Tag Archive for '37mm'

3.7 Stielgranate 41: 3.7 cm Stick Grenade

3.7 Stielgranate 41: 3.7 cm Stick Grenade Hollow-Charge Antitank

This deadly device is a hollow charge finned bomb for use on the 37 mm German Pak. It is believed that this type of ammunition was developed for the purpose of making this obsolescent gun more effective for antitank use.

The stick bomb which is made of pressed steel has a steel rod which fits into the bore and a perforated sleeve which fits around the barrel of the gun. The hollow charge is at the rear of the steel cup (or cone) and consists of two blocks of TNT with cyclonite. A nose fuze of the instantaneous percussion type and an instantaneous tail fuze are used. The nose fuze is used for impact against armor and the tail fuze is for graze action. Both fuzes arm on setback. The propelling cartridge consists of a steel case and is charged with tubular stick powder, an igniting charge of granular powder, and a percussion type primer.

Twenty-nine of these grenades were tested at Aberdeen. One was statically detonated against the face of 7-inch homogeneous armor plate. It penetrated completely, leaving a hole 2 1/8 inches wide at the face and 1 1/8 inches at the rear. The other rounds were fired from a German 37 mm A.T. gun for which they were designed. Range was found to be 203 yards at 5° elevation and 857 yards at 25° elevation. Accuracy was hard to determine because of the inexperienced gun crew.

SPECIFICATIONS

Caliber of rod       37 mm
Weight of grenade as fired18 lb., 12 oz.
Weight of burster5 lb., 5 oz.
Weight of propelling cartridge1 lb., 6 oz.
Overall length of round 29 1/8 ins.
Diameter of projectile body6 1/4 ins.
Types of fuze 1—P. D. Instantaneous
2—B. D. Instantaneous
Average velocity350 f/s
Average pressure18,600 p.s.i.
Range
     5° elevation203 yds.
     25° elevation857 yds.

German: p. 306

3.7 cm Pak: Antitank Gun

3.7 cm Pak: Antitank Gun

The 3.7 cm, formerly the chief German antitank gun, has been largely replaced by the 5 cm (1.97 in.) antitank gun. A stick bomb, 6 1/4 inches in diameter and with an overall length of 29 1/8 inches, has been recently introduced for use with the gun. The bomb, a hollow charge type, has a steel rod which fits into the bore of the piece, and a perforated sleeve which fits around the barrel. Its use is likely restricted to short ranges.

The gun is normally towed on its own wheels by a tractor but may also be carried on a lorry. Weighing 950 lbs., it is a suitable weapon for use by air-borne troops.

The piece consists of an “A” tube, jacket and breech ring combined. The breech block is of the horizontal sliding block type with a hand operated block stop.

The axle incorporates independent suspension which is, however, locked when firing, the freeing and locking being controlled by the opening and closing of the trail legs.

The lower carriage has a pivot housing and bearing face for the top carriage. It also carries the traversing rack, the travelling clamp and the locking gear for the trail legs and houses the axle.

The layer stands on the left side of the weapon and operates the traverse with his right hand by a small handwheel (clockwise to the right, anticlockwise to the left). The arc of traverse is 60°. The arc of 21° elevation and 13° depression is completed by 32 1/2 turns of the handwheel, which the layer operates with his left hand.

A hydraulic buffer and spring recuperator are provided.

The straight tube telescope sights are mounted on an upright bracket carried on the top carriage.

The shield is composed of the gun shield and leg shield, of 3/16″ armor plate. The leg shield folds under the lower carriage when travelling, and folds down to ground level when in action.

SPECIFICATIONS

Caliber         3.7 cm (1.45 in.)
Weight (firing position) 970 lbs.
Length of tube 65.52 ins. (50 cals.)
Rate of fire 8-10 r.p.m.
Muzzle velocity (A.P. shell) 2,625 f.s.
Range (maximum—horizontal) 600 yds.
Elevation 25°
Depression
Traverse 60°
Ammunition A.P.H.E.; H.E.; stick grenade

German: p. 130

3.7 cm Flak 18 and 36: Antiaircraft Gun

3.7 cm Flak 18 and Flak 36: Antiaircraft Gun

The performance of both the Flak 18 and the Flak 36 are approximately the same, the latter being the lighter and the more mobile version. The weapon is transported on a trailer; the chassis consisting of a “U” shaped steel frame mounted on two pneumatic tires. The weapon and its firing mount may be detached from the chassis by the aid of two winches. In firing position the mount rests on three adjustable firing pads. There are three seats provided; two for the gun pointers and one for the ammunition loader.

The gun has a monobloc tube. The firing mechanism is operated by recoil and residual pressure of gas in a manner similar to the 2 cm Flak 38.

The recoil mechanism is located inside the trough-shaped cradle with the buffer above and the recuperator below. Traversing and elevating mechanisms are operated by handwheels; the former providing a 360° traverse with 35 1/2 turns, and the latter giving a rate of about 4° for each turn. The gun is fired by means of a foot pedal connected to the trigger by a system of levers.

Armor-piercing ammunition is provided in addition to the regular high explosive ammunition, permitting the guns to be employed as antitank weapons.

SPECIFICATIONS

Caliber       37 mm (1.45 ins.)
Weight (traveling position) Flak 36—5,290 lbs.
Weight (firing position) Flak 36—3,430 lbs.
Length of piece (including flash hider) 129 ins.
Length of rifling 71 ins.
Height of trunnions 44 ins.
Width (overall)
Length of bore
No. of grooves 20—R.H. plain section,
  Twist, increasing (1 in 50 to 1 in 40)
Width of grooves 0.197 in.
Depth of grooves 0.02 in.
Width of lands 0.08 in.
Muzzle velocity (H.E. Shell) 2,610 f/s*
Max. range (vertical) 13,775 ft.*
Max. range (horizontal) 7,080 yds.*
Effective ceiling 5000 ft.*
Rate of fire (practical) 80 r.p.m.
Traverse 360°
Elevation 85°
Depression -5°
Length of recoil
Ammunition A.P., H.E.
Wt. of projectile A.P.—1.5 lb.
  H.E.—1.4 lb.

*Not verified.

German: p. 130.1 (August 1, 1945)