This howitzer is a standard German light field-artillery weapon and
compares favorably with the U.S. 105-mm howitzer (see Tactical and Technical
Trends, No. 6, p. 12 for tactical employment). This howitzer, marked by a long
barrel and split trail, and by the counter-recoil cylinder mounted above the tube,
is so constructed that it can be fired either as a gun or a howitzer. Its semifixed
ammunition and maximum elevation of 47° give it the characteristics of a
howitzer. The long barrel allows high muzzle velocity, and the long split trail gives
stability when the weapon is fired as a gun.
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German 105mm Howitzer |
The following table presents general data on the complete German 105-mm howitzer:
Maximum range | | 11,674 yds |
Maximum muzzle velocity | | 1,542 f/s |
Weight of shell (std) | | 32.65 lbs |
Weights |
Complete howitzer | | 4,260 lbs |
Upper shield with stays | | 107 lbs |
Breech mechanism (exclusive of breech ring) | | 109 lbs 2 ozs |
Elevating mechanism (less arc) | | 67 lbs 9 3/4 ozs |
Traversing mechanism | | 22 lbs 14 1/2 ozs |
Top carriage | | 75 lbs 14 ozs |
Dimensions |
Overall width of carriage (hub to hub) | | 78.8 in |
Ground clearance (bottom of top carriage) | | 13.5 in |
Trunnion height (to center) | | 46.25 in |
Diameter of wheel | | 50.75 in |
Width of tire | | 4.00 in |
Overall length of piece (travelling position) | | 220 in |
Trail length, overall | | 11.32 ft |
Shield thickness of plate | | 0.157 in |
Total length of howitzer | | 115.78 in |
Depth of breech recess | | 9.06 in |
Depth of chamber | | 11.2 in |
Length of bore | | 92 in |
Depth of groove | | 0.047 in |
Width of lands (at bottom) | | 174 in |
Number of lands | | 32 |
Number of grooves | | 32 |
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The performance of the howitzer is limited by the use of the
zone 5 charge as the standard charge instead of the
zone 6 charge. The muzzle velocity is thus reduced
from 1,542 feet per second to a standard of 1,283 feet per
second, and the maximum range is reduced from 11,674 yards to a
standard of 10,007 yards.
The performance of the howitzer has also been limited by using separate
loading ammunition. This has lowered the maximum rate of fire of the howitzer
and thus reduced its effectiveness.
The breech mechanism is simply designed and can be completely disassembled. The
firing mechanism can be operated only in the fully opened or
fully closed positions, and a manna1ly-operated safety lock is provided as an
additional safety device. The breech mechanism is very heavy, weighing
109 pounds.
The recoil and recuperator system is of the hydropneumatic type.
The top carriage is principally of welded design and made of sheet steel
0.3 centimeters thick. The trunnion caps are of the split-bearing type.
The elevating mechanism is completely enclosed except for the elevating
arc and its pinion. The total elevating arc is 47 degrees and 37 minutes. The
mechanism is designed to absorb the recoil and counter-recoil forces by
permitting a movement of the worm and the worm wheel against Belleville springs.
The traversing mechanism is of the screw-and-nut type and is almost
completely enclosed. The total traversing arc is 56 degrees and 14 minutes, equal
on both sides. The mechanism can be assembled as a complete unit before
being assembled to the carriage.
The howitzer can be emplaced for firing with a minimum number of
operations, as it is automatically placed in three-point suspension for firing and
the trails locked in position when the trails are opened.
The bottom carriage is of complicated design and includes a larger
number of parts than the U.S. design.
The trails are of heavy riveted construction but move freely. After road
tests, with the lower carriage splattered with mud and dust, the trails were
opened without difficulty, but could not be closed.
The trail lock (a spring-operated pin) functioned satisfactorily in locking
the trails in the open position, but at times it was difficult to release the trail
lock to close the trails.
The optical fire-control equipment is very similar in its general features
of design and construction to that used by the United States.
The complete round is of the separate-loading type and consists of a
propelling charge (in a case) and a fuzed projectile.
The propelling charge consists of the following components:
(1) A cartridge case made of either steel or brass.
(2) A primer of the same type and contour as the British 40-mm primer. The
German primer is not renewable.
(3) The propelling charge consists of five zones in cloth bags and a
nitroglycerine powder which is not flashless. The powder used in the base
zone is in the form of sheets, and in the other zones is in the
form of small, square flakes.
(4) A flash-reducer, consisting of approximately 0.9 ounces of spun lead wire, is
attached on top of the base zone.
(5) A cardboard closing-cover is supplied with a cloth lifting-handle. This
cardboard is sealed in place and is very difficult to take off for removal
of the zone charges.
The projectile consists of the following components:
(1) A contoured, superquick, 0.25-second delay fuze.
(2) A booster inserted in the top of the projectile.
(4) A spotting charge consisting of a pellet of 3.7 ounces of red phosphorus.
(5) A two-piece steel shell similar in contour to the U.S. 105-mm shell, M1. The
rotating band of the shell consists of a single strip of copper bonded to
a mild steel base and apparently rolled into place.
(6) The design of the round greatly reduces its effectiveness, since only 3 pounds
of high explosive are contained in the shell.
The howitzer may be either tractor-or horse-drawn. In tractor-drawn units, a light
tractor is used. When horse-drawn, the howitzer is pulled behind a limber
of a six-horse team.