G L O S S A R Y     of common wooden boat design/construction words.

A - I         J - Z

Alpha Apex - The lowest point in a cut rabbet where the inside face of a plank would end. In profile, it lies between the rabbit and bearding line. Sometimes called the middle line. Apron - A structural backing piece fit behind the stem. Often wider than the stem and set to form the after part of the rabbet. Ashcroft Construction - Double diagonal planking system with the planks of both skins raking in the same direction. Athwartships - At right angles to the centerline plane of the hull.

Bravo Backbone - The "spine" of the hull from which the frames radiate. Back Rabbett - The surface against which the side of a plank lies in a rabbetted member. The end fastenings of the plank penetrate the back rabbett of a stem or sternpost; the lower or inner edge fastenings of a plank penetrate the back rabbett of a keel or horn timber. See diagram below. Rabbett line = Outer Rabbett Line Apex Line = Middle Rabbett Line, Margin Line  Bearding Line = Back Rabbett Line, Inner Rabbet Line    Ballast - Added weight either within or external to the hull added to improve the stability of a vessel or bring it down to its designed lines. Balsa Sandwich - End grain balsa wood used as a core between FRP laminates. Bastard Sawn - Hardwood lumber in which the annual rings make angles of 30 degrees to 60 degrees with the surface of the piece. Batten - A thin flexible piece of wood. Used to create a smooth, fair, line. Beam - A structural member supporting a load applied transversely to it. The transverse members of a deck framing system; the width of a vessel. Beam Knee - A gusset like member used to connect a beam to a frame. Bearding Line - The line formed by the intersection of the inside of the planking with the side or face of the keel. Bending Steam - The process of forming a curved wood member by steaming or boiling the wood and bending it to a form. Bilge Plank - A strengthening plank laid inside or outside of a vessel at the bilge's turn; also known as "Bilge Stringer". Binding Strake - An extra thick strake of side or deck planking. Box Section Mast - A hollow mast of round, square or rectangular section made up of long strips of wood. Breasthook - Timber knees placed horizontally between two fore ends of stringers to reinforce their connection to the stem. Butt Block - A short longitudinal piece of wood used to back up the connection of two plank ends. Buttock - That part of a vessel's stern above her waterline which overhangs or lies abreast of the stern post; the counter. Buttock Lines - Lines representing fore and aft vertical sections from the centerline outward.

Charlie Camber - The curve of a deck athwartships. Cant Frames - Frames whose plane of support is not perpendicular to the fore and aft line. Capping - Fore and aft finished piece along the topside of an open boat, often improperly termed gunwale; called a covering board, margin plank or plank sheer in a decked vessel. Carlin - The fore and aft members of the deck framing system. Carvel Planked - Smooth skinned planking whose strakes run fore and aft. Caulking (calking) - Cotton, oakum or other fiber driven into planking seams to make them watertight. Ceiling - An inner skin of the hull often used to add strength in boats having sawn frames. In some cases the ceiling is not structural but merely serves to line the hull for decorative purposes or for ease in cleaning.  Chain Plate - (Shroud Plate) A flat strip of metal fastened through the hull, either from inside or outside, to which the lower ends of the shrouds are attached. Check - A lengthwise separation of the wood that usually extends across the rings of annual growth and commonly results from stresses set up in wood during seasoning. Chine - The line of intersection of the bottom with the side of a vee or flat bottomed vessel. Clamp - The fore and aft member at the sheer line of the vessel to which the deck beams usually fasten. Clench Planking - Lapstrake, in which the adjacent planks overlap like clapboards of a house. Clench Fastening - Securing a nail or rivet by placing a rove (washer) over the inboard side and then bending the fastening over it. In many cases they are simply bent over by driving them against a backing iron, causing them to reenter the frame. Clinker Built - See clench planking. Coat, Mast - A protective piece, usually canvas, covering the mast wedges where the mast enters the deck. Cold Bent (frames) - Frames which are bent on forms and after shaping are fitted to the vessel. Cold Molded - A method of boat construction using a male mold over which layers of thin wood and/or plywood are diagonally laid and glued together. Can be covered with epoxy or FRP. Cove Line - A hollowed out decorative line found along the sheer of a boat. Covering Board - A plank used as a "washboard" or "plank sheer" along the outer edge of the deck. - See Capping. Cutwater - The forward edge of the stem at the waterline.

Delta Dead Rise - The amount the bottom rises from keel to chine - most properly applied to "Vee" bottom construction but also used in reference to the rising bottom of round bottom boats. Deadeye - A stout disk of hard wood, strapped with rope or iron, through which holes (usually three) are pierced for the reception of lanyards. They are used as blocks to connect shrouds and chain plates. Deadwood - The vertical structure built up from the keel to support the cant frames at the stern or stem; longitudinal timbers of a vessel's structural backbone which lie entirely outside the keel, sternpost, and horn timber rabbett lines Decay - The decomposition of wood substance by fungi. 1. (Advanced or typical) - The older stage of decay in which the destruction is readily recognized because the wood has become punky, soft and spongy, stringy, ringshaked, pitted or crumbly. Decisive discoloration or bleaching of the rotted wood is often apparent. 2. (Incipient) - The early stage of decay that has not proceeded far enough to soften or otherwise perceptibly impair the hardness of the wood. It is usually accompanied by a slight discoloration or bleaching of the wood. Deck Head - The underside of the deck. Diagonal Planking - Planking laid on an angle to the keel. Displacement - The actual weight of a boat as it "displaces" its weight when afloat; not to be confused with admeasurement tonnages. Drift (Pins, Bolts) A long fastening driven (pin) or threaded (bolt) to receive end nuts, used for joining heavy timbers such as horn timbers and stern frames; also used to fasten and reinforce wooden panels on edge, such as rudders and centerboard trunks. Dry Rot - A term loosely applied to any dry, crumbly rot but especially to that which, when in an advanced stage, permits the wood to be crushed easily to a dry powder. The term in actually a misnomer for any decay, since all fungi require over 20% moisture to grow. Dutchman - Wooden block or wedge used to fill the void in a badly made butt or joint; a graving piece or repairing patch in a deck; filler; shim; short plank.

Echo Edge-Grained Lumber - Lumber that has been sawed so that the wide surfaces extend approximately at right angles to the annual growth rings. Lumber is considered edged grained when the rings form an angle of 45 degrees to 90 degrees with the wide surface of the piece. Edging - Amount required to be cut away from the edge of a plank in fitting strakes. Edge Nailed - A method of fastening a strip plank to adjacent planks.

Foxtrot Facing - Building one piece of timber on another for strength or finish purposes. False Keel - Sacrificial batten added to the keel to protect the keel from grounding and from marine borers; eg. worm shoe. Faying - Joining closely together. Flat-Grained Lumber - Lumber that has been sawed in a plane approximately perpendicular to a radius of the log. Lumber is considered flat grained when the annual growth rings make an angle of less than 45 degrees with the surface of the piece. Floor or Floor Timber - A transverse structural member lying across the keel and tying the frames on either side of the keel together. The central futtock or futtocks of a sawn frame, lying across the keel. Floor timbers join both sides of a vessel together and make up the substructure for external keel fastenings, engine beds, and mast steps. Floorboards - Planking laid on top of the floors to provide a walkway. Also known as the "sole." Frame - The transverse structure at each section giving form to the hull. Frames connect to the keel or keels on and to the clamp or shelf at the sheer. Also known as "ribs." Freeing Port - Any direct opening through the vessel's bulwark or hull to quickly drain overboard water that has been shipped on exposed decks. Futtock - Curved parts or sections of transverse frames extending from the floor timbers to the top timbers.

Golf Garboard - The strake of planking nearest the keel. Green - Freshly sawed lumber, or lumber that has received no intentional drying; unseasoned. The term does not apply to lumber that may have become completely wet through waterlogging. Grub Beam - A built up beam of short heavy timbers used to shape a round stern. Gusset - Any piece that is used to join or strengthen the joint of two other pieces.

Hotel Hanging Knee - A strengthening bracket used between frames and deck beams. Heartwood - The wood extending from the pith to the sapwood, the cells of which no longer participate in the life processes of the tree. Heartwood may be infiltrated with gums, resins, and other materials that usually make it darker and more decay resistant than sapwood. Horn Timber - One or more timbers forming the main support for an overhanging stern and extending aft from the upper end of the stern post. Also used for timber connecting the shaft log and body post with the rudder post. Horse (n) - The form upon which a small boat is built. Horse (v) - To drive home, as to horse caulking. Hot Frame - A frame which, after being softened by heat, is bent into shape as it is installed.

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