The =axle traveling lock= is a device employed to relieve the traversing mechanism from unnecessary stress when the carriage is in traveling position. When the carriage is prepared for traveling the traveling lock engages a series of square grooves cut in the center of the axle. The lock is operated by an eccentric on the end of the traveling lock shaft which is controlled by the lock lever fixed on outer end. The lock lever may be placed in two positions marked “to travel” and “to fire,” by means of its handle which is provided with a spring plunger engaging the traveling lock catch. In order to properly lock the carriage in traveling position it is necessary to traverse the carriage to the center position on the axle, thus permitting the locking device to engage the grooves cut in the center of the axle. =The air pump= is furnished for the purpose of charging and maintaining the necessary pressure in the counter recoil reservoirs. When in operation it is attached to a bracket on the carriage by means of a screw clamp and connected to the reservoir by the filling pipe. The pump will operate against a pressure of 400 to 600 pounds per square inch. =The liquid pump= is a single-acting-plunger used for charging the counter-recoil system and for the purpose of replenishing losses of liquid from the cylinders. Power is applied through a hand lever connected by parallel links and a cross-beam at the lower end of the piston. The hand lever is detachable and also used in connection with the air pump. When in operation the pump is attached to a bracket on the carriage by means of a screw clamp. The filling pipe is employed to connect the liquid pump with the recuperator cylinder. =The reservoir for compressed gas= is a commercial seamless cylinder with a capacity of 2,842 cubic inches and is charged with nitrogen gas at a working pressure of 2,000 pounds per square inch (140 kilograms per square centimeter). The reservoir is provided with a needle valve and a connection for the pressure gage or filling pipe. This cylinder is used for charging the counter-recoil system and may be carried on the artillery supply truck furnished with 155-mm organizations. [Illustration: 155 MM HOWITZER, MODEL OF 1918 (SCHNEIDER) AIR AND LIQUID PUMPS] [Illustration: 155 MM HOWITZER, MODEL OF 1918 (SCHNEIDER) TRAVELING POSITION] =The filling pipe= is used to connect the counter-recoil reservoirs with the air or liquid pump or with the compressed gas reservoir. =Pressure Gage.= The gage for the compressed gas reservoir is calibrated from 0 to 150 kilograms per square centimeter. It is used to ascertain the pressure of gas in the reservoir and must be attached before screwing on the filling pipe. The gage for the pressure-gage adapter is calibrated from 0 to 60 kilograms per square centimeter, is screwed into the side of the adapter and used to test the pressure in the counter-recoil system.