...Railway artillery - Personal Page of GENE SLOVER

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296. GUN CARRIAGE.-The gun carriage, plates 256 and 53, comprises
the cradle carrying the recoil mechanism, and the elevating and
traversing mechanisms already described, all mounted, or carried
on a structure of cast-steel side frames and transoms. The carriage
is provided with a heavy pintle at its forward end, which fits into a
bearing machined in a cast-steel transom of the car body. The rear
of the carriage rests on the car body by means of spring-supported
rollers already described under Traversing mechanism. A structuralsteel
working platform carrying the ammunition table and crane is
bolted to the rear of the cast-steel top carriage. Between the cradle
trunnions and side frames antifriction devices already described
under elevating mechanism are incorporated to reduce the effort
required to elevate and depress the gun.
297. CAR BODy.-The car body, plates 35 and 53, is made up
of two single web structural steel side girders connected by structural
and cast steel transoms. Toward the forward end a cast steel transom,
machined at its center to serve as a bearing for the pintle
of the top carriage, is bolted to the side girders. Center plates and
- side bearings are provided at either end of the car through which it
is supported on two trucks. Outrigger struts, jack supports and ties
are attached to the lower cord of the side girders for use in anchoring
the mount to its emplacement.
298. ANcHoRAGE.-When the mount was designed it was intended
to operate it on a timber platform of the design shown on plate
53. The platform is in two principal parts. The one comprises a
horizontal bed of timbers on which the mount rests through four
jack screws and which. takes the dead-weight of the car and vertical
component of the shock of recoil. The other is composed of two
triangular braces resting against a timber pad. These braces are
connected with the mount by means of baH end struts hinged to the
mount and testing in foot plates on the ends of the braces, plate 359.
This part of the platform takes the horizontal component of the shock
of recoil. When the gun is being operated above elevations of 45
degrees, it is necessary to have a pit about 2 feet deep between the
two heavy horizontal timber beds, into which the gun may recoil.
The rails which bridge this pit and on which the mount is run, are
carried on I-beam stringers, plate 53. They are removed for tiring.
The time required for the installation of platforms for similar French
340 millimeter gun and 400 millimeter howitzer carriages, varies between
two and five days according to the nature of the ground and
weather. When the gun is fired at angles of 45 degrees or less, the
mount may be operated on a track of he.avy construction without the
use of any firing platform. The brakes are set at a pressure to'barely
permit rolling of the wheels and the entire mount rolls back a distance
of from 30 to 40 feet. .To secure any large degree of traverse
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