Month: January 2010

Categories
Japanese

150 mm Mortar, Model 97 (1937)

150 mm Mortar, Type 97 (1937)

This mortar, of conventional design, is a smooth bore, muzzle-loading weapon referred to by the Japanese as a medium mortar. Although its tactical use is not fully defined, it is known to have been used in fixed concrete emplacements as a part of the island defense system.

The Model 97 is very heavy and sturdily constructed, weighing 770 pounds complete with sight. The breech cap and stud, with assembled firing mechanism, are screwed on in the normal manner. The firing pin may be adjusted to three different positions by means of a cam lock. When the lock is in the rear center position the firing pin is in a safe position; when the lock is turned to the right, the pin is “Floating,” or, in other words, may be actuated by a sharp blow on the end of the cam shaft. When the firing pin is locked forward, the operation is the same as that of a mortar with a fixed firing pin.

The bipod is of normal construction with but one exception. The elevating screw is actually two concentric screws, comparing very favorably with a single screw in stability and overall length. The traversing screw, buffer mechanism, and collar assembly are of the same design as other Model 97 Japanese mortars. The bipod and cradle may be separated for handling.

The base plate is a heavy ribbed stamping of 0.25 inch metal built up by reinforcing ribs welded to the original stamping. It has the usual ball and socket locking arrangement. The sight is a panoramic elbow telescope of three power and thirteen degree field.

SPECIFICATIONS

Caliber         150 mm (5.906 ins.)
Weight (complete) 770 lbs.
Weight of tube 257 lbs.
Weight of bipod & traversing assembly (total) 174.5 lbs.
Weight of sight & extension 1.5 lb.
Weight of baseplate 337 lbs.
Length of tube 75.37 ins.
Length of tube (internal) 66 ins.
Length of baseplate 47.75 ins.
Width of baseplate 35.5 ins.

Japanese: p. 127 (March 1, 1945)

Categories
Japanese

140 mm Seacoast Gun Type 3

140 mm Seacoast Gun Type 3 -- Japanese, WWII

It is believed that this naval coast defense weapon was designed primarily for use against ships, as the fuzes used with the gun’s ammunition are not sensitive enough to function satisfactorily upon impact with soft ground. This gun uses separate loading ammunition, and has a standard type mushroom head obturator. The breechblock is the horizontal swinging, interrupted screw type, having three threaded segments with two step threads. A hydropneumatic recoil mechanism is located above the barrel.

A naval pedestal type mount is used. Strips of iron fastened to and radiating from the pedestal are buried in the ground to insure stability. The piece is sometimes fitted in a casemate, the front and sides of which are cast in one piece. The top is rolled plate. A mantlet is fitted to the gun on the inside of the casemate. Gun and casemate are rotated manually, as no power system is provided.

No fire control equipment, with the exception of a telescopic sight mount, was recovered with the gun, and it is believed that the piece is fired by direct laying.

SPECIFICATIONS

Caliber         140 mm (5.5 ins.)
Weight (firing position)
Length (overall) 23 ft., 8 ins.
Length (firing position)
Height (firing position)
Width (overall)
Length of tube 22 ft., 10 1/2 ins.
Length of rifling 19 ft., 3 1/2 ins.
No. of grooves 42
Width of grooves
Depth of grooves 0.051 in.
Width of lands
Muzzle velocity (shell) 850 meters (2,789 ft.) per sec.
from range disc on gun
Max. range (horizontal) 17,000 meters (18,598 yds.)
from range disc on gun
Rate of fire
Traverse 360°
Elevation 30°
Depression -7°
Length of recoil
Ammunition
Wt. of projectile (H.E.) Common         83.8 lbs.

Japanese: p. 114.6 (August 1, 1945)

Categories
Japanese

120 mm, 45 Caliber, Naval Dual Purpose Gun, Type 10

120 mm, 45 Caliber, Naval Dual Purpose Gun, Type 10 (Japanese WWII)

The Japanese Type 10 dual purpose gun has a 45-caliber barrel of monobloc construction with uniform right hand rifling. A long, narrow rectangular projection on the bottom of the barrel slides in a groove in the sleeve type cradle, preventing the barrel from rotating. The bearing surface for recoil being the machined barrel surface. The cradle is mounted on a pedestal mount which permits a traverse of 360 degrees.

The elevating handwheel is on the right side of the mount, while the traversing handwheel is on the left. An auxiliary handwheel on the left side permits the piece to be elevated and traversed by the gunner. To compensate for muzzle preponderance, a spring pusher type equilibrator is used. The gun is well balanced, and exceptionally easy to elevate. The recoil mechanism is a hydrospring type, the two outside cylinders housing the counterrecoil springs, and the center cylinder the hydraulic mechanism. A semiautomatic horizontal sliding breechblock is used.

The mount is of riveted construction.

SPECIFICATIONS

Caliber       120 mm (4.7 ins.)
Weight (firing position) 6,500 lbs.
Length (gun and mount) 19 ft., 6 1/2 ins.
Length (firing position)
Height (gun and mount) 7 ft., 8 1/2 ins.
Height (firing position)
Width (gun and mount) 7 ft., 1 in.
Length of tube 17 ft., 1 1/2 ins.
Length of rifling 14 ft., 9 1/2 ins.
Length, of chamber 29.5 ins.
No. of lands 34
Width of grooves 1/4 in.
De-th of grooves .050 in.
Width of lands 1/8 in.
Muzzle velocity (shell) 2,700 f/s
Max. range (horizontal) 17,000 yds.
Max. range (vertical) 32,800 ft. (fuze)
Rate of fire 10-12 rds.
Traverse 360°
Elevation 75°
Depression 10°
Length of recoil 19.3 ins.
Ammunition H.E. shrapnel; H.E. phosphorus
Wt. of projectile 45.75 lbs.

Japanese: p. 114.5 (August 1, 1945)

Categories
Japanese

120 mm, 45 Caliber, 11 Year Type Gun

Japanese 120mm 45 Caliber 11 Year Type Gun

This gun is a naval coast defense weapon manufactured at Sasebo Arsenal. It uses semi-fixed ammunition. The barrel is of built-up construction with uniform right hand twist rifling. A manually operated, horizontal sliding block breech mechanism is used. It is unusual in that the block does not pass all the way across the rectangular breech ring. The rear of the breech ring is cut in a keyhole shape. The operator of the elevation handwheel may fire the gun by means of a lever mechanism, or it may be fired by a lanyard attached to the right side of the breechblock.

The recoil system comprises three cylinders, two located above and one below the barrel.

The mount consists of a rectangular upper carriage which is mounted on a pedestal normally embedded in a solid foundation. A traversing scale is located on the pedestal. The traversing handwheel is in a horizontal position with the vertical shaft engaging a series of gears in the base mount. Platforms attached to the upper pedestal are provided for the gun layers and move in traverse with the gun.

Fire control equipment is of the usual Japanese naval coast defense gun type.

SPECIFICATIONS

Caliber      120 mm (4.72 ins.)
Weight (traveling position)
Weight (firing position)
Length of gun (overall)18 ft., 3 1/4 ins.
Length of tube 17 ft., 3 3/4 ins.
Height of gun 6 ft., 11 ins.
Height (firing position)
Width (overall)
Length of rifling 14 ft., 8 1/2 ins.
No. of lands34
Width of grooves
Depth of grooves
Width of lands
Muzzle velocity (H.E. shell)2,700 f/s
Max. range (horizontal)
Max. range (vertical)
Rate of fire
Traverse360°
Elevation50°
Depression10°
Length of recoil
AmmunitionH.E.
Wt. of projectile (H.E.)44.75 lbs.

Japanese: p. 114.4 (August 1, 1945)

Categories
Japanese

88 mm Antiaircraft Gun Type 99

Japanese 88 mm Antiaircraft Gun Type 99

This weapon which was recovered at Rangoon has a barrel of monobloc construction, machined to take a rectangular breech ring. A large threaded brass locking collar holds the breech ring in position. Rifling is right hand twist. The breech mechanism is semi-automatic of the vertical sliding type; the firing mechanism is a percussion type.

The piece fits in a sleeve type cradle to which are fitted the buffer cylinder, the recuperator cylinders, the trunnions, and the elevating arc. The recoil mechanism is hydropneumatic. Two recuperator cylinders are located one on each side of the recoil cylinder which is centrally mounted above the piece. The elevating arc is mounted under the piece offset slightly to the left. It is operated by a handwheel and crank on the left of the gun, and like the traversing handwheel, on the right of the gun, is forward of the trunnions.

The upper carriage consists of two side plates joined by three cross members, and revolves on a ball race fitted to its base. A pintle, bolted to the center of the base, extends down into a bearing in the pedestal. Three brackets are set at regular intervals around the upper carriage to prevent lateral play. The pedestal is a single cast truncated cone, reinforced internally and externally by six ribs. Twelve bolts secure it to a circular steel base plate.

Follow-the-pointer dials are provided for azimuth, elevation, and fuze setting. Three mechanical fuze-setters are also provided. Some of the guns examined were equipped with open sights of very primitive design.

SPECIFICATIONS

Caliber         88 mm (3.5 ins.)
Weight (complete) 14,560 lbs.
Weight of cradle 1,256 lbs.
Weight of carriage (including elevating & traversing mech.) 4,894 lbs.
Length (traveling position)
Length of barrel assembly 255.8 ins.
Height (traveling position)
Height (firing position)
Width (overall)
Length of bore
No. of grooves 32
Width of grooves
Depth of grooves 1 mm
Width of lands
Muzzle velocity (shell) 2,650 f/s
Max. range (horizontal)
Max. range (vertical)
Rate of fire
Traverse 360°
Elevation 80°
Depression 7°
Length of recoil (approx.) 14-15 ins.
Ammunition H.E.
Wt. of projectile (H.E.) (approx.) 18 lbs.

Japanese: p. 114.2 (August 1, 1945)

Categories
Japanese

47 mm Tank Gun Type I (1941)

47mm Tank Gun Type I (1941)

The Japanese Type I (1941) 47 mm tank gun is mounted in the Type 97 Improved Medium Tank, replacing the 57 mm tank gun, a weapon of much lower velocity. The 47 mm tank model is very similar to the Type I, 47 mm antitank gun described on page 106. The breech mechanism, however, is of the semi-automatic, vertical sliding block type instead of the horizontal sliding block type. The barrel, 7 feet, 11 1/2 inches long, is of built-up construction. The firing mechanism is of the percussion hammer type, the recoil mechanism is a hydro-spring type.

The piece is free mounted in a mantlet in the turret which permits a total traverse of approximately 15 degrees. Elevation and depression of from 8 to 10 degrees may be obtained. The gun fires high explosive and armor-piercing high explosive ammunition.

Two types of telescopic sights for this gun have been recovered. Although different in size and design, they are both 4 power by 14 degrees.

Firing tests on this gun reveal that A.P.H.E. ammunition at 500 yards will penetrate 2.7 inches of homogeneous armor at normal, and 2.2 inches of homogeneous armor at 30° from normal.

SPECIFICATIONS

Caliber         47 mm (1.85 ins.)
Weight 904 lbs.
Length (overall) 9 ft., 7 ins.
Length of tube 7 ft., 11 1/2 ins.
Length of bore (including chamber) 7 ft., 3/4 in.
No. of grooves 16
Width of grooves
Depth of grooves
Width of lands
Muzzle velocity (A.P.H.E. shell) 2,700 f/s
Max. range
Rate of fire
Traverse 15°
Elevation 8° to 10°
Depression 8° to 10°
Length of recoil
Ammunition H.E. and A.P.H.E.
Wt. of projectile (H.E.) 3.08 lbs.
     (A.P.H.E.) 3.37 lbs.

Japanese: p. 106.1 (August 1, 1945)

Categories
Japanese

Motor Tricycle (Kurogane)

Japanese WWII Motor Tricycle (Kurogane)

This motor tricycle has been recovered in two adaptations: as a light cargo vehicle and as a small personnel carrier. The motor is a 2-cylinder, V-type, air-cooled, gasoline engine with cooling fins made of ferrous metal. The ignition, of the automotive type, comprises battery, generator, coil, and distributor. Motorcycle type coil springing is used on the front wheels and leaf type springs on the rear part of the vehicle. The automotive type transmission provides three speeds forward and one reverse. Power is transmitted to the rear by a shaft and both rear wheels are driven through a differential. The brakes are mechanical, rod-operated, internal expanding, and operate on the two rear wheels only.

The motor tricycle has been developed as a commercial freight carrier in Japan since 1930. Many commercial versions exist, with engines ranging from 350 cc to 1,000 cc displacement. Lighter types have single-chain drive without differentials, whereas heavier types may have shaft or double-chain drive with differentials. Load capacities vary from 300 to 1,000 pounds. It is believed that the army adopted whatever types were available, and that no standard army model exists.

SPECIFICATIONS

CARGO CARRIER
Weight         1,185 lbs.*
Loading capacity
Length (overall) 8 ft., 11 1/2 ins.
Length of body 4 ft., 2 ins.
Width (overall) 4 ft., 1/2 in.
Width of body 3 ft., 8 1/2 ins.
Height (overall) 4 ft., 1/2 in.
Ground clearance 6 ins.
Tread centers 3 ft., 6 3/8 ins.
Wheelbase 6 ft., 3 ins.
Tire size 4.75 x 18 ins.
4.75 x 27 ins.
Fuel tank
Fuel consumption
Fording depth
Speed
Engine 2-cylinder, V-type, air-cooled, gasoline
Bore and stroke
Ignition
Transmission 3 speeds forward; 1 reverse

*Not verified

Japanese: p. 31 (May 1, 1945)

Categories
Japanese

Locomotive Truck

Japanese Locomotive Truck

The partial disruption of the Burma railway system has brought into being a very effective locomotive truck. One report states that use of the Japanese locomotive truck has not only aided in the transportation of supplies over damaged rail lines, it has made it possible to carry over the damaged railroad considerably more tonnage than could be moved by the use of locomotives alone.

The “Loco-truck” is a highly specialized vehicle specifically designed to overcome the problem of breaks in the rails. The inner sections of the six wheels are cut to run along rail tracks; the outer sections are designed for tire mounts. On both front and rear of the truck are two permanently attached hydraulic jacks equipped with rollers. To remove the vehicle from the tracks, it is necessary to put one rail under the rear jacks and one under the front jacks at right angles to the tracks, lift the truck off the rails, and roll the truck to the side. The truck is then let down on its wheels, driven past the break in the rail line, and returned to the tracks.

A diesel engine estimated at about 60 horsepower is used to power the vehicle. Overall length, including couplings, is 19 feet, 2 inches and width is 6 feet, 3 inches.

Japanese: p. 26.1 (April 1, 1945)

Categories
Japanese

“Kato” 70 Artillery Tractor

Japanese Kato 70 Artillery TractorThis is a slow speed tractor equipped with a towing hook and is believed to be the standard Japanese artillery prime mover. There are two bogies on each side, each bogie having three bogie wheels, two bearing on the outside and one on the middle of the tractor. Clutch and brake steering are provided. The power plant is a 4-cylinder, water-cooled, gasoline engine. The cylinder block is of two separate sections. Each section is joined into one piece at the top, but the base of each cylinder is separate from all other cylinders.

SPECIFICATIONS

Weight
Winch capacity
Length
Wheel base        85 ins.
Diameter of drive sprocket 26 ins.
Width of track 13 3/4 ins.
Length of track in contact with ground 89 ins.
Width of tread (from outside edge of tracks) 67 ins.
Engine Kato, K-3, 70 h.p.
Bore 4.75 ins.
Stroke 6 ins.

Japanese: p. 18.6 (August 1, 1945)

Categories
Japanese

Armored Tank Recovery Vehicle

Japanese Armored Tank Recovery Vehicle

This is an armored, self-propelled crane designed to retrieve damaged A.F.V.’s up to a weight of about 12 tons. The manufacturing date of one recovered specimen is given as 1941. The crane is mounted towards the rear of the chassis on a platform traversing through 360° on an electrically powered turntable. The crane is prowered by the main engine through a drive shaft from the transmission to a gear box and thence through another box to the cable drums. The crane is controlled by three hand levers and three foot control clutches. When not in use, the boom which has a total length of 18 ft., 2 ins., rests on the top of the drive compartment and is held in place by two screw clamps. The conventional Japanese type of suspension is used. Four bell cranks are resisted by four armored compression springs per side. Eight-and-one-half-inch dual steel bogie wheels per side are mounted four inches apart and paired to each bogie. An 18 13/16-inch diameter double-tooth front drive sprocket, a rear idler, two 10 3/4-inch diameter rubber-covered return rollers, and the center guide steel track complete the suspension.

The driver’s compartment measures 45 1/2 x 59 inches, and is fitted with a door on the right side. The 6-cylinder, in-line, air-cooled, Ikegai gasoline engine delivers 60 horsepower. The steering system is of the clutch brake principle, a separate spring-loaded clutch being fitted to each track. Two pressed steel fuel tanks are located at the right rear of the hull; an additional one is utilized as the driver’s seat. They have a combined estimated capacity of 40 gallons.

SPECIFICATIONS

Weight        8 1/4 tons
Trailer load capacity
Length 14 ft., 4 1/2 ins.
Width 6 ft., 7 ins.
Height (to top of vehicle) 5 ft., 3 ins.
         (to top of jib) 6 ft., 9 ins.
Ground clearance 11 ins.
Tread centers
Ground contact 11 ft., 4 ins.
Track width 9 3/4 ins.
Track links
Fuel tank 40 gals. (est.)
Fuel consumption
Fording depth
Speed 21 m.p.h.
Engine Ikegai, gasoline, 6-cylinder, in-line, air-cooled, 60 hp.
Transmission
Steering Clutch brake
Crew 2
Armor
   Front 1/4 in.
   Sides 5/16 in.
Length of cable drums 10 1/4 ins.
Diameter of cable drums 10 1/2 ins.
Diameter of cables 3/4 in. (approx.)
Overall length of boom 18 ft., 2 ins.

Japanese: p. 18.5 (August 1, 1945)