port-sill

One end of a tripping-line is fastened to the middle of the toggle, and the other to the breeching-bolt in the side of the ship; by this arrangement the toggle is tripped from its place at the commencement of the recoil, and the muzzle is raised so as to clear the port-sill by the preponderance of the breech.

Ordnance Instructions for the United States Navy. 1866. Fourth edition. United States. Navy Dept. Bureau of Ordnance

Hook the garnet and haul it taut, so as to raise the breech of the gun as much as the port-sill will permit; hook or toggle the gun-purchase, and sway away.

Ordnance Instructions for the United States Navy. 1866. Fourth edition. United States. Navy Dept. Bureau of Ordnance

Height of securing-bolt (side-tackle bolt) above port-sill 8. 8.

Ordnance Instructions for the United States Navy. 1866. Fourth edition. United States. Navy Dept. Bureau of Ordnance

When home, the men run the gun out as quickly as possible; the Captain of the gun clears the vent, primes in running out, points and fires in the usual manner, but as rapidly as is consistent with a good aim, taking care that the muzzle is clear of the port-sill, and on lower decks that the port is triced up clear of the explosion.

Ordnance Instructions for the United States Navy. 1866. Fourth edition. United States. Navy Dept. Bureau of Ordnance

For IX-in. guns, the port-sill should not be less than 20 inches in height, and no port-sill less than 16 inches; otherwise, the carriages will not give sufficient elevation, and the position of the Gun

Ordnance Instructions for the United States Navy. 1866. Fourth edition. United States. Navy Dept. Bureau of Ordnance

Bring the gun under the yard and sling it as follows: place one bight of the slings under the neck of the cascabel, and pass the lashing which is attached to the slings round the chase, at such a distance from the trunnions as will allow them to go into the trunnion-holes without bringing too great a pressure of the slings against the upper port-sill.

Ordnance Instructions for the United States Navy. 1866. Fourth edition. United States. Navy Dept. Bureau of Ordnance

When the breech of the gun is above the port-sill, hook the garnet and the thwart-ship-tackle to the cascabel, and bowse on both.

Ordnance Instructions for the United States Navy. 1866. Fourth edition. United States. Navy Dept. Bureau of Ordnance

Thus fitted, when the gun is run in and levelled, breechings must be long enough to allow the muzzle of the gun to come a foot inside of the upper port-sill, if the breadth of the vessel will allow it.

Ordnance Instructions for the United States Navy. 1866. Fourth edition. United States. Navy Dept. Bureau of Ordnance

When the slings bear hard on the upper port-sill, lower the gun-purchase, and bowse on the garnet until the breech is high enough for the trunnions to clear the cap-square bolts in the carriage; then bowse on the thwart-ship-tackle until the trunnions are over the trunnion-holes, lowering the purchase as required to bring the gun into its place.

Ordnance Instructions for the United States Navy. 1866. Fourth edition. United States. Navy Dept. Bureau of Ordnance

The Handspikemen raise the breech to free the quoin; the 2d Captain withdraws it and the bed; the Handspikemen lower the breech upon the axletree, so that in case the gun should break adrift, the muzzle will take the upper port-sill; and the Port-tacklemen lower the port-lid.

Ordnance Instructions for the United States Navy. 1866. Fourth edition. United States. Navy Dept. Bureau of Ordnance