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Rabbet. A groove in the stem, keel or stern frame into which the edges of planking or plating are fitted.

Racing. See Propeller Racing.

Racking. Spun yarn or other small stuff used to wind two ropes together.

Racking. The tendency to deformation in built up structures or shapes which results from the action of racking stresses. In a ship the transverse racking tendencies are of more importance than the longitudinal. This is due both to the character of the structure and to the nature of the stresses to which the structure is usually exposed.

Racking Stresses. Stresses which tend to produce racking strains.

Radiator. A pipe coil or casting designed to radiate heat from a steam or hot water pipe line.

Radio. Radio is the transmission of intelligence by means of electromagnetic waves. Briefly, the apparatus consists of a transmitter, receiver and antenna ("aerial" consisting of an elevated system of wires). The same antenna is usually used for both sending and receiving. The transmitter is a device for causing high frequency alternating currents (oscillations) to flow up and down the antenna. These oscillations cause a disturbance in the surrounding ether somewhat similar to those caused on the surface of a sheet of still water into which a stone is dropped. When these waves impinge on an antenna which is being used for reception, it is set into oscillation (as a cork would bob, floating on the surface of the sheet of water). The receiver translates these oscillations into an audible sound in a pair of head telephone receivers.

Raft, Life. See Life Raft.

Raft Port. See Port, Bow or Stern.

Rail. Channel bars, shapes or flat pieces of wood fitted at the top of bulwark plating or at the top of rail stanchions. Also applied to the tiers of guard rods running between the top rail and the deck.

Rail, Brest. The top rail running athwartship on a bridge, the after end of a forecastle deck or the fore end of the poop deck.

Rail, Hand. A term applied to a rail fitted along the side of a ladder or a companionway.

Rail, Main. The top rail running along the top of the bulwark or rail stanchions on the upper or weather deck.

Rail, Poop. A term applied to the rail around the top of the bulwark or rail stanchions on the poop deck.

Rail Stanchions. Steel or wood stanchions that serve as fence posts for the guard railing or ropes enclosing the deck, bridge, forecastle, etc., of a vessel. They are spaced at approximately equal distances and are fitted permanently or removable as the requirements demand.

Rail, Topgallant or Monkey. The rail running along the top of a topgallant or upper extension of the bulwark.

Raised Quarter Deck. See Deck, Raised Quarter.

Raising Iron. A tool used by caulkers to remove dirt from a seam preparatory to caulking.

Rake. A term applied to the inclination from the vertical of a mast, smoke stack, stem post, etc.

Rally. Men uniting in driving wedges when launching a vessel.

Ram. A forward, strongly constructed, underwater projection of the stem post. They were until recently fitted on most warships. On account of the severity of the stresses set up by the shocks of a collision and also on account of the fact that action between warships is generally conducted at long range, the ram as a means of offence is becoming less used. The bulbous shape, although not projecting forward, is still retained at the bottom of the stern post on American warships. A name given to a vessel that is designed for the purpose of sinking vessels by head on collision or for icebreaking.

Range, Galley. The stove, situated in the galley, which is used to cook meals.

Rate. The class in which a vessel is placed. In the merchant service rating is based upon the character of material and the construction. In the naval service the displacement, number of guns, protection, speed, etc., are the determining factors. The process of determining the error of a shipís chronometer relative to true time.

Ratline Stuff. A right handed, three stranded small stuff of usually four to eight threads to the strand making "l2-thread," "l5-thread," etc., ratline stuff.

Ratlines. Short lengths of ratline stuff secured to the shrouds parallel to the waterline. These serve the purpose of latter rungs for the crew in ascending or descending.

Rave Hook. A thin hook shaped tool use by caulkers to remove old oakum -threads from seams.

Reamer. A term applied to a rotary cutter used in enlarging punched and drilled holes.

Reamers. Workmen who operate a tool, usually power driven, so shaped as to enlarge holes already punched or drilled. Where the holes are unfair they cut away the overlapping material so bolts or rivets may be inserted.

Reaming. A term applied to the operation of enlarging a punched or drilled hole by a rotary cutter called a reamer.

Recess Bulkhead. See Bulkhead, Recess.

Recess, Tunnel. See Tunnel, Recess.

Reciprocating Engine. See Engine, Reciprocating.

Reciprocating Pump. See Pump, Reciprocating.

Rectifier, Mercury Vapor. An electrical device for changing alternating current to direct current.

Red Lead. See Paint.

Red Leaders. Painters who paint faying surfaces with red lead paint before they are placed together. Also painters who apply the coats of red lead paint to the structure while it is being erected to protect it from the weather.

Reducing Valve. See Valve, Reducing.

Reduction Gearing. Generally applied to gearing designed for use with marine steam turbines. When so fitted its purpose is to step down from the turbine speed to a speed suitable for the shipís propellers.

Reef. To reduce sail spread or area by rolling or folding that portion adjacent to a yard or boom and making it fast thereto. In square sails this reduction is made in the head, while in fore-and aft sails it is done in the foot

Reef Points. Short lengths of cordage fitted at equal distances apart on the reef bands of sails for tying up the sail in reefing. Sometimes referred to as nettles.

Reef Tackles. Tackles used for hauling the leeches of square sails up to the yards and out in reefing. The upper blocks are secured under the ends of the yard-arms, the lower blocks to the reef tackle cringles on the leech ropes of the sails at the upper ends of the reef tackle patches. The falls are led to the deck and when hauled on, the upper part of the leeches are slacked for passing the earrings and rousing the cringles to the yards.

Reel, Hawser. See Hawser Reel.

Reeled Riveting. See Riveting, Staggered.

Reem. To open the seams of the planking by means of a reaming iron that the oakum may be more readily driven in.

Reeming Iron. A chisel shaped tool used by caulkers to open up seams so that threads of oakum may be driven into them.

Reeving. The act of passing a rope or chain through an aperture as a rope through a block, dead-eye, bullís eye, etc., or a lacing through an eyelet.

Reflector, Cargo. A reflector for electric lights suitable for illuminating cargo holds.

Reflecting Circle. An instrument to measure angles up to 180 degrees in the horizontal and vertical planes.

Refrigerating Machine Foundation. A term applied to a seating prepared for a refrigerating machine. This seating may be built up from the deck or the deck may be reinforced by thicker or extra plates and shapes.

Refrigerator Coils. A series of pipes surrounding the sides of a refrigerating box for maintaining a low temperature.

Register Breadth. See Breadth, Register.

Register Depth. See Depth, Register.

Register Length. See Length, Register.

Regulator Valve. See Valve, Regulator.

Relay. An electrical device which will perform a certain operation in one electric circuit when a certain predetermined condition exists in another.

Releasing Gear. This gear is composed of specially constructed hooks attached to the davit heads and rods, chains or fittings installed in lifeboats. By the use of this gear both ends of a lifeboat may be released or picked up quickly and simultaneously.

Relief Valve. See Valve, Relief.

Relieving Tackles. Tackles used for emergency steering in case of accident to the steering gear or to assist the gear in heavy weather. The tackles are secured to the head of the tiller or to the cross head, the opposite ends being made fast to any convenient structure as a bulkhead or deck.

Render. To pass through an aperture freely, as a rope through the swallow or mortise of a block.

Reserve Buoyancy. The difference between the amount a vessel would displace if she were watertight and totally submerged, and the amount she actually does displace at her designed draft.

Resistance, Air. That part of a shipís total resistance to motion which is due to the above water portion of the vessel moving through the air.

Resistance, Bare Hull. The sum of the frictional and residual resistances of a vesselís hull to which no appendages such as bilge or docking keels, struts, spectacle frames, rudders, etc., have been fitted.

Resistance, Center of Lateral. That point through which a signal force could act producing an effect equal to the total lateral resistance of the vessel. The center of lateral resistance is ordinarily assumed to be coincident with the center of gravity of the central immersed longitudinal plane.

Resistance, Eddy-Making. Resistance due to the formation of eddies at the stern, usually resulting from the abrupt termination of the after ends of waterlines, from the action of propellers and rudder, and from the addition to the hull of projections such as struts, docking keels, etc.

Resistance, Electrical. Property of materials which opposes the free flow of an electric current through them, but does in no way tend to cause a current in the opposite direction to that in which the electric current actually moves.

Resistance, Frictional. The resistance due to the friction of the water upon the surface of the ship.

Resistance, Lateral. The resistance which a vessel offers to a lateral motion of translation through the water. The lateral resistance of a vessel is of especial moment in sailing ships, and it is for the purpose of increasing the lateral resistance that keels and center-boards are sometimes fitted.

Resistance, Residuary. The total resistance less the resistance due to skin friction, is termed the residuary resistance.

Resistance, Skin. The frictional resistance existing between the shell or skin of a ship and the water through which she is progressing.

Resistance, Tow Rope. The total resistance overcome in towing a ship or model. It equals the sum of the frictional resistance, eddy making and wave making.

Retaining Strip, Stern Tube. See Stern Tube Retaining Strip.

Reverse Frame. See Frame, Reverse.

Reversing. The act of turning completely about. Used with reference to either motion or position.

Reversing Shaft. A threaded shaft actuated by the reversing wheel and forming part of the reversing gear.

Reversing Wheel. A hand operated wheel by means of which the reverse gear is controlled. It is located in front of an engine and easily reached from the starting platform.

Revolution Counter. A device arranged to register automatically and sum up engine revolutions.

Rheostat. An electrical device consisting of several resistances of different values arranged so that they may be cut in or out of an electric circuit.

Rhumboscope. A variation of the Station Pointer which was used to locate positions on charts. The "rhumb" was any one of the thirty-two compass points. All meridians were cut by this instrument at the same angle.

Rypsometer. This was introduced about 1871, for measuring a shipís speed.

Ribband. A painted stripe or molding around a vesselís side. Applied for decorative purposes.

Ribbands, Fore-and-Aft. Pieces of timber arranged longitudinally around the building site outlining the form of the ship at different levels and having the frame stations marked on them. When a frame is erected it bears against the ribbands which hold it in its correct athwartship position and by setting it to the ribband frame station marks it assumes its proper fore and aft position.

Ribs. A term applied to the transverse frames of a boat or the skeleton.

Ride. To float in a buoyant manner while being towed or lying at anchor.

Rider. A plate or girder fixed to the inner side of the framing at the center line for extra strength.

Rider Keelson. See Keelson, Rider.

Rider Plate. A continuous flat plate attached to the top of the vertical center keelson, to the top of the floors, or both.

Ridge Rope. See Rope, Ridge.

Rig. As applied to a vessel, the method according to which spars and sails are designed and fitted. Rigs of all kinds fall into two classes, viz: square or fore-and-aft.

Rigger. A workman who makes up the standing and running rigging from cordage and fittings and fits same on shipboard. During the construction of a ship riggers have charge of the hoisting in place of such heavy parts as the stem stern post, boilers, engines, masts and spars.

Rigging. A term used collectively for all the ropes and chains employed to support and work the masts, yards, booms and sails of a vessel.

Rigging Screws. See Screws, Rigging.

Rigging, Steel Wire. The standing rigging in practically its entirety as well as a large part of the running rigging on modern vessels. The use of hemp cordage for rigging purposes is now nearly obsolete,

Right Rudder. A term recently adopted in the Navy which is applied to the operation of moving the rudder to starboard and consequently turning the bow of the ship to the right.

Righting Arm, Maximum. The maximum length of the righting arm attained by any given vessel with a given loading when heeled from the upright throughout her entire range of stability.

Righting Lever or Arm. The perpendicular distance between two vertical lines, one through the center of gravity and one through the center of buoyancy, the ship being inclined from the vertical. If the relative positions of the center of gravity and center of buoyancy are such as to produce a righting couple, the lever is positive and is a true righting lever. If, however, the couple produced tends to overturn the vessel, this righting lever becomes negative and is then more properly termed an upsetting lever. The displacement of the vessel multiplied by the righting lever equals the righting moment. At small angles of inclination, the righting arm is equal to the metacentric height multiplied by the sine of the angle of inclination.

Righting Moment. The product of the displacement and length of the righting arm. The displacement being expressed in tons, and the righting arm in feet, the righting moment is therefore given in foot-tons.

Right-laid Rope. See Rope, Right-Laid.

Rimer. See Reamer.

Riming. See Reaming.

Ring Dial. Another name for the Gemmaís Ring, a form of sun-dial used as a sun clock to determine the hour for any given latitude, and probably the most common and simplest form of altitude dial.

Rise of Floor. See Deadrise.

Riser. The upright board of a stair.

River Steamer. A steam driven vessel designed for service on inland waters. Vessels of this type usually carry both passengers and cargo. For use on deep rivers, sounds, etc., large vessels of moderate draft, good hull free board, lofty superstructures, and either paddle or screw propulsion are present practice.

River Steamer, Shallow Draft. For shallow rivers the shallow draft type with small hull freeboard, lofty superstructures, and either stern wheel or tunnel screw is used.

Rivet. A pin used for connecting two or more pieces of material by the means of passing it through a hole drilled or punched for the purpose and hammering down one or both ends. Rivets should be made from high grade iron or mild steel, except that in cases where high tensile steel parts are to be connected high tensile steel rivets are generally used. Copper rivets are used for various minor purposes. In the shell plating, decking, bulkheads and the framing of a ship, as well as in the boilers, the joints must be very firm and in most cases watertight; therefore, for this reason, and because of the fact that rivets 3/8" diameter or over can be more efficiently worked while hot, it is the practice to heat rivets before passing them through the holes and to hammer the points down before the rivet cools. The contraction of the rivet due to cooling will aid very materially in producing the firm joint desired.

Rivet Counter. Men who count rivets in ship construction. A person so engrossed in a particular ocean liner or vessel, that he researches the structure of his subject down to the number of rivets. In some cases, Rivet Counterís are thought, by friends or mates, to have a compulsive disorder. Some rivet counterís are actual researchers and offer their information to the general public, and will provide documentational evidence to support said information, over and above hear-say.

Rivet Cutter. A tool similar to a pneumatic riveting hammer used for cutting and punching out rivets.

Rivet Forge. See Furnace, Rivet.

Rivet, Furnace. See Furnace, Rivet.

Rivet Heading Machine. See Bolt Heading Machine.

Rivet Heater. One who heats the rivets. This work is generally done by one or two boys with a portable forge. They should be careful to place the rivets in the fire shank down so that the heads will not become too plastic when thrown or passed to the holder on. Care should also be taken not to burn the rivets or to leave them in the fire too long.

Rivet Holes. A term applied to the holes that are punched or drilled in plates, shapes, forgings and castings for rivet connections.

Rivet, Keel. A term applied to a rivet used in attaching the keel to the garboard strake.

Rivet Set. A caulking tool for use around a rivet.

Rivet Spacing. A term applied to the distance between the centers in a row of rivets.

Riveter, Hydraulic. Usually a large C-shaped cast steel, frame with a hydraulic ram fitted at the open end which carries the rivet set.

Riveters. Workmen who drive rivets by hammering the points into the required shape either by means of hand or power tools. Riveters usually work in gangs, a gang including one or two riveters, a holder on, a heater, and perhaps one or more passers. Riveters should be responsible for the fairness of the surfaces riveted and should see that there are no lateral bends, bumps or irregularities in the plating,: because when once riveted the structure is permanent. They should also see that the surfaces are rigidly and firmly united when they perform the operation of swaging down the points of the rivets.

Riveting. The art of fastening two pieces of material together by rivets.

Riveting, Bull. A term applied where rivets are driven by power machines, usually air or hydraulic.

Riveting, Chain. A term applied to two or more rows of rivets that have their centers opposite each other. A line drawn perpendicular to the edge of the plate through the center of a rivet in one row will also pass through the centers of the corresponding rivets in the other rows.

Riveting, Double. A term applied when a connection is made with two rows of rivets. In butt joints there are two rows in each piece connected.

Riveting Hammer, Hand. Either a long double headed hammer of medium diameter with flat faces or having a long head and a narrow peen.

Riveting Hammer, Pneumatic. A light machine operated by compressed air, in which a rivet set with its shank having a sliding fit in the bore is given very rapid, short and powerful strokes.

Riveting, Hydraulic. A term applied where the rivets are driven by a machine actuated by hydraulic pressure.

Riveting Machine. A machine designed for upsetting and forming rivet points.

Riveting, Reeled. See riveting, Staggered.

Riveting, Single. A term applied where a connection is made with one row of rivets. In butt joints there is one row in each piece connected.

Riveting, Staggered. A term applied to two or more rows of rivets where the centers of the rivets in one row are one-half the pitch or spacing ahead of the other row.

Riveting, Three-ply. A term applied where three thicknesses of material are connected by one rivet.

Riveting, Treble. A term applied when a connection is made with three rows of rivets. In treble riveted butt joints there are three rows in each piece connected.

Riveting, Zig Zag. See Riveting, staggered.

Rivets, Row of. A term applied to a continuous line of rivets whether vertical, diagonal or horizontal. The spacing of the rivets from center to center depends upon the nature of the connection.

Roasting Ovens. The heated chambers constituting the interior portion of a shipís range.

Rock Shaft. See Shaft, Weigh.

Rojas Dial. Also called a Geminus Dial, one more from of sun-dial, made vertically, and found sometimes on the backs of Quadrants, Nocturnals, and Astrolabes.

Roller Bearings. The inherent principle of the roller bearing is the substitution of a true rolling motion for the sliding friction of plain bearings. The low coefficient of friction for rolling contact as compared with sliding contact is utilized in such a practical way that the power consumed in overcoming friction is reduced by from 60 to 75 per cent. Flexible roller bearings are wound helically from flat strip steel into a hollow, cylindrical roller, which, because of its flexible construction, can adapt itself to slight irregularities in either the journal or the housing without causing excessive pressure or permanent deformation. The hollow center of the roller serves as a reservoir for the lubricant which is distributed through the helical slots over all the bearing surfaces. Roller bearings are extensively used on all type of machinery and can be applied in practically every place where a wheel or shaft turns. They minimize friction, give a smoother and easier operating machine, eliminate sticking bearings, hot boxes and bearing replacements, insure positive and care free operation, greatly reduce maintenance costs, and are capable of years of satisfactory service with no appreciable wear. They are the logical bearing for cranes, hoists, plate castors, and all shipbuilding equipment where a durable, dependable, easy running bearing should be used.

Rolling. The oscillating motion of a vessel from side to side due to ground swell, heavy sea, or other causes.

Rolling Chock. A term applied to a bilge keel.

Rolling Ruler. This brass rule, 12in. or more long, and 3in. wide, was introduced at the beginning of the 19th century to serve as a Parallel Ruler.

Rolls, Bending. A machine in which power driven steel rolls are used to give curvature to plates. Three rolls are provided and two are adjustable allowing the arc to which a plate may be rolled to be varied within wide limits. A slot is usually cut in the forward roll to allow the rolls being used for flanging plate brackets, etc.

Rolls, Hand Power. A small machine designed to give curvature to light metal plates. This type is operated by hand, a large wheel with wood spokes being usually provided for this purpose.

Rolls, Mangle. A machine in which power driven steel rolls are used to straighten plates

Roofing. A term applied to waterproof materials used in covering roofs.

Rope. The product resulting from twisting a fibrous material, such as manila, hemp, flax, cotton, coir, etc., into yarns or threads, which in turn are twisted into strands and several of these laid up together. Fiber rope is designated as to size by its circumference. Wire rope is made of iron, steel, or bronze wires twisted together like yarns to form strands, which in turn are laid up to form a rope. Wire rope is designated as to size both by its diameter and its circumference.

Rope, Back Hand. A rope in which the fibers are twisted up left handed, the yarn right handed, and the strands left handed.

Rope, Bolt. A rope used around the boundaries of sails, awnings, canvas, tarpaulins, etc. It is made from selected yarns of the best quality of hemp cordage, which are rather loosely laid up and tarred.

Rope, Buoy. The rope by which a buoy is attached to its anchor. It should be of sufficient strength to lift the anchor should a vessel be obliged to slip her cable or the cable part.

Rope, Cable-Laid. A term that was formerly exclusively applied to a rope consisting of nine strands, being made by laying three plain ropes together left-handed; but now used to denote three, sometimes four, plain laid three-stranded ropes twisted together in the opposite direction to the twists in the several ropes. Also known as hawser laid and water laid rope.

Rope, Cast Steel Wire. A rope made from cast steel wires. It is used for standing rigging and derrick guys and when so used should be galvanized.

Rope, Check. A term applied to a rope used in checking the way of vessel when docking or warping. A hawser having one end fastened to a dock and the other end turned around a bitt so that it may be slackened or held taut.

Rope, Coir. Rope made from the fibrous husks of the cocoanut having about one-fourth the strength of manila rope. It is sufficiently buoyant to float upon the surface of the water, but is disagreeable to handle.

Rope, Cotton. A rope of small diameter made from cotton fibers and used for sheets and halyards on yachts and sail boats.

Rope, Flat. A rope having its strands braided instead of twisted up.

Rope, Hawser. A term applied to warping and towing lines.

Rope Heart. When a fiber rope has a heart it consists of a small pliable rope whose diameter is about one- third that of the strands. In a wire rope the heart may consist of a tarred hemp rope where pliability is the chief consideration and a wire heart where strength is more important.

Rope, Hemp. A rope made from fibers of the hemp plant. As in manila rope the fibers are made into yarn, the yarn into strands, and three or more strands twisted up to form a rope. Hemp rope where exposed to the weather requires tarring as it otherwise decays rapidly. Hemp rope is used principally for bolt ropes and standing rigging.

Rope, Hide. A rope made from strips of uncured hide and principally used as wheel rope.

Rope, Iron Wire. A rope made of iron wires. It has less strength but is more pliable than steel rope of the same make up.

Rope Knots. See Knots.

Rope Lay. The direction in which it is twisted up.

Rope, Left-Laid. Rope in which the strands are twisted together in the same direction as that of the hands of a clock.

Rope, Manila. A rope made from fibers of manila which are obtained from the wild banana plant growing in the Philippines. The fibers are made into yarn, the yarn into strands and three or more strands twisted up to form a rope. Manila rope is usually made up of three strands up to 3" circumference and above that diameter four strands with a heart center. This rope is more desirable than hemp for hawsers and running gear because it is lighter and more pliable and does not require tarring for preservation. Manila rope is stronger than tarred hemp rope but a little weaker than white rope.

Rope Marline. See Rope Spun Yarn.

Rope, Mast. A heavy rope used in hoisting or striking down a topmast, topgallant mast, etc.

Rope, Parceling. This operation consists of wrapping straps of canvas around the rope with the upper edges overlapping similar to shingles. For wire rope the strips should be coated with red lead and linseed oil and for fiber rope they should be tarred. The rope is usually wormed if parceled.

Rope, Plain-Laid. A term that was formerly exclusively applied to the three-stranded right-handed rope, but is now applied commercially to three, four or six stranded rope laid up in the contrary direction to the twist in the strands.

Rope, Plow Steel. A rope made from plow steel wires. It is very strong and durable, and is used for running gear.

Rope, Ridge. A rope running through the eyes at the heads of the awning stanchions to which the edge of an awning is hauled out and stopped. The term is sometimes applied to the center rope of an awning, but "backbone" seems to be a more satisfactory term for it.

Rope, Right-Laid. Rope in which the strands are twisted together in the opposite direction to the motion of the hands of a clock.

Rope Seizing. A method of making a joint between two ropes by binding with marline or spun yarn.

Rope Serving. Consists of wrapping a complete layer of marline or cord around a rope to protect it against chafing. The rope is usually wormed or wormed and parceled before serving.

Rope, Shroud-laid. A rope made by laying up four strands around a core or heart in a right handed direction.

Rope, Sisal (a substitute for manila). The fiber for Sisal rope is procured from a plant grown in Yucatan Mexico and Key West, Fla. Its tensile strength is not more than three-quarters that of Manila fiber. Unlike Manila, Sisal is stiff and harsh, and deteriorates rapidly when exposed to the elements.

Rope Splicing. A method of making a rope joint which is accomplished by braiding the strands. A splice in wire rope is from 10 to 15 per cent weaker than the rope.

Rope, Spun Yarn. Hemp fiber loosely twisted and tarred. Also called Marline and Hambroline.

Rope, Stern. A rope leading from the stern of a vessel to a wharf or buoy for mooring. Also known as "stern line" or "stern fast."

Rope Strand. This is composed of rope yarns twisted up and usually in a left handed direction.

Rope, Tapered. A rope having a relatively large diameter where strength is required and tapering down to a smaller diameter where more pliability is desirable.

Rope, Tiller. A term applied to the ropes actuating a tiller. A very desirable type is made up of small bronze wires which is quite pliable.

Rope, Tow. A hawser of either fiber or wire by which a vessel is towed or tows another.

Rope, Twice-Laid. Rope made from old yarns laid up a second time.

Rope Walk. A place where rope is manufactured by the less modern machine methods. A long walking space is required for the workmen in their back and forth motion in the operation of spinning, hence the name.

Rope, White. A term applied to untarred hemp rope. It is used for log and lead lines. The white rope is stronger than manila.

Rope, Wire. A rope made up of wires twisted up into strands and strands twisted up into rope. The strands are usually twisted up around a heart of hemp or wire. Particular care should be taken with wire rope to prevent kinking. It should never be pulled out from a coil as fiber rope but should be unwound from an axis or the coil should be rolled along like a wheel.

Rope Wire Fittings. See the respective headings for clips, clamps, sockets, thimbles, etc.

Rope, Wire, Marline Clad. A wire rope in which each strand is served with tarred marline before being twisted about the core. flat steel wire before being twisted about the core.

Rope, Wire, Steel Clad. A wire rope in which each strand is served with flat steel wire before being twisted about the core.

Rope Worming. Filling in the valleys between the strands of a rope with marline. The marline should run with the lay of the rope.

Rope Yarn. This consists of fibers of manila or hemp which are usually twisted up in a right handed direction.

Rose Box. See Pump Strainer.

Rose Box, Strum or Strainer. See Strum Box.

Rose Lashing. A lashing made by alternately passing the parts over and under the object lashed, then finishing by turning the end around the crossing point. Also known as Rose Seizing.

Rose Seizing. See Rose Lashing.

Roses. Perforated metal plates, fitted over the outside of injection sea cocks in order to prevent the entrance of weeds or other foreign substances to the shipís piping system or pumps. A perforated nozzle for delivering water in a fine jet.

Rosin, Wood. A solid substance exuded from various trees, or left as a residue from the distillation of turpentine.

Rot. A term applied to wood that has become soft or discolored.

Rotary Air Pump. See Pump, Rotary.

Rotary Converter. A rotary electrical machine for transforming alternating current to direct current or vice versa. Also called Synchronous Converter.

Rotary Pump. See Pump, Rotary.

Rotary Shear. See Shear, Rotary.

Rotor, Turbine. See Turbine Rotor.

Round In. To haul in a rope rapidly.

Round Stern. The Stern of a ship whose decks terminate aft in semi-circular or elliptical shape.

Rounded Gunwale. See Gunwale, Rounded.

Roundline. A three-stranded, right-handed, tarred hemp, small stuff used for seizings, service, etc.

Rouse. To overhaul rapidly as a rope or cable. To "rouse out" the crew to get them on deck quickly.

Row Locks. U-shaped fittings with shank or socket attachments to the gunwale of a boat. They are used as a fulcrum for oars in rowing, sculling and steering.

Royal. A light square sail set next above a topgallant sail.

Rubbing Strip. A plate riveted to the bottom of a keel, to afford protection in docking and grounding. Also a strip fastened to the outside of a fender or to the shell plating where contact is likely to occur.

Rudder. A device used in steering or maneuvering a vessel. The most common type consists of a flat slab of metal or wood, hinged at the forward end to the stern or rudder post and rounded at the after end to make a fair ending to the lines of the vessel. When made of metal it may either be built up from plates, shapes and castings, with or without wood filling or it may be a casting. The rudder is attached to a vertical shaft called the rudder stock, by which it is actuated or turned.

Rudder Area. The area of the effective rudder blade. Usually referred to as a percentage of the area of the immersed middle line or lateral plane of the ship.

Rudder Arms. A term applied to the frames or arms projecting or radiating from the vertical main piece for the purpose of supporting and stiffening the rudder plating.

Rudder, Auxiliary. A term applied to bow rudders. They are fitted to ferry and sometimes paddle-wheel boats.

Rudder, Balanced. A rudder having the forward or leading edge of the whole or a portion of the rudder far enough forward of the center line of the rudder stock to bring the center of pressure of the water on the rudder at the maximum helm angle on or near the centerline of the rudder stock.

Rudder, Bearing. A fitting usually constructed in two parts which are bolted together around the rudder stock. The upper portion of the bearing is usually fitted with an annular groove and a flat ring floating in oil upon which the rudder carrier turns.

Rudder, Bow Piece. A term applied to the curved frame forming the after edge of a rudder.

Rudder Brace. See Gudgeons. .

Rudder Bushings. A term applied to brass or metal sleeves fitted around the pintles.

Rudder Carrier. A fitting usually constructed in two parts which are bolted together around the rudder stock and which forms a means of transferring the weight of the rudder to the rudder bearing. The upper portion of the carrier consists of a sleeve that forms a close fit around the stock which is usually turned to a larger diameter at the top and bottom of the carrier sleeve to form shoulders. The upper shoulder aids in transferring the weight of the rudder through the carrier to the bearing and the lower shoulder prevents the stock from slipping up through the carrier. Set screws or a key and keyway are usually fitted to insure that the carrier turns with the stock. The lower portion of the carrier consists of a flange having a flat bearing surface that works on an annular ring floating in oil in a groove on the top of the rudder bearing.

Rudder, Cast Steel. A term applied to a rudder having the plate and framework of cast steel. It may be made in one piece or in two or more pieces bolted together.

Rudder Coupling. A term applied to the flanges or palms fitted to the lower end of the rudder stock and to the top of the main piece to provide a means of efficient connection.

Rudder, Double Plate. A rudder constructed by two planes of plating tapering in section from the width of the main piece in the way of the rudder stock down to the width of a bar at the edges. The space between the two plates is usually filled with wood.

Rudder, Flat Plate. A term applied to a rudder constructed by one plane of steel plating. The plating is supported and stiffened by arms projecting from a vertical main piece. The rudder arms may all be on the same side of the plate or alternating on one side and then on the other.

Rudder Frame. A term applied to a vertical or main piece and the arms that project from it, forming the frame work of a rudder.

Rudder Gudgeons. See Gudgeons, Rudder.

Rudder Head. The upper end of the main piece to which the rudder stock is attached. The head consists of a flange or thick palm to which a flange or palm on the lower end of the rudder stock is bolted.

Rudder Heel. A term applied to the lowermost portion of the main piece of a rudder.

Rudder, Jury. See Jury Rudder.

Rudder Keeper. A term applied to wedge shaped pieces of metal that are fitted between and prevent the nuts on the coupling bolts from working loose.

Rudder Lugs. A term applied to the projection, cast or fitted to the forward edge of the rudder frame for the purpose of taking the pintles.

Rudder, Main Piece. The vertical or main frame of the rudder to which the rudder arms are attached.

Rudder Pendants. A term applied to a pair of chains or ropes attached by a shackle to a hole bored through the upper after end of a rudder frame or to a monkey tail for the purpose of providing a temporary steering gear. The upper ends of the pendants are usually attached to pads fitted to the shell.

Rudder Pintles. See Pintles, Rudder.

Rudder Scores. A term applied to the portions of the forward edge of a rudder that are cut out between pintles. This scoring allows the rudder to be unshipped readily.

Rudder, Side Plate. See Rudder, Double Plate.

Rudder Stays. See Rudder Arms.

Rudder Stock. A vertical shaft having a rudder attached to its lower end and having a yoke, quadrant or tiller fitted to its upper portion by which it may be turned. In addition to the function of turning, the stock should take the weight of the rudder through a carrier attached to the stock which works on a bearing fitted at the top of the rudder trunk or on a platform or deck.

Rudder Stock Stuffing Box. See Stuffing Box, Rudder.

Rudder Stops. A term applied to fittings attached to the structure of the ship or to shoulders on the stern post which have the function of limiting the swing of the rudder to an angle of about 35 degrees.

Rudder, Telltale. See Telltale Rudder.

Rudder Trunk or Tube. A term applied to a casing fitted around the rudder stock and extending from the counter to a platform or deck. Its purpose is to prevent water from entering the hull, and for this reason a stuffing box is fitted at its upper end.

Rudder, Underhung. A rudder that is not hinged or stepped on the stern post but supported entirely by the rudder stock. In this form of rudder the bending stress on the stock at maximum speed is generally quite large and becomes the most important factor in calculating the size of the stock.

Rules of the Road. Regulations for preventing collisions and for promoting safety to navigation

Run. The under water portion of a vessel aft of the midship section or dead flat.

Runner. A length of rope made fast at one end and rove through a single movable block, i. e. a single whip reversed.

Running Rigging. Ropes which are hauled upon at times in order to handle and adjust sails, yards, etc., such as sheets, clewlines, halyards, downhauls, out-hauls, reef-tackles. etc.

Rutter. A book containing information on tides, sailing directions, marine routes, entries into ports and harbors, signs and tokens of the sun, moon and stars at various times and the appearance and sound of the sea.


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