GERMAN 88-MM ANTIAIRCRAFT GUN AND MOUNT
CARE AND PRESERVATION
(1) The cannoneer will examine the bore before each loading to ascertain and remove, if necessary, portions of powder bag or unburned powder remaining in the bore.
(2) In cleaning after firing, wash the bore with a solution of ½ pound of SODA ASH in 1 gallon of water. Wipe dry with the bore sponge covered with clean white rags. Oil the bore with OIL, engine, SAE 10, if temperature is between plus 32 F and 0 F. Use OIL, engine, SAE 30, above plus 32 F.
(3) Lubricating instructions are given in paragraph 33.
(4) When the materiel is not in use, covers must be used.
b. Breech Mechanism. The breech mechanism should be kept clean and the parts well lubricated. Disassemble daily or after firing, clean with SOLVENT, dry-cleaning, and oil with OIL, engine (seasonal grade).
c. Firing Mechanism. These parts require the same attention as the breech mechanism. Therefore, frequent disassembly for the purpose of cleaning and lubrication according to the lubrication guides (figs. 54 and 55), is required.
a. Attention should be given to cleaning, lubricating, and to loose or broken parts. Lubrication, with the method and frequency of application, is carried in detail in paragraph 33.
b. The mount should be given a daily general inspection by the chief of section of the gun crew.
36. RECOIL LIQUID.
a. The recuperator, recoil, and rammer cylinders are filled with the same liquid. The liquid used is 60 percent glycerine and 40 percent distilled water by volume with 1 ounce of caustic soda per 3 gallons of liquid. This mixture, while not a duplicate of the German liquid, is entirely satisfactory as a substitute. If the recommended liquid is not available, COMPOUND, antifreeze (ethylene glycol type), may be used in the same proportion as glycerine with the same gas pressures as when using liquid.
37. FILLING AND CHARGING THE RECUPERATOR CYLINDER.
a. Remove the liquid and gas filling plug and the drain plug at the rear end of the recuperator cylinder. Open the gas valve at least three full turns (fig. 56).
|Figure 56 — Filling the Recuperator Cylinder with Liquid|
b. Place the gun at a zero-degree elevation and a zero-degree cant. Using a funnel, pour in recoil liquid at the gas and liquid filling hole (fig. 56) until it overflows at the drain hole. Approximately 4½ gallons will be required. Replace the drain plug.
c. Screw adapter and pressure gage into the gas and liquid filling
hole (fig. 57) and connect to nitrogen supply. NOTE: To make the
American adapter fit the liquid and gas filling hole in the recuperator
cylinder, as shown in figure 57, an adapter must be improvised. The
male threads at one end of this improvised adapter are 14 threads per
inch and the outside diameter is 0.900 English thread. The female threads
will receive the American adapter. An
|Figure 57 — Charging Recuperator Cylinder with Nitrogen|
|Figure 58 — Improvised Adapter|
d. Close the gas valve on the recuperator cylinder and check the gas line for leakage.
e. If the gas line is tight, open the gas valve on the recuperator cylinder about two turns and charge with gas until approximately 600 pounds per square inch are recorded on the pressure gage. Close the gas valve on the recuperator cylinder and disconnect the gas line. Replace the gas and liquid filling plug.
38. FILLING THE RECOIL CYLINDER.
a. Elevate the gun to approximately a 2-degree elevation and a 0-degree cant.
b. Remove the two liquid filling plugs at the top front end of the recoil cylinder. Also remove the two overflow plugs, one at the front end and one at the left side of the cylinder.
c. Using a funnel, pour in recoil liquid at one of the liquid filling holes (fig. 59) until it overflows at the front overflow plug (fig. 59). Approximately 2½ gallons are required. Replace the front overflow plug.
|Figure 59 — Filling Recoil Cylinder with Liquid|
d. Continue to pour until the liquid overflows at one of the top filling holes. As entrapped gas will cause the liquid to overflow, it is desirable to wait until the turbulence subsides; then continue to fill. Replace the liquid filling plugs.
e. Depress the gun to the horizontal and pour recoil liquid in the side overflow hole until it overflows. Replace the plug.
f. Elevate and fully depress the piece at least three times to free the entrapped gas, and then elevate to a 2-degree elevation. Remove the liquid filling plugs again and add liquid if necessary.
39. FILLING AND CHARGING THE RAMMER CYLINDER.
a. Place the gun at a zero-degree elevation and a zero-degree cant.
b. Remove the liquid and gas filling plug.
c. Open the gas valve about two turns (fig. 60).
|Figure 60 — Filling Rammer Cylinder with Liquid|
d. Using a funnel, add recoil liquid until the liquid overflows at the gas and liquid filling hole.
e. Screw adapter and pressure gage into the gas and liquid filling hole (fig. 61) and connect to nitrogen supply. NOTE: Use the same improvised adapter described in paragraph 37 c (fig. 58).
|Figure 61 — Charging Rammer Cylinder with Nitrogen|
f. Close the gas valve on the rammer cylinder and check the gas line for leakage.
g. If the gas line is tight, open the gas valve on the rammer cylinder about two turns and fill with nitrogen until approximately 225 pounds per square inch are recorded on the pressure gage. Close the gas valve fully and disconnect the gas line. Replace the gas and liquid filling plug.