Categories
Japanese

81 mm Mortar Model 3

Japanese 81 mm Mortar Model 3

The Japanese 81 mm Mortar, Model 3, is a forerunner of the Model 97 (1937). It was manufactured at the Yokosuka Navy Arsenal in 1943.

The tube is a smooth-bore type and has two collars machined on the forward part for securing the bipod clamp. The bipod, constructed of light weight tubing, is very unstable. There is no cross leveling device, and rough cross leveling adjustments could be made by breaking the bipod support and moving the leg on the low side inward.

The base plate is relatively heavy, and is believed to be identical with that now used with the 90 mm Mortar, Model 94. It is interchangeable with the base plate for the Model 97.

Both traversing and elevating mechanisms employ the square type threads rather than the usual and more efficient buttress type as used on Model 97. No sight was recovered with the mortar.

SPECIFICATIONS

Weight of tube        47 lbs.
Weight of bipod 25 lbs.
Weight of base plate 95 lbs.

Japanese: p. 122.1

Categories
German

20 cm K. (E): Railway Gun

20cm-railway-gun

Batteries of these railway guns in concrete emplacements were found on both the Cherbourg and Brest Peninsulas in France. Equipment consisted of the gun, carriage, turntable, power plant and electrical operating unit, and ammunition car.

The piece is of the built-up type, consisting of a tube and two jackets. It is screwed into the breech ring. The breechblock is of the horizontal sliding wedge type. The hydropneumatic recoil system has two cylinders located under the carriage; the pistons are fastened to the lower end of the breech ring.

The carriage, when mounted on a turntable, has a traverse of 360 degrees; it is estimated that elevation is from 0 to 840 mils.The turntable, consisting of two sections bolted together, rotates on a central pivot and a portable circular track. Four wheels at each end of the turntable support it on the track. Electric motors are geared through these wheels to rotate the piece in azimuth. It is very similar to the 28 cm K. 5 (E) reported on page 100.2.

A small ammunition car, equipped with a removable roof, is mounted on trucks and runs on a two-rail track which is built in as a part of the turntable track.

SPECIFICATIONS

Weight of gun       45,500 lbs.
Weight of carriage w/ gun 189,000 lbs.
Caliber 203 mm (7.982 ins.)
Weight (firing position) 92.5 tons
Length (traveling position) 63 ft. (approx.)
Height (traveling position) 13 ft.
Height (firing position)
Width (overall) 13 ft. (approx.)
Track Std. railway gage 56 1/2 ins.
Length of tube 30 ft., 7 ins.
Length of tube and breech 32 ft., 8 1/2 ins.
Length of rifling 22 ft.
Rifling Uniform R.H. twist
No. of grooves 64
Width of grooves 0.188 in. (approx.)
Depth of grooves .125 in. (approx.)
Width of lands
Muzzle velocity (shell) 2,800 f/s
Range (est.) 36,000 yds.
Traverse (on turntable) 360°
Elevation (estimated) 47°
Depression
Length of recoil (from recoil index slide) 25 1/2 ins.
Ammunition APCBC, APBC, HE, Practice, Illuminating with parachute
Wt. of projectile 259 lbs.
Wt. of propellant (max. charge) 96.5 lbs.

German: p. 102.1 (May 1, 1945)