demand increased production was added to Chevrolet’s St. Louis plant. The hull, designed by an America's Cup winner, had excellent sea-keeping abilities. A very successful design, 21,147 were built.

Gallery

• 

  80th Division crossing the Rhine near Mainz

• K-53 shop van.jpg

  Van with canvas roof and doors in place

• G-508 6x6 GMC CCKW-353-2 Air Compressor truck pic1.JPG

  Restored maintenance vehicle

• GMC Airportable3.JPG

  Restored two part chassis for air transport

• 

  GMC AFKWX-353 C.O.E

• 

  Restored CCKW 353 Cargo truck with open cab, machine gun ring, and front-mounted winch

See also

• List of U.S. military vehicles by supply catalog designation (G508)
• List of U.S. military vehicles by model number
• List of U.S. Signal Corps Vehicles
• DUKW
• General Motors
• M35 2½ ton cargo truck
• Chevrolet G506 trucks
• Studebaker US6
• 17th Armored Engineer Battalion

External links

• http://www.cckw.org/
• http://www.transchool.eustis.army.mil/Museum/ExhibitsIndex.htm
• http://www.olive-drab.com/idphoto/id_photos_cckw.php3
• GMC CCKW at U.S. Veterans Memorial Museum