Tag Archive for 'sig 33'

Gw. II für 15 cm s.I.G. 33: S.P. Heavy Infantry Howitzer

Gw. II für 15 cm s.I.G. 33: S.P. Heavy Infantry Howitzer

This vehicle consists of the 15 cm. heavy infantry howitzer mounted in the hull of a modified, turretless Pz. Kpfw. II chassis. The chassis is approximately three feet longer than that of the standard Pz Kw II tank and has six bogie wheels instead of the usual five. The sprockets, rear idlers, bogie wheels, return rollers, steering assembly, gear box and hull nose are those of the Pz. Kpfw. II; the instrument panel is that of a Pz. Kpfw. III. The front shield is in one piece extending straight across the full width of the superstructure. The driver’s visor is of the double shutter type. The road performance of this equipment approximates that of the Pz. Kpfw. II tank.

The gun, a standard infantry support weapon, is mounted low in the hull, projecting through a vertical slot in the shield. The gun shield is 15 mm thick and is of shallow construction. It extends about a third of the distance of the superstructure to the rear. Unlike the “Wasp” there are no protecting side plates along the entire length of the superstructure.

The gun is 64.57 inches in length, has a muzzle velocity of 790 f.s. and a maximum effective range of 5140 yards. The casting containing the recuperator and buffer, housed underneath the barrel, extends almost to the end of the barrel. The breech mechanism is similar to the 10.5 cm. I.F.H. 18. The elevating qear is operated from the right and the traversing gear from the left. In field mounting its traverse is 11°, its elevation 0° to +73°.

Two types of ammunition are fired, the 15 cm. I. Gr. 33 and the 15 cm. I. Gr. 38. The H.E. capacity is high, 21.8%. The only other shell that the weapon is known to fire is a smoke shell, the 15 cm. I. Gr. 38 Nb. The same percussion fuze, s. I. Gr. Z. 23, which weighs 75 lbs., is used in each case.

SPECIFICATIONS

Weight         (approx.) 12 tons
Length (approx.) 18 ft.
Width 7 ft., 4 ins.
Height (approx.) 5 ft., 6 ins.
Ground clearance 13 ins.
Tread centers 6 ft., 2 ins.
Ground contact
Width of track 11 1/8 ins.
Pitch of track 3 5/8 ins.
Track links
Fording depth 3 ft.
Theoretical radius of action
     Roads 118 miles
     Cross-country 78 miles
Speed
     Roads 25 m.p.h.
     Cross-country 15 m.p.h.
Armor
     Front plate 15 + 20 mm
     Sides 15 mm
Gun shield 15 mm
Armament 15 cm. s.I.G. 33
Ammunition (rds.)
Engine 140 B.H.P. Maybach, HL 62 TRM
Transmission 6 forward speeds, 1 reverse
Steering Epicyclic clutch brake
Crew Probably 4

German: p. 13

Gw. I für 15 cm s.I.G. 33: S.P. Heavy Infantry Howitzer

Gw. I für 15 cm s.I.G. 33: S.P. Heavy Infantry Howitzer -- Bison I

This equipment consists of the 15 cm heavy infantry howitzer mounted on a turretless Pz. Kpfw. I model “B” chassis. This howitzer is also mounted on the Pz. Kpfw. II, and the Pz. Kpfw 38 (t) chassis. Due to the additional weight carried by the chassis, which approximates 3 tons more than its normal Pz. Kpfw. I complement, its road performance does not equal that of the Pz. Kpfw. I tank. The general appearance suggests that the equipment is overloaded.

The howitzer, which probably retains its wheels and trails, in addition to its original shield, traversing and elevating mechanisms, is mounted high in a tall, three-sided shield, and fires forward. The shield is 10 mm thick and is open at the top and rear.

The 15 cm. s.I.G. 33 is a standard German infantry support weapon. It has a length of 64.57 ins. and is used for either high or low trajectory shooting. It has a muzzle velocity of 790 f.s. and a maximum effective range of 5140 yards firing the 83.6 lb. H.E. shell with percussion fuze s.I. gr. Z. 23. The breech mechanism is of standard German type, and is similar to the 10.5 cm. l.F.H. 18 breech mechanism. The elevating gear is operated from the right. It consists of a worm gear, rack, pinion and shafting. The traversing gear is operated from the left by a system of gear wheels and shafting. The recoil system of buffer and recuperator is housed in a casing underneath the barrel.

Two types of ammunition are fired, the 15 cm I. Gr. 33 and the 15 cm I. Gr. 38. The two types of ammunition are for all practical purposes identical except that the former has a screwed-in base plate. The only other shell that this weapon is known to fire is a smoke shell, the 15 cm I. Gr. 38 Nb. The same percussion fuze, s.I. Gr. Z. 23, which weighs 75 lb., is used in each case.

SPECIFICATIONS

Weight         9 tons
Length 14 ft., 6 ins.
Width 6 ft., 9 ins.
Height (approx.) 11 ft.
Ground clearance 11 1/2 ins.
Tread centers 5 ft., 5 ins.
Ground contact 8 ft.
Width of track 11 ins.
Pitch of track 3 11/16 ins.
Track links 99
Fording depth 2 ft.
Theoretical radius of action
     Roads 87 miles
     Cross-country 72 miles
Speed
     Roads
     Cross-country
Armor
     Front plate 15 mm
     Sides 10 mm
     Gun shield 10 mm
Armament 15 cm S.I.G. 33
Ammunition (rds.)
Engine 100 h.p. Maybach Model N.L. 38 T
Transmission 5 speeds forward, 1 reverse
Steering Clutch brake
Crew         Probably 4

German: p. 5

15 cm s. I. G. 33: Heavy Infantry Howitzer

15 cm s. I. G. 33: Heavy Infantry Howitzer

The 15 cm s. I. G. 33 (schweres Infanterie Geschütz 33) is a standard German infantry support weapon that may be used for either high- or low-trajectory firing. Both high-explosive and smoke shells are used with the gun.

The breech mechanism is of the usual German design, a horizontal sliding block opening to the right. A trough-shaped cradle is provided with guide ways in which guides on the gun move during recoil. On either side, at the front of the cradle, is a pad to receive the unabsorbed force of run out. Between the pads is the expansion chamber which receives the buffer fluid forced from the buffer by expansion as it becomes heated. Both the buffer and recuperator are housed in a casing underneath the barrel. The recoil system differs from that of most German artillery in that the expansion chamber of the buffer is outside the buffer itself, connected to it by a pipe; and no cooling cylinder is provided.

Toward the rear are the two small cradle arms to which the trunnions are fixed. Each trunnion is provided with a cranked compensator lever which compresses the equilibrator spring. The elevating arc is secured underneath and the recoil indicator at the right rear. When traveling, the cradle is secured to the carriage by a clamp which is operated by a lever secured to the clamp shaft.

The box-type carriage is fitted with a fixed spade and a detachable sand spade. Spring equilibrators situated one on either side of the carriage neutralize muzzle preponderance at all angles of elevation. The elevating gear, consisting of a worm gear, rack, pinion, and shaft, is operated from the right of the carriage; the traversing gear is operated from the left side by a system of gear wheels and shafting. A standard German Zieleinrichtung 34 is used for sighting.

SPECIFICATIONS

Caliber       150 mm (5.9 ins.)
Weight in action 1.5 tons
Length 5.38 ft.
Rifling 44 grooves, twist 8° constant
Chamber capacity 11.5 tons per sq./in.
Muzzle velocity 790 f/s (charge #6)*
Wt. of projectile 83.6 lb.
Range (maximum) 5,140 yds. (charge #6)*
Elevation 73°
Depression
Traverse 11° 15′
Ammunition H.E. (two types), Smoke

*There are six zones of propellant. The maximum is obtained in Zone 6.

German: p. 104