Month: September 2010

Categories
German

m. Zgkw. 5t (Sd. Kfz. 6): Medium Semitrack Prime Mover

m. Zgkw. 5t (Sd. Kfz. 6): Medium Semitrack Prime Mover

This is the medium 5-ton semitrack prime mover. It is designed as an artillery tractor to tow the piece and carry the gun crew of fourteen men. It is similar in design to all of the standard line of semitrack prime movers for artillery. It can tow a trailer load of 11,000 pounds when loaded to a combat weight of 19,360 pounds. The weight distribution on the front axle is 2,860 pounds, and on the track 16,500 pounds.

The suspension is made up of six dual-rim, rubber-tired bogie wheels, three of which are alternately straddle-mounted to torsion bars, followed by the idler which just clears the ground. The sprocket is fitted with contact rollers and rigidly mounted to the frame.

The vehicle is powered by a Maybach NL 38 TRKM 95 horsepower engine fitted with standard 12-volt Bosch magneto ignition and No. 40 JFF 2 Solex Carburetor.

The transmission combines the final drive which includes an epicyclic reduction gear for each sprocket. Steering is effected from the steering wheel in the usual manner up to 15°, after which the epicyclic steering brakes cause a reduction in the speed of the track on the inside of the turn, while through the differential a relative compensating action takes place.

This vehicle has a fuel tank capacity of 47 gallons; its highway fuel consumption is 1 gallon in 4 miles. The lifting winch which is fitted to the rear has a lifting power of 2.7 tons.

SPECIFICATIONS

Weight         8 tons
Length 19 ft., 9 ins.
Width 7 ft., 2 ins.
Height 8 ft., 2 ins.
Ground clearance 15 ins.
Tread centers 5 ft., 7 ins.
Ground contact 6 ft., 6 ins.
Width of track 12.6 ins.
Track links 55
Pitch of track
Fording depth 2 ft.
Theoretical radius of action
     Roads 180 miles
     Cross-country 71 miles
Speed
     Roads 30 m.p.h.
     Cross-country 18 m.p.h.
Armor
     Front plate
     Sides
Armament
Ammunition
Engine 6-cyl. Maybach HL 42 TRKM—100 hp.
Transmission 4 speeds forward, 1 reverse, high and low range
Steering 15° and over—Epicyclic controlled differential
Crew 15

German: p. 53

Categories
German

l. Zgkw. 3t (Sd. Kfz. 11): Light Semitrack Prime Mover

l. Zgkw. 3t (Sd. Kfz. 11): Light Semitrack Prime Mover

The following variations of the 3-ton light semitrack prime mover are known: (1) medium armored personnel carrier (Sd. Kfz. 251); (2) smoke vehicle (Sd. Kfz. 11/1) when it is apparently fitted with racks to carry generators; (3) medium decontamination vehicle (Sd. Kfz. 11/2); (4) medium bulk contamination vehicle (Sd. Kfz. 11/3); (5) ambulance. The vehicle is also used for mounting antiaircraft weapons.

The body and frame are constructed of electrically welded steel.

The suspension is the normal type as used for semitrack vehicles. Six pressed-steel, double-rim bogie wheels are straddle mounted on torsion bars which are housed in cross tubes, each containing two torsion bars. The track consists of rubber-pad track blocks which contain needle-bearings.

A normal type forged front axle is used to carry two pressed-steel wheels with 7.5 x 18 tires. No front brakes are provided. Triangular radius rods similar to conventional Ford system are attached from axle to cross members at rear of engine.

The power plant consists of a 6-cylinder, in-line, valve-in-head, liquid-cooled engine Maybach engine, type NL 42 TUKRR, rated 100 horsepower.

The vehicle has a radius of action of 168 miles on roads and 84 miles cross-country. It has a seating capacity for eight men, including the driver.

SPECIFICATIONS

Weight         6 tons
Length 18 ft.
Width 6 ft., 7 ins.
Height 7 ft., 3 ins.
Ground clearance 12.5 ins.
Tread centers 5 ft., 3 ins.
Ground contact 5 ft., 11 ins.
Width of track 11 ins.
Track links 54
Pitch of track 5.5 ins.
Fording depth 20 ins.
Theoretical radius of action
     Roads 168 miles
     Cross-country 84 miles
Speed
     Roads
     Cross-country
Trailer load 3.3 tons
Engine Maybach, NL 42 TUKRR—100 hp.
Transmission 4 speeds forward, 1 reverse, high and low range
Steering Front wheel and track epicyclic, controlled by normal steering wheel
Crew         8

German: p. 52

Categories
German

30 mm Mk. 101 (Rheinmetall): Aircraft Machine Gun

30 mm Mk. 101 (Rheinmetall): Aircraft Machine Gun

The Mk. 101, also known as the M.G. 101, is a scaled-up version of the Solothurn S-18-1000, 20 mm antitank rifle used by the Swiss, Italians, Hungarians, and to some small extent the Germans. It is Germany’s first attempt to put a gun of over 20 mm caliber in an airplane. It was designed to be used principally for antitank work, but a high-explosive round is furnished for antipersonnel use.

It has been used mostly on the Russian front in the Heinkel 129, a heavily armored plane especially designed for ground attack. Neither the Mk. 101 nor the plane has worked out too well, and a new 23 mm Mauser cannon and two new 30 mm guns, the Mk. 107 and Mk. 108, are now coming into use in the German Air Force.

In the Heinkel 129, the Mk. 101 was fixed to a mount that could be attached to the bomb racks under the fuselage when the plane was sent on a tank-hunting or other special mission. The gun is a recoil-operated, magazine- or drum-fed, semi- or full-automatic, air-cooled weapon. It does not have a particularly high velocity; the armor-piercing, high-explosive tracer ammunition gives a velocity of 2,330 f/s, and the light armor-piercing tungsten carbide-cored round, 2,800 f/s.

SPECIFICATIONS

Caliber         30 mm (1.18 ins.)
Operation Recoil
Feed system 10- or 20-round box magazine; 30-round drum
Weight 394 lb. (without mount)
Length 96 ins. (overall)

German: p. 253

Categories
German

20 mm M.G. 151/20 (Mauser): Aircraft Machine Gun

20 mm M.G. 151/20 (Mauser): Aircraft Machine Gun
The M.G. 151/20 mm and M.G. 151/15 mm (Mauser) were designed and built by the famous Mauser factory. The M.G. 151/20 is a fixed aircraft cannon, recoil-operated and belt-fed, using a disintegrating metallic link belt. It was manufactured also in a 15 mm form. Although the receiver group and the recoiling portions are not identical, the superficial appearance of the two guns is very similar.

Two of these guns are mounted in each of the Focke-Wulf FW 190 types of planes. In this installation, they are synchronized, firing through the propeller arc. They are installed in the wing roots about 12 inches out from the engine cowling with the barrels protruding about 2 feet beyond the leading edge.

This gun is electrically cocked and fired, and electric detonation of the cartridge has been adopted in order to facilitate interruption when it is used as a synchronized gun. A longer-barreled version with mechanical detonation is used when the gun is mounted to fire through the propeller hub as in the ME-109.

In the version mounted in the fuselage, the feeding device has a capacity of 50 rounds, but more rounds are usually carried for each gun when it is wing mounted. A streamlined container holds the gun and the belted ammunition in newer installations.

The following types of ammunition are used in the 20 mm version: H.E. with S.D. fuze; H.E.I./T. with S.D. fuze; A.P.I., A.P.H.E., and two different H.E.I. (S.D. fuze) rounds.

SPECIFICATIONS

Caliber         20 mm (.787 in.)
Weight including electric control 93 1/2 lb.
Weight of barrel 22 lb., 14 oz.
Overall length 69 1/2 ins.
Length of barrel 43 1/2 ins.
Principle of operation Short recoil, no muzzle recoil booster, rotating bolt head
Cooling system Air
Feeding device Disintegrating metallic link belt
Capacity of belt 50 rds. and multiples thereof
Muzzle velocity (H.E.) 2,656 f/s
Rate of fire 780 r.p.m.
Ammunition used H.E. with S.D. fuze; H.E.I./T. with S.D. fuze; A.P.I.; A.P.H.E.; and two different H.E.I. (S.D. fuze) rounds.

German: p. 252

Categories
German

20 mm M.G. F.F.M. (Oerlikon): Aircraft Machine Gun

20 mm M.G. F.F.M. (Oerlikon): Aircraft Machine Gun

This flexible 20 mm aircraft machine gun, Oerlikon M.G. F.F., is the German Air Force version of the Swiss Oerlikon 20 mm machine gun.

The weapon is a blowback, inertia-operated, air-cooled machine gun for fixed or flexible mounts. It fires from an open bolt and has an electrically operated trigger mechanism. The cartridge-counting mechanism is also electrically operated. It has a pneumatic charging mechanism to retract the bolt for the first shot.

Some minor modifications of the Swiss version of this machine gun have been introduced. It is chambered to fit the short German 20 mm round, and the travel of the recoiling parts has been redesigned to conform. The barrel has been shortened and the gun lightened considerably. It has been in use in this form without material alteration since the beginning of the war.

The gun was originally intended as a fixed weapon and was termed the M.G. F.F. A later type, the F.F.M., is mechanically the same but in some cases is provided with a cooling cowling and a hand firing device for use as a free gun. It is used both as a flexible and a fixed gun.

SPECIFICATIONS

Caliber         20 mm
Weight 76 1/2 lb.
Length 57 ins.
Feed Drum—60 rd. capacity
Length of barrel 32 1/4 ins.
Cooling Air
Operation Blowback (inertia) with solenoid trigger
Fire Automatic only
Rate of fire 450 to 500 rds./min.—cyclic

German: p. 251

Categories
German

13 mm M.G. 131: Fixed or Flexible Aircraft Machine Gun

13 mm M.G. 131: Fixed or Flexible Aircraft Machine Gun

The German flexible aircraft machine gun, M.G. 131, 13 mm, is the Nazi tactical counterpart of the U.S. Browning, cal. .50, M2. Action is a Solothurn type—that is, the locking cam on a rotating bolt head engages a cylindrical locking collar to lock the action for firing. It is fed by a metallic disintegrating-link belt.

The M.G. 131 is used singly and in twin-mounted versions in hand-operated mounts and power-operated turrets in many German bombers. The recoil operation is assisted by a muzzle recoil booster. It is unusual in that the cartridges are ignited electrically instead of by a mechanically operated firing pin.

It is a recoil-operated, gas-assisted, belt-fed, air-cooled, automatic weapon that is coming into more extensive use in the German Air Force.

SPECIFICATIONS

Caliber         13 mm (.512 in.)
Weight 40 lb.
Length 46 ins.
Rate of fire 900 rds./min.—cyclic
Muzzle velocity 2,370 f/s
Sights Refractor type on mount
Ammunition 13 mm Solothurn types—A. P., T; H. E., T

German: p. 222

Categories
German

28 cm Wurfkörper Spr.: 28 cm Rocket Projectile

28 cm Wurfkörper Spr.: 28 cm Rocket Projectile

This package-type rocket is a self-contained unit fired from a metal or wood crate. Firing is accomplished by “pointing” the crate at the target, resting the front part of the crate on a mound of dirt (or a similar rest) at an angle from 5° to 45°, and firing by means of a hand electrical firing system.

The propellant charge, contained in the motor tube, is in the form of one stick weighing 14 lb., 9 oz. with one central hole and eight annular holes.

Eight grooves are formed in the sides of the propellant stick, and celluloid tubes are fitted into these grooves. A length of quickmatch in the central hole is inclosed in a celluloid tube.

There are two igniters, one at the front and one at the rear of the propellant. The rear igniter consists of a cloth bag containing 10 grams (154 grains) of NC powder. The front igniter is a metal holder containing a flash composition with a layer of initiating composition.

The bursting charge is contained in the large section, directly forward of the rocket motor tube.

The booster, known as Zdlg. 36, consists of a cylindrical aluminum container filled with penthrite wax and perforated at the top to house a thimble-shaped detonator.

The fuze, Wgr. Z. 50, is a point-detonating or graze action type. The safety pin is removed before firing, leaving the two centrifugal bolts and a split ring to act as a safety feature in flight. The detonator is situated in the inertia pellet.

There are 26 jets at the end of the motor tube inclined approximately 12° right, giving it rotation in flight for stability. The internal diameter of the jets is 0.5 cm (.19 in.) and the external diameter 1 cm (.38 in.).

SPECIFICATIONS

Weight (total)         181 lb.
Length (overall) 3 ft., 11 ins.
Length (body) 2 ft., 4 1/2 ins.
Length (tail) 1.85 ft.
Diameter (body) 11 ins.
Diameter (tail) .59 in.
Number of ports 26
Contents 110 lb. TNT
Range (maximum) at 42° 2,337 yds. (estimated)

German: p. 354

Categories
German

32 cm Wurfkörper M. Fl. 50: 32 cm Rocket Projectile (Incendiary)

32 cm Wurfkörper M. Fl. 50: 32 cm Rocket Projectile (Incendiary)

The operation of this rocket is very similar to that of the 28 cm Wurfkörper. It is fired from the crate, either metal or wood.

This rocket is stabilized by rotation due to the angle of the jets, of which there are 26 inclined at an angle of 14°. The internal throat diameter of the jets is 5.5 mm.

The motor tube is a solid forging, machined inside and out and threaded externally at both ends. The closed end screws into the bomb section; the open end receives the venturi block.

The propellant charge consists of a single multiperforated stick. It is supported at the venturi end on a flat grid held to the venturi block by means of a bolt. The grid consists of a ring 3/16 inch thick, 4 3/8 inches in external diameter, and 3 1/8 inch in internal diameter supported by six small cylindrical spacers 1/2 inch in diameter and 3/8 inch high from a flat plate 1/10 inch thick and 4 3/8 inches in diameter. The free space at the closed end of the 4 3/8 inches in diameter.

The ignition system consists of an electrical igniter inserted in place of the screw in the bolt in the center of the venturi block. Behind the igniter lies a bag of rough cloth containing 10 grams of the primary igniter composition in the form of six-pointed star-shaped flakes. A maintainer composed of compressed pellets in an aluminum container is situated at the closed end of the tube and acts as an igniter composition. The rapid transmission of the flash between these two is effected by the lengths of inflammable tubing housed in the conduits of the charge. The one in the center conduit is quickmatch; the tube is closed at each end by a gunpowder pellet.

A thin sheet of aluminum acts as a sealer at the venturi end. This does not appear to be sufficient to prevent the entrance of moisture. The bomb head contains 11 gallons of oil and a point-detonating fuze.

SPECIFICATIONS

Weight (total)         174 lb. (approx.)
Weight of motor tube 23 lb., 14 oz.
Weight of motor tube (filled) 49 lb., 8 oz.
Weight of venturi block and bolt 9 lb., 6 oz.
Weight of propellant charge 14 lb., 7 oz.
Weight of grid 1 lb., 1 oz.
Length (total) 5.08 ft.
Length (body) 3.3 ft.
Length of motor tube (overall) 18 5/8 ins.
Diameter of bomb 32 cm
Diameter of motor tube (external) 5 1/2 ins.
Diameter of motor tube (internal) 5 ins.
Depth of motor tube (internal) 18 ins.
Range (maximum) at 42° 2,217 yds. (approx.)

German: p.353

Categories
German

S. Mi. 35: Antipersonnel Shrapnel Mine

S. Mi. 35: German WW2 Antipersonnel Shrapnel Mine

The German shrapnel mine is an antipersonnel device which may be operated by direct pressure of about 15 pounds on a push igniter in the head, or by a pull on one or more trip-wires attached to pull-igniters. It may also be fired by electrical methods.

The mine is cylindrical in shape; its height is 5 inches, its diameter is 4 inches, and it weighs approximately 91/2 pounds. It contains an explosive charge of about 8 ounces in some models and 1 pound in others, and approximately 350 steel balls.

An inner cylinder of pressed steel is fitted into the outer jacket, resting on a metal disk which is fixed to the bottom of the outer cover. The charge is contained in a movable cylinder which is screwed to the disk in the bottom of the mine. This cylinder has a central tube and three other parallel tubes. A train of powder in the bottom of the central tube, 2 grams of powder in a recess under the movable cylinder, and the shrapnel, which is contained in the space between the inner jacket and the movable cylinder, complete the assembly.

A cover plate is attached to the mine. This plate has an opening through which the central tube passes, and three other openings in alinement with the three parallel tubes in the powder container.

For firing, an igniter is screwed to the central tube, and a detonator is inserted (sometimes two) in each one of the three other tubes. When the igniter fires, the flame produced flashes down the center tube, setting off the small powder charge which throws the inner cylinder into the air. At the same time, the detonators are ignited, and they in turn set off the main charge. The delay in detonation of this charge permits the casing to rise from 6 to 7 feet into the air before exploding. The shrapnel filling is effective up to a range of about 150 yards to 200 yards.

SPECIFICATIONS

Height (without igniter)         5 ins.
Weight of mine (approximate) 9 1/2 lb.
Weight of filling (approximate) TNT 8 oz. to 1 lb.
Type of filling TNT and PETN
Diameter of mine 4 ins.
Diameter of steel balls .372 in.
Mine wall thickness .050 in.
Weight of 350 steel balls 2 lb., 10.67 oz.
Black powder propellant 0.15 oz.
Explosive carton complete 1 lb., 0.14 oz.
Three types of igniters are used:
     Pressure type
     “Y” adapter w/2 pull igniters
     Electric squib type

German: p. 305

Categories
German

Behelfs-Schützenmine S. 150: Antipersonnel Mine

Behelfs-Schützenmine S. 150: Antipersonnel Mine

The German Behelfs-Schutzenmine S. 150, known to allied troops in the field as the “Pot Mine,” “Picric Pot,” “Mustard Pot,” or “Jerry Mine,” consists of a cylindrical body, a top plate, and a crush igniter.

The body, which is made of pressed steel, contains a 5 1/4 oz. explosive charge of powdered picric acid. A chemical crush-actuated igniter is screwed into the mine by means of a brass or plastic adapter which fits into the top of the body. A synthetic rubber washer is provided between igniter and adapter for waterproofing the mine. The igniter, known as the German Buck Igniter (Chemischer Zünder Buck) consists of a thin metal drum with circumferential grooves to reduce its resistance against vertical pressure. It contains a glass ampule half filled with acid and surrounded by a white powdered flash composition. A small brass detonator (German Nr. 8) is inserted into the detonator pocket.

A moderate pressure on the top of the igniter crushes the metal drum and the glass inside it. The acid pours into the white powder, and a flash resulting from their chemical interaction sets off the detonator which in turn sets off the mine.

SPECIFICATIONS

Height of body         2 ins.
Diameter of body 2 1/2 ins.
Diameter of top plate 3 ins.
Height of igniter 1 1/2 ins.
Diameter of igniter 3/4 in.
Depth of detonator pocket 1 1/2 ins.
Total weight 12 1/2 ozs.
Weight of igniter with adapter 1 oz.
Explosive charge Powered picric acid (5 1/4 oz. approx.)
Color Mustard brown

German: p. 304.7