Glossary from “Building Small Boats” by Greg Rössel
Apex - The lowest point in a cut rabbet where the inside face of a plank would end. In profile, it lies between the rabbet 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.
Athwartships - At right angles to the centerline plane of the hull.
Batten - A long, thin, flexible piece of wood, usually rectangular in shape and made of clear, straight-grained softwood. Used to create a smooth, fair line.
Backbone - The full assembly of all the components, including the stem, keel, and transom, that make up the center foundation of the hull.
Beam Mold - A pattern or template used for marking the shape (camber) of deckbeams.
Bed Logs (for centerboard case) - The rabbeted structural members of the centerboard case that run fore and aft next to the centerboard slot. The logs are fastened to the keel with screws or bolts. The rabbets are designed to accept the side panels of the trunk and face inward toward the slot.
Bedding Compound - A non-hardening putty that is used as a gasket between two pieces of wood to exclude water.
Bearding Line - The point where the inside face of the planking touches the outside face of the stem as it enters the rabbet.
Bevel - An angle cut into a piece of wood, usually to facilitate the joining of that piece of wood to another. A lapstrake plank is beveled on the outside upper edge to allow the lower edge of the next plank to overlap it for a watertight fit.
Bevel Gauge - A two-bladed tool used to capture angles.
Breasthook - A triangular structural member fit at the sheer immediately behind the stem. Fitted and fastened to the stem and the adjacent planking, the breasthook acts as a gusset in a truss to add great strength to the upper part of the stem.
Body Plan - The view on a set of lines or lofting portraying the athwartships view of the stations. Generally only one-half of the width of the stations is illustrated. The Body Plan normally offers a split view, one side illustrating the stations as they would appear if viewed from the bow, the other, as they would appear if viewed from the stern.
Bore - To drill a cylindrical hole.
Broadstrake - The second strake up from the keel, next to the garboard.
Bulkhead - A vertical partition in the interior of the boat.
Bung - A wooden plug used to cover a countersunk fastening.
Butt Block - A gusset-like block of wood used to join two parts of a strake together.
Buttock - A fore-and-aft slice or plane through the hull that runs parallel to the centerline plane.
Camber (or Crown) - A convex curve on a deck, cabintop, breasthook, or any other transverse member. Also the term used to describe an unwanted curve on a flat-planed bevel.
Carlin - Deck framing that runs fore and aft, forming the foundation for the inboard edge of the side deck; connected to, and supports, the stud beams.
Carvel - Planking fit edge to edge to produce a smooth hull.
Ceiling - Fore-and-aft planking laid on the inside of the frames; adds to structural strength and prevents debris from getting between frame members.
Centerboard - A pivoting, sliding keel made either of wood or metal.
Cheeks - Pieces affixed to the side of a structure to strengthen it.
Chine (or Chine Log) - A longitudinal member in a V-bottom hull running along the knuckle where the side and bottom legs of the frames are joined.
Clench Nail - A square-cut nail that is driven through a pre-drilled hole; the point of the nail is bent over to make a one-legged staple.
Clinch Ring - A round, dished washer with a hole in the center into which the tip of a metal rod can be inserted and peened over to create the head of a drift pin.
Clinker - See Lapstrake.
Counterbore - A cylindrical hole that is drilled to allow the head of a fastening to be sunk below the surface. Usually filled with a bung or putty.
Crook - A naturally grown branch or root of a tree in a shape suitable for a structural member, such as a knee, stem, deckbeam, or frame.
Cross Spall - A member used to hold together the two sides of a mold. Also the name for a temporary spreader running athwartships from sheer to sheer to hold the shape of a hull until permanent interior bracing is installed.
Deadrise - The angle the bottom of the boat makes with the horizontal plane at the keel.
Deadwood - Solid pieces of wood used as fillers in the backbone assembly.
Deckbeam - An athwartships structural component that not only supports the deck but also ties the hull together at the sheer. Deckbeams usually have camber and are made of either solid or laminated stock.
Diagonal - A diagonal slice drawn through the lines plan when lofting to check the fairness of the hull.
Diminishing Device - An architectural tool used to graphically divide up distances; often used for lining out the planking.
Dory Lap - A planking method similar to lapstrake, except it uses two complementary bevels in the laps rather than a single one.
Drift (or Drift Pin) - A homemade spike often used to blind-fasten heavy keel members together. Also used to edge-fasten rudders, centerboards, and transoms
Edge-Set - The forcing sideways of a plank on the Hat. Edge-set is undesirable when using a spiling batten, sometimes necessary when hanging a plank.
Expand - To draw out a part, such as a transom, to its full size and shape from a foreshortened view.
Fair - A smooth line, without any unnatural distortions, lumps, or hollows in it.
Flitch Sawn - Planks or timbers sawn through and through as two-sided slabs with bark on either side. Also known as live edge.
Floor (or Floor Timber) - A framing member roughly the same thickness as a frame running athwartships across the keel, fitted and fastened to the garboard strake and the keel. It is a key component that ties one side of the boat to the other.
Forefoot - The lower portion of a built-up stem that falls in the region between the stempiece and the keel.
Frame - The nautical equivalent of a stud in house construction. Sawn or steam-bent to shape, frames generally run perpendicular to the keel and the planks are fastened to them.
Garboard - The plank next to the keel.
Green Wood - Newly cut wood with a high moisture content.
Grid - A pattern of regularly spaced horizontal and vertical lines forming squares on a set of plans or a lofting board and used as a reference for locating points.
Gripe - See Forefoot.
Gudgeon - A fitting that takes a pintle fitted to the rudder, forming a hinge on which the rudder swings.
Half-Breadth - Distance measured out from the centerline.
Hanging Knee - A vertical knee, usually used to tie the underside of the end of a deckbeam to the hull.
(To) Hog - A distortion of the hull in which the forward and after ends droop lower than the middle section.
Hog Piece - Similar to a keel batten. Used on top of the keel to give better landing for the garboard plank.
Hood End - The forward end of the plank where it fits into the rabbet.
Horn (or Horn In) - To check the squareness of an athwartships member (thwart, frame, mold) by measuring from a point on the centerline to the outermost edges of the piece being checked - thus forming an isosceles triangle. If both legs of the triangle are the same, the piece is square to the centerline.
Inside of Plank - The shape of the hull minus the plank thickness.
Inwale - A longitudinal member fastened at the top inside face of the frames in an open boat. It generally serves the same purpose as a clamp in a decked boat.
Joining - The mating of one piece of wood to another.
Keel - The main longitudinal structural member of a hull.
Keelson (or Keel Batten) - A structural member fastened to the top of the keel for added strength. Wider than the keel, it also adds greater bearing surface for the planking.
Kerf - Groove or slice made by a cutting tool, such as a saw.
Kiln Dried - Wood that has been artificially dried in an oven to a specific moisture content.
Knee - A brace or bracket between two adjoining members.
Landing (or Lap) - The flat bevel planed into the edge of a plank to allow the next plank to lie flush against it.
Lapstrake - A system of planking where the lower edge of one strake overlaps the top edge of another.
Ledges (or Centerboard Case Posts) - The fore-and-aft vertical end pieces of the centerboard case.
Limber - Drain hole cut in the lower edge of a floor next to the keel.
Lining Off - Determining the layout of the planking on the hull.
Live Edge - See Flitch Sawn.
Load Waterline (or LWL) - The theoretical level at which the hull will float when carrying its designed weight.
Lodging Knee - A horizontal knee; used primarily to tie the side of a deckbeam to the hull.
Lofting - The full-size lay-down of the lines of a hull.
Long Lines - In lofting, drawn lines that run the length of the vessel; e.g., sheerline, buttocks, waterlines, diagonals, etc.
Loom - The portion of an oar between the handle and the blade.
Mast Partner - Extra framing added around an opening for the mast to provide strength.
Maststep - Piece used to anchor the heel (bottom end) of the mast.
Mold - Three-dimensional manifestation of the station curves drawn on the lofting.
Molded - See Sided.
Nib - A square cut made at the wedge or featheredge end of a piece of wood. Usually used on planking and on the ends of mechanical scarf joints.
Normal - In lofting, a line drawn square, or 90 degrees, to the tangent of a curve.
Outwale - The rubrail or longitudinal chafing strip on the outside sheer of the boat.
Plank - A longitudinal piece fastened to the outside of the frames to form part of the skin of a boat. A strake can be made up of one or more planks.
Poppet - A brace for supporting a boat during construction or storage.
Profile - The side view of the vessel as seen at a right angle to the keel or centerline.
Quartersawn - Lumber sawn so the grain runs at a right angle to the flat side of a board. Sometimes called edge- or vertical-grain lumber.
Rabbet - A cut or groove in a structural member to allow another piece to fit flush against it. An example would be the cut rabbet in the side of a stem into which the hood end of the strake is fit and fastened.
Rake - An angle or inclination (generally aft) from the vertical. Transoms on traditional small craft tend to be raked aft.
Ribbands - Temporary batten-like wooden straps bent around the molds to which the steamed frames are bent. The ribbands not only dictate the shape of the frames but also strengthen the setup and provide resistance to wracking.
Riser - A longitudinal member fastened to the inside of the frames to support the thwarts.
Rivet - A fastening consisting of a nail and a washer-like burr - also known as a rove or ring - over which the nipped-off end of the nail is peened.
Rocker - Fore-and-aft curvature of the keel.
Rove - See Burr.
Scantlings - Dimensions and sizes of all structural parts used in building a vessel.
Scarf - A beveled joint between two short pieces of wood to make one long one. A scarf joint in a keel member is generally fastened with bolts; that in planking is generally glued.
Scribe - To mark a piece of wood for fitting with either a compass, or a block of wood and a pencil. The word also refers to the scratching or etching of a line into a piece of wood with a sharp tool.
Shaftlog - The part of the backbone assembly through which the propeller shaft passes. Some shaftlogs are made of a single piece of wood with a hole bored all the way through; others are built up of two pieces, bolted together.
Sheer - The uppermost visible line of the hull in profile view, the outermost (usually) in the half-breadth view. The line of the sheer probably has the least to do with how well the boat performs and the most with how well it looks.
Shutter Plank - The final plank that is hung to close up the hull when planking from the keel up and the sheer down. It is usually fitted in an area with little shape and/or twist to minimize complications.
Sided and Molded - Two terms used to describe the thickness of a given part. The sided dimension of a part is a constant thickness throughout the part; i.e., the side-to-side thickness of a frame is the sided dimension. The molded dimension is the varying thickness of the piece as cut and is usually at right angles to the skin of the boat; i.e., the dimension of a frame measured from the skin of the hull inboard is the molded dimension.
Spall - See Cross Spall.
Spar - A round- or square-sectioned mast, boom, yard, or bowsprit for the support of the sails and rigging.
Spile - To make a pattern for an oddly shaped piece, such as a plank, by recording measurements onto another piece of expendable stock. These measurements are then transferred to the actual stock and connected by battens and drawn in pencil to provide the proper shape of the new piece.
Spiling Batten - A long, flexible batten made of light stock to record information when spiling a plank.
Springback - Any bent stock, either steamed or laminated, will retain “memory” and try to straighten out to some extent when released from its clamps. The amount the piece straightens is called springback.
Stanchion - A supporting post or pillar, such as a vertical brace under a thwart.
Stations - Cross-sectional slices of the hull made at regular intervals. Similar to slices in a loaf of bread.
Staving - In boat construction, the equivalent of wain-scotting.
Stealer - A short plank used to fill in an area or straighten out a run of planks.
Stemband - Protective strip of metal (usually half-round or oval) fastened to the face of the stem.
Sternpost - The vertical, or nearly vertical, backbone member that supports the transom.
Sternsheets - The seat and benches in the after end of an open boat.
Stopwater - A softwood dowel placed in a drilled hole where the rabbet crosses an underwater backbone joint. Used to stop water from leaking by into the hull, hence the pithy name.
Strake - A continuous longitudinal run of hull planking. A strake can be either a single plank or more than one plank fastened end to end.
Stretcher - A foot brace, usually adjustable, for the rower.
Strongback - A frame or horse to support a boat while under construction.
Stud Beam - A short beam under a side deck.
Template - A pattern made of thin stock for any structural member.
Thwart - A transverse seat in a small boat. It not only provides a place to sit but also ties the boat together.
Trammel Points - Two discrete points, usually steel or brass, that can be positioned anywhere on a bar, usually wooden, making a tool that can be used in the same manner as a compass or a pair of dividers.
Transom - The transverse structure (usually flat) at the after end of the boat on which the planks land.
Trunnel - A homemade dowel-like fastening that is driven into a pre-drilled hole and wedged at either end.
Tumblehome - The narrowing or returning inward of the topsides as they approach the sheer.
Turnbutton - A small button or cleat for holding in place doors, panels, and floorboards.
Waterline - On a set of plans, it is a regular height of elevation above a base - similar to those found on a topographic map. In profile view, the waterlines are straight and parallel. In the half-breadth view, they are curved.
