Shipbuilding Terms and Phrases "M"

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.

M 

MADE MAST (MADE BLOCK): is a mast built up from several pieces of timber, likewise a made block. Topmasts and topgallant masts are nearly always whole spars or made from one stick. 

MAGAZINE: the compartment or room in which ammunition for guns or rifles is stored. 

MAGNUS OR MAGNER'S HITCH: a rope knot; a method of attaching a rope to a spar. 

MAIN-BREADTH: the widest part of the hull (or any particular timber) which is designated on the sheer draught plan by the upper and lower heights of the breadth line. 

MAIN-DECK: the principal deck of a vessel, usually continuous from stem to stern; this deck gives great strength to the hull; called upper deck in the Ferris type of vessel. 

MAINMAST: the mast that is next abaft the foremast of a vessel carrying two or more masts. The mast in a single-masted vessel is also called the mainmast. 

MAIN-RIGGING: the shrouds or ratlines of the lower mainmast. 

MAINSAIL: the square sail bent on to the main yards; a fore-and-aft sail, which is stretched on the main boom. In order to be mainsails these sails must be attached to the mainmast. 

MAIN-SHROUDS: the shrouds of the lower mainmast. 

MAINSTAY: the hemp or wire stay that leads from the mainmast head to the deck near the foot of the foremast, where it is made fast and set up tight. This stay is a fore-and-aft brace for the mainmast. 

MAIN-WALES: the lower wales of the outside planking of a vessel; they are generally placed in the side planking, so the main deck knee bolts of fastenings may be secured into or through them. 

MAKE SECURE: the term signifies the process or act of securing or fastening securely in place, as "Make secure the anchor." 

MANGER: a partition or low bulkhead extending athwartship immediately back of the hawse hole. It prevents the passage of water aft along the deck, which may flush up through the hawse pipe in a heavy sea or may drip from cable when heaving in. Scuppers or freeing ports are fitted into the side of the vessel near the manger to carry the water overboard. 

MANHOLE: a round or oval-shaped hole cut in a bulkhead, partition or deck, etc., which is large enough for a man to pass through. 

MANIFOLD: see Pump Manifold. 

MAN-ROPE KNOT: a knot made in a rope in such a way that a man may climb the vertical sides of a vessel, using the knots to increase his hold. 

MAN-ROPES: ropes that hang down over the vessel's sides to assist in ascending or descending. They are often fitted on a Jacob's ladder. 

MARL: to hitch a marlin, spun yarn, etc., around the parceling to keep it in place while it is being served. 

MARLIN: a two-threaded strand tarred hemp about one-eighth inch diameter used for seizing rope. 

MARRY: to sew the ends of two ropes together temporarily, so there will be no enlargement, and the ropes so bound will render or pass through the ship's block. This is the method of reeving a new signal halyards, and saves sending a man aloft. 

MASTER SHIPBUILDER: a highly skilled and experienced directing superintendent, who is responsible for the good workmanship in the construction of a vessel's hull. 

MASTHEAD: the top or upper part of a mast; when referring to the masthead of a lower mast it indicates that part of the mast from the crosstree to the cap or extreme end. To masthead a man, a method of punishment, is sending him aloft to remain a definite time. Mastheading a yard or sail is to haul it up by the halyards as high as it will go. 

MAST-HOLE: a hole in the deck of a vessel or in the thwart of an open boat, through which the mast is fixed or stepped. 

MAST-HOOP: a wood or metal hoop that goes around a mast and to which the luff of a fore-and-aft sail is seized by lashing or robands. These hoops hold the sail to the mast and travel up and down when the sail is hoisted or lowered; they are sometimes called "sail hoops." 

MASTING: a term indicating the process of determining the position in which the masts of a vessel are to be placed; also indicates the mechanical process of stepping the masts. 

MAST: the long principal spar generally placed nearly vertical on the center line of a vessel; all the ship's rigging and spars are attached to or carried on the masts. 

MATTHEW WALKER KNOT: a rope knot named after the originator, used as a finish of deadeyes, lanyards and mastheads. 

MAULS: heavy steel-faced hammers, used for driving bolts, treenails or other fasteners. Top mauls have a hammer face on one end, and the other is drawn out small and pointed. Two-faced or double-faced mauls, a steel face on each end, are used for driving bolts, etc. A two-faced or double-faced maul is similar to a sledge except the weight is less. 

MEASUREMENT: measurements when applied to a vessel are the dimensions of length, breadth, depth, capacity or weight. 

MESSENGER: a tackle-block rigged on a rope in such a manner that it can travel the length of the rope and carry anything, such as a case, timber or part of the cargo. 

METACENTER: the shifting center; the limiting position of the point of intersection between a vertical line passing through the center of gravity of a floating body, as a vessel, when in equilibrium, and the vertical line drawn through the center of buoyancy when the body is slightly displaced. To insure stable equilibrium, this point must be above the center of gravity. 

MIDDLE A ROPE: to double a rope into two equal parts. 

MIDDLE LINE: a line dividing a ship exactly in the middle; a meridian line. In a half-breadth plan it is a line bisecting the ship from stem to stern. In a body plan it is a perpendicular line bisecting the ship from the keel to the highest part of the vessel, as shown on the plan. 

MIDSHIPS: a term indicating the middle of the ship's length. 

MIDSHIP SECTION: that cross-sectional part of a vessel which is the fullest; it is generally located midway between the perpendiculars, but in some cases is nearer the stem. It is also, in most hull designs, at the lowest point of the sheer. 

MIZZEN-MAST: the after mast on a three-masted vessel. 

MIZZEN-RIGGING: the shrouds and ratlines of the mizzen-mast. 

MIZZEN-SHROUDS: the shrouds bracing the lower mizzen-mast. 

MIZZEN-STAY: the fore-and-aft hemp or wire rope that leads from the mizzen-mast head to the foot of the mainmast, where it is made fast to the deck and set up tight. This is a fore-and-aft brace for the mizzen-mast. 

MOLD (MOULD): a pattern or template of a part of a vessel's frame, structure, etc.; molds are usually made of thin wood, battens or boards. 

MOLDED (MOULDED): cut to the shape of a mold or template. 

MOLDED BEAM (MOULDED BEAM): molded breadth; the greatest width of a ship from outside face of frame to outside face of frame at the amidship section. 

MOLDED DEPTH (MOULDED DEPTH): the depth measured from the top of the keel to the- top of the upper deck beam, less the round or camber of the beam. 

MOLDER (MOULDER): same as loftsman; the man who makes the mold or does the molding. 

MOLDING EDGE (MOULDING EDGE): the edge of a mold, template or piece of wood from which the shape or contour of frames, bevels, etc, are laid off or the outlines of the timbers or planks are shaped. 

MOLD-LOFT (MOULD-LOFT): a shed or building with a smooth floor of great area on which the lines of a vessel can be laid or drawn to full size. 

MONKEY-BLOCK: a small swivel block containing one sheave; the block is generally stropped with a manila line. 

MONKEY-GAFF: a light signaling gaff placed above the spanker gaff on the mizzen-mast of a ship; it generally projects from the topmast head. Signal halyards are rove through the end of this gaff. This method of securing signal halyards enables the signal flag to be carried high up, away over the mast and unobstructed by the sails, giving it great visibility. 

MORTISE: a hole or hollow made a certain size and depth in the side or face of a timber, to receive a tenon worked on the end of another piece of timber. With careful workmanship the tenon should exactly fit the hole; the hole out in the shell of a pulley or tackle block to receive the sheave. 

MORTISE-BLOCK: a tackle-block the shell of which was formerly made of one piece of wood, but now generally built up from several pieces in such a manner that the sheave is entirely protected by the cheeks or sides of the block. 

MOUSE: a kind of washer put over a chain or rope to prevent the latter from slipping or passing down through a hole; a term applied to the process of passing a rope, yarn or marlin around the shank and over the point of a hook, and thus effectively closing the gap in the hook and preventing the hook from being detached. 

MUNIONS: the pieces that are placed vertically to divide the panels in frame bulwarks, also between the lights in the ship's stem and quarter-galleries. These pieces make a finish and break up the effect of a large or long flat surface.