Lengthening to Limber Passage

The operation of separating a ship athwartships and adding a certain portion to her length. It is performed by clearing or driving out all the fastenings in wake of the butts of those planks which may be retained, and the others are cut through. The after-end is then drawn apart to a limited distance equal to the additional length proposed. The keel is then made good, the floors crossed, and a sufficient number of timbers raised to fill the vacancy produced by the separation. The kelson is then replaced to give good shift to the new scarphs of the keel, and as many beams as may be necessary are placed across the ship in the new interval, and the planks on the outside are placed with a proper shift. The clamps and footwaling within the ship are then supplied, the beams kneed, and the ship completed in all respects as before.

To fix or fit one timber or plank into another, as the ends of carlings into the beams, and the beams into the clamps, vacancies being made in each to receive the other.

Lines determining the shape of a ship's body horizontally, or square from the middle line of the ship.

A passage or channel formed throughout the whole length of the floor, on each side of the keelson, for giving water a free communication to the pumps. It is formed by the limber-strake on each side, a thick strake wrought next the keelson, from the upper side of which the depth in the hold is always taken. This strake is kept at about eleven inches from the keelson, and forms the passage fore-and-aft which admits the water with a fair run to the pump-well. The upper part of the limber passage is formed by the limber boards, which are made to keep out all dirt and other obstructions. These boards are composed of short pieces of oak plank, one edge of which is fitted by a rabbet into the limber-strake, and the other edge beveled with a descent against the keelson. They are fitted in short pieces for the convenience of taking up any one or more readily in order to clear away any obstruction in the passage. When the limber boards are fitted care should be taken to have the butts in those places where the bulkheads come, as there will be then no difficulty in taking those up which come near the bulkheads. A hole is bored in the middle of each butt to admit the end of a crow for prizing it up when required. To prevent the boards from being displaced, each should be marked with a line corresponding with one on the limber-strake.

Limber Holes are square grooves cut through the underside of the floor-timber, about nine inches from the side of the keel on each side, through which water may run toward the pumps in the whole length of the floors. This precaution is requisite in merchant ships only, where small quantities of water, by the heeling of the ship, may come through the ceiling and damage the cargo. It is for this reason that the lower futtocks of merchant ships are cut off short of the keel.