Tag Archive for 'model 97'

Stereoscopic 2 Meter Base Range Finder Model 97 Type 2

Stereoscopic 2 Meter Base Range Finder Model 97 Type 2

This range finder is believed to be designed for use with seacoast defenses. It is provided with an elbow telescope for tracking purposes and a graphical computer for converting slant range to altitude.

A number of its design features are quite similar to those in the Japanese 2 meter base Height Finder. Similarities are noted in the penta prism mounting, central prism assembly, reticle and eyepiece assemblies, night lighting of scales, and the filter assembly. The instrument is constructed with an outer tube, optical tube, and two tubular diaphragms, all of steel. The outer tube is covered with asbestos treated canvas. The tracking telescope provided with this instrument has a power of 10 diameters and a 5 degree field of view. The body is made of cast aluminum. The tracking telescope is attached to the main instrument by means of a dovetail bracket and is locked in place by a spring latch.

Another accessory, the graphical altitude computor, consists of a pendulum arm inclosed in a circular holder. The pendulum is graduated with a vertical scale in increments of 50 meters from 100 to 1,000 meters, which represents slant range. Angle of site is indicated by a graduated scale on the face of the holder. The cradle has the trunnion bearing arms cast as an integral part of the body. The eyeguard assembly is a copy of the Carl Zeiss design.


Power        24
Field of view Undetermined
Diameter of entrance pupil 1.9 ins.
Diameter of exit pupil .08 ins.
Base length 2 meters
Diopter movement +2 to -4 diopters
Measuring limits 500 to 20,000 meters
Inter-trunnion distance 35 1/2 ins.
Overall length 86 ins.
Weight 148 lbs.

Japanese: p. 182 (March 1, 1945)

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.


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)

Medium Tank Model 2597 (1937) (Special)

Japanese Medium Tank Model 2597 (1937) (Special)

The Model 97 Special Medium Tank was first placed in operation in the early spring of 1942. It is a modification of the Model 2597 Medium Tank (see page 9) with a modified turret to accommodate the 47 mm Model 1 (1941) tank gun instead of the normal short-barreled 57 mm gun.

The 47 mm tank gun conforms to the 47 mm Model 1 (1941) antitank gun (page 106) in the dimensions of chamber, caliber, and rifling and its performance is similar. The tank gun, however, has a vertical sliding breechblock, while the antitank gun has the horizontal type. The tank gun has a total traverse of 22° with an elevation from -11° to +17°. It is shoulder-controlled, with geared elevation and depression. However, free movement can be obtained, if desired. Penetration tests on the antitank gun indicate a penetration of 2 1/2 inches of homogeneous plate at normal at a range of 1,050 yards.

The Special Tank is readily recognized by its elongated turret, slightly offset to the right. This turret measures six feet from front to rear and three feet across the rear bulge. There is a door 19″ x 16″ in the turret back plate, an exit hatch 23″ x 16″ in the turret top plate, and an observation hatch 25″ in diameter in the cupola with a vision port 4″ in diameter in the cupola top plate. The gun mantlet of 30 mm thickness, sloped at 10° to the vertical, is bolted to the turret front. A 7.7 mm Model 97 L.M.G. is mounted at the turret rear. Another is mounted in the superstructure front plate at the left of the driver.

The armor plate thickness of the Special Tank is essentially the same as that of its predecessor except that the hull side plates of the former have been increased in thickness to 35 mm.


Weight (approx.)      15 tons
Length18 ft., 1 in.
Width7 ft., 8 ins.
Height7 ft., 11 ins.
Ground clearance14 ins.
Tread centers6 ft., 7 ins.
Ground contact11 ft., 7 ins.
Width of track13 ins.
Pitch of track4 3/4 ins.
Track links96
Fording depth3 ft., 3 ins.
Theoretical radius of action 
   Roads100 miles
   Cross country 
   Turret front25 mm at 10° to vertical
   Gun mantlet30 mm cast at 10° to vertical
   Front vertical plate25 mm at 10° to vertical
   Glacis plate 17 mm at 80° to vertical
   Nose plate15 mm at 62° to vertical
   Side superstructure20 mm at 40° to vertical
   Side hull plates35 mm
   Top rear plate12 mm
ArmamentOne 47 mm model 1 (194) tank gun; two type 97 light machine guns.
Ammunition (Rds.)104 rounds of 47 mm ammunition; 2,575 rounds of small arms ammunition.
EngineAir-cooled, V-12 diesel.
TransmissionMain gear box—4 speeds forward, 1 reverse—high and low ratios.
SteeringClutch brake

Japanese: p. 8.1 (August 1, 1945)