EDUCTOR-A mixing tube (jet pump) that is used in the GTM exhaust system. It is physically positioned at the top of the stack so the gas flow from the GTM exhaust nozzles will draw outside air into the exhaust steam as it enters the mixing tube. It may also be a liquid pump used to dewater bilges and tanks.

EMERGENCY-An event or series of events in progress which will cause damage to equipment unless immediate, timely and correct procedural steps are taken.

EVEN KEEL-When a boat rides on an even keel, its plane of flotation is either coincident with or parallel to the designed waterline.

EYE BOLT-A bolt having either a head looped to forma worked eye or a solid head with a hole drilled through it forming a shackle eye.

FAHRENHEIT SCALE-A temperature scale, at which, under atmospheric pressure, the boiling point is 212 and the ice point is 32 above zero.

FANTAIL-(1) The overhanging stern section of vessels which have round or elliptical after endings to uppermost decks and which extend well abaft the after perpendicular. (2) The after end of the main deck.

FIREMAIN SYSTEM-A seawater system provided for the primary purpose of extinguishing shipboard fires and controlling CBR decontamination. The firemain has a secondary function to supply seawater to other systems such as equipment cooling and waste disposal.

FLAMMABLE-A combustible material that burns easily, intensely or quickly.

FLOOD-(1) To fill a space with water; (2) a rising tide.

FLOODABLE LENGTH-The length of vessel which may be flooded without sinking her below her safety or margin line. The value of the floodable length of a given vessel varies from point to point throughout her length due to change in form. Similarly at a given point it varies from time to time, depending upon the condition of loading and the permeability y of the cargo.

FORECASTLE-A short structure at the forward end of a vessel formed by carrying up the ship's shell plating a deck height above the leveI of her uppermost complete fleck and fitting a deck over the length of this structure. The name applied to the crew's quarters on a merchant ship when they are in the forepart of the vessel. (Pronounced foksul.)

FORE-A term used in indicating portions or that part of a ship at or adjacent to the bow. Also applied to that portion and parts of the ship lying between the midship section and stem; as forebody, forehold, foremast and forward.

FORE AND AFT-The entire length of a ship, as in "Sweep down fore and aft."

FORWARD PERPENDICULAR-A line perpendicular to the baseline and intersecting the forward side of the stem at the designed waterline.

FRAME-(1) A term generally used to designate one of the transverse ribs that makeup the skeleton of a ship. The frames act as stiffeners, holding the outside plating in shape and maintaining the transverse form of the ship. (2) The athwartship strength member of a ship's hull.

FRAME LINES-(1) Molded lines of a vessel as laid out on the mold loft floor for each frame, showing the form and position of the frames. (2) The outline of transverse plane sections of a hull.

FRAME SPACING-The fore-and-aft distances between frames, heel to heel.

FREEBOARD-The vertical distance from the waterline to the top of the weather deck at side.

GAGE, DRAFT-An installation comprising a graduated glass tube, connected at the bottom end with the sea and with the top end open to the air, on which the draft of the vessel is shown by the level of the water in the tube.

GAUGE PRESSURE-Pressure which is measured using atmospheric pressure for zero reference.

GENERAL QUARTERS-The condition of full readiness for battle.

GUNWALE-A term applied to the line where a weather deck stringer intersects the shell. The upper edge of the side of an open boat. The upper edge of the sides of a ship. (Pronounced gunnel.)

HALF DECK-A partial deck below the main deck.

HATCH, HATCHWAY-An opening in a deck through which cargo may be handled, machinery or boilers installed or removed, and access obtained to the decks and holds below. Hatch is properly a cover to a hatchway but is often used as a synonym for hatchway.

HATCHWAY TRUNK-A term applied to the space between a lower deck hatchway and the hatchway or hatchway immediately above it when enclosed by a casing. A trunk may be either watertight or nonwatertight.

HEEL-(1) The convex intersection point or corner of the web and flange of a bar. (2) The inclination of a ship to one side, caused by wind or wave action or by shifting weights onboard.

HOLD-The space or compartment between the lowermost deck and the bottom of the ship, or top of the inner bottom if one is fitted. The space below decks allotted for the stowage of cargo.

HULL-(1) The framework of a vessel, together with all decks, deck houses, and the inside and outside plating or planking, but exclusive of masts, yards, rigging, and all outfit or equipment. (2) The shell, or plating, of a ship from keel to gunwale.

INBOARD-Toward the center; within the vessel's shell and below the weather decks.

INERT GAS-A gas which has no active chemical properties.

INITIAL STABILITY-The stability of a vessel in the upright position or at small angles of inclination. It is usually represented by the metacentric height.

INNER BOTTOM-A term applied to the inner skin or tank top plating. The plating over the double bottom.

KEEL-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.

LENGTH BETWEEN PERPENDIC-ULARS-The length of a ship measured from the forward side of the stem to the aft side of the stern post at the height of the designed water line. In naval practice, the total length on the designed water line.

LENGTH OVER ALL-The length of a ship measured from the foremost point of the stem to the aftermost part of the stern.

LIST-The deviation of a vessel from the upright position, due to flooding, shifting of cargo, or other cause of unbalance.

LONGITUDINALS-A term applied to the fore-and-aft girders in the bottom of a ship. These girders are usually; made up from plates and shapes and are sometimes intercostal and sometimes continuous.

MAGAZINES-Spaces or compartments devoted to the stowage of ammunition. Often specifically applied to compartments for the stowage of powder as a distinction fromn shell stowage spaces.

MAIN DECK-The principal deck of the hull, usually the highest extending from stem to stern and providing strength to the main hull.

MANHOLE-A round or oval hole cut in decks, tanks, boilers, etc., for the purpose of providing access.

MARGIN PLANK-A plank forming the boundary or margin of the deck planking.

MARGIN PLATE-The outer boundary of the inner bottom, connecting it to the shell plating at the bilge.

MIDSHIP BEAM-A deck beam of the transverse frame located at the midpoint between the forward and after perpendiculars. Also applicable to the transverse dimension of the hull at the same point.

MIDSHIP FRAME-The frame located at the midpoint between the perpendiculars.

MIDSHIPS-Same as Amidships.

MIDSHIP SECTION-The vertical transverse section located at the midpoint between the forward and after perpendiculars. Usually this is the largest section of the ship in area. Also, applied to a drawing showing the contour of the midship frame upon which is depicted all the structural members at that point with information as to their size and longitudinal extent.

NAVAL STANDARDS-Requirements for advancement for all ratings including military conduct, naval organization, military justice, security, and watchstanding.

OAKUM-A substance made from soft vegetable fibre such as hemp and jute impregnated with pine tar. It is principally used for talking the planking on wood decks of steel vessels and for talking all the planking on wood ships where watertightness is desired. It is also used for talking around pipes.

OCCUPATIONAL STANDARDS-Requirements that are directly related to the work of each rating.

ONE-LINE SCHEMATIC-Drawing of a system using only one line to show the tie-in of various components; for example, the three conductors needed to transmit three-phase power are represented by a single line.

ONE-LINE SKETCH-Drawing using one line to outline the general relationship of various components to each other.

OVERHEAD-The underside of a deck forms the overhead of the compartment next below. Never called a ceiling.