Monthly Archive for August, 2009

“Kato” General Purpose Tractor

Kato General Purpose TractorThis is a commercial type wheeled tractor used for general purpose work. The front wheels are 29 x 5 inches and the rear dual wheels are 40 x 10 inches, all fitted with solid rubber tires. The drive is from the rear wheels only, and steering is effected by a worm gear system operating the front wheels. Normal automotive controls are provided, save for a hand throttle. The transmission provides three speeds forward and two in reverse.

The K3 type engine is identical to that used in the “Kato” 70 tractor–a 4-cylinder, valve-in-head, gasoline type. There are two cylinder blocks of two cylinders each instead of a solid cylinder block. The generator, high-tension magneto, and water pump are all linked together with universal joints and driven from a single shaft extending from the timing gear on the right of the engine.

The tractor is fitted with front and rear towing pintles cast solid with the frame.


Winch capacity
Wheel base 90 ins.
Overall width of tractor (rear) 74 ins.
Overall height of tractor 5 ft.
Capacity of fuel tank 30 gals.
Tread centers (front) 63 ins.
Ground clearance 8 ins.
Fuel capacity (approx.) 30 gals.
Engine 60 h.p. at 1,200 r.p.m.
Bore 121 mm
Stroke 152 mm

Japanese: p. 18.6 (August 1, 1945)

Kommando-Gerät 40: Antiaircraft Director

The Kommando-Gerät 40 is a director used principally for major caliber weapons such as the 8.8 cm and 10.5 cm antiaircraft guns. However, by installing the proper ballistic cams, it may be used with any type of gun.

The director is operated by five men. Two are required to track in azimuth and elevation; a third sets in slant range by means of a 4-meter base stereo range finder mounted on the director; the fourth man sets in horizontal angle of approach; and the fifth man operates various switches. Data are transmitted to the guns for reception by a signal-light manual follow-up system. A trailer equipped with devices for lifting the director is used for transport.

The Kommando-Gerät 40 computes continuously Case III data (for invisible targets) by a target speed and angle of approach method, and can handle diving and curving target courses. The time from initial pickup to first round is estimated to be 20 or 30 seconds. When shifting to a new target in the vicinity of the target previously tracked and flying an approximately parallel course, as little as 10 seconds may be required.

A change in course which requires a change in operating procedure upsets firing data for only a few seconds. In principle, the director will predict correctly for a target flying at constant speed with a constant rate of change of altitude and constant curvature. The stability is not affected by gradual changes in course.

After an abrupt change in speed, altitude rate, or course azimuth, about 10 to 15 seconds are required to evaluate the new course.


Azimuth       No limit
Elevation -1.5° to 90.5°
Slant range 1,200 to 18,000 m
Present horizontal range 570 to 14,500 m
Future horizontal range 570 to 14,500 m
Future altitude -500 to 12,000 m
Present altitude 0 to 12,000 m
Ground speed of target 0 to 300 m/s
Vertical speed of target 0 to 200 m/s
Horizontal travel during time of flight 0 to 6,000 m
Lateral deflection +/- 1,065 mils
Course azimuth correction +/- 1,600 mils
Altitude prediction +/- 3,000 m
Maximum tracking rates
     Azimuth +/- 130 mils/sec.
     Slewing +/- 700 mils/sec.
     Elevation +/- 105 mils/sec.
     Time of flight 0 to 30 sec.
     Horizontal parallax 500 m
     Vertical parallax +/- 210 m
     Fuze dead time 0 to 10 sec.
     Wind velocity 0 to 28 m/s
     Muzzle velocity 24 numbers (Gebrauchsstufe)
     dØ +/- 60/16°
     dA +/- 70 mils
     dF due to dead time +/- 5 secs.
     dF due to MV and wind +/- 5 secs.

German: p. 176

8 mm Paratrooper’s Submachine Gun, Type 100 (1940)


This Japanese paratrooper’s submachine gun is a light, blowback operated, automatic weapon which fires the regular issue bottle-necked 8 mm pistol cartridge.

The gun, which is provided with a bayonet, also has a folding stock; that is, the stock is cut through just behind the receiver and hinged so that by releasing two locking hooks on the left side, the stock swings to the right and forward 180 degrees at the hinge and parallel with the barrel. The barrel and barrel jacket are held in place by a single screwpin threaded at the base and with a folding wingnut head, enabling changes without tools. The receiver assembly is machined in two units, with the units shrunk fit in final assembly.

Two features of the firing mechanism which are of unusual interest are the fixed firing pin which screws into the face of the bolt, and the feeding and chambering bar which insures that the cartridge is very nearly chambered before the firing pin can touch the primer.

In the illustrations above, the top picture shows the weapon as fired, and the photograph at lower left shows the method of folding. A bipod is frequently used with this gun as illustrated in the photograph at lower right.


Caliber       8 mm
Weight (without bayonet, magazine, & sightleaf) 7 lbs., 11 ozs.
Length (stock extended, without bayonet) 34 ins.
Length (stock extended, with bayonet) 49 ins.
Length (stock folded, without bayonet) 22.25 ins.
Sight radius 20 ins.
Principle of operation Blowback, bolt action
Feeding device Curved box magazine; staggered feed type.
Capacity of feeding device 30 rounds
Cooling system Air
Ammunition types 8 mm bottle-necked pistol cartridges
Rate of fire 400-450 r.p.m.
Type of sight Leaf
Length of barrel 9 ins.
Length of rifling 8.125 ins.
     Twist Uniform R.H., approx. 1 in 12
     No. of grooves 6
Muzzle velocity 1,080 f/s

Japanese: p. 204.1 (August 1, 1945)

15 cm Panzerwerfer 42 (Sd. Kfz. N. W. 41): Self-Propelled Rocket Projector


The chassis of this self-propelled rocket projector follows the half-track design but differs materially from the standard German half-track series of prime movers.

A standard commercial chassis manufactured by Opel (Chevrolet) has been modified to carry a spacious armored body of welded plates. The hull thus formed provides a firm and stable firing platform, and permits of easy mass production. The armor is intended only for protection against small arms fire of .30 caliber. The rear wheels and springs of the original truck chassis have been displaced by a track assembly, prefabricated and then bolted to the original frame. The original rear end differential has been retained but the drive shaft has been shortened and the asembly moved forward to mount the drive sprockets. The hydraulic brake system is retained only for the front wheels. A separate cable for each sprocket brake is connected to two hand levers mounted to the right of the driver’s seat. Normal steering is assisted by the sprocket brake when necessary.

The rocket projector consists of ten tubes mounted in two layers of five each. Provision is made for a simple optical sight, and for hand wheels for a maximum of 80° elevation and a maximum traverse of 290°. The projectiles are the same as those fired from the 15 cm Nebelwerfer 41 and can be electrically fired, singly or ripple, by means of a squib placed in each round. They are loaded with high explosive, smoke, and chemical warfare ammunition.

Auxiliary weapons include one 7.92 mm machine gun, M. G. 34, and three 9 mm submachine guns. Ammunition stowage is provided for ten extra rockets, 2,000 rounds for the M. G. 34, and 2,000 rounds for the submachine guns.


Weight (net)       13,558 lb.
Trailer load capacity 2,425 lb.
Length (overall) 19 ft. 5 ins.
Width (overall) 7 ft. 2 ins.
Wheel base (approx.) 130 ins.
Height (overall) 8 ft. 6 ins.
Armor 5/32 ins. to 5/16 ins.
Ground clearance (minimum) 10 ins.
Tread centers 5 ft. 2 ins./5 ft. 11½ ins.
Ground contact (tracks) 78 ins.
Track width 10¼ ins.
Track links 82
Fuel tank 22.4 gals.
Fuel consumption Unknown
Fording depth 32 ins.
Speed 25 m.p.h.
Engine Open (Chevrolet) 6 cyl. O.H.V.
Displacement 220 cu. ins.
Horsepower 67 U.S.A.
Ignition Bosch 12 Volt (Coil)
Battery 12 Volt with special heater
Transmission 5 speeds forward, 1 reverse
Steering Normal assisted by differential brake
Crew 3

German: p. 48.1