IRON SHIPBUILDING.

807

PLATING, &c.—The thickness of the plates in a vessel is to beaccording to Lloyd’s, Liverpool , or other rules. No plates tobe less in length than from five to eight spaces of frames, exceptthe fore and after hoods.—No butts of outside plating in adjoiningstrakes to be nearer to each other than two spaces of frames, andthe butts of the alternate strakes not to be under each other, butshifted not less than one frame space.

The butts of the upper or main deck and of spar deck Stringerplates, in all cases, are to be shifted not less than two spaces of framesclear of the butts of the sheer strakes. The butts of the garboardstrakes to be shifted clear of the keel scarphs, and not to be nearereach other on opposite sides of the vessel than two spaces of frames.

All butts of plating, when practicable, must be planed and fittedclose; the edges of the plating to be sheared from their faying sur-faces, or the burr caused by the shearing to be carefully chipped off,and all outside edges of plating are to be either planed or chippedfair. The butts and edges to be carefully caulked.

The sheer strakes in one, two, three decked, and spar-decked ves-sels, where the butt straps do not extend to the upper edge in onelength, to be fitted sufficiently high above the upper deck-beam ends,so as to take two rows of rivets vertically in the butts above theupper flange of the gunwale angle iron. When plates forming theoutside strakes of plating exceed 44 inches in breadth, their buttsare to be treble rivetted.

Where gutter water-ways are adopted at the upper deck, the buttstraps of the bulwark plating are to be sufficiently broad to receivethe spur in the middle of the bulwark stay; and when the plates donot exceed 12 feet in length they are to have stays fitted againstthe butt straps, and an intermediate stay is to be fitted between thebutts. In no case are the stays which support the bulwarks to be morethan 6 feet apart. Their size may be from 1 $4 inch to 3 inches in dia-meter, regulated by the length of the stay and the size of the vessel.

Butt straps .—The breadth and thickness of the straps are to beaccording to rules by Lloyd’s, &c., the fibre of the iron to be in thedirection of the fibre of the plates they connect. In vessels of acertain size, for half the vessel’s length amidships they are treblerivetted, while in vessels of smaller size they are double rivetted.

When plates have to be doubled, the butts of these plates and ofthe doubling plates are to have butt straps double rivetted, and inaddition, these doubling plates are to be well rivetted at the edges