Q. Describe the general parts of the throttling-valve and how it operates.
A. The two equalizing-pipes connecting the front and rear of opposite recoil-cylinders have a pipe connecting them; if this pipe is open completely, oil can move freely from the front to the rear of the cylinders. If it be closed partly by a valve called the throttling-valve, much less oil will pass this way. Thus, by regulating the adjustment of this valve, the recoil of the gun is regulated. It is seen that the throttling-bars work with the throttling-valve. (See Fig. 31.)
Q. How much oil should be removed from recoil-cylinders having the filling-plugs on the top of the cylinders?
A.
12-inch disappearing carriages, all models, 3 gallons.
10-inch disappearing carriages, all models, 1½ gallons.
8-inch disappearing carriages, all models, 1 gallon.
6-inch disappearing carriages, model 1898, ½ gallon.
Q. Where new filling-plugs have been inserted explain how the cylinders are filled.
A. For full charges remove the two filling-plugs (one from each cylinder), pour oil into one filling-hole until it flows out of the hole in the other cylinder, wait a moment to allow the oil to settle, and examine for any pocketed air or any temporary obstruction. If necessary, pour in more oil until the oil is observed to be in both cylinders up to the level of the filling-holes, then insert the screw-plugs without removing any oil.
Q. Prior to firing, what should be done to the bore of the gun?
A. Prior to artillery practice the bore, including the powder-chamber, of each piece to be used in practice will be thoroughly cleaned and freed from lubricant before any shot is fired.
Q. How is powder residue removed after firing?