Tag Archive for '7.5cm'

Sturmgeschütz 7.5 cm Stu. K. 40 (Sd. Kfz. 142): S.P. Assault Gun

StuG III: Sturmgeschütz 7.5 cm Stu. K. 40 (Sd. Kfz. 142): S.P. Assault Gun

This development of the Sturmgeschütz mounts the Stu. K. 40 assault gun, with muzzle brake, on a Pz. Kpfw. III chassis. The gun. is identical to the Kw.K. 40 with the exception that in the Stu. K. 40 the buffer and recuperator systems are mounted on each side of the barrel to accommodate the S. P. mounting, while the Kw.K. 40 mounts the recoil mechanism above the barrel. The road performance of this vehicle will approach that of the Pz. Kpfw. III tank.

The superstructure is a box-like arrangement, closed in on the top and welded to the chassis. A commander’s cupola, loader’s entrance hatch, and an opening for the sight are provided on the roof of the superstructure. There is no hull entrance door. A circular hole approximately 9 inches in diameter, cut in the rear of the superstructure, houses a small electric fan which draws air into the fighting compartment. A circular plate 12 inches in diameter and 30 mm thick is fitted over the hole at a distance of 3 inches from the superstructure by means of 3 bolts. The thickness of superstructure armor is as follows: front vertical plate 50 + 30 mm, gun mantlet 50 mm, sides 30 mm, top 20 mm. Side skirting armor is often mounted on this vehicle.

The gun has a length of 126 inches, without the muzzle brake, a muzzle velocity of 2525 f/s for the 15.0 lb. projectile and an effective range of 2000 yards firing A.P.C. shell. Its approximate radius of elevation is -5 to + 20°; traverse 10° left and right. It utilizes the following types of ammunition—A.P.C., H.E., and hollow charge. The penetration of A.P.C. shell against homogeneous plate is reported as follows: 500 yards, 4.0 inches at 30° obliquity; 4.8 inches normal—1000 yards, 3.6 inches at 30°, 4.3 inches normal—2000 yards, 2.8 inches at 30°, 3.4 inches normal.

SPECIFICATIONS

Weight         26.5 tons
Length 17 ft., 9 ins.
Width 9 ft., 7 ins.
Height 6 ft., 5 ins.
Ground clearance 14 ins.
Tread centers 8 ft., 2 1/2 ins.
Ground contact 9 ft., 4 1/2 ins.
Width of track 15 ins.
Pitch of track 43 ins.
Track links 90
Fording depth 3 ft.
Theoretical radius of action
     Roads 100 miles
     Cross-country 60 miles
Speed
     Roads 25 m.p.h.
     Cross-country 15 m.p.h.
Armor
     Front plate 50 + 30 mm
     Sides 30 mm
Armament 7.5 cm Stu. K. 40
2 Machine pistols
Ammunition 54 rds.
Engine Maybach, HL 120 TRM, V-12, 320 hp.
Transmission 6 speeds forward, 1 reverse
Steering Epicyclic, clutch brake
Crew 4

German: p. 28

Pz. Kpfw. IV Aus. F1, F2, G, H, K (Sd. Kfz. 161): Medium Tanks

Pz. Kpfw. IV Aus. F1, F2, G, H, K (Sd. Kfz. 161): Medium Tanks

Model F—The hull, superstructure, and turret, as in all other known models of the Pz. Kpfw. IV, is of welded construction. The basic frontal armor, including superstructure and turret of Model F, was increased to 50 mm; on the sides to 30 mm. The main hull superstructure projects over the top of the tracks, providing additional stowage space and a wide base upon which to mount the turret. The turret floor is carried by brackets from the turret ring and consequently rotates with the turret.

The suspension consists of 4 bogie assemblies, each fitted with two rubber-tired bogie wheels 18 1/2 inches in diameter on each side, with a quarter elliptic spring anchored beneath the leading axle arm of each assembly. There is a front sprocket, the spokes of which are bent outward from the hub cap giving the outside a dished appearance, a rear idler which has 7 spokes instead of 8 as in previous models, and 4 return rollers.

The power plant consists of a Maybach HL 120 TRM, V-12 O.H.V., 4-stroke, gasoline engine, rated 320 B.H.P. at 3,000 r.p.m.

The armament consists of a 7.5 cm Kw. K., 24 cals. in length, a coaxial 7.92 mm MG 34 mounted in the turret, and a 7.92 mm MG 34 at the right of the front plate of the superstructure.

Model F2—Same as Model F except that it carried the initial experimental mounting of the Kw. K. 40, 43 cals. in length.

Model G—Produced in 1942. Same as Model F except that the mounting of the Kw. K. 40 was continued. The gun was fitted with a double baffle muzzle brake.

Models H, K—These models are referred to in German documents published during 1943.

SPECIFICATIONS

Weight         26 tons
Length 19 ft., 4 ins.
Width 9 ft., 7 ins.
Height 8 ft., 6 ins.
Ground clearance 15 ins.
Tread centers 7 ft., 11 ins.
Ground contact 11 ft., 6 ins.
Width of track 15 ins.
Pitch of track 4 3/4 ins.
Track links 98
Fording depth 3 ft.
Theoretical radius of action:
     Roads 130 miles
     Cross-country 80 miles
Speed:
     Road 28 m.p.h.
     Cross-country 15 m.p.h.
Armor:
     Front plate 50 mm
     Sides 30 mm
Armament 7.5 cm Kw. K. 40
2 MG’s 34
Ammunition 7.5 cm gun—87 rds.
MG’s—2,250 rds.
Engine Maybach HL 120 TRM, 320 hp.
Transmission Synchromesh—6 speeds forward, 1 reverse.
Steering Epicyclic, clutch brake
Crew 5

German: p. 32

Sturmgeschütz lg. 7.5 cm Stu. K. (Sd. Kfz. 142): S.P. Assault Gun

Sturmgeschütz lg. 7.5 cm Stu. K. (Sd. Kfz. 142): S.P. Assault Gun

This version of the Sturmgeschütz is similar to its predecessor, the Stu. G. 7.5 cm K., except for its armament. The 7.5 cm Kw.K. short gun which appeared in the original Sturmgeschutz was replaced by the 7.5 cm Stu. G. lg. K., 87 inches long as shown above. The arrangement of the recoil mechanism also differs, the long version having what appears to be the original mounting provided for the Kw.K. 40 and is evidently a forerunner in its design and development. Photographs show the 7.5 cm Stu. G. lg. K. to be equipped at times with a muzzle brake. The front superstructure has been modified to accommodate the improved armament.

This vehicle is made up of the Pz. Kpfw. III tank chassis and an early development of the 7.5 cm Pak 40, and includes the hull and superstructure improvements made at this time on the original Sturmgeschütz. A roof was added, a commander’s cupola, smoke pot projectors and heavier front plate. The piece represents the trend in design from the short barrel 7.5 cm Kw.K. to the Stu. K. 40.

SPECIFICATIONS

Weight         21 tons
Length         17 ft., 9 ins.
Width 9 ft., 7 ins.
Height 6 ft., 5 ins.
Ground clearance 15 ins.
Tread centers 8 ft., 2 1/2 ins.
Ground contact 9 ft., 4 1/2 ins.
Width of track 15 ins.
Pitch of track 4 3/4 ins.
Track links 90
Fording depth 3 ft.
Theoretical radius of action
     Roads 100 miles
     Cross-country 60 miles
Speed
     Roads 25 m.p.h.
     Cross-country 15 m.p.h.
Armor
     Front plate 50 mm
     Sides 30 mm
Armament 7.5 cm lg. Kw.K.
Ammunition 84 rds.
Engine Maybach HL 120 TRM, 320 hp.
Transmission 6 speeds forward, 1 reverse
Steering Epicyclic clutch brake
Crew 4

German: p. 27

Sturmgeschütz 7.5 cm K. (Sd. Kfz. 142): S.P. Assault Gun

StuG III: Sturmgeschütz 7.5 cm K. (Sd. Kfz. 142): S.P. Assault Gun

The Sturmgeschütz is an assault weapon. Unlike the two other classes of self-propelled guns, antitank and artillery, which consist merely of guns placed in the hull of a tank with shields erected around the front and sides thereof, the assault gun is built into the hull and is consequently nearer the ground and has a much more solid superstructure built round the gun. The original Sturmgeschütz consisted of the turretless chassis of a Pz. Kpfw. III tank, upon which was mounted the Stu. G. 7.5 cm K., a short-barreled (69.5 inch) piece found in the first models of the Pz. Kpfw. IV. Since the power plant and other mechanical components of the chassis of the Sturmgeschütz are identical to those of the Pz. Kpfw. III tank, and their weights are approximately the same, the performance data of the two are comparable.

The turret of the original tank has been removed and replaced by a squat superstructure, reducing the height of the vehicle from 8 feet, 3 inches as a tank to 6 feet, 5 inches as an assault weapon. The gun compartment is roofed over, but there is no rotating turret. The fighting compartment is armored as follows: front 53 mm, sides 43 mm, top 11 mm.

The gun, which is mounted low in the hull and fires forward, is identical to the 7.5 cm Kpfw. K. short tank gun, originally the main armament of the Pz. Kpfw. IV tank. It is primarily a close support weapon, the ammunition scale comprising only 25% A.P. against 10% smoke and 65% H.E.; its armor-piercing performance is relatively poor. Its muzzle velocity and maximum range firing H.E. shell is 1,378 f.s. and 6,758 yards, respectively. The penetration of A.P.C.B.C. shell against homogeneous armor is reported as follows: 500 yards, 1.81 inches at 30° obliquity, 2.16 inches normal—1000 yards, 1.61 inches at 30°, 1.97 inches normal—1,200 yards, 1.57 inches at 30°, 1.89 inches normal.

SPECIFICATIONS

Weight         21 tons
Length 17 ft., 9 ins.
Width 9 ft., 7 ins.
Height 6 ft., 5 ins.
Ground clearance 14 ins.
Tread centers 8 ft., 2 1/2 ins.
Ground contact 9 ft., 4 1/2 ins.
Width of track 15 ins.
Pitch of track 4 3/4 ins.
Track links 90
Fording depth 3 ft.
Theoretical radius of action
     Roads 100 miles
     Cross-country 60 miles
Speed
     Roads 28 m.p.h.
     Cross-country 15 m.p.h.
Armor
     Front plate 50 mm
     Sides 30 mm
Armament 7.5 cm Kw. K.
Ammunition 84 rds.
Engine Maybach V-12, HL 120 TRM, 320 hp.
Transmission 6 speeds forward, 1 reverse
Steering Epicyclic, clutch brake
Crew 4

German: p. 26

7.5/5.5 cm Pak 41: Tapered Bore Antitank Gun

7.5/5.5 cm Pak 41: Tapered Bore Antitank Gun

The 7.5 cm Pak 41, Germany’s latest antitank gun to be brought into service, is designed on the Gerlich or tapered-bore principle. The bore tapers from 7.5 cm at the breech to 5.5 cm at the muzzle, but the taper is not constant. The first part of the bore is cylindrical and rifled; the second, conical and unrifled; and the third, measuring 27.6 inches in length, is cylindrical and unrifled. There is also a muzzle brake. The life of the barrel is estimated at approximately 500-600 rounds. The weapon is long, low, and sturdy in appearance and has a semi-automatic breech mechanism of the vertical wedge type.

The carriage has a split trail and is mounted on metal wheels with solid rubber tires. As traction is by motor tractor, the carriage is fitted with pneumatic brakes controlled by the driver of the tractor. Torsion bar suspension is automatically cut out when the trails are opened.

An elevating mechanism of the sector type is on the right-hand side of the cradle, and a traversing mechanism of the screw type on the left. There is no equilibrator mechanism. The recoil mechanism contains a hydraulic cylinder and spring-type recuperator.

The sighting system, which is graduated up to 1,500 meters (1,635 yards), has four scales for use according to the actual muzzle velocity of the gun. Muzzle velocity drops considerably because of wear.

SPECIFICATIONS

Caliber           7.5/5.5 cm
Weight in action         1.4 tons
Length of barrel (approx.)         170 ins.
Muzzle velocity (estimated)         4,123 f/s
Elevation         -10° to 18°
Traverse         60°
Armor penetration—A.P.C.

       Range in yards          Thickness of armor in inches 
                   Normal               30°    
       500  6.67  5.75  
       1,000  5.94  5.12  
       1,500  5.28  4.49  
2,000  4.63  3.94  

German: p. 123

7.5 cm Pak 97/38: Antitank Gun (Ex-French)

7.5 cm Pak 97/38: Antitank Gun (Ex-French)

The 7.5 cm Pak 97/38, introduced by Germany in 1942, consists of the 7.5 cm French Model ’97 equipment which was modified in 1940 as an antitank gun, and the German 5 cm Pak 38 carriage. The built-up tube, to which a Solothurn type perforated muzzle brake is fitted, has four hoops sweated on for additional strength.

The breechblock is the Nordenfeld eccentric screw type commonly used in the French 75 mm tube. The high-pressure, hydropneumatic recoil mechanism contains a floating piston with nitrogen gas in the recuperator cylinder which brings the gun back into battery. The recoil cylinder is of smaller diameter and contains the piston rod which recoils with the tube and forces the recoil oil into the recuperator cylinder where throttling checks the rearward movement of the tube.

The elevating and traversing mechanisms are located on the top carriage; the elevating handwheel is slightly in front of and to the left of the traversing handwheel. There is a single hydropneumatic equilibrator at the right trunnion. The protecting armor consists of two sheets of 4 mm steel plate curved to envelop the front of the weapon. Below the spaced armor is an 8 mm hinged apron. There is also a small shield above the apron that moves with the tube in elevation.

The sighting gear, which is the same as that used with the 5 cm Pak 38, is situated on an arm and bracket which move with the left trunnion. An opening in the shield allows vision for sighting instruments.

The low-slung, light-weight carriage has relatively short split trails of tubular steel. The wheels are of small diameter spokes made of compressed steel and entirely covered with buna rubber tires 4 inches wide. They are independently mounted to absorb traveling shock by free wheeling action. When the trails are spread, however, the free wheel movement is locked by a bracket so the gun will not bounce on firing. A third wheel supports the rear of the trails for transportation.

SPECIFICATIONS

Caliber         75 mm (2.95 ins.)
Weight (complete) 2,870 lb.
Length of tube & breech ring 8.8 ft.
Length (overall) 15 ft.
Breech mechanism Eccentric screw
Firing mechanism Percussion hammer
Recoil mechanism Hydropneumatic
Rifling 20 lands and grooves; R.H. twist
Muzzle velocity (reported) 2,100 f/s
Elevation 18°
Depression 10°
Traverse 60°
Ammunition H.E.; A.P.-H.E.; Hollow charge
Also some Polish types of ammunition
Penetration 60 mm @ 900 yds., 30°

German: p. 121

7.5 cm l.F.K. 18: Light Field Gun

7.5 cm l.F.K. 18: Light Field Gun

The 7.5 cm Gun, l.F.K. 18, was standard equipment for German Divisional Field Artillery until it was replaced by the 7.5 cm l.F.K. 38 and 7.62 cm F.K. 39 (r). The barrel is a solid-forged tube that screws into a detachable breech. The breech mechanism is a crank-operated, single-motion, horizontal sliding block type, fitted with a repeating trip-lock. It can be arranged for firing from the right-hand side only, or from either side at will. The top carriage is arranged to traverse about a vertical pivot up to 30° right and left. The cradle is mounted on the top carriage by trunnions set far to the rear. Forward preponderance is balanced by a pair of equilibrators, located one on either side of the cradle.

The screw type traversing gear is operated by a handwheel on the left side of the carriage; the elevating gear, of the toothed arc type, may be operated from either side in the case of light guns, and from the right-hand side only with heavier types.

Sighting gear consists of a pointed or indicating system on the left side. The sight is adapted to correct for 7° transverse out-of-level at any angle up to 45°. Adjustment for angle of site is provided up to +/- 12°. A panoramic telescope is also used.

The carriage of split trail construction is provided with spring suspension which is put into action automatically by closing the trails for traveling and out of action by splaying out the trails for firing. A traveling brake of the expanding type acts upon the inside of the brake drums on the wheels.

Separate-loading, high-explosive or shrapnel ammunition is used.

SPECIFICATIONS

Caliber 75 mm (2.95 ins.)
Weight of gun in action        2,259 lb.
Weight of gun 628.1 lb.
Weight of gun in traveling position (including 3 rounds of ammunition) 2,975 lb.
Length in calibers 6.4 ft.
Length of recoil (maximum) 3.77 ft.
Length of recoil (minimum) 2.13 ft.
Muzzle velocity (maximum) 1,558 f/s
Range 10,935 yds.
Elevation 45°
Depression -7°
Traverse 30°

German: p. 120

7.5 cm L.G. 40: Recoilless Airborne Gun

7.5 cm L. G. 40: Recoilless Airborne Gun German

The “Recoilless Gun” is a short rifled howitzer containing a tube of monobloc steel construction, a breech ring, breech mechanism and block, and a venturi tube. Intended for airborne operations, the weight of the L.G. 40 has been kept to a minimum by the use of hollow machine parts, plastic washers, tubular platform, and aluminum alloy body. It is used for antitank and antipersonnel purposes.

Interrupted collars on the breech end of the tube are used to attach it to the breech rings. The tube is also machined to seat the extractor and the barrel lock. The breech, which is of the horizontal sliding block type, is operated by a lever. This lever, when depressed, also cocks the piece.

The gun has no recoil or counterrecoil system. A funneled tube (venturi) attached to the rear of the bored breechblock allows the gases to escape to the rear, thus eliminating recoil.

The sighting equipment consists of a base bracket, oscillating bracket, cross-leveling gear, range gear, telescope carrier, and telescopes.

The carriage has a circular base to which three tripod legs are pivoted in lugs. The wheels, which can be detached for transport, are light-weight metal disks fitted with solid rubber tires.

The gun can be traversed 360° by locking the elevating mechanisms, but its ordinary traverse is 60°. Elevation is limited to 42° by stops, but the rack can be locked at 20°.

SPECIFICATIONS

Caliber        7.5 cm (2.95 ins.)
Length of tube
Weight (travelling position) 325 lb.
Weight (firing position) 321 lb.
Length (travelling position) 45 ins.
Length (firing position)
Height (travelling position)
Height (firing position)
Width (overall)
Width of trail spread
Length of bore 17.5 ins.
No. of grooves 28
Width of grooves .2 in.
Depth of grooves .03 in.
Width of lands
Muzzle velocity (H.E. shell) 1,197 f.s.
Max. range (horizontal) 7,400 yds.
Max. range (vertical)
Rate of fire
Traverse 30° x 2—360°
Elevation -15 +42°
Depression -15°
Length of recoil
Ammunition 3 types
Wt. of projectileH.E. 12 lb., 9 oz.; A.P.C.B.C. 15 lb.; hollow charge 10 lb., 2 oz.

German: p. 119

7.5 cm Geb. G. 36: Mountain Gun

7.5 cm Geb. G. 36: Mountain Gun: Gebirgsgeschütz

The 7.5 cm Geb. G. 36, used in the Tunisian campaign, is of comparatively recent manufacture. It can be broken down into six loads, each load having a maximum weight of 300 pounds. This enables the weapon to be used in mountainous country, as it can be easily transported by pack animal or in an airplane.

The tube is of monobloc construction, fitted with a perforated, six-baffled muzzle brake (some models of the gun are fitted with a perforated Solothurn type). The rear end of the piece is rectangular in shape, and dovetailed to fit into prepared recesses of the breech ring. A horizontal sliding type breech mechanism and continuous pull type firing mechanism are used in this gun. The recoil mechanism is hydropneumatic, but contrary to the usual design, both buffer and recuperator are positioned below the barrel.

The carriage is constructed of riveted and welded steel, with trunnion bearings to the rear. To preserve the proper balance, a spring equilibrator is located in the carriage immediately under the cradle. As is usual with most mountain guns, there is no shield. The carriage is mounted on steel disk wheels with solid rubber tires, and supported in firing position by riveted steel split trails with spade attachments.

The sight is graduated in mils from 0 to 1,250 (0° to 70° approx.) and also in meters from 0 to 1,000 (0 yds. to 1,094 yds.) for use with the hollow charge shell, 7.5 cm Gr. 38.

Both hollow-charge and high-explosive ammunition is used.

SPECIFICATIONS

Caliber         75 mm (2.95 ins.)
Weight (complete) 1,090 lb. (approx).
Length of gun (overall) 66 ins.
Length of barrel (overall) 56 ins.
Carriage Steel, mounted on solid disk wheels with solid rubber tires
Breech mechanism Horizontal sliding block
Firing mechanism Continuous pull
Recoil mechanism Hydropneumatic
Rifling Lands and grooves; R.H. twist
Elevation 65°
Depression
Traverse 30°

German: p. 118

7.5 cm Pak 40: Antitank Gun

7.5 cm Pak 40: Antitank Gun

The Pak 40, an antitank and antipersonnel weapon, has a barrel of monobloc con­struc­tion to which is screwed a two-baffled muzzle brake. The horizontal sliding type breechblock operates semi-automatically. Recoil and counterrecoil are effected by means of a hydraulic buffer and a hydropneumatic recuperator.

The welded steel carriage has tubular trails, light alloy steel wheels with solid rubber tires, and a 5 mm spaced armor shield for the protection of the gun crew. There are two types of brakes: air brakes, which are operated from the prime mover, and hand brakes for placing the gun in firing position.

Although no sighting equipment was captured with the gun, it is assumed that there was a telescopic sight for direct fire, a sight for indirect fire, and an auxiliary open sight. Mounts for these sights are attached to the breechring and the left trunnion.

There is also a gun known as the 7.5 cm Pak 97/40. This gun consists of a French Model 1897 piece mounted on the carriage of a German 7.5 cm Pak 40, but usually on Pak 38 carriage.

A modification of this gun is used on the chassis of the Pz. Kw. II tank and the Czech Pz. Kw. 38 (t) converting these vehicles into gun motor carriages.

The 75 mm tank gun, KwK. 40, used in Pz. Kw. IV is an adaptation of the Pak 40.

SPECIFICATIONS

Caliber       75 mm (2.95 ins.)
Length of tube126.1 ins.
Weight (travelling position)3,350 lb.
Length (travelling position)19 ft.
Length of bore96.89 ins.
No. of grooves32
Width of grooves.175 in.
Depth of grooves.025 ins.
Width of lands.116 in.
Muzzle velocity (A.P.C. shell)2525 f/s
Traverse65°
Elevation+22°
Depression-5°
Length of recoil35.43 ins.
AmmunitionA.P.-H.E.-H.E. hollow charge
Wt. of projectile (A.P.C.)15 lb.

German: p. 117