Monthly Archive for October, 2009

30 cm Nebelwerfer 42: Rocket Projector

30 cm Nebelwerfer 42: Rocket ProjectorThis rocket projector very closely resembles the 28/32 cm Nebelwerfer 41. The individual projectors are of similar construction, each one being shaped to the contours of the standard 30 cm rocket ammunition. The rear portion, however, is considerably larger than that of the 28/32 cm projector to accommodate the larger propelling chamber of the 30 cm rocket. As a result of the heavier charge, this rocket achieves a range of 4,976 yards.

Both traversing and elevating mechanisms are identical with those of the 28/32 cm piece. Total traverse is 30 degrees, and elevation is 45 degrees. The firing mechanism is electric with a contact box located at the right side of the piece.

A sight bracket is located at the rear of the framework.

There is a small spade under the frame in the rear, but no other evidence of supports.

The ammunition for this projector is described on page 354.1.

German: p. 350 (May 1, 1945)

Schweres Wurfrahmen 40: Rocket Projectors on Semitrack Vehicles

Schweres Wurfrahmen 40: Rocket Projectors on Semitrack Vehicles This rocket projector is designed for use on half-tracked armored personnel carriers. The principal feature of the device is the carrier plate, three of which are mounted on each side of the half-track. Each is adjustable for elevation of 5° to 45°, and is believed to be equipped with an elevating scale. The actual projector consists of the crate in which the 28 cm or 32 cm rocket is packed, and which may be secured to the plates. Reports indicate that each vehicle carries six rounds, five of which are 28 cm high explosive and one 32 cm incendiary. Range figures are identical to those applying to the Schweres Wurfgerät 40 and 41 and the 28/32 cm Nebelwerfer 41. The photos above show the 3-ton armored semi-track (m. gp. Zgkw.) fitted with rocket projectors as described above.

German: p. 350 (May 1, 1945)

38 cm R. Sprgr. 4581: Rocket Projectile for Raketenwerfer 61

38 cm R. Sprgr. 4581: Rocket Projectile for Raketenwerfer 61

This projectile is fired from the Raketenwerfer 61 (see pages 38.3 and 38.4). It shows a radical departure from standard spin-stabilized rocket design by the use of insert splines at the after end of the motor body. These splines, fitting into the rifling of the projector liner, aid in giving an initial spin to the projectile.

The rocket consists of three main assemblies: the high explosive body, motor body, and nozzle assembly.

The high explosive body of two-piece welded construction is threaded internally at its after end to receive the motor body. The booster pocket and fuze adapter assembly is welded in position at the nose of the high explosive body. The bourrelet is located just behind the welded junction of the ogive and the cylindrical section.

The motor body is threaded externally to screw into the high explosive body and internally to receive the nozzle assembly. Both the explosive body and nozzle assembly are secured by means of two diametrically opposed set screws. Nine grooves for the splines are machined into the base of the periphery of the motor body. The high explosive body is filled with 270 pounds of the German explosive charge 13A, which is 50/50 poured amatol.

The 32 venturi holes in the nozzle plate are set at an angle of 14° to the axis of the rocket. In the center of the nozzle plate there is a threaded hole to receive the igniter primer for the rocket propellant.

A rear spacer ring welded to the nozzle plate aids in the positioning of the outer row of propellant charges.

SPECIFICATIONS

Caliber         38 cm (15 ins. approx.)
Total weight of rocket 761 lbs.
Overall length (not including fuze) 56.68 ins.
Diameter of bourrelet 14.94 ins.
Maximum range 6,179 yds.
Weight of explosive charge 270 lbs.
Weight of propellant charge 88.5 lbs.
Fuze Point detonating
Weapon from which fired Raketenwerfer 61

German: p. 354.2 (June 1, 1945)

X 4: Aircraft Launched Antiaircraft Rocket

X4: German Aircraft Launched Antiaircraft Rocket

The X 4 is an antiaircraft rocket designed by the Germans to be launched from planes. It was manufactured and reported to have been successfully tested, but never reached the point of combat operation. It is a wire-controlled, rocket-propelled, fin-stabilized missile fitted with a proximity fuzed warhead. The propulsion system is a bi-fuel rocket. Stabilization is achieved by means of four large fins fitted to the body of the rocket, and four smaller fins fitted to the tail. The smaller fins bear solenoid-operated control surfaces through which two-dimensional directional control is achieved. These are operated from the parent aircraft by means of a control unit and two insulated wires leading to the rocket. These wires are about 3 3/4 miles long.

Precise information about the warhead and fuzing system has not so far been recovered. The warhead consists of an uncased moulded grain of dinitroglycol-based explosive which depends on high blast effect. The fuze is a combination of acoustic proximity, impact, and self-destroying type. The proximity feature is functioned by aircraft propeller noises and a delay of 1/50-second is provided to enable the missile to approach the target after the acoustic impulse initiates the fuze. The body of the rocket houses the helical aluminum tube fuel tanks and combined two-compartment steel air bottle. The venturi protrudes from the tail portion. The rocket is made to rotate about its axis at the rate of one rotation per second. This permits stabilization in line of flight by a single gyro. The missile is carried on the parent aircraft on a conventional bomb carrier modified for this special purpose

SPECIFICATIONS*

Length (overall)       200 cm (6 ft., 6 3/4 ins.)
Length of warhead45 cm (1 ft., 5 3/4 ins.)
Diameter of warhead (at base)22 cm (8.675 ins.)
Total weight before launching60 kg. (132.3 lbs.)
Weight of warhead20 kg. (44.1 lbs.)
Fuel4.5 liters (approx.) 98-100% nitric acid
 2 liters (approx.) 57% crude m-xylidine
                          43% triethylamine
Thrust Initial 270 lbs. to 315 lbs. falling off progressively to 45 to 68 lbs. after 30 seconds.

*Not verified.

German: p. 375 (August 1, 1945)

150 mm Self-Propelled Howitzer

Japanese 150 mm Self-Propelled Howitzer

This weapon is the 38 year type (1905) 15 cm howitzer mounted on a medium tank chassis. The chassis resembles that of the Medium Tank Model 2597 (1937), Special, described on page 8.1. The armor is riveted in the characteristic Japanese fashion, and on the chassis is of the same thickness as on the corresponding tank chassis, with a maximum of approximately one inch. On the superstructure, the gun shield has one-inch frontal armor and one-half-inch side armor.

The vehicle uses the standard V12, air-cooled, diesel engine, and the type 97 medium tank suspension, consisting of six dual rubber-tired bogie wheels on each side. The weapon mounted on this vehicle is the type 38 (1905) 15 cm howitzer, a very short weapon. It has an interrupted screw breechblock opening to the right, and uses a percussion primer. The rifling is 58 inches long and has increasing right hand twist. The maximum range of the field howitzer is reported as 6,500 yards. The maximum elevation is 30 degrees.

A self-propelled vehicle mounting a gun of 75 mm or 105 mm caliber, employing the same chassis and with a superstructure somewhat resembling the present vehicle has been reported.

SPECIFICATIONS

Weight         15 tons
Length 18 ft.
Width 7 ft., 6 ins.
Height (overall) 93 ins.
Height of chassis 47 ins.
Height of shield 61 ins.
Ground clearance 14 ins.
Tread centers 6 ft., 7 ins.
Ground contact (approx.) 160 ins.
Width of track 13 ins.
Pitch of track 5 1/8 ins.
Track links 96
Fording depth 39 ins.
Theoretical radius of action:
   Roads 100 miles
   Cross country
Speed:
   Roads 25 m.p.h.
   Cross country
Armor: gun shield
   Front plate 1 in.
   Sides 1/2 in.
Armament 15 cm Howitzer, Model 38 (1905)
Ammunition (Rds).
Engine V12, air-cooled, diesel
Transmission 4 speeds forward; 1 reverse (high and low range)
Steering clutch brake
Crew probably 5

Japanese: p. 8.2 (August 1, 1945)

8 cm (7.62) High Angle Gun, Type 3

8 cm (7.62) High Angle Gun, Type 3 - Japanese

This weapon, previously erroneously called the Type 10, is a naval type antiaircraft gun, mounted on a pedestal which permits a traverse of 360 degrees. The gun tube, of built-up construction, recoils inside a sleeve type cradle. A guide on the bottom of the tube rides in a groove, preventing rotation of the tube. Since the trunnions are located at the rear of the tube, muzzle preponderance is compensated for by an equilibrator inside the pedestal.

A hand-operated, semi-vertical sliding type breechblock and a hydrospring recoil mechanism are used. Recoil and recuperator are located over the tube. A small cylinder above the recoil cylinder is apparently for storing an oil reserve.

The elevating handwheel is located to the left of the weapon, and the traversing handwheel to the right. Two platforms, one on either side attached to the superstructure, allow the layers to move with the gun in traverse.

A bracket on the left of the piece is believed to mount a telescope and range drum.

SPECIFICATIONS

Caliber       76.2 mm (3 ins.)
Weight of gun and mount5,290 lbs.
Weight of gun1,100 lbs.
Length of barrel40 cals.
Length of tube9 ft., 6 ins.
Height (traveling position)
Height (firing position)
Width (overall)
Length of chamber1 ft., 8 ins.
RiflingR. H. twist
No. of grooves24
Width of grooves
Depth of grooves
Width of lands
Muzzle velocity (H.E. shell)2,200 f/s
Max. range (horizontal)
Max. range (vertical)26,000 ft.
Rate of fire10 to 12 r.p.m.
Traverse360°
Elevation75°
Depression
Length of recoil
AmmunitionH.E. w/ powder train time fuze

Wt. of projectile12 lb., 11 ozs.

Japanese: p. 114.1 (August 1, 1945)

300 mm Short Howitzer, Type 7

Japanese 300 mm Short Howitzer, Type 7

This howitzer was captured on Luzon. The emplacement, circular in shape and measuring 33 feet in diameter and 8 feet in depth, was camouflaged by a house on rails which was rolled back when the guns were to be fired. A small garden of banana trees was planted around the emplacement to add to the effect.

The howitzer tube is believed to be a built-up type. The liner is rifled with a uniform right hand twist, calculated to be one turn in 9.4 calibers. Two air flasks are mounted on the carriage for blowing out the tube after firing. Two equilibrators are mounted below the tube. The breech mechanism is an interrupted screw type having 8 segments of 20 threads. A percussion hammer firing mechanism is operated by a lanyard. A short cartridge case is used for obturation.

The upper carriage is a rectangular steel frame approximately 18 feet, 9 inches long, and 4 feet, 8 inches wide, fixed to a baseplate. The lower carriage is a truncated steel cone embedded in concrete approximately 6 to 8 feet under the ground. The upper carriage baseplate rests on a rail above a worm wheel, fixed to the lower carriage which engages a spur rack fitted to the base of the upper carriage.

The traversing handwheel is mounted in a horizontal position engaging a vertical shaft which terminates in the worm gear. The elevating handwheels, one on either side of the tube, are mounted on the carriage in a vertical position. A direct shaft from the elevating handwheel terminates in a spur gear which engages the elevating arc.

A panoramic sight is mounted on the right side of the gun.

SPECIFICATIONS

Caliber     305 mm (12 ins. approx.)
Weight (firing position)
Length of tube and breech16 ft., 6 ins.
Length of carriage base18 ft., 9 ins.
Width of carriage base4 ft., 8 ins.
Length (firing position)
Height (firing position)
Width (overall)
Length of bore
No. of lands72
Width of grooves
Depth of grooves
Width of lands
Muzzle velocity (shell)
Max. range (horizontal)—Trans. document13,000 yds.
Max. range (vertical)
Rate of fire
Traverse360°
Elevation, scale reading70°
Depression, scale reading
Length of recoil, scale reading420 mm
Ammunition
Wt. of projectile—Trans. document970 lbs.

Japanese: p. 116.3 (August 1, 1945)

30 mm Mk. 108 A-3: Aircraft Machine Gun

30 mm Mk. 108 A-3: Aircraft Machine Gun

The Mk. 108 A-3 is an automatic, air cooled, belt-fed weapon operated by blowback and firing electrically from an open bolt. Initial cocking and initial depression of the sear to release the bolt are accomplished by compressed air. The gun is mounted on its side, and fires through the propeller hub in ME 109 G fighters. It is attached at the forward end of the receiver to a blast tube which extends through the engine. This gun is unusual in being a blowback operated, low muzzle velocity weapon.

Sixty rounds of ammunition are fed by means of a disintegrating belt from an ammunition can mounted above the gun. On release of the sear, the bolt travels forward under the action of two driving springs. A projection on top of the bolt passes through the ring extracting a round and forcing it into the chamber. After firing the empty cartridge case reseats itself in its link. The ejection is accomplished by pawls actuated by camming grooves cut in the top of the bolt. Position of a new round takes place by the same action. A feature of the gun is the fact that the barrel and receiver do not move in recoil, the entire force of which is taken up by the rearward motion of the bolt against driving springs which act as buffers on recoil. There is no locking action between the barrel and bolt at any time.

All ammunition found to date has been high explosive, high explosive-tracer, incendiary and incendiary tracer. It is doubtful if the muzzle velocity is high enough for the effective use of armor piercing ammunition.

SPECIFICATIONS

Caliber         29.6 mm (1.17 in.)
Weight (total) 265 lb.
Weight of gun 136 lb.
Weight of mount 28 lb.
Weight of ammunition can 36 lb.
Weight of ammunition (60 rounds) 65 lb.
Weight of recoiling parts 24 1/2 lb.
Length of gun with blast tube 7 ft. 6 3/4 ins.
Length of gun 3 ft. 5 1/4 ins.
Length of barrel 21 1/2 ins.
Number of lands and grooves 16
Maximum length of recoil of bolt 11 1/2 ins.
Rate of fire 500 rds./min.
Muzzle velocity (approx.) H.E.—1,650 f/s.*

*Not verified

German: p. 255

10.5 cm “Sabot” Type H. E. Shell

10.5 cm Sabot Type H. E. Shell

This new type projectile consists of an 8.8 cm streamlined shell body fitted with centering and rotating band rings which permit it to be fired from a 10.5 cm weapon. Both the centering ring and rotating band ring are so designed that they become detached from the shell body under the influence of centrifugal force on leaving the muzzle of the gun. The advantage of such a design, provided it functions properly, is that a lighter weight projectile of smaller diameter is fired from a 10.5 cm weapon instead of the normal 10.5 cm projectile. The effect is to give a higher muzzle velocity and longer range for the 8.8 cm streamlined shell body than would be obtained with the standard 10.5 cm high explosive projectile. However, the effectiveness is reduced due to lower weight of projectile.

One disadvantage of this type of shell lies in the possibility of injury to friendly troops when the centering rings and rotating band are cast from the projectile. The centrifugal force would make these pieces into dangerous missiles.

The complete weight of the projectile is 23 pounds. Projectiles examined have been filled with a high explosive charge, and fitted with a percussion type nose fuze (AZ 23v.). The 15 cm shell of similar design employs the same fuze. The explosive trains of these projectiles are similar to those for the usual type of German high explosive shell.

German: p. 311

7.92 mm M SS 41: Antitank Rifle

7.92 mm M SS 41: Antitank Rifle

This antitank weapon, a manually operated, magazine-fed, air-cooled, high-velocity rifle which was standardized for production in 1941, fires the same necked-down cartridge as the Panzerbüchse 39. Although classified as an antitank rifle, the use of heavier armor on modern tanks has rendered the weapon effective against lightly-armored vehicles only.

A hinged bipod similar to that of the MG 34 is attached to the front of the receiver jacket. It folds forward for convenience in carrying. The gun is also equipped With carrying handle and sling; the former is fitted to the top of the barrel group, and the latter is attached on the right side at the bipod and back plate assembly.

A “U” type rear sight and an adjustable front sight of the square block type fold to the rear when not in use.

The gun is put in a “Safe” position by pulling the barrel housing lock extension 1/4-inch to the rear so that its rear alignment mark is aligned with the mark “S” on the barrel housing lock. When in this position, the trigger cannot be pulled, nor can the action be opened. If the trigger is pulled while the action is not entirely closed, the gun will not fire. It is necessary to release the trigger and pull it again in order to release the sear. When the magazine is empty, the action is kept open by the protrusion of the magazine follower which stops the rearward movement of the barrel housing.

SPECIFICATIONS

Caliber       7.92 mm (.312 in.)
Weight (with empty magazine)29 3/4 lbs.
Length (overall)59 1/4 ins.
Sight radius30 15/16 ins.
Principle of operationManually operated
Feeding deviceMagazine
Capacity of feeding device6 rounds
Cooling systemAir
Ammunition types13 mm case necked down to 7.92 mm. Same as used in the PZ B39. See Page 211.)
Rate of fire
Type of sight“U” type rear sight; square block type front sight.
Weight of barrel (w/fittings)13 1/4 lbs.
Length of barrel43 3/8 ins.
Length of rifling
Rifling
     TwistR. H.
     Form
     No. of grooves4
     Depth of grooves
     Width of grooves
Muzzle velocity (estimated)3,540 f/s
Type of mountBipod

German: p. 210.1 (May 1, 1945)