Monthly Archive for September, 2009

Page 2 of 2

28/32 cm Nebelwerfer 41: Rocket Projector

28/32 cm Nebelwerfer 41: Rocket Projector This rocket projector fires the 28 cm high explosive rocket (page 354) and the 32 cm incendiary rocket (page 353). Ranges are given below.

This device, which functionally does not differ from the 15 cm and 21 cm Nebelwerfers, consists of six projectors grouped in two tiers of three each, mounted on a two-wheel trailer. The cages are constructed of round steel bars shaped to the outside contours of the 32 cm rocket. Detachable liners for the forward end of the projectors permit the use of 28 cm rockets. The portion of the projector holding the propelling chamber remains the same for both rounds.

The firing mechanism is electric. Traverse (approximately 30°) and elevation (from 0 to 45°) are bymeans of cranks.

The piece is fired from its mounting and is held in position by two jacks in front and a small spadelike arrangement in the rear.

The equipment weighs approximately 2,460 lbs.

German: p. 349 (May 1, 1945)

8.8 cm R. Pz. B. Gr. 4322: High Explosive-Antitank Rocket Grenade

8.8 cm R. Pz. B. Gr. 4322: High Explosive-Antitank Rocket Grenade

This fin stabilized rocket projectile is fired from the German counterpart of the U.S. “Bazooka” (see page 217) and has a maximum effective range of 165 yards. Eight and one-half-inch armor penetration has been obtained in static tests with a standoff of approximately 6 1/2 inches.

The complete round consists of a point fuzed high explosive, hollow charge loaded projectile assembled to a steel tube with a venturi and stabilizer assembly attached, containing an igniter, propellant and electric primer. The AZ 5095 fuze is of the point detonating type which in tests gave an approximate fuze functioning time of 0.0002 seconds (impact to detonation). The projectile assembly consists of the following stamped sheet steel parts: a body which contains the bursting charge, an adapter, a collar, a band, and a slightly heavier sheet steel nose. A detonator-booster of the German Kl. Zdlg. 34 NP type is embedded in the bursting charge to the rear of the flash tube. The bursting charge is cyclotol (41.2% TNT, 58.8% cyclonite) weighing 1 lb., 7.2 ozs. The propellant and tube assembly consists of the propellant tube and the seven propellant grains and igniter assembly, located in the forward end which it holds. The seven propellant powder grains are approximately 7.6 inches in length x .45 inch outside diameter, and have a central perforation .22 inch in diameter throughout their length. The composition is 64½% nitrocellulose and 34½% DEGN, with a small percentage of stabilizer.

A new type of ammunition, the R. Pz. B. Gr. 4999 is reported to give good performance up to a range of 220 yards, 25° C. (77° F.).

SPECIFICATIONS

Weight (complete, rocket as fired)       7.26 lbs.
Weight of high explosive filler 1.47 lbs.
Weight of fuze assembly .175 lb.
Weight of igniter assembly .021 lb.
Weight of propellant charge .382 lb.
Length (overall) 25.56 ins.
Diameter (external) 3.437 ins.
Burnt velocity at 50° F. (approx.) 340 f/s*
Burning distance (approx.) 7 ft.*
Fuze functioning time (approx.) .0002 seconds
Maximum pressure 6,910 lbs. per sq. in.*
Maximum thrust 1,716 lbs.*
Impulse 87 lbs. second**
Maximum effective range 165 yds.

*These figures are from firing a single round.
**These values doubtful; only one rocket motor was statically tested with propellant temperature 41° F.

German: p. 357 (August 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.

SPECIFICATIONS

Weight
Length (overall)       15 ft., 9 ins.
Width (overall) 6 ft., 8 ins.
Height
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
     Roads
     Cross-country
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)

57 mm Tank Gun Model 97

57 mm Japanese Tank Gun Model 97

This gun, manufactured at Osaka Arsenal in 1939, is mounted on the Japanese Medium Tank Type 97. The tube, of monobloc construction, is fastened to the breech ring by twelve interrupted threads and secured by a lock on the right side of the tube. The breech ring is box-shaped. The breechblock of the vertical sliding type rides in two dovetailed slots in each side of the breech ring, and may be operated manually or semi-automatically.

The firing pin is automatically cocked when the breech is opened. The trigger, on the left side of the gunner’s shield, is protected by a trigger guard with a pistol grip. The recoil mechanism is a hydro-spring type.

The gun is mounted in the turret of the tank, and has a 360° traverse. It may also be freely elevated or traversed independently of the turret by means of two sets of trunnions. The inner vertical trunnions are set in a heavy steel bracket fitted to the cradle and permit a 5° left and right traverse. The bracket has a sighting window which may be closed for the gunner’s protection. The outer horizontal trunnions fit into another steel bracket and give approximately 11° elevation and 9° depression.

Although no sighting equipment was recovered with the gun, the appearance and location of the head rest, shoulder rest, and sight bracket indicate that a straight tube telescope is used.

SPECIFICATIONS

Caliber         57 mm
Weight of tube and breech ring 138 lbs.
Weight (firing position) 293.5 lbs.
Length of tube and breech ring 41 5/8 ins.
Length (firing position)
Height (traveling position)
Height (firing position)
Width (overall)
Width of trail spread
Length of tube and breech ring 41 5/8 ins.
Rifling R.H., uniform twist; approx. 1 turn in 28 1/2 cals.
Length of rifling 32.5 ins.
No. of grooves 20
Width of grooves .25 in.
Depth of grooves .039 in.
Width of lands
Muzzle velocity (shell)
Max. range (horizontal)
Max. range (vertical)
Rate of fire 20 r.p.m.
Traverse 360° with turret and 5° right and left independent of turret
Elevation 11°
Depression
Length of recoil 11 ins.
Ammunition H.E. and A.P.H.E.
Wt. of projectile

Japanese: p. 106.2 (August 1, 1945)

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)

Pz. Jäg. 38 für 7.5 cm Pak 39 (L/48): Self-Propelled Antitank Gun

Pz. Jäg. 38 für 7.5 cm Pak 39 (L/48): Self-Propelled Antitank Gun

The chassis of this self-propelled antitank gun is a modified version of the chassis for the Czech Model 38 tank. The lower nose of the hull is 60 mm thick set at 40° and interlocked with the sides and upper nose plate. The upper nose plate is 60 mm thick. It is positioned at an angle of 60° and extends to the top of the superstructure. Brinell hardness is approximately 240. All-welded construction is employed except in attaching roof and superstructure rear plates which are bolted on for reasons of accessibility. The two latter plates are 8 mm horizontal and 8 mm at 70° respectively. The side superstructure plates are 20 mm set at 40° with a brinell hardness of approximately 195. The hull floor plate is 10 mm. Side apron plates of 5 mm give added protection against high explosive shell fire.

The 7.5 cm Pak 39 (L/48), mounted 15 inches to the right of the hull center line, has an improved type of recoil mechanism. This allows the muzzle brake to be discarded. Elevation is from -6° to +10°. Traverse overall is 16° (-11° right -5° left). A new type machine gun mount is built in the roof. The machine gun is fitted with a periscopic sight and extended trigger, and may be traversed in any direction and fired from within. A Sfl ZF 1a sight and an episcope is provided for the main gunner. The sight projects through the roof. The loader has an episcope fitted in the rear portion of his hatch fixed at 6 o’clock.

The steering mechanism is the usual controlled differential type which allows curves of 29½ foot radius without “steering losses.” Curves of smaller radius are obtained by using the track brakes of the additional clutch brake system also provided.

There are two fuel tanks with a total capacity of 85 gallons. Ground pressure is 11.9 pounds per square inch. The power to weight ratio is approximately 9 HP per ton. The Fu 5 radio is fitted. Commanders equipments carry an additional Fu 8.

SPECIFICATIONS

Weight in action       17.6 tons
Length (overall excluding gun) 15 ft., 11 ins.
Width (overall) 8 ft., 7 1/8 ins.
Height (overall) 6 ft., 10 1/2 ins.
Ground clearance 1 ft., 4 3/4 ins.
Tread centers 6 ft., 10 1/2 ins.
Ground contact 8 ft., 11 1/2 ins.
Width of track 1 ft., 1 3/4 ins.
Pitch of track 4.1 ins.
Track links 96
Fording depth 2 ft., 11 ins.
Theoretical radius of action
     Roads 100 miles
     Cross-country 50 miles
Speed
     Roads 16 m.p.h.
     Cross-country 9 m.p.h.
Armor
     Hull nose plate (lower) 60 mm at 40°
     Hull side plate 20 mm undercut 15°
     Hull tail plate 20 mm at 15°
     Glacis plate (upper nose) 60 mm at 60°
     Superstructure side plates 20 mm at 40°
     Superstructure rear plate 8 mm at 70°
     Gun mantlet 30 mm rounded
Armament 7.5 cm Pak 39 (L/48); one M. G. 34; one M. G. 44.
Ammunition (Rds.) 7.5 cm gun, 41 rds.; M. G. 34, 600 rds.;* M. G. 44, 180 rds.
Engine Czech EPA (Type TZJ), 6-cyl., inline, 158 hp. at 2,600 r.p.m.
Transmission 5 speeds forward, 1 reverse
Steering Epicyclic, clutch brake type
Crew 4

*In addition to the ammunition mentioned above, 12 rounds of signal ammunition, 20 egg hand grenades, and 6 smoke candles are carried.

German: p. 20.1 (April 1, 1945)

6.5 mm Heavy Machine Gun Model 3 (1914)

6.5 mm Heavy Machine Gun Model 3 (1914)

The Japanese 6.5 mm Model 3 Heavy Machine Gun, a gas-operated, air-cooled, full-automatic weapon with a comparatively low cyclic rate, although obsolescent, is being recovered in small quantities from battle areas. It is similar to the 7.7 mm Model 92, but is chambered for the 6.5 mm cartridge.

The gas piston and bolt assemblies, and the barrel and barrel sleeve may be interchanged in the two weapons. However, it is impossible to convert the Model 3 for use with the 7.7 mm ammunition as the strip feed port in the Model 3 is one-eighth of an inch narrower than that in the Model 92.

Various machining cuts found in the internal parts of the Model 3 were eliminated in the later model, to provide for ease of production. The oil reservoir is of slightly different shape and probably has a lower capacity than that of the Model 92. The trunnions are of two diameters. The part of the trunnion which contacts the trunnion bearing in the mount is of smaller diameter than that portion which extends beyond the mount. The head thus formed tends to reduce transverse motion.

The weapon has conventional spade grips provided with two finger triggers fixed integrally with the trigger lever so that either or both will fire the gun. There is no safety device.

Two rear sights are provided: one, a folding ring type anti-aircraft sight, is attached permanently to the rear top of the receiver; the other, a tangent curve, radius arm type, is offset to the right. The latter sight is graduated from 300 meters to 2,200 meters (328 yards to 2,406 yards). It is believed that a cartwheel typefront sight is used, as an adaptor for such a sight is riveted to the front of the cooling jacket.

SPECIFICATIONS

Weight (w/ tripod)         122 lbs.
     (w/o tripod) 61.7 lbs.
Length 47.2 ins.
Sight radius 23.6 ins.
Principle of operation Gas
Feeding device Metal strips
Capacity of feeding device 30 rounds
Cooling system Air
Ammunition types Mod. 38, 6.5 mm ball ammunition
Rate of fire Cyclic — 450-500 r.p.m.
  Practical — 200 r.p.m.
Type of sight Two rear sights: folding ring, antiaircraft type; tangent curve, radius arm type, grad. 328-2,406 yds.
Weight of barrel
Length of barrel 29.2 ins.
Length of rifling 26.4 ins.
Rifling
     Twist Uniform, R.H., one turn in 7.88 ins.
     Form Metford segmental
     No. of grooves 4
Depth of grooves
Width of grooves
Chamber pressure 58,800 lbs. per sq. in.
Muzzle velocity 2,434 ft. per sec.
Muzzle energy
Maximum range 4,376 yds.
Effective range 1,500 yds.
Type of mount Tripod
Elevation -15° to +90°
Traverse 33.5°

Japanese: p. 210.1

7.7 mm Lewis Machine Gun Model 92 (1932)

7.7 mm Lewis Machine Gun Model 92 (1932)

The Lewis type machine gun is used widely by the Japanese. Markings on a number of these guns found in the New Georgia area indicate that the weapon as used by the Japanese is of naval origin. It is also believed that the gun is used extensively for ship or air base protection as the tripod mount is adaptable for antiaircraft fire.

The Model 92 is of standard Lewis gas-operated, air-cooled, drum-fed design, equipped with a blade front sight and a rear peep-sight calibrated in hundreds of meters from 0 to 17. No allowance is made for windage or drift. Although no antiaircraft sight was discovered with the gun, a mount for such a sight is attached to the weapon.

The gun is mounted on a tripod having tubular steel legs which may be locked at various angles from the vertical. The tripod legs are attached to flat square plates which have holes in the center to accommodate bolts which are used to secure the tripod to the deck of a ship.

The head of the tripod has a 360° traverse. Without removing the gun from the mount, the main portion of the tripod head can be moved from a horizontal to a vertical position, and the gun attached to the top of the head for antiaircraft use. In this position, the limits of elevation are approximately -80° to +85°. Azimuth is calibrated in 2 mil intervals from 0 to 6,400 mils.

7.7 mm rimmed Navy ammunition fed from a 47-round drum is used. Ammunition chests recovered were found to hold 21 loaded drums.

SPECIFICATIONS

Weight gun and tripod       122 lbs.
Length 39 ins.
Principle of operation Lewis gas-operated system
Feeding device Drum magazine
Capacity of feeding device 47 rounds
Cooling system Air
Ammunition types 7.7 mm full-rimmed ammunition
Rate of fire Cyclic-600 r.p.m.
Type of sight Blade front sight: rear peepsight calibrated from 0 to 1700 meters
Weight of gun 49 lbs.
Length of barrel 24 ins.
Length of rifling
Rifling
     Twist Uniform, R.H.
     Form Concentric
     No. of grooves 4
     Depth of grooves
     Width of grooves
Chamber pressure
Muzzle velocity 2411 ft. per sec.
Muzzle energy
Maximum range 4000 yds.
Effective range 500 yds.
Type of mount Tripod
Elevation
Ground mount -15° – +60°
Antiaircraft mount -80° – +85°
Traverse 360°

Japanese: p. 214.1 (June 1, 1945)

leichtes Schützenpanzerwagen (2 cm) (Sd. Kfz. 250/9): German Halftracked Armored Car

Leichtes Schutzenpanzerwagen Sdkfz 250/9

This vehicle, adapted from the light armored personnel carrier, mounts the 2 cm tank gun, Kw. K. 38, and is effective for reconnaissance, action against lightly armored ground targets, protection of troop and supply trains, and as a personnel and supply carrier.

It differs from the basic vehicle principally in the addition of an armored turret which has been found in three forms: 10, 8, and 6-sided. The turret is of truncated cone shape and is similar to that used in the German 4-wheeled armored cars. The turret has no roof, but instead is provided with a wire mesh grill as anti-grenade protection.

The gun is mounted in the center with a 7.92 mm M. G. 34 on the left, and a telescopic sight on the right. The armament is controlled by one man who sits in a seat suspended from the right rear of the turret. A single handwheel controls traverse and elevation, or, by use of a small lever, the gun may be locked in a horizontal position. Counterbalance is maintained by two spring equilibrators, one mounted on each side. The turret is mounted on a ring permitting traverse through 360 degrees. Access to the turret is through a large entrance door in the left rear of the superstructure. The vehicle is provided with a transmitter-receiver, Fu. Spr. f, with intercommunicating facilities.

SPECIFICATIONS

Weight (approx.)       6 tons
Trailer load capacity
Length 15 ft.
Width 6 ft., 5 ins.
Height 6 ft., 10 3/4 ins.
Ground clearance 11 ins.
Tread centers 5 ft., 5 ins.
Ground contact 3 ft., 11 ins.
Track width 10 1/4 ins.
Track links 38
Fuel tank 20-25 gals.
Fuel consumption
Fording depth 27 ins.
Speed 35 m.p.h.
Engine 6 cylinder Maybach: Watercooled, 100 hp.
Bore and stroke 90 x 110 mm
Ignition Bosch magneto
Battery 12 volt
Transmission Semi-automatic, preselective type. 7 speeds forward, 3 reverse.
Steering Front wheel-track epicyclic
Crew 3
Armament 1 20 mm tank gun (Kw. K. 38)
  1 7.92 mm machine gun (M. G. 34)
Armor
     Front plate (approx.) 15 mm
     Side plate (approx.) 6 mm
     Rear plate (approx.) 8 mm

German: p. 44.1 (April 1, 1945)

Goliath – B I: Cable-Controlled Demolition Vehicle

Goliath: German Cable-Controlled Demolition Vehicle
This miniature tank, weighing less than 700 pounds, is controlled by a 2000-foot electric cable from a hand control box carried in the rear. It is used to send a demolition charge to a point at which detonation destroys the tank as well as the target. The hull is fabricated from a mild 16 gauge steel with front upper and lower sloping plates 9 mm thick. These are set at 48 degrees and 50 degrees to the vertical. The hull contains three compartments. The rear compartment houses the cable and drum; the central compartment houses the power unit and control mechanism; and the front compartment contains the high explosive charge.

The power plant consists of a 2-cylinder, 2-cycle air-cooled engine. Ignition is by coil and 6 volt battery. The power is transferred through chain drives to each track by means of electromagnetic clutches. The total reduction from the clutches to the sprocket is 9.33:1. Steering is accomplished by breaking the circuit to the side to which the turn is to be made. This releases the magnetic clutch, cutting the power from the engine for that side of the vehicle. The suspension consists of five small bogie wheels on the bottom with two return rollers on top, and an idler wheel at the rear. Each bogie is independently sprung by coil springs. The chain driven sprocket is at the front of the vehicle. The track is 6 5/16 inches wide, with a simple grouser placed on every other track pin.

This vehicle carries an estimated 100-125 pounds of explosive, and has sufficient power to operate on practically all types of terrain. The control cable consists of three strands, in pairs, two for steering, and the third for setting off the detonator. In operation, the engines are started by a hand crank, the clutches engaged, and the tank then handled from the control box through the cable. Another version of this tank is powered by two electric motors.

SPECIFICATIONS

Weight      650 lbs.
Length 5 ft., 3 ins.
Width 2 ft., 10 ins.
Height 2 ft.
Ground clearance 5 1/4 ins.
Tread centers 2 ft., 3 ins.
Ground contact 2 ft., 6 1/2 ins.
Width of track 6 5/16 ins.
Pitch of track 2 13/16 ins.
Track links 47
Theoretical radius of action 770 yds.
Speed 4 to 6 m.p.h.
Armor
     Front plate (upper and lower nose) 9 mm
     Hull 16 gauge steel
Armament (100-125 est.) pound explosive charge
Engine Inline 2 cylinder, 2 cycle
Transmission Chain drive, through electric magnetic clutch.
Steering Controlled by two electric clutches

German: p. 40.1 (April 1, 1945)