A report of a preliminary examination of the German 75-mm mountain
gun, 7.5-cm Geb. G. 36, appeared in Tactical and Technical Trends,
No. 38, p. 9. Additional information and a sketch of this
gun are now available.
a. General*
Weight (complete) | | 1,090 lb (about) |
Length of gun, including brake | | 66 in |
Length of barrel, including brake | | 56 in |
Elevation | | 65° |
Depression | | 8° |
Maximum traverse | | 40° (20° L and 20° R) |
Rate of traverse | | 40 minutes per turn of handwheel |
Rate of elevation | | 1° per turn of handwheel |
Height of wheels | | 32 in |
Maximum length of recoil | | 29 in |
Minimum length of recoil | | 23 in |
A number of quick-release devices enables the gun to be broken down
speedily. These devices are simple in design so that the gun can be
easily disassembled after the first inspection. It is reported that
this weapon can be broken down into six loads, the maximum weight
of any of the loads being about 300 pounds. This enables it to be
used as a mountain gun and enables easy packing in a plane, and
allows man handling or animal packing for short distances.
b. Barrel
The breech end of the barrel is rectangular and is machined on each side
to provide wedges. The wedges are arranged so that they drop into corresponding
spaces machined from a trough-shaped portion of the breech ring. The barrel and
breech ring are secured together by a heavy plate which slides over both
components, thereby preventing the barrel from jumping out.
c. Breech
The breech ring is machined transversely to receive the breech block and
prepared at the top to carry the plate referred to above.
The breech mechanism is of the horizontal, wedge-sliding block type and
is actuated by a hardened steel cam plate, which slides in a groove cut in the upper
side of the block.
d. Firing Mechanism
The firing mechanism is the continuous pull type.**
e. Cradle
The cradle is fitted internally with a small hydro-pneumatic recoil system. On
the rear of the cylinder block an extension is formed, and provided with slides
and fiber strips for the reception of the breech ring. Bolted to the rear of the
underside of the cradle is an elevating arc formed with extensions, which are
machined to form trunnion journals. A gun securing stay is pivoted underneath, to
lock the gun for traveling.
f. The Saddle
The saddle is pivoted at its forward end on a large pin, having a bearing
in a tubular cross member behind the axle tree.
At the rear, it carries phosphorus bronze trunnion bearings, the cap squares
of which are locked by quick release plungers.
g. Counterbalance
Counterbalance consists of a strong spiral spring encased in a telescoping
tube. The lower portion of the case is anchored on a shaft at the underside of
the saddle, while the upper portion bears on suitably prepared surfaces under the
cradle.
The mechanism can be readily disassembled, by depressing the piece until
a lever on the cross shaft can be moved to the closed position, when the spring is
locked in full compression, facilitating the safe removal of the cradle.
h. The Axle Assembly
Consists of two main parts. The axle tree, and a tubular saddle support, which
are carried on two solid rubber-tired, light alloy wheels.
The axle tree is a forging which is machined at the ends to form stub-axles. These
stub-axles fit into tapered housings (which run in bearings) in each wheel. Each
tapered housing is provided with a quick release spring-loaded plunger, which
engages with a locating hole on the body of the axle.
The complete axle tree is arranged to pivot on the saddle support, in order
to compensate for lack of level of wheels.
The tubular saddle support is provided with a bearing at the center to
receive the center pivot.
Pivoted at both ends are housings which receive the trail legs, which, at
the bottom, fit into claw recesses, and at the top are locked by clamps.
i. The Trail Legs
These are of riveted box construction, and are arranged to split, to form
an angle of 30° in the firing position, where they are locked by spring-loaded
plungers engaging with holes in the ends of the saddle support. In the traveling
position the legs are clamped together by a cross-member which pivots from the
left leg. The center of the cross-member is provided with a towing attachment.
Hand operated screws pass through brackets in the under side of each leg and,
by means of beveled bearing blocks, stabilize the saddle during traveling.
When fully unscrewed a traverse of two degrees either side is possible. The
legs are 73.62 inches long.
*The weight, length of gun and barrel, elevation and depression are based on data
given in an Aberdeen Proving Ground memorandum dated 18 Sept 1943.
**Aberdeen Proving Ground memorandum dated 18 Sept 1943.