All the numbers, excepting 11 and 12, who attend purchase-falls, move up to their ordinary stations for serving the gun, unhook side-tackles, and remove the old carriage, under the direction of No. 1: and—
At the word "Mount!" the same men bring the new carriage into position for mounting.
At the word "Lower!" Nos. 11 and 12 lower the gun into its place; all the numbers then proceed, respectively, to reverse what they had done in dismounting.
Guns on covered decks may also be dismounted by means of a muzzle-lashing, the runner and the train-tackles, assisted by the handspikes.
The gun is run in and laid square under the housing-bolt, the bed and quoin removed, the muzzle elevated and secured as in the housing position; then, after un-keying and throwing back the cap-squares, the breech is bowsed up clear of the carriage by means of the train-tackle, hooked in the eye of a runner, the block of which hooks in an eye-bolt in the beam over the gun. If preferred, this mode of dismounting may be adopted by substituting the muzzle-lashing for the toggle-block of the griolet, and toggling the runner-block in the hole made in the deck for the breech-purchase of the griolet.
THROWING GUNS OVERBOARD.
509. The gun's crew being assembled at Quarters, remove the pin and chock from the cascabel, into the jaws of which place a selvagee strap; hook the double block of the train-tackle into the housing-bolt over the port, and its single block into the selvagee strap; remove the cap-squares, and place a round block of wood on the sill of the port, high enough to let the chase bear on it when slightly depressed; raise the breech as much as possible, without lifting the gun out of the carriage. When all is ready man the train-tackle well; have the handspikemen also ready to assist in raising the breech; and if the vessel is not rolling, it will be well to have additional handspikes under the rear of the carriage to lift it also, so as to give free egress to the gun. When all is ready, give the order: "All together—launch!" In a gale of wind advantage should be taken of a favorable roll to give the word, that the action of the sea and of the men at the guns may be simultaneous.
If the guns are to be thrown overboard for the purpose of lightening a ship which is aground, they must be buoyed, and care is to be taken that each buoy-rope is of a proper length and strong enough to weigh the gun. The best mode of securing the buoy-rope to the gun is to form a clinch or splice an eye in the end which goes over the cascabel, and take a half-hitch with the bight around the chase of the gun, and stop it with spun-yarn.
The buoy must be sufficient to float the rope when saturated; or, in deep water, a smaller line may be used for the buoy, and attached to the rope intended for weighing the gun, that it may be hauled up when wanted.