Tag Archive for 'prime mover'

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Armored Prime Mover

Armored Prime Mover - World War II, Japanese

The chassis of this Japanese armored prime mover incorporates the better design features of the tankette development shown on pages one to three. This vehicle is an important link in the chain of Japanese transportation of personnel and supply in the large mainland areas. Its construction proves that the Japanese attach considerable importance to the interchange and utilization of standard tank component parts on combat vehicles for greater simplification of their supply problem.

The hull provides for a layout of the engine and power train on the right, while the driver’s compartment is located on the left side. A large load and stowage compartment at the rear extends over the tracks. Tubular bows are raised for protective covering and camouflage nets. Double doors open at the rear, below which a towing pintle is attached. There is no main armament; however, there is an observation turret built in the roof of the crew compartment behind the driver. Speaking tubes with ear phones are used for crew communication. Four hinged flap-covered openings provide additional vision for the crew and allow employment of small arms weapons.

The power train in this vehicle is made up of the engine, four-speed and reverse transmission, controlled differential with steering brakes and a final drive single reduction gear. The engine is a four-cylinder in-line diesel with Bosch type automatic fuel injection. A 12-volt ignition system is also provided with spark plugs located in the fuel injection ports. The electrical system utilizes parts standard and interchangeable with other vehicles. Two fuel tanks hold 38 gallons.


Weight       5 tons
Length 12 ft., 8 ins.
Width 6 ft., 4 ins.
Height 5 ft., 2 ins.
Ground clearance 14 ins.
Tread centers
Ground contact 124 ins.
Width of track 8 ins.
Pitch of track 3 ins.
Track links 88
Fording depth 31 ins.
Theoretical radius of action
   Roads 28 m.p.h.
   Front plate 6 mm
   Sides 12 mm
   Floor 12 mm
Armament Small arms weapons
Ammunition (Rds.) Unknown
Engine 4-cylinder air-cooled OHV Diesel
Transmission 4 speeds forward; 1 reverse
Steering Controlled differential
Crew 2

Japanese: p. 18.1

13-Ton Prime Mover Model 95B (1935)

13-Ton Prime Mover Model 95B (1935)

This prime mover makes use of the same chassis as the Model 95A, the only difference being its accommodation of a 6-cylinder, in-line, water-cooled, valve-in-head Diesel engine. The cylinder diameter is 140 mm, the piston stroke 190 mm, and compression ratio 15.5:1. The normal horsepower is rated at 145 at 1,300 r.p.m. Maximum hp. is 165. The firing order is 1-5-3-6-2-4. There is a 24-v., 300-w. capacity charging generator, two 12-v., 80 amp.-hr. batteries, and two 24-v., 6-hp. electric starting motors.

Details are lacking on the reduction gear, which has a ratio of 2.92:1. The steering system is of the clutch brake type assisted on short turns by hand- and foot-operated control brakes, which include a locking feature. The transmission is said to be synchromesh with 4 speeds forward and 1 reverse. The maximum speedis 8.68 m.p.h. A gear-type forced-feed system is used for distributing lubricating oil in the crankcase. An oil pressure gage and oil-level stick are also fitted. Diesel oil fuel is supplied from a total storage capacity of 68 gals. Forty-four liters (11.6 gals.) of water are circulated from the radiator to the engine block with the normal type pump. This vehicle is said to be capable of ascending a 15° grade while towing a 14-ton load, or a 7 1/2° grade pulling a 32-ton load. The winch capacity is 11 tons.


Weight       15 tons
Trailer load capacity 32 tons
Winch capacity 11.25 tons
Length 16 ft.
Width 7 ft., 6 ins.
Height 9 ft., 3 ins.
Ground clearance 1 ft.
Tread centers 5 ft., 11 ins.
Ground contact 10 ft., 4 ins.
Track width 16 1/2 ins.
Track links
Fuel tank 68 gals.
Fuel consumption
Fording depth
Speed 8.6 m.p.h.
Engine 6-cyl., water-cooled, Diesel
Bore and stroke 140 mm x 190 mm—5.51 ins. x 7.48 ins.
Horsepower 145 at 1,300 r.p.m.
Ignition Diesel
Battery 2 12-v., 80 amp./hr.
Transmission Synchromesh—4 speeds forward, 1 reverse
Steering Clutch brake

Japanese: p. 18 (May 1, 1945)

13-Ton Prime Mover Model 95A (1935)

13-Ton Prime Mover Model 95A (1935) - Japanese, World War II

This vehicle is powered by a 6-cylinder, in-line, water-cooled gasoline engine with a cylinder bore of 135 mm and piston stroke of 150 mm and a compression ratio of 5.1:1. Normal horsepower is 130 at 1,300 r.p.m.; maximum horsepower, 160 at 1,900 r.p.m. The firing order is 1-5-3-6-2-4. Ignition for the vehicle is distributed by a high-tension type magneto. The electrical system includes charging generator; two 12-v., 80 amp.-hr. batteries, and a 24-v. electric starting motor of 8-hp. capacity.

The final drive has a reduction ratio of 2.93:1. A dry multiple plate clutch is used. Both foot- and hand-operated brakes are employed and the vehicle is steered by the clutch brake principle and is said to utilize a locking feature of the control brakes. The transmission is of the synchromesh type with 4 speeds forward and 1 reverse.

Lubricating oil is distributed by gear-type force-feed system through an oil-pressure regulator. The oil-pressure gage registers 29-44 lb. and an oil-level stick is used for checking the crankcase, which has a capacity of 5 3/4 gals. It has been stated that the fuel feed equipment includes a fuel pump between the carburetor and storage tank and that the heavy-duty type of fuel is forced fed to a NIPPON B 45 model carburetor.

There are two models of fuel storage tanks manufactured for this vehicle—one is the Mitsubishi type with main tank holding 70 gals. and an auxiliary holding 43 gals., and the other is the NIIGATA type main tank holding 50 gals. and an auxiliary tank holding 38 gals. Fuel consumption is stated to be 7.5 gals. per hour. The radiator holds 11 gals., circulated by a pump to the engine block. The grade-ascending ability of this prime mover is quoted as 14 tons up a 15° incline, or 32 tons on a 7 1/2° incline. The winch capacity is 11 tons.


Weight        14.3 tons
Trailer load capacity 32 tons
Winch capacity 11.25 tons
Length 16 ft.
Width 7 ft., 6 ins.
Height 9 ft., 3 ins.
Ground clearance 1 ft.
Tread centers 5 ft., 11 ins.
Ground contact 9 ft., 9 ins.
Track width 16 1/2 ins.
Track links
Fuel tank Main, 70 gals.; aux., 43 gals.
Fuel consumption .83 m.p.g.
Fording depth
Speed 6.2 m.p.h.
Engine 6-cyl., water-cooled, gasoline
Bore and stroke 135 mm x 150 mm—5.31 ins. x 5.91 ins.
Horsepower 130 at 1,300 r.p.m.
Ignition High-tension magneto
Battery 2 12-v., 80 amp.
Transmission Synchromesh; 4 speeds forward, 1 reverse
Steering Clutch brake

Japanese: p. 17 (May 1, 1945)

5-Ton Prime Mover Model 92A (1932)

5-Ton Prime Mover Model 92A (1932): Japanese

It is reported that there are two variations of this vehicle. Model A is powered by a 6-cylinder in-line L-head Sumida gasoline engine, and Model B by a 6-cylinder in-line air-cooled Isuzu Diesel. As far as may be ascertained, with exception of a modification in radiator design, the general appearance and suspension of these two models is similar.

The Model A engine is an L-head type with the valves on the side. The cylinder bore is 110-mm, the stroke 135 mm, and the compression ratio is 4.5:1. The normal hp. is 64 at 1,200 r.p.m.; the maximum hp. is 98. Ignition is provided by a Bosch high-tension magneto with 12-v. charging generator and two 12-v. 60 amp.-hr. vibration-proof batteries. The electric starting motor is 12-v. with a rating of 2.5 hp. Bevel spur pinion and ring gears have reduction ratios of 2.66 and 5.

The steering system is the clutch brake type with both hand and foot-operated brakes. The transmission provides four speeds forward and one reverse. The maximum speed is 19 k.p.h. (11.8 m.p.h.). The lubricating oil is distributed by gear pump force-feed system. Oil pressure registers 1.0 kg. (2.2 lb.) at low speed and 2 kg. (4.4 lb.) at 1,100 r.pm. The oil capacity measures 14.65 liters (3.7 gal.). A vacuum fuel system is used with Stromberg UT 4 model carburetor. The main fuel storage tank holds 125 liters (32 gal.), the auxiliary tank 55 liters (14.5 gal.). Fuel consumption is 17 liters (4.5 gal.) per hour, or 1.05 liters per km. (2.4 mi./gal.). The cooling liquid is circulated by a centrifugal pump from a radiator, which carries 39.5 liters (10.4 gal.). The grade ability of this vehicle pulling a fixed weight is 30°. The winch capacity is 2.5 metric tons (2.8 tons). The winch cable length is 20 meters (65 1/2 ft.).


Weight        4.8 Metric tons—5.28 tons
Trailer load capacity 4.5 Metric tons—4.9 tons
Winch capacity 2.5 Metric tons—2.75 tons
Length 3.55 m—11 ft., 8 ins.
Width 1.71 m—5 ft., 11 ins.
Height 2.35 m—7 ft., 8 ins.
Ground clearance .295 m—11.75 ins.
Tread centers 5 ft., 11 1/2 ins.
Ground contact 7 ft., 4 1/2 ins.
Track width 9 7/8 ins.
Track links 59
Fuel tank Main, 32 gals.; aux., 14.5 gals.
Fuel consumption 2.4 m.p.g.
Fording depth 24 ins.
   Hard roads 18 m.p.h.
   Cross-country 8 m.p.h.
Engine Sumida, 6-cyl., gasoline
Bore and stroke 110 mm x 135 mm—4.33 ins. x 5.31 ins.
Horsepower 64 at 1,200 r.p.m. (normal)
Ignition Bosch high-tension magneto
Battery 2 12-v., 60 amp.-hr.
Transmission 4 speeds forward. 1 reverse
Steering Clutch brake
Crew 6

Japanese: p. 12 (April 1, 1945)

4-Ton Prime Mover Model 94 (1934)

4-Ton Prime Mover Model 94 (1934) - Japanese WWII

The 4-ton Prime Mover is powered by a 90°, V-8 air-cooled gasoline engine with a cylinder bore of 90 mm and a piston stroke of 125 mm. The normal horsepower is 73 at 1,600 r.p.m.; maximum horsepower is 88. The firing order is 1-8-7-3-6-5-4-2. The electrical system includes a Bosch type magneto (Gesal model); a Bosch R.T.C. 900 LI model, 75-watt generator; a 12-v., 80 amp.-hr. storage battery, and a Bosch 2.5 hp. electric starting motor. The ratio of the final drive is 5.657:1. Clutch brake steering is used and both hand and foot operation applies the brakes. The transmission is the central selector type with 4 speeds forward and 1 reverse.

The vehicle is capable of towing its complement of artillery at 25 m.p.h. There is a main and auxiliary type of lubricating oil pump. Oil pressure is 4.4 to 6.6 lb. of gage pressure when warmed up. A Stromberg UR Z model carburetor is used. The main fuel storage tank has a capacity of 26.6 gals. In addition, there is an auxiliary tank having a capacity of 15.8 gals. A Sirocco type fan provides circulation for the air-cooled engine. A dry two-plate clutch is used. The grade-ascending ability is said to be 30° under the towing load. This vehicle can pivot turn. The winch capacity is 2.2 tons. The theoretical radius of action is 125 miles in 10 hours.


Weight        4 tons
Trailer load capacity
Winch capacity over 2 tons
Length 12 ft., 5 ins.
Width 6 ft., 1 in.
Height 7 ft., 3 ins.
Ground clearance 11.5 ins.
Tread centers 5 ft., 4 ins.
Ground contact 7 ft., 8 ins.
Track width 10 ins.
Track links 5 1/2 ins.
Fuel tank Main, 26.6 gals.; aux., 15.8 gals.
Fuel consumption
Fording depth 20 ins.
Speed 25 m.p.h.
Engine V-8 cyl., air-cooled, gasoline
Bore and stroke 90 mm x 125 mm—3.54 ins. x 4.92 ins.
Horsepower 88 (max.)
Ignition Magneto
Battery 12 v., 80 amp.-hr.
Transmission Selector type; 4 speeds forward, 1 reverse
Steering Clutch brake
Crew 6

Japanese: p. 11 (April 1, 1945)

Armored Tracked Personnel Carrier

Armored-tracked Personnel Carrier: Type 1 Ho-Ki

This vehicle serves as an artillery prime mover and as a personnel carrier for 24 men. It appears to be of recent manufacture, and its first known appearance in combat was during the Leyte campaign in the Philippines.

It is a full-tracked vehicle armored with 1/4-inch plate throughout. The engine which is located at the right front of the body is a 6-cylinder, in-line, valve-in-head, air-cooled diesel of a type similar to those used in the Model 2595 light tank and the combination prime mover and wrecker. Two fuel tanks provide an estimated total capacity of 50 to 60 gallons.

The tracks and suspension are of the conventional Japanese design, using dual bogie wheels and a steel center guide track. The four bogie wheels, apparently identical with those on the Model 2595 light tank, are mounted on bell cranks and are sprung by horizontal coil springs which are inclosed within the body armor with only the bogie arms exposed. There are two return rollers. The track is driven from the rear. A clutch and brake steering system is used. The transmission provides four speeds forward and one reverse. A high and low transfer case is also provided.

A mount for a 7.7 mm machine gun is located on the left front of the driver’s compartment. The vehicle does not mount a winch, but is provided with a spring mounted towing pintle for use as a prime mover. It has a capacity of from 2 to 3 tons if used as a cargo carrier. Maximum speed is reported as approximately 35 miles per hour, with exceptionally good cross-country performance due to the amount of track area in contact with the ground in relation to the weight of the vehicle.


Length (overall)       15 ft., 9 ins.
Width (overall) 6 ft., 8 ins.
Ground clearance
Tread centers
Ground contact 9 ft., 10 ins.
Width of track 10 ins.
Pitch of track 3-13/16 ins.
Track links 125
Fording depth
Theoretical radius of action
Speed (maximum) 35 m.p.h.
Armor (reported) 1/4 in.
Armament 7.7 mm machine gun
Ammunition (Rds.)
Engine 6-cylinder, in-line, valve-in-head, diesel.
Transmission 4 speeds forward, 1 reverse; high and low range.
Steering Clutch and brake system
Seating capacity 24

Japanese: p. 18.3 (May 1, 1945)