Dictionary Search: search=keel

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For a selection of basic naval terms, see the log and report glossary.

Results: keel

abeam: nautical: At right angles to the keel.
appendages: nautical: Relatively small portions of a vessel extending beyond its main outline as shown by transverse and water plane sections, including such items as shafting, struts, bossings, docking and bilge keels, propellers, rudder, and any other feature, extraneous to the hull and generally immersed.
B. K.: blueprints: Bilge Keel, same as Rol. K.
bearding line: nautical: A term applied to the intersection of the molded line of planking or plating and the stem, stern post, and keel, usually in connection with wood shipbuilding.
bottom: nautical: That portion of a vessel’s shell between the keel and the lower turn of the bilge.
buttock lines: nautical: The curves shown by taking vertical longitudinal sections of the after part of a ship’s hull parallel to the ship’s keel. Similar curves in forward part of hull are "bow lines".
cant frame: nautical: A frame the plane of which is not square to the keel.
center of gravity: nautical: The point at which the combined weight of all the individual items going to make up the total weight of the vessel may be considered as concentrated; generally located longitudinally forward or aft of the middle perpendicular and vertically above bottom of keel or below a stated waterline.
club-foot: nautical: A fore foot in which displacement or volume is placed near the keel and close to the forward perpendicular, resulting in full water lines below water and fine lines at and near the designed water line, the transverse sections being bulb-shaped. Also called a bulb or bulbous bow.
deadwood: nautical: The reinforcing structure built in between the keel and keelson in the after body of a ship or back of the joint between the stem and the keel in the fore body.
dog shores: nautical: Diagonal braces placed to prevent the sliding ways from moving when the shores and keel blocks are removed before launching. Dog shores are the last timbers to be knocked away at a launching. Also called "daggers" or "dagger shores".
draft marks: nautical: The numbers which are placed on each side of a vessel near the bow and stern, and often also amidships, to indicate the distance from the number to the bottom of the keel or a fixed reference point. These numbers are six inches high, are spaced twelve inches bottom to bottom vertically, and are located as close to the bow and stern as possible.
dry dock, floating: nautical: A hollowing floating structure of L- or U-shaped cross section, so designed that it may be submerged to permit floating a vessel into it, and that it may then raise the vessel and itself so that the deck of the dock and consequently the bottom of the vessel is above the level of the water. The bottom of a floating dry dock consists of one or more pontoons or rectangular-shaped vessels with high wing structure erected on one or both sides according to whether the section is to be L- or U-shaped. The deck of the pontoon is fitted with stationary keel blocks and movable bilge blocks which can be pulled under a vessel from the top of the wing structure. Pumps are fitted in the wings by which the dock can be quickly submerged or raised. Floating dry docks are used for repairing and painting the under-water portions of vessels and for docking a damaged vessel.
dry dock, graving: nautical: A basin excavated at a waterway and connected thereto by gates or a caisson which may be opened to let a vessel in or out and then closed and the water pumped out. The dock is fitted with stationary keel blocks and movable bilge blocks, which usually are fitted on rack tracks, allowing them to be pulled under a vessel before the water is pumped out. Graving docks are common in navy yards, and although more expensive to construct than floating dry docks, they are practically permanent and supply a more rigid foundation for supporting a ship. The gate of a graving dry dock is usually a caisson which is a complete vessel in itself, having a strong rectangular-shaped keel and end posts which bear against the bottom sill and side ledges at the entrance of the dry dock. The caisson is designed so that its draft may be adjusted by water ballast until it bears against the sill and ledges and is equipped with flood valves and power pumps to make this adjustment. When a ship is to be docked, sluice valves in the caisson or in the deck structure are opened until the water in the dock reaches the same level as the water outside. The caisson is then floated to one side, allowing a vessel to enter the dock. The caisson is then floated back to close the entrance, completely separating the basin from the waterway, and after the vessel is lined up over the keel blocks the water is pumped out of the dry dock.
dry dock, railway: nautical: A railway dock consists of tracks built on an incline on a strong foundation and extending from a distance in-shore sufficient to allow docking a vessel of the maximum size for which the dock is built, to a distance underwater sufficient to allow the same vessel to enter the cradle. The cradle running on the tracks may be of wood or steel fitted with keel and bilge blocks and sufficiently weighted to keep it on the track when in the water. A hoisting engine with a winding drum or wild cat is fitted at the in-shore end of the railway which operates the cradle by a cable or chain. This type of dry dock is used for docking small ships. It is commonly called a "marine railway".
even keel: nautical: When a boat rides on an even keel, its plane of flotation is either coincident with or parallel to the designed waterline.
F. K.: blueprints: Flat Keel.
fin: nautical: A projecting keel. A thin plane of metal projecting from hull, etc.
floor: nautical: A plate used vertically in the bottom of a ship running athwartship from bilge to bilge usually on every frame to deepen it. In wood ships, the lowest frame timber or the one crossing the keel is called the floor.
forefoot: nautical: The lower end of a vessel’s stem which is stepped on the keel. That point in the forward end of the keel about which the boat pivots in an endwise launching.
futtocks: nautical: The pieces of timber of which a frame in a wood ship is composed. Starting at the keel they are called the first futtock, second futtock, third futtock, and so on.
garboard: nautical: The strakes of outside plating next to the keel. These strakes act in conjunction with the keel and are usually thicker than the other bottom strakes.
gooseneck: nautical: A swiveling fitting on the keel or mast end of a boom for connecting the boom to the mast. Also called a Pacific iron.
gripe: nautical: The sharp forward end of the dished keel on which the stem is fixed. A curved piece of timber joining the forward end of the keel and the lower end of the cutwater. A lashing, chain, or the like, used to secure small boats in the chocks and in sea position in the davits.
groundways: nautical: Timbers fixed to the ground and extending fore and aft under the hull on each side of the keel, to form a broad surface track on which the ship is end-launched. "Groundways" for a side launching embody similar basic features.
Hold water: orders: An order to check a pulling boat’s headway by holding the blades of the oars vertically in the water with the oars at right angle to the keel.
horning: nautical: Setting the frames of a vessel square to the keel after the proper inclination to the vertical due to the declivity of the keel has been given.
horse timber: nautical: The after longitudinal strength member (often called counter timber) fastening the shaft log or keel and the transom knee together. A small boat term.
K.: blueprints: Keel.
keel, bilge: nautical: A fin fitted on the bottom of a ship at the turn of the bilge to reduce rolling. It commonly consists of a plate running fore and aft and attached to the shell plating by angle bars. It materially helps in steadying a ship and does not add much to the resistance to propulsion when properly located.
keel, blocks: nautical: Heavy timber blocks piled one above the other on which the keel of a vessel is supported when being built, or when she is in a dry dock. They are placed under the keel from bow to stern and a sufficient distance apart to allow working between them.
keel, docking: nautical: In dry docking, the weight of a ship is carried almost entirely on the keel and bilge blocks. The keel and keelson provide the means of distributing the pressure on the center line, and docking keels composed of doubling strips of plate or a heavier plate or built-up girders are sometimes fitted on the bottom at a distance from the center line corresponding to the best position for the bilge block. The docking keels are fitted in the fore and aft direction, generally parallel or nearly so to the keel.
keel: nautical: A center-line strength member running fore and aft along the bottom of a ship and often referred to as the backbone. It is composed either of long bars or timbers scarfed at their ends or by flat plates connected together by riveting or welding.
keelson, vertical center: nautical: The lower middle-line girder which, in conjunction with a flat plate keel on the bottom and a rider plate on top, forms the principal fore-and-aft strength member in the bottom of a ship. In addition to its importance as a "backbone" or longitudinal strength member, it serves to distribute and equalize the pressure on the transverse frames and bottom of the ship when grounding or docking occurs. In steel ships this keelson usually consists of a vertical plate with two angles running along the top and two along the bottom. The girder, however, may be made up of various combinations of plates and shapes. This member should continue as far forward and aft as possible. Usually called the Vertical Keel.
knuckle: nautical: An abrupt change in direction of the plating, frames, keel, deck, or other structure of a vessel.
launching: nautical: A term applied to the operation of transferring a vessel from the building ways into the water. End launching and side launching methods are employed; the former method is used when the vessel is built at an angle, usually at right angles, to the waterfront and the vessel is launched stern first, while in side launching the vessel is built parallel to the waterfront and launched sidewise. In preparing for an end launching, usually groundways, made of heavy timbers are laid with an inclination of about ½" and ⁵/₈" to the foot parallel to the center line of the ship one on either side of the keel, and spaced about one-third of the beam of the vessel apart. These groundways run the length of the vessel and for some distance out under the water. On top of the groundways are placed the sliding ways, also heavy timbers, and between these two ways is placed a coating of launching grease. The sliding ways are prevented from sliding on the greased groundways by a trigger or similar device and dog or dagger shores. Cradles are built up to fit the form of the vessel, and between the sliding ways and the cradle, wedges are driven and the weight of the ship thus transferred from the building blocks to the sliding ways. After the building blocks and shores are removed, the trigger is released and gravity causes the vessel to slide down the inclined ways. In some cases hydraulic jacks are set at the upper end of the groundways to exert pressure on the sliding ways to assist in overcoming initial friction along the ways. A similar procedure is followed in the case of side launchings, except that more than two groundways are usually used, depending on the length of the ship, and the inclination of the ways is steeper.
Lay in oars: orders: An order to a pulling boat’s crew to stop pulling and to hold their oars with the blades horizontal and the oars at right angles to the keel of the boat.
rabbet: nautical: A groove, depression, or offset in a member into which the end or edge of another member is fitted, generally so that the two surfaces are flush. A rabbet in the stem or keel would take the ends or edges of the planking or shell plating.
rider plate: nautical: A continuous flat plate attached to the top of a center line vertical keel in a horizontal position. Its under side is attached to the floors, and when an inner bottom is fitted, it forms the center strake.
rolling chocks: nautical: Same as keel, bilge.
rubbing strip: nautical: A plate riveted to the bottom of the keel to afford protection in docking and grounding. A strip fastened to the face of a fender or to the shell plating where contact is likely to occur.
Rudder amidships: orders: Place the rudder in line with the keel of the ship.
skeg: nautical: The extreme after part of the keel of a vessel, the portion that supports the rudder post and stern post.
sleepers: nautical: Timbers placed upon the ground or on top of piling to support the cribbing, keel, and bilge blocks.
slipway or berth: nautical: The space in a shipyard where a foundation for launching ways and keel blocks exists and which is occupied by a ship while under construction. The term berth is more properly applied to the space a ship occupies pier or at an anchorage.
stem: nautical: The bow frame forming the apex of the intersection of the forward sides of a ship. It is rigidly connected at lower end to the keel.
stern frame: nautical: A large casting or forging attached to the after end of the keel to form the ship’s stern. Includes rudder post, propeller post, and aperture for the propeller in single-screw vessels.
stocks: nautical: A general term applied to the keel blocks, bilge blocks, and timbers upon which a vessel is constructed.
strake, bottom: nautical: Any strake of plating on the bottom of a ship that lies between the keel and the bilge strakes.
V. K.: blueprints: Vertical Keel.
water line: nautical: A term used to describe a line drawn parallel to the molded base line and at a certain height above it, as the 10-foot water line. It represents a plane parallel to the surface of the water when the vessel is floating on an even keel, i.e., without trim. In the body plan and the sheer plan it is a straight line, but in the plan view of the lines it shows the contour of the hull line at the given distance above the base line. Used also to describe the line of intersection of the surface of the water with the hull of the ship at any draft and any condition of trim.
wedges: nautical: Wood or metal pieces shaped in the form of a sharp V, used for driving up or for separating work. They are used in launching to raise the vessel from the keel blocks and thus transfer the load to the cradle and the sliding ways.