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M19 Twin 40-mm Gun Motor Carriage

Diagram of the M19 Twin 40-mm Gun Motor Carriage, from Technical Manual TM 9-1729A, U.S. War Department, 1944.

M19 Twin 40-mm Gun Motor Carriage

 

GMC Trucks


 

155-mm Gun on Gun Motor Carriage M40

Two views of the U.S. 155-mm Gun on Gun Motor Carriage M40 from TM 9-350, the Technical Manual on the 155-mm Gun M2 printed in 1945.

155-mm Gun on Gun Mount M13 on Gun Motor Carriage M40 -- Side View

155-mm Gun on Gun Mount M13 on Gun Motor Carriage M40 -- Side View

155-mm Gun on Gun Mount M13 on Gun Motor Carriage M40 -- Rear View

155-mm Gun on Gun Mount M13 on Gun Motor Carriage M40 -- Rear View


 

M36B2 Tank Destroyer Rear Deck

Top view of the rear engine deck of the M36B2 tank destroyer from TM 9-745: 90-mm Gun Motor Carriage M36B2, War Department Technical Manual, July 1945:

M36 Tank Destroyer Rear Deck

A-GUN TRAVELING LOCK
B-LIFTING HOOKS
C-LEFT TAILLIGHT
D-ENGINE COMPARTMENT DOORS
E-ENGINE COMPARTMENT LEFT COVER PLATE
F-LEFT WATER EXPANSION TANK FILLER CAP COVER
G-LEFT FUEL TANK FILLER CAP COVER
H-FIRE EXTINGUISHER EXTERIOR PULL HANDLES
J-LEFT (LC) ENGINE LUBRICATING OIL TANK FILLER CAP COVER
 K-RIGHT (LA) ENGINE LUBRICATING OIL TANK FILLER CAP COVER
L-AUXILIARY GENERATOR FUEL TANK FILLER CAP COVER
M-RIGHT WATER EXPANSION TANK FILLER CAP COVER
N-RIGHT FUEL TANK FILLER CAP COVER
P-ENGINE COMPARTMENT RIGHT COVER PLATE
Q-ENGINE COMPARTMENT REAR COVER PLATE
R-RIGHT TAILLIGHT

 

Howitzer Motor Carriage M8

Schematic cutaway view of the 75-mm Howitzer Motor Carriage M8 from TM 9-732B: 75-mm Howitzer Motor Carriage M8, War Department Technical Manual, January 1944.

75-mm Howitzer Motor Carriage M8
 

Watch on the Rhine

The nine main causes for failures of U.S. Army GMC trucks were outlined on the back cover of Army Motors, Dec. 1944.

Watch on the Rhine -- GMC Truck Repair and Maintenance

THE 1ST ARMY POINTS OUT 9 THINGS TO
WATCH ON THE RHINE

… or anywhere else 2½-ton, 6×6 GMC’s are taking a beating. Whenever overloads are authorized, wherever long hauls or tough terrain are everyday stuff, you’ll do well to double-check these items the nine “main causes of failures” reported by the 1st Army from the Western Front.

1. CHECK VALVE CLEARANCES: INTAKE .012, EXHAUST .016

2. ADJUST CLUTCH-PEDAL FREE TRAVEL (TO 2½”)

3. KEEP FOOT OFF CLUTCH PEDAL EXCEPT TO START, SHIFT AND STOP

4. DON’T TOW WITH JUST A ROPE OR CHAIN. USE TOW BAR TO PREVENT FRONT-END DAMAGE TO TOWED VEHICLE

5. TIGHTEN RADIATOR HOLD-DOWN BOLTS

6. TIGHTEN TRANSFER CASE, TRANSMISSION & PILLOW-BLOCK MOUNTING BOLTS

7. TIGHTEN CAB HOLD-DOWN BOLTS

8. CLEAN & RE-OIL HYDROVAC AIR CLEANER

9. TIGHTEN BOLTS THAT HOLD BOGIE ASSEMBLY TO FRAME

ALL THIS—AND THE REST OF FORM 461, TOO!
 

Ordnance Assembly of Crated Trucks

Ordnance WW2 Mediterranean Theater Operations The following pictures of uncrating and assembly of GMC CCKW trucks appeared in Ordnance Activities in the Mediterranean Theater of Operations, November 1942 – June 1945 published by the Ordnance Department. The GMC CCKW 2½ ton 6×6 cargo truck was typically shipped in crates as shown below, and assembled by Ordnance personnel in theater.

Through North Africa, Sicily, and Italy, the Ordnance Service successfully supported the Allied forces as they slugged their way to victory in the MTO. In two and one half years of Ordnance Service in MTOUSA, the shops repaired 1,307,382 small arms; renovated 249,979 rounds of artillery ammunition; assembled 126,669 vehicles and did repair work on 341,048 vehicles of all types; repaired 247,242 pieces of artillery; and repaired 846,863 tires. Ordnance provided critical transportation throughout the theater, and the unpacking and assembly of crated trucks was a key part of that effort.

GMC CCKW 2½ ton Truck Crated WW2

This is how a 2½ ton truck is received in case you didn't know.

GMC CCKW 2 1/2 ton Truck Begins to Take Shape in WW2 Ordnance Center

A GMC begins to take shape.

WW2 Ordnance Final Assembly of GMC CCKW Truck

As the body goes onto the chassis, and after it has had a test run, another truck will be ready for issue to the using arms.

 

M40 and M43 Gun Motor Carriage

The 155-mm Gun Motor Carriage M40 and 8 in. Howitzer Motor Carriage M43 were self-propelled artillery vehicles based on major components of the medium tank M4A1 with the Continental engine and HVSS suspension. The M40 Gun Motor Carriage was designed to replace the earlier M12 Gun Motor Carriage. Prototypes of the M40 were tested in WWII, but the M40 and M43 were not widely deployed until after WWII.

The following data on the M40 and M43 is taken from Technical Manual TM 9-1747.

155-mm Gun Motor Carriage M40 and 8 in. Howitzer Motor Carriage M43

DESCRIPTION:

a. The 155-mm gun motor carriage M40 and the 8-inch howitzer motor carriage M43 are identical, the model designation depending entirely upon the weapon mounted in the vehicle. When designated as gun motor carriage M40, the vehicle carries the 155-mm gun, M1 or M1A1. When designated as gun motor carriage M43, the 8-inch howitzer, M1 or M2, is used. The weapons are mounted in the rear compartment and point forward when in traveling position.

M43 Howitzer Motor Carriage

Figure 1. 8-inch howitzer motor carriage M43, three-quarter rear view.

b. This carriage is improved version of the 155-mm gun motor carriage M12, based on major components of the medium tank M4A1. The motor carriage is of the armored, full-track laying type having horizontal volute spring suspension. The hull is divided into three compartments. The drivers’ compartment is at the front, the engine compartment in the middle, and the fighting compartment at the rear. Universal-type ammunition racks for the 155-mm gun or 8-inch howitzer ammunition are installed in each vehicle. Seats are provided for a crew of eight men.

M40 Gun Motor Carriage

Figure 2. 155-mm gun motor carriage M40, three-quarter left rear firing position.

c. The M40 or M43 vehicle is powered by a 485-horsepower, 9-cylinder, radial gasoline engine, Ordnance Model No. R974-C4 (Continental) mounted in the center of the vehicle.

d. The vehicles are equipped with radio for intervehicle, and telephone for intravehicle communication.

M43 Gun Motor Carriage

Figure 3. 8-inch howitzer motor carriage M43, three-quarter left front traveling position.

e. The hull is constructed of armor plate and is divided into the fighting compartment at the rear, engine compartment in the center, and the driver’s compartment at the front. The compartments a separated by bulkheads. With the exception of several removable sections, the sided, roof and floor are welded together to form a single box-like unit. The removable sections are provided to permit access to the interior of the hull for inspection, machinery replacement and personnel. The removable parts of the hull are: spade assembly which hold the carriage against the kickback when the gun is fired; tailgate and loading ramp assembly; spotlight; drivers’ seats; oil cooler shutter assemblies; cupola hatch assemblies; spade winch and cable; exhaust and tail pipes; shell racks; and towing hooks and pintle assemblies.

155-mm Gun Motor Carriage M40

Figure 4. 155-mm gun motor carriage M40, three-quarter right front view.

f. The vehicle is propelled forward and backward by two individually driven tracks. The drive sprockets at the front end of the vehicle pull the tracks from the rear and lay them down in front of the advancing road wheels. The track and suspension system consists of the tracks, which the vehicle travels on; the suspension and road wheels, which carry the load of the vehicle and travel on the tracks; the track rear idler, which is the turning point for the track and is the adjustment point for taking up slack in the track; and the support rollers, which support the upper half of the track.

DATA (M40 and M43):

GENERAL
     Purpose         Gun carriage
     Type Full-track laying
     Crew 8 men
     Fighting weight:
          M40 83,000 lb.
          M43 83,000 lb.
     Length:
          M40 357 in.
          M43 289 in.
     Width, over-all 124 in.
     Height, overall 129 3/4 in.
     Ground clearance 19 1/4 in.
ENGINE
     Manufacturer Continental
     Model R975–C4
     Type Single-row, static-radial, air-cooled
SUSPENSION
     Type Horizontal volute
     Track shoe width 18 3/4 in.
     Track pitch 6 in.
     Ground contact area of both tracks 7,544 sq. in.
     Number of blacks per track 87
     Weight of track 4,042 lb.
     Ground pressure (psi) 10.2
POWER TRAIN (1-PIECE DIFFERENTIAL)
     Manufacturer Iowa Transmission