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Shipbuilding Terms and Phrases "L"


Shipbuilding Terms and Phrases 

The following definitions are from United States Shipping Board Emergency Fleet Corporation publication The Building of a Wooden Ship by Charles G. Davis (1918), a long out-of-print book that we have republished and is available on Amazon. They will be very handy when reading the works of such authors as Davis, Howard I. Chapelle, V.R. Grimwood, and others I will reference in this blog. In some cases, I have added further clarification to a definition in the form of editor's notes. These are in italic, contained in parentheses, and attribute the modern author of the clarification.


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LABORSOME: a vessel subject to or likely to labor, pitch or roll violently in a heavy sea, by which the masts and even the hull may be endangered. Oftentimes a vessel receives a series of heavy rolls and the rigging, shrouds, etc., become stretched, the masts strain upon the shrouds with such force that they are carried away, and the masts go overboard ; the continual motion of the vessel under these conditions loosens her joints and planking or calking, making her spring a leak. Vessels are often lost under these conditions. 

There are two or three remedies: The first and most important is a high standard of construction of the vessel, such as careful and neat framing of the timbers, ceiling and planking, care and neatness and thorough workmanlike fastenings. This is a matter that is directly under the control of the men constructing the vessel. The shipyard workers should remember that a defective fastening or a poorly fitted calked seam might start a leak in heavy weather, when the vessel is laboring in a rough sea, and endanger the lives of all on board, and might result in the loss of the vessel and cargo. 

Second, the stability of a vessel can be greatly improved by a careful stowing of her cargo, putting the heaviest weights as near to the metacenter as possible This improves her stability and will prevent excessive rolling. 

LACING: a small rope or lanyard used to lash the head of a fore-and-aft sail to the gaff; also the rope or line used to lace or sew an awning to the awning ridge or foot-rope, by passing around the awning ridge or foot-rope stretched tightly over the awning stanchion, and sewing it through eyelets in the edge or through grommets attached to the bolt-rope of the awning. 

LADDER: the inclined or vertical steps aboard a vessel, taking the place of stairs; a ladder may be used to furnish means of getting from one deck to another or from the surface of the water up the sides of the vessel to the bulwarks or on to the deck. 

LAG-SCREW: a heavy round-shanked wood screw with a square head. 

LANYARDS: a rope rove through the deadeyes attached to the end of the shrouds and to the channels; a strain is set on the lanyards which in turn tightens up the shrouds; a rope made fast to anything for securing it, as awning lanyards, davit lanyards, guy lanyards. 

LAP: a joint in which one part overlaps the other. 

LAP OVER OR UPON: the mast carlings are said to lap upon the beam; the head ledges are also said to lap at their ends over the hatch coamings. 

LARKSHEAD: a rope knot. 

LATERAL RESISTANCE: the resistance of the water against the sides of a vessel in a direction perpendicular to her length. 

LAUNCHING: the operation of placing the hull of a vessel in the water, by sliding it down the launching ways; during the process of launching, the weight of the vessel's hull is borne by the sliding ways or cradle on which she rests; the upper side of the cradle is curved and fitted to the underneath side of the hull. This cradle bears on the greased surface of the launching or ground ways, and when the cradle is released it slides down, carrying the vessel into the water. 

LAUNCHING PLANK: a center plank generally used to form the track on which the bilge ways, sliding ways or cradle slide when launching, also known as ground ways. 

LAUNCHING WAYS: sometimes called ground ways; outboard below the water they are called "under water ways;" the timber track, with timber ribbands or flanges on the side, which carries and guides the cradle supporting the hull, from the point where it was constructed, into the water. 

LAY: the direction in which the strands of a rope are twisted; in a rope the lay is from left to right or "with the sun"; in a cable-laid rope the lay is from right to left or “against the sun”; “lay to anchor” to be attached to an anchor or mooring which is overboard and hooked on to the bottom. 

LAYING OFF OR LAYING DOWN: the act of drawing the various parts of a vessel's hull full sized upon the mold loft floor; the dimensions are taken from the plans furnished by the Naval Architect. The molds are made by the loftsman from the plans drawn upon the mold loft floor. 

LAZY-GUY: a term sometimes applied to a boom guy or boom pendant. 

LAZY-JACK: the length of a small rope or lanyard rove through thimbles seized unto the sides of the boom topping lift and made fast to the boom. When the sail is lowered these small lines prevent the folds of canvas from falling below the boom or upon the deck. 

LEACH (LEECH): the vertical edge or side of a square sail, or the vertical after edge of a fore-and-aft sail. 

LEACH CRINGLE: the cringle attached to the leach of a sail. 

LEACH ROPE: the rope which reinforces the after vertical edge of a fore-and-aft sail, or the vertical sides of a square sail. 

LEADING PART: that part of a tackle upon which the hauling is done; "the hauling part" 

LEAK: an opening which permits the entrance or escape of any substance intended to be excluded or contained in a receptacle, tank or container. 

LEDGES: oak or other hardwood scantling, which is used in framing the decks ; this scantling is let into the ceiling athwartships. The ledges for gratings are similar, but are arched or rounded up to conform to the head ledges. 

LEE: away from the wind, as the lee-side of a vessel. 

LEEWARD: the side of the vessel or thing away from the wind. 

LEFT-HAND ROPE: the three or more stranded rope, the strands of which are laid “against the Sun,” meaning laid over from right to left. 

LENGTH BETWEEN PERPENDICULARS: the length of a vessel measured from the forward side of the stem, or forward perpendicular, to the afterside of the stern or rudder-post as the case might be, called the "after perpendicular." The after perpendicular in a sailing vessel, or where the stern and rudder-posts are combined, is the after side of the stem-post. In a steamer or vessel where the stem- and rudder-post are two separate structures, the after perpendicular would be the after side of the rudder-post. 

LENGTH OVER ALL: is the length of the vessel measured from the forward side of the stem to the after side of the stern, or the permanent part of the hull structure. 

LENGTHENING: the operation of spreading a vessel apart lengthways at her midship section and building in a new portion amidship to increase her length. 

LET-IN: to notch or fit one timber or plank into another. Carlings are let into beams; beams are let into clamps, etc. 

LEVEL LINES: the lines which determine the shape of the hull horizontally. They are made by horizontal planes coinciding with the water lines, when the ship is on an even keel. 

LIFELINES: small ropes or lanyards stretched along the deck in heavy weather as a protection to the crew, to prevent them from being washed overboard; also the line shot over a stranded vessel or a vessel in distress by a life-saving crew. 

LIMBER: the longitudinal gutter cut or notched into the lower side of floor frame on each side of the keelson, to permit water to drain freely into the pump well. 

LIMBER-CHAIN: a chain running through the gutter or limber along the bottom of a vessel inside the planking, and used to clean out the dirt and free or clear the limber, so that water will drain freely to pump well. 

LIMBER-HOLE: a hole a few inches in diameter, cut in the floor frame near the bottom to allow the bilge water to drain from one compartment space to another or to the pump well.

LIMBER-STRAKE: the bottom or lower strake in the ceiling, next to the keelson. This strake is generally made up of removable planks, which can be taken up, so as to get at the pump wells or limber and clear them from obstructions, if necessary. 

LINER: a man who locates and marks out the location for the next strake of planking. He is generally a leading ship carpenter. Also a very narrow strip of wood or flling-in piece used to make up a deficiency in width or thickness of anything. 

LINES: the plan of a ship that shows its form; from the lines drawn on the mold-loft floor the templates or molds are made for the various parts of the hull. A spiling line is a term used to signify a point on a plank from which the spiling measurements are taken; ropes used for various purposes aboard ship. There are many kinds of rope lines, such as head lines, bow lines, breast Unes, quarter lines, spring lines, stem lines, bunt lines, leach lines, towing lines, hauling lines, etc. 

LINES OF FLOTATION: in shipbuilding the plane or line in which the horizontal surface of a fluid, such as water, cuts a body or thing, as a ship floating in it; the dividing line between that part of a ship or other floating body below the surface of the water and that above it. In ships this line has an intimate relation to their buoyancy and equilibrium. 

LINESMAN: a loftsman. 

LINES PLAN: a drawing showing the general layout or form of a vessel. The lines comprise three plans: first, the sheer plan, a side view or elevation, a longitudinal section showing the water lines, bow and buttock lines; second, the half breadth plans, a top view, showing horizontal or floor plan at any water line; third, body plan, an end view, showing curves of the frames at any point of the vessel. 

LINING-CLOTH: reinforcing piece of canvas sewed on a sail or awning over points where they are liable to chafe. 

LIPS OF SCARPHS OR NIBS: the blunt top end left on each of the pieces of timber which form a scarph. The purpose is to give a chance to calk the scarph if necessary, and to increase the bearing. 

LIST: a tilting or inclination to one side; "a list to starboard" signifies the vessel has an inclination towards the starboard side. Also to cut a narrow strip of wood out of a vessel's frame, plank or deck to examine the condition of the wood for rot. 

LIZARD: a length of rope having one or more thimbles spliced on to it, and used as a leader for halyards or similar ropes. 

LOCKER: a storage compartment under a seat or transom in a cabin, stateroom, store- room, or saloon. 

LOCK STRAKE: timber, ceiling or planking notched into other timber members. 

LOG: an apparatus for measuring rapidity of a ship's motion. In the most common form it consists of a log chip or thin quadrant of wood about 5" radius fastened to a line wound on a reel. When the log chip is thrown overboard its motion is arrested on striking the water, and after it has been allowed to trail a certain distance behind the ship until it has a good hold on the water, the reel is released, at the same time a sand-glass is turned over and the sand started, and after allowing the line to run the full length of time indicated by the sand-glass it is stopped. The distance run out in this interval divided by a certain constant represents the speed per hour that the ship was then running. See Knot. 

LONG SPLICE: a method of splicing two ropes together by weaving the strands in such a manner that there is no enlargement of the rope diameter. This type of splicing is used on running rigging, and enables the spliced rope to pass freely over the sheave or through the mortise in a block. 

LONG TIMBERS: timbers reinforcing the cant frames which lead from the dead-wood to the head of the second futtock. 

LOOF: that part of the vessel where the planks are bent as the hull fines down or the planking approaches the stem. 

LOPSIDED: a term which describes a vessel which does not float perpendicularly or with a level deck. This may be caused by the shape of her sides not being similar, or to the weights of her machinery or equipment in her hold being more on one side of the keel than the other. 

LOWER MAST: the mast next the deck which is stepped on to the keel or the top of the shaft tunnel, lower hold beam or partners. The lower masts are named from their location in a vessel, as lower foremast, lower mainmast, lower mizzen-mast, lower jigger-mast, etc. 

LOWER RIGGING: the shrouds, back-stays and ratlines that brace the lower masts. 

LOWER SHROUDS: the shrouds and back-stays of the lower fore, main, mizzen and jiggermasts. 

LUBBER'S HOLE: an opening in the mast top through which the shrouds pass when leading from bulwark channels to the lower masthead. When a masthead is rigged like this and has futtock-shrouds over the outside of the masthead top, a sailor or seaman who, in order to get to the top climbs through this hole instead of going over the outside, is called a "lubber" or "land lubber.”

LUBBER'S POINT (LUBBER-MARK, LUBBER-LINE): the fine black vertical line which is painted on the fixed inside of the compass bowl and indicates the head or fore-and-aft line of the vessel, to the deck officer, quartermaster or helmsman when steering by compass. 

LUFF: the forward edge of a fore-and-aft sail. 

LUFF- CRINGLE: the iron ring or shape which is spliced into the bolt-rope of a gaff sail, at the angle formed by the boom and luff, or into the angle of a fore-and-aft sail formed by the junction of the head and luff. Triangular or jib-headed sails have but three cringles, head, tack and clue. Gaff sails have four cringles; peak, tack or nock, throat and clue. 

LUFF-TACKLE: a light handy tackle purchase, formed of a length of rope and a double and single block. The double block is always the head-block through which hauling part is rove. 

LUFF UPON LUFF: one luff-tackle applied to the hauling part of another luff-tackle. This gives an extremely powerful purchase for the power applied to hauling part. 

LUMBER-PORT: the port or opening fitted with a water-tight door on each side of the bows and stern of a vessel, used for passing long lengths of timber into the hold. Long lengths of timber can be handled in this way that could not be stowed or passed into the hold through the hatches.

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