GMC Engineer Shop Truck

In another article on this website, I wrote about the GMC Shop Trucks with the ST-5 and ST-6 bodies. There were a lot of models with different purposes for specific tasks built. Besides these mentioned vehicles other Shop Trucks were built. One of these is the GMC Engineer Shop Truck. A complete and very detailed description of this vehicle is depicted in the Technical Manual TM 5-9352 titled "Shop, Engineer, Motorized, General Purpose, Repair" from February 1944.
In TM 9-2800 from 1943, the following presentation of this vehicle is given. An unaltered page was committed to this vehicle in TM 9-2800 from 1947. So it's safe to assume that these Shop Trucks served unaltered during the later war years.
The General Purpose shop truck was designed for repair and maintenance work in both operating organizations and higher echelon maintenance organizations. In general Engineer organizations, it ordinarily operated in the Headquarters and Service Company as the center ol' second echelon organizational maintenance. When issued to general Engineer organizations, it was frequently accompanied by the trailer-mounted set of electric arc welding equipment. This set supplemented the oxyacetylene welding equipment furnished on the General Purpose shop itself. In Engineer maintenance companies or Engineer heavy shop companies, the shop functioned as a third and fourth echelon job-site repair unit.
The General Purpose shop truck often operated in conjunction with the following other motorized shops of the Engineer maintenance company:

- Shop, Motorized, Tool and Bench. This shop provided general repair facilities of the type normally found in well equipped commercial repair establishments. It had the widest variety of hand and power tools of any of the Engineer motorized shops. Its equipment included a valve-refacing and valve seat grinder and required accessories, a 1-ton capacity differential chain hoist, a 100-ton hydraulic press, a diesel injector repair set, a complete group of pulling and extracting tools, a tractor maintenance set, valve and piston service tools, babbitting equipment, battery servicing tools, radiator test and repair sets, and a chain saw sharpener.

- Shop, Motorized, Welding. This shop had both electric arc and gas welding facilities, and was designed to accomplish welding operations on location. It was equipped with a 300-amp gasoline engine driven welder with a 3-kw auxiliary generator, a 27-piece oxyacetylene welding and cutting set, a large assortment of electrodes, a blacksmith forge with shovel, a 100-lb anvil, and other blacksmith accessories.

- Shop, Motorized, Electrical Repair. This shop provided facilities required for the repair of searchlights, searchlight power plants, control stations, electric generators and other items of electrical equipment. It contained most of the equipment of the General Purpose shop truck, except that it lacked the bench grinder. It had, in addition, a universal vulcanizing set containing 517 items, a set of electrical measuring instruments (ammeter, millivolt-meter, AC-DC test unit, growler, megohmmeter and low voltage circuit tester), soldering copper, a grease gun, and other materials required for electrical repair work.

- Shop, Motorized, Emergency Repair. This shop had a limited assortment of power tools, a 3/4-inch heavy-duty drill, a portable grinder, a 1-1/2 kw generator, and hand tools.

- Shop, Motorized, Machine Shop. Light. This shop provided machine shop facilities, including a 10-inch lathe, a 16-inch floor-type drill press, a 7-inch bench shaper, a 1/2-inch drill, a 7-inch bench grinder, a lathe grinder, a 5 x 5-inch capacity power hack saw, and a universal dial test indicator.

- Shop, Motorized,Machine Shop, Heavy. This shop was capable of heavier machine tool operations than the Light Machine shop, being equipped with a 14-inch lathe, a tool post grinder, an 18-inch swing, 1-inch capacity floor-type drill press, a brake reliner and a cylinder boring bar.

- Shop, Motorized, Small Tool Repair. This shop was designed for the repair of portable gasoline and pneumatic-powered tools such as the gasoline chain saw, the gasoline hammer and the tools furnished on the motorized air compressor. It was fundamentally different from all other shops in that it was equipped with pneumatic power, which gave it wide adaptability, including greater reliability of operation under extremely wet conditions. It had a pneumatic drill, a pneumatic grinder, a 32-piece pneumatic tool set, a 10-ton hydraulic press, and a 60-cfm air compressor.

Both open and closed cabin versions of this vehicle. The closed cab was until july 1943 the only version as the TM 9-2800 from 1943 states that the open cab versions were supplied after July 1943. So later in the war both versions could be deployed.

Above the vehicle is shown from different sides. The above pictures show the vehicle with the canvas cover rigged for travel.

Above the Engineer Shop, Motorized, General Purpose with its top removed to show location of tools and accessories. (1) Tool set. carburetor service. (2) 3-kw generator set. (3) Tool set, ignition. (4) Pump of hydraulic press. (5) Ram and frame of hydraulic press. (G) Drill on drill stand. (7) Work bench. (8) Drill, electric. (9) Grinder, bench. (10) Tap and die set. (11) Grinder, portable. (12) Floodlight. (13) Trouble lights. (14) Stove. (15) Tool set. master mechanic. (16) Valve lifter and compressor. (17) Welding and brazing rod. (18) Flux, brazing. (19) Torch, gasoline. (20) Cylinder, oxygen. (21) Lathe. (22) Gas welding hose.

Above the layout of the Engineer motorized General Purpose shop truck. The 100-ton press was supplied only when the shop was issued to certain aviation battalions and other specified organizations.

Inside right side view of shop withe the cancas cover extended for use in the field.

Interior view of shop partially packed. Packing box for tools and supplies showing use of compartmentsand wood block brace for generator tank. Protective caps on oxygen tanks.

Below rhe vehicle is shown with the bumper mounted derrick.

The manual gives us the following information: Derrick, Bumper-Mounting, Cable-Operated, 5-Ton. The 5-ton A-frame derrick is mounted on the bumper. It is powered by a drum-type standard winch permanently mounted on the front of the truck. Anchor Bracket. When the shop is delivered. all the derrick parts shown in the picture below are stored in the body.

Derrick assembly parts. (1) Booms. (2) Stilfenor plates. (3) and (4) Bolts. (5) Legs (Jacks). (6) Guy wire. (7) Pin and cotter for sheave. (8) Sheave block. (9) Sheave pin and locking device. (10) Anchor brackets. (11) Bolts for boom.

Assembly of anchor bracket and jacks.

Assembly of sheave block.

Fastening the guy line.

The first picture shows the vehicle with a light load. The second with the derrick secured for travel.

For overseas shipment the truck body was secured with a wooden structure seen below. In these pictures this structure is clearly visible. Also a complete drawing from the manual is provided.

Last but not least a gallery with pictures from a restored vehicle can be found here.