Monthly Archive for March, 2010

7.92 mm Granatbüchse 39 (Gr. B. 39): Grenade-Launching Rifle

7.92 mm Granatbuchse 39 (Gr. B. 39): Grenade-Launching Rifle

The German grenade-throwing rifle (Granatbüchse 39) is a modification of the Pz. B 39 antitank rifle. The breech and shoulder stock are the same. Some parts, such as the bipod, bipod lock, carrying sling, sling band, and carrying handle are the same as on the Pz. B 39 but are at different locations on the barrel.

The barrel has been shortened to 24 1/8 inches. At the forward end, 4 7/16 inches of the barrel have been turned down to 13/16-inch diameter, and threaded back approximately 1 3/8 inch to accommodate the launcher base. The standard sights have been replaced by special sight equipment. The wooden forearm has been removed, and the carrying sling has been changed to the right side because of the position of the new sights. The bipod mount is located 6 3/4 inches forward of the breech.

The launcher threaded to the barrel is the Scheissbecher, which is also used on the Mauser Kar 98K rifle, firing the same grenades as with the present weapon. The launcher is 7 inches long; the inner tube is 5 1/8 inches long and 1 1/2-inch in external diameter.

Three types of grenades can be fired from the weapon: (1) antipersonnel grenade (Gewehr Sprenggranate); (2) small antitank grenade (Gewehr Panzergranate); (3) large antitank grenade (Gross Gewehr Panzergranate). The propelling medium used is a wooden bulleted blank cartridge. The cartridge case used is a standard 7.92/13 mm case such as is used in the Pz. B 39 antitank rifle.

SPECIFICATIONS


Caliber of launcher         3 cm (1.18 in.)
Weight 23 lb.
Length 48 1/2 ins. extended
35 3/4 ins. folded
Length of barrel 24 1/8 ins.
Length of barrel with discharger 29 1/2 ins.
Feed Handfeed
Effective range 80 yds. on moving targets
136 yds. on stationary targets
Front sight Special grid type sight graduated up to 150 meters for the Gewehr Panzergranate grenade
Hear sight Fixed sight with open U notch

German: p. 212

7.92 mm Panzerbuchse 39 (Pz. B. 39): Antitank Rifle

7.92 mm Panzerbuchse 39 (Pz. B. 39): Antitank Rifle

The German antitank rifle, Pz. B 39, 7.92 mm, is a weapon of opportunity which is used by the German Army against vehicles having light and medium armor. It fires a cartridge similar to that used in the Polish Mascerzek antitank rifle. This cartridge also resembles the American .50/.30 which has been under development in this country since 1931.

The projectile has a tungsten carbide core and is known to have a small pellet of a lachrymator as well as a tracer mixture. Penetrating power of the bullet at 300 yards’ range is 3/4 inch at 20°, and 1 inch at normal against face-hardened plate. At 100 yards’ range, penetration is 1 1/4 inches at normal.

The weapon has proved to be a simple and reliable gun. The recoil is comparatively light. The rifle is manually loaded and fired single shot from the shoulder with the aid of a bipod. It is equipped with a circular turbine muzzle brake.

The Germans also have an earlier version of this weapon known as the Pz. B 38 which is 7 pounds heavier, has a self-ejecting action, and is more elaborate than the hand-operated Pz. B 39. It fires the same ammunition as the more recent rifle.

The Pz. B 39 uses ammunition boxes holding 10 rounds each, mounted on brackets on each side of the wood stock. These are not magazines but serve to hold the ammunition so that it can be quickly and easily removed for hand loading.

SPECIFICATIONS

Caliber         7.92 mm (.312 in.)
Weight 27.25 lb.
Length (with shoulder stock extended) 62.25 ins.
Ammunition 13 mm case necked down to 7.92 mm. Bullet has tungsten carbide core with tracer and lachrymotor mixture.
Sights Rear, fixed with open U notch. Front covered blade.
Capacity Single rounds
Muzzle velocity 3,540 f/s

German: p. 211

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

4.2/2.8 cm Pak 41: Tapered Bore A.T. Gun

4.2/2.8 cm Pak 41: Tapered Bore A.T. Gun

The Pak 41 first appeared in the European Theater of Operations in 1942. It is the second of the German tapered-bore antitank guns. The monobloc barrel is long, with marked external as well as internal taper. There is no muzzle brake. The breechblock is of the horizontal sliding wedge type opening to the left. There is no provision for automatic opening; it is manually opened by means of the operating handle situated on top of the breech ring. The firing mechanism is a combination percussion inertia type.

The recoil mechanism of the hydro-spring constant type is similar in construction to the 3.7 cm Pak. It is housed in the cradle. The recoil cylinder moves with the barrel; the piston rod, secured to the front of the cradle, remains stationary. The buffer rod is centrally fixed to the rear of the recoil cylinder and slides in the hollow piston rod.

The elevation and traverse mechanisms are both fitted to the left side of the upper carriage.

The piece is mounted on the 3.7 Pak carriage fitted with sheet-metal, pneumatic-tired wheels, with tubular trails approximately 7 feet, 3 inches long. A light, steeply sloping, spaced armor shield is also provided.

A curved arm, riveted to the left side of the upper carriage, houses at its upper end the sight bracket trunnion from which the telescope carrier is hung.

Gerlich type ammunition, both H.E. and A.P., is used with the piece.

SPECIFICATIONS

Caliber         42/28 mm
Weight 1,360 lb.
Rate of fire 10-12 rds./min.
Muzzle velocity 4,101 f/s
Weight of projectile (A.P.)* .80 lb.
Elevation 19°
Depression -14°
Traverse 44°
Penetration

          30°         Normal
500 yds. 77 mm 94 mm
1,000 yds. 55 mm 68 mm
*This is a lightweight projectile consisting of a small tungsten carbide core embodied in a lightweight metal jacket. The jacket is so constructed that it is swaged to a smaller diameter as it moves through the tapered bore. This design permits a high muzzle velocity, but can be used for short ranges only as the velocity falls off rapidly. Penetration is accomplished by the core only, and because of its relatively small size very little damage is effected by it.

German: p. 128

Pz. Jäg. II Aus. A-E u.F für 7.5 cm Pak 40 (Sd. Kfz. 131): S.P. Antitank Gun

Pz. Jäg. II Aus. A-E u.F für 7.5 cm Pak 40 (Sd. Kfz. 131): S.P. Antitank Gun: Marder II

Produced in 1942. This antitank equipment was encountered in the battle of Tunisia. It is composed of the 7.5 cm antitank gun mounted on a Pz. Kpfw. II chassis and its road performance will closely follow that of the Pz. Kpfw. II tank.

The gun, which retains its original shield, recoil system, traversing and elevating gears, is mounted on a platform high on the hull and fires forward. A protective shield 10 mm thick, which slopes away to the rear of the chassis, has been provided. The shield is nearly rectangular except for a projecting portion in front of the gun mounting itself and the top and back are apparently open. The traverse of the gun is limited due to the gun shield fouling the protective shield. A barrel support for travelling is fitted in front of the hull.

The piece, 134 inches in length, is a monobloc type, semi-automatic, with horizontal sliding breech. It consists of barrel with shoes; breech ring with locking ring; breech block with firing mechanism; semi-automatic gear and muzzle brake. The recoil mechanism is comprised of a buffer cylinder, filled with a mixture of glycerine and distilled water, mounted in the cradle and secured by a nut to the front end plate. The piston rod, which is connected to the gun lug, is hollow, and is fitted with a bronze piston head. Ports are drilled in the conical part of the piston. A tapered rod is screwed into the front plug of the cylinder and projects into the hollow piston rod. During recoil the piston moves to the rear and the oil is forced from the buffer cylinder through the ports in the piston and hence through the annular space between the tapered rod and a bushing fitted in the piston. Recoil control is effected by a brass control plunger screwed to the end of the tapered rod. The recuperator is hydro-pneumatic.

SPECIFICATIONS

Weight         10 tons

Length 15 ft., 2¾ ins.
Width 7 ft., 4 ins.
Height 6 ft., 5¾ ins.
Ground clearance 13 ins.
Tread centers 6 ft., 2 ins.
Ground contact 7 ft., 10 ins.
Width of track 11 1/8 ins.
Pitch of track 3 5/8 ins.
Track links 105
Fording depth 3 ft.
Theoretical radius of action
   Roads 118 miles
   Cross-country 78 miles
Speed
   Roads 25 m.p.h.
   Cross-country 12 m.p.h.
Armor
   Front plate 15 + 20 mm
   Sides 15 mm
Armament 7.5 cm Pak 40 A.T. gun
   Max. effective range 3200 yards
   M.V. (Wt. 12.6 lb.) H.E. 1800 f.s.
   M.V. (Wt. 15 lb.) A.P.C. 2525 f.s.
   Elevation -5° to +22°
   Traverse 65°

    Penetration of homogeneous
armor—A.P.C.B.C. shell
  30° Normal
500 yds.         4.0″         4.8″
1000 yds. 3.6″ 4.3″
1500 yds. 3.2″ 3.9″
2000 yds. 2.8″ 3.4″
2500 yds.         2.5″         3.0″
Ammunition
Engine Maybach HL 62 TRM, 140 h.p.
Transmission Crash-type gear box, 6 fwd. speeds, 1 reverse
Steering Epicyclic clutch brake
Crew Probably 4

German: p. 11

Pz. Kpfw. I Aus. A (Sd. Kfz. 101): Light Tank

Pz. Kpfw. I Ausf. A (Sd. Kfz. 101): Light Tank

This tank was evolved from the experimental model K-1 which appeared in 1934. Manufactured by the Krupp Company, both tanks were equipped with an air-cooled, four-cylinder, 65 horsepower gasoline engine, Krupp Model M305.

The turret is of horseshoe design, with flat front, the sides and rear being one rolled plate. The superstructure is octagonal with driver’s vision port on the left side of the front plate. Pistol ports are located on three corners of the fighting compartment. An exhaust silencer is placed on each track guard to the rear.

The suspension consists of four rubber-tired bogie wheels, adjustable trailing idler, front sprocket, three return rollers and outside center-guide steel track with dry pin. The idler and rear bogie wheel are paired to articulate on a stub axle. The two center bogie wheels are paired also. Quarter elliptic springs, assisted by a coil spring, absorb road shock. The front bogie is independently mounted and resisted by a coil spring plus a luvax shock absorber. Both articulating bogies are connected by a steel girder.

From the engine the drive is taken to the propeller shaft to the clutch, thence to the crash-type transmission, which is mounted forward on the right of the driver. There are 5 speeds forward and one reverse.

From the transmission the drive is taken through a bevel gear box to steering units of the clutch and brake type on each side. The two steering levers are each provided with two grips, one for normal steering and the other with thumb plunger which operates a “fly-off” type catch for holding the levers back and thereby providing a parking brake. No normal hand brake is fitted. From the steering units the drive is taken via two rubber disc-type universal joints to the final drive reduction gears, mounted inside the hull, to single sprockets driving from the front.

SPECIFICATIONS

Weight        5.7 tons
Length 13 ft., 2 ins.
Width 6 ft., 9 ins.
Height 5 ft., 7 ins.
Ground clearance 12 ins.
Tread centers 5 ft., 5 ins.
Ground contact 8 ft., 1 in.
Width of track 11 ins.
Pitch of track 3 11/16 ins.
Track links 89
Fording depth 2 ft.
Theoretical radius of action
   Roads 112 miles
   Cross-country 81 miles
Speed
   Roads 25 m.p.h.
   Cross-country 15 m.p.h.
Armor
   Front plate 14 mm
   Sides 10 mm
Armament Two 7.92 mm M.G. 13
Ammunition (rds.) 1525
Engine 65 h.p. Krupp Model M305
Transmission 5 speeds forward, 1 reverse
Steering Clutch brake
Crew 2

German: p. 1

s. Betr. St. Kess. Kw. (o): Heavy Fuel Servicing Truck

s. Betr. St. Kess. Kw. (o): Heavy Fuel Servicing TruckGerman nomenclature: schwerer Betrieb­stoff­kessel­kraft­wagen (o) mit Fahr­gestell des schwerer Last­kraft­wagen (o).

English designation: Heavy fuel servicing truck with special chassis for heavy motor truck (standard commercial vehicle).

SPECIFICATIONS

Net weight         8,000 kg         17,636 lb.
Pay load* 5,000 kg 11,023 lb.
Gross weight 13,000 kg 28,659 lb.
Weight: Front axle 5,000 kg 11,023 lb.
Weight: Rear axle 8,000 kg 17,636 lb.
Length (overall) 8,500 mm 27 ft., 10 ins.
Width (overall) 2,500 mm 8 ft., 2 ins.
Height (overall) 2,600 mm 8 ft., 6 ins.
Ground clearance 200 mm 7 7/8 ins.
Tread centers 1,980 mm 6 ft., 6 ins.
  2,150 mm 7 ft.
Wheelbase 5,200 mm 204 ins.
Wheel width 320/680 mm 12½/26¾ ins.
Angle of approach   45°
Angle of departure   30°
Seating capacity   1
Fording depth 450 mm 17¾ ins.
Climbing ability   15°
Overturn gradient (lengthwise)   50°
Overturn gradient (crosswise)   30°
Turning radius 23 meters 75 ft., 5 ins.
Trailer load
Engine horsepower 110 c-v 108.5 hp
Piston displacement 10,000 cu cm 600 cu. ins.
Fuel tank capacity 150—150 liters 39.6 gal.
Highway fuel consumption   5.9-7.8 m.p.g.
Average terrain fuel consumption
*Cyl. of 6,500 l. cap   1,717 gal.

German: p. 74.50

m. Betr. St. Kess. Kw. (o): Medium Fuel Servicing Truck

m. Betr. St. Kess. Kw. (o): German Medium Fuel Servicing TruckGerman nomenclature: mittlerer Betriebstoffkesselkraftwagen (o) mit Fahrgestell des mittleren Lastkraftwagen (o).

English designation: Medium fuel servicing truck with special chassis for medium motor truck (standard commercial vehicle).

SPECIFICATIONS

Net weight         5,500 kg         12,125 lb.
Pay load 2,800 kg 6,173 lb.
Gross weight 8,300 kg 18,298 lb.
Weight: Front axle 2,600 kg 5,732 lb.
Weight: Rear axle 5,700 kg 12,566 lb.
Length (overall) 6,750 mm 22 ft., 1 in.
Width (overall) 2,250 mm 7 ft., 4 ins.
Height (overall) 2,600 mm 8 ft., 6 ins.
Ground clearance 240 mm 9½ ins.
Tread centers 1,600 mm 5 ft., 3 ins.
  1,880 mm 6 ft., 2 ins.
Wheelbase 4,500 mm 177 ins.
Wheel width 220/460 mm 8 5/8 / 18 1/8 ins.
Angle of approach   60°
Angle of departure   23°
Seating capacity   1
Fording depth 500 mm 20 ins.
Climbing ability   15°
Overturn gradient (lengthwise)   40°
Overturn gradient (crosswise)   25°
Turning radius 20 meters 65 ft., 7 ins.
Trailer load 2,000 kg 4,409 lb.
Engine horsepower 80 c-v 78.9 hp
Piston displacement 7,000 cu cm 420 cu. ins.
Fuel tank capacity 120 liters 31.7 gal.
Highway fuel consumption   6.7-8.4 m.p.g.
Average terrain fuel consumption

German: p. 74.50

Werkstattzug: Work Shop Train

Werkstattzug Machine Shop Truck

The German workshop train is reported to consist of eight vehicles, among which are (1) the spare parts truck which has a stake body and canvas top and carries various types of spare parts for automotive equipment stowed in cabinet bins; (2) the machine shop truck which has a van-type body and is equipped with electrically driven lathe, drill press, bench grinder, and valve grinding-machine, together with various tools used for automotive repair; (3) the electrical repair truck which has a van-type body and is equipped with armature grinder, battery chargers, soldering irons, spark plug tester, etc. The electrical repair truck is used in conjunction with automotive repair work as it is also equipped with wheel aligner and diesel injector testing machine.

The electrical motor-driven units of the two van-type trucks require an external source of current, believed to be either 220 volts or 380 volts inasmuch as the trucks have no generating equipment except for the starter and light circuits. By means of an electrical control panel, switches, and circuit breakers the correct voltage for use by the electric motors is selected from the external current, believed to emanate from a truck-drawn trailer fitted with generating equipment.

All three vehicles have the Bussing Nag 4½-ton truck chassis, Model 4500A four wheel drive.

The personnel of the entire train, including the foreman, drivers, electricians, tinsmiths, blacksmith, saddlemaker, painter, carpenter, and mechanics, numbers about thirty.

MACHINE SHOP TRUCK
SPECIFICATIONS

Weight         9.5 tons
Load 9,620 lb.
Length 24 ft., 11 ins. (overall)
Width 7 ft., 6¾ ins.
Height 10 ft., 1 in. (to top of body)
Ground clearance 11 in. (front), 11¾ in (rear)
Wheelbase 15 ft., 10 ins.
Length of body panel 14 ft., 7¼ ins.
Front wheel centers 6 ft., 4¾ ins.
Weight distribution
   Front 7,900 lb.
   Rear 11,060 lb.
Tires
   Front 270 x 20, single
   Rear 270 x 20, double
Fording depth 30 ins.
Theoretical radius of action
   Roads 310 miles
   Cross-country
Speed
   Roads 40 m.p.h. max.; 26 m.p.h. normal
   Cross-country
Fuel tank capacity 29 gals.
Engine Diesel, 4 cycle, 105 hp. at 1,800 r.p.m.
Transmission 5 speeds forward, 1 reverse
Clutch Double plate, dry
Steering Normal, worm gear
Differential gear Spiral bevel type
Driving axle Floating type rear axle
Brakes Compressed air-hydraulic, 4 wheels
Crew

German: p. 61

Raupenschlepper OST (Steyr typ RSO/01): Full Track Light Prime Mover

Raupenschlepper OST (Steyr RSO): Full Track Light Prime Mover

The German full track truck has recently appeared on the battlefield as a supply vehicle and prime mover. Basically it is a tracked version of the Steyr 1½-ton truck. Designed to operate in mud and soft terrain, it has a tractive effort in first gear of 6,700 pounds, and carries a load of 3,360 pounds. This truck averages 3 to 5.5 miles per gallon of fuel.

The chassis is of rectangular form and welded construction and supports a forward-mounted, pressed-steel driving cab behind which is mounted a wooden truck body. A spring-loaded pintle is fitted at the rear and towing hooks in front.

The V-8 air-cooled gasoline engine made by Steyr develops about 70 hp. at 2,500 r.p.m. and is mounted in the floor of the driving cab. The drive is taken through a single plate clutch built on the flywheel to the transmission which has four silent forward gears and one reverse. There is a differential with a lock incorporated at the rear, and a reduction gear to the rear sprockets.

The suspension consists of four large pressed-steel disk wheels on each side which return the track. They are mounted in pairs and attached to a common even lever at each side and joined in the center by a cross member. A quarter elliptic spring anchored at each corner of the chassis is attached one to each end of the two common even levers. Steering is accomplished through upright steering levers to four hydraulic brakes on the sprockets and idlers.

SPECIFICATIONS

Weight        7,728 lb. (unladen)
Length 14 ft., 6 ins.
Width 6 ft., 6 ins.
Height 8 ft., 6 ins.
Ground clearance 22 ins.
Tread centers
Ground contact
Width of track 13 ins. (with snow plates, 24 ins.)
Track links
Pitch of track
Fording depth 34 ins.
Theoretical radius of action
   Roads 155 miles (est.)
   Cross-country
Speed
   Roads 11 m.p.h.
   Cross-country 11 m.p.h.
Armor
   Front plate
   Sides
Armament
Ammunition (rds.)
Engine Steyr air-cooled 70 hp.
Transmission 4 speeds forward, 1 reverse
Steering Steering levers to hydraulic brakes
Crew 2

German: p. 57