Radio house or space. A structure or ace in which the radio apparatus is stalled and which may or may not prole accommodations for the operator or erators when off duty.

Side house. A small house at the side the upper, forecastle, bridge, or poop ck, etc., of a vessel. Superstructure. Any

superstructure

e breadth of which (at all points roughout its length) is approximately quivalent to the breadth of the upper ck, and the side frames of which are tirely independent of the main frames the vessel. This definition is not apicable to forecastle, bridge, or poop.

2.70 Definitions of items of deduction. Anchor gear. The space below deck ecupied by chains or cables, machinery, c., for handling the anchor.

Boatswain's stores. The spaces for Eoring paints, oils, blocks, hawsers, riging, deck gear, etc., in charge of the boatswain and for daily use on the essel.

Chart house. (See definition in 2.69.)

Crew spaces. The space approprited exclusively to the use of the crew of a vessel, except such spaces as the Engineer's workshop, carpenter shop, Slumber shop, butcher shop, etc., whereEver situated. The total of all crewpace deductions will be shown on vessel's documents under the head of "Crew pace."

Master's cabin. A space for the exclusive use of the master, consisting of sleeping room, bathroom, dressing room, Office, and passageways serving his acCommodations. Radio house. 2.69.) Steering gear. The space below deck Occupied by machinery, fittings, etc., for Operating the steering gear.

(See definition in

Storage of sails. The space in a vessel propelled wholly by sails used exclusively for storing the same, subject to the limitation of 22 percent of the vessel's gross tonnage.

$2.71 Definitions of structural terms,

etc.

right angles to the fore and aft center line of a vessel.

Batten. A board several inches in breadth, usually fitted on the side frames in holds and between decks of vessels instead of ceiling.

Beam. An athwart member supporting a portion of a deck. Also the breadth of the vessel.

measurement

Between decks. For purposes it is the space between the second and third and third and fourth decks, etc., the decks being numbered from below.

Body plan. A drawing consisting of a pair of half transverse elevations or end views of a vessel, both having a common vertical middle line, so that the righthand side represents the vessel as seen from ahead and the left-hand side as seen from astern. On the body plan appear the forms of the various cross sections. The curvature of the rail and deck lines at the sides, and with the water lines, buttock lines, and diagonal lines indicated as straight lines.

Booby hatch. A small companion fitted with a sliding top.

Break in double bottom. The point where the line of the inner bottom is broken by being either raised or lowered from the normal line of same.

Bulkhead. Bulkheads are partitions by which compartments, etc., are formed, or the hold of a vessel is divided.

Bulwark. A term applied to the strake of shell plating or the side planking above the weather deck and usually extends between the forecastle and the bridge or the bridge and the poop.

Ceiling. The covering of wood planking on the inboard face of a vessel's side frames, bottom frames, floor timbers, and sometimes on the under side of deck beams.

Cellular double bottom. A term applied when the double bottom is divided into numerous compartments by the floors and longitudinals.

Coaming. The vertical boundary around a hatch, skylight, etc., the "sill" below a tonnage opening in a bulkhead. Cockpit. A space at the bottom of which is a platform sunk below the line of the upper deck on small craft.

Companion. A small structure sheltering a deck opening affording entrance to a companionway.

Companionway. A stairway or ladderway leading to a space above or below.

Covering board.

A plank or a strake of planking fitted horizontally on top of frame heads at the line of weather deck.

Crown. A term sometimes used to denote the round up or camber of a deck.

Deck hook. A wooden hook or knee on the level of deck beams on which the extreme forward ends of deck planks rest and to which they are fastened. On iron or steel vessels, a plate connecting the extreme ends of deck stringer plates.

Depth of frame. The depth of a bottom frame is its perpendicular height. (See d, Figure 1 (§ 2.65)). The depth of a side frame is the athwart distance between its inboard and outboard face.

Double bottom. Compartments at bottom of ship between inner and outer bottom plating, used for ballast tanks, water, fuel oil, etc.

Fidley hatch. Hatch around smokestack and uptake.

Flange. Portion of a plate or shape at, or nearly at right angles to main portion.

Flare. A spreading outward and upward.

Floor or floor timber. The lowermost piece of timber connecting the main frames, notched to fit over the keel or keelson and extending the full depth of the frames to which it is fastened. In an iron or steel vessel a plate placed vertically in the bottom, extending from bilge to bilge, in way of each frame, to which it (the frame) is connected. In double bottoms of the usual construction it extends from the outer to the inner bottom thereof.

Frame. One of the numerous transverse (longitudinal in Isherwood-type vessels) "ribs" that form the framing of a vessel.

Frame bracket. A plate connecting a side frame to the margin plate.

Freeing port. An opening in the bulwark or shell plating between the shelter and upper decks for discharging large quantities of water which may be shipped.

General arrangement plans. Plans showing the various quarters, spaces and compartments into which a vessel is usually divided.

Gudgeon.

Fittings on the sternp

to take the rudder pintles. Gunwale. A term applied to the 1 where an upper deck stringer interse the shell.

Hatchway. An aperture in a vess deck through which cargo is laden discharged; in common practice term "hatch" is also applied.

Hold. For admeasurement purpo that portion of the vessel below tonnage deck.

Horn timber. The center line fra in the stern of a wooden vessel, exter ing aft from the sternpost.

a

Inboard profile. Drawing of a ves cut vertically through its longitudi center line, showing its forward after perpendiculars, line of deck at ce ter and side, height of decks, tan height of bottom frames or floors a their spacing, assignment of vario spaces, machinery, etc.

Inner bottom. Plating forming t upper boundary of the double botto Also called the tank top.

Keel. In wooden and composite ve sels it is composed of pieces of timb and extends from stem to sternpost a is the bottom member of the vesse structure. In iron or steel vessels consists of long bars fitted vertically of plates fitted horizontally at the midd line.

Keelson. In wooden vessels the ke son is composed (like the keel) of vario pieces of timber placed on the botto frames directly over and in line with t keel and extending all fore and aft. iron or steel vessels the middle-line ke son is the keelson at the center li directly over the keel.

Length between perpendiculars. T length of a vessel measured from t forward edge of the stem where it inte sects the load water line to the aft perpendicular.

Length over all. The length of a ve sel measured from the foremost part the stem to the aftermost point of t stern.

Limber strake. The fore and aft pla of bottom ceiling laid next to the keelso

Longitudinal framing. A system construction in which, in conjuncti with deep web frames, the main fram are run fore and aft instead of athwar ships.

Main rail. Rail fitted on the upper ige of bulwark plating, or upon the anchions surrounding an upper deck. Margin plate. The outer boundary of he inner bottom, connecting it to the nell plating at the bilge.

Midship cross section. A drawing of vessel cut athwartship at about midength, showing moulded depth, moulded readth, round or pitch of beam, depth f side and bottom frames, floors, etc. Orlop deck. The lowest partial deck. Outboard. Away from the center line, owards the side of the vessel.

Pintle. Fitting or pin on the rudder hich turns in a gudgeon.

Planking. A term applied to wood lecks and to the outside planking of Wood or composite vessels.

Plating. ulkheads, etc. Quadrant. A casting, forging or builtup frame in the shape of a sector of a circle attached to the rudder stock and through which the steering gear leads turn the rudder.

The plates of the shell, decks,

Rabbet. A groove or channel cut in a piece of timber to take the edge of a plank, or the ends of a number of planks.

Rake of the bow. The inclination of the line of the stem from the forward perpendicular.

Rake of the stern timber. Its (stern timber) inclination from the after perpendicular.

• Reverse frame. An angle bar or other shape riveted to the top of floors and/or the inner edge of a transverse frame to reinforce it.

= Rudder post. See sternpost.

Rudder stock. The main piece of the rudder frame, to which the pintles are connected and to the upper end of which the quadrant or tiller is fitted.

Samson post. A heavy vertical post that supports cargo booms.

Scantlings. Dimensions of various members that are used in the construction of a vessel.

Scupper. A round or oval aperture usually fitted in decks for the purpose of drainage.

Settling tanks. Oil tanks used for separating entrained water from the oil. The oil is allowed to stand for a time, to permit the water to settle at the bottom when it is drained or pumped off.

Shaft tunnel. Enclosed alley-way around propeller shaft.

Shelf. A fore and aft timber fitted to the frames and forming a support for the ends of the deck beams.

Shell plating. The plates forming the outer skin of the hull.

Sheer. The amount by which the height of the weather deck at the forward and after perpendiculars exceeds this height at the mid-perpendicular.

Skin. A term usually applied to the outside planking or plating.

Skylight. A built-up frame of wood or metal having glass lights fitted in the top and installed over a deck opening for the purpose of furnishing light and air to the spaces below.

Stem. In the case of wooden vessels, it is the heavy piece of timber at which the outside planking terminates at the forward end of the hull. In iron or steel vessels it is the heavy piece of iron or steel extending from the keel to above the uppermost weather deck, and forming the extreme fore end of a vessel.

Stern. The after end of a vessel. Sternpost (main). In wooden vessels, the piece of timber extending from the after end of the keel to the uppermost deck and to which the rudder braces are fixed to receive the pintles by which the rudder is hung. In iron or steel sailing vessels, paddle and twin-screw steamers, the heavy forging or casting of iron or steel extending from the after end of the keel (to which it is scarfed) to an appropriate distance within the hull; in single screw steamers, the after part of the stern frame.

Stiffener. An angle bar, T-bar, channel bar, etc., used to stiffen plating of the bulkhead, etc.

Strake. A fore and aft continuous course or row of shell or other plating or planking.

Tank top. Plating forming the top of a double bottom. The inner bottom.

Transom. A floor plate extending across the vessel at the forward side of the sternpost and attached thereto.

Transverse framing. Athwartship and vertical members forming the vessel's framing. Opposite to the longitudinal system of framing.

Tumble home. An inboard sloping of the vessel's side. (The opposite to flare.)

Web frame. Members built of plates and angles, spaced at required intervals, and fitted in lieu of main frames for the purpose of local strengthening.

Longitudinal. A fore and aft vertical member running parallel, or nearly parallel, to the center vertical keel through the double bottom.

Wheelhouse (or pilot house). The house in which a steering wheel is located for the steering and navigation of the vessel.

§ 2.72 Suez and Panama Canal certi

cates.

Suez Canal special tonnage certi cates and also Panama Canal tonna certificates will be issued, upon a plication, by collectors of customs American shipowners requiring them f ships which will use the said cana Collectors of customs will also issue su tonnage certificates to public vessels the United States requiring them.