Such trunkways or tunnels shall not extend through the first subdivision bulkhead abaft the collision bulkhead.

Where it is proposed to fit tunnels or trunkways for forced draft, piercing main transverse watertight bulkheads, these shall receive the special consideration of the Administration.

REGULATION X.-Openings in Ship's Sides Below the Margin Line.

(1) The arrangement and efficiency of the means for closing any opening in the ship's sides shall be consistent with its intended purpose and the position in which it is fitted and generally to the satisfaction of the Administration.

(2) (a) If in a between decks, the sills of any sidescuttles are below a line drawn parallel to the bulkhead deck at side and having its lowest point 22 percent of the breadth of the ship above the deepest subdivision load line, all sidescuttles in that between decks shall be of a nonopening type.

(b) If in a between decks, the sills of any sidescuttles other than those required to be of a nonopening type by subparagraph (a) are below a line drawn parallel to the bulkhead deck at side and having its lowest point at a height of 12 feet (3.66 meters) plus 212 percent of the breadth of the ship above the deepest subdivision load line, all sidescuttles in that between decks shall be of such construction as will effectively prevent any person opening them without the consent of the master of the ship.

(c) Other sidescuttles may be of an ordinary opening type.

(d) If in a between decks, the sills of any of the sidescuttles referred to in subparagraph (b) are below a line drawn parallel to the bulkhead deck at side and having its lowest point 42 feet (1.37 meters), plus 22 percent of the breadth of the ship above the load line at which the ship is floating on her departure from any port, all the sidescuttles in that between decks shall be closed watertight and locked before the ship leaves port, and they shall not be opened during navigation.

The time of opening such sidescuttles in port and of closing and locking them before the ship leaves port shall be entered in the official log book.

The Administration may indicate the limiting mean draught at which these sidescuttles will have their sills above the line defined in this paragraph and at which it will be permissible to open them at sea on the responsibility of the master. In tropical waters in fair weather this limiting draught may be increased by 1 foot (0.305 meter). (3) Efficient hinged inside deadlights arranged so that they can he easily and effectively closed and secured watertight shall be fitted to all sidescuttles

(a) which are required to be of a nonopening type;

(b) which are to be fitted within one-eighth of the ship's length of the forward perpendicular;

(c) which are to be fitted in positions defined in subparagraph (2) (b);

(d) which will not be accessible during navigation;

(e) which are to be fitted in spaces intended for the accommoda

tion of sailors and firemen;

(f) which are to be fitted in spaces intended for the accommoda

tion of steerage passengers.

(4) Sidescuttles fitted below the bulkhead deck, other than those referred to in the preceding paragraph, shall be fitted with efficient inside deadlights which may be portable and stowed adjacent to the sidescuttles.

(5) Sidescutties and their deadlights, which will not be accessible during navigation, shall be closed and secured before the ship proceeds to sea.

(6) No sidescuttles shall be fitted in any spaces which are appropriated exclusively to the carriage of cargo or coal.

(7) Automatic ventilating sidescuttles shall not be fitted in the ship's sides below the margin line without the special sanction of the Administration.

(8) All machinery and other inlets and discharges in the ship's sides shall be arranged so as to prevent the accidental admission of water into the ship.

(9) The number of scuppers, sanitary discharges, and other similar openings in the ship's sides shall be reduced to the minimum either by making each discharge serve for as many as possible of the sanitary and other pipes, or in any other satisfactory manner.

(10) Discharges led through the ship's sides from spaces below the margin line shall be fitted with efficient and accessible means for preventing water from passing inboard. It is permissible to have for each separate discharge either one automatic nonreturn valve fitted. with a positive means of closing it from above the bulkhead deck, or, alternatively, two automatic nonreturn valves without such means, the upper of which valves is so situated above the deepest subdivision loadline as to be always accessible for examination under service conditions.

Where a positive-action valve is fitted, the operating position above the bulkhead deck shall always be readily accessible and means shall be provided for indicating whether the valve is open or closed.

(11) Gangway, cargo, and coaling ports fitted below the margin line shall be of sufficient strength. They shall be effectively closed and secured watertight before the ship leaves port, and shall be kept closed during navigation.

Cargo and coaling ports which are to be fitted partly or entirely below the deepest subdivision loadline shall receive the special consideration of the Administration.

(12) The inboard opening of each ash shoot, rubbish shoot, etc., shall be fitted with an efficient cover.

If the inboard opening is situated below the margin line, the cover shall be watertight, and in addition an automatic nonreturn valve shall be fitted in the shoot in an easily accessible position above the deepest subdivision loadline. When the shoot is not in use both the cover and the valve shall be kept closed and secured.

REGULATION XI.-Construction and Initial Tests of Watertight Doors, Sidescuttles, etc.

(1) The design, materials, and construction of all watertight doors, sidescuttles, gangway, cargo, and coaling ports, valves, pipes, ash shoots, and rubbish shoots referred to in these Regulations shall be to the satisfaction of the Administration.

(2) Each watertight door shall be tested by water pressure to a

head up to the margin line. The test shall be made before the ship is put in service, either before or after the door is fitted. REGULATION XII.-Construction and Initial Tests of Watertight Decks, Trunks, etc.

(1) Watertight decks, trunks, tunnels, duct keels, and ventilators shall be of the same strength as watertight bulkheads at corresponding levels. The means used for making them watertight, and the arrangements adopted for closing openings in them, shall be to the satisfaction of the Administration. Watertight ventilators and trunks shall be carried at least up to the margin line.

(2) After completion a hose or flooding test shall be applied to watertight decks and a hose test to watertight trunks, tunnels, and ventilators.

REGULATION XIII.-Periodical Operation and Inspection of Watertight Doors, etc.

In all new and existing ships drills for the operating of watertight doors, sidescuttles, valves, and closing mechanisms of scuppers, ash shoots and rubbish shoots, shall take place weekly. In ships in which the voyage exceeds 1 week in duration a complete drill shall be held before leaving port, and others thereafter at least once a week during the voyage, provided that all watertight power doors and hinged doors, in main transverse bulkheads, in use at sea shall be operated daily.

The watertight doors and all mechanisms and indicators connected therewith, and all valves the closing of which is necessary to make a compartment watertight, shall be periodically inspected at sea, at least once a week.

REGULATION XIV.—Entries in the Official Log Book.

In all new and existing ships hinged doors, portable plates, sidescuttles, gangway, cargo and coaling ports, and other openings, which are required by these Regulations to be kept closed during navigation, shall be closed before the ship leaves port. The time of closing, and the time of opening (if permissible under these Regulations), shall be recorded in the official log book.

A record of all drills and inspections required by Regulation XIII shall be entered in the official log book with an explicit record of any defects which may be disclosed.

REGULATION XV.-Double Bottoms.

(1) In ships 200 feet (61 meters) and under 249 feet (76 meters) in length a double bottom shall be fitted at least from the machinery space to the forepeak bulkhead, or as near thereto as practicable.

(2) In ships 249 feet (76 meters) and under 330 feet (100 meters) in length a double bottom shall be fitted at least outside the machinery space, and shall extend to the fore and after peak bulkheads, or as near thereto as practicable.

(3) In ships 330 feet (100 meters) in length and upwards a double bottom shall be fitted amidships, and shall extend to the fore and after peak bulkheads, or as near thereto as practicable.

(4) Where a double bottom is required to be fitted the inner bottom shall be continued out to the ship's sides in such a manner as to protect the bottom to the turn of bilge.

Such protection will be deemed satisfactory if the line of intersection of the outer edge of the margin plate with the bilge plating is not lower at any part than a horizontal plane passing through the point of intersection with the frame line amidships of a transverse diagonal line inclined at 25 degrees to the base line and cutting it at a point one-half the ship's molded breadth from the middle line.

(5) Wells constructed in the double bottom in connection with the drainage arrangements shall not extend downwards more than necessary, nor shall they be less than 18 inches (457 millimeters) from the outer bottom or from the inner edge of the margin plate. A well extending to the outer bottom is, however, permitted at the after end of the shaft tunnel of screw ships.

REGULATION XVI.-Fire-Resisting Bulkheads.

Ships shall be fitted above the bulkhead deck with fire-resisting bulkheads which shall be continuous from side to side of the ship and arranged to the satisfaction of the Administration.

They shall be constructed of metal or other fire-resisting material, effective to prevent for 1 hour, under the conditions for which the bulkheads are to be fitted in the ship, the spread of fire generating a temperature of 1,500° F. (815° C.) at the bulkhead.

Steps and recesses and the means for closing all openings in these bulkheads shall be fire-resisting and flametight.

The mean distance between any two adjacent fire-resisting bulkheads in any superstructure shall in general not exceed 131 feet (40 meters).

REGULATION XVII.-Side and Other Openings, etc., Above the Margin Line.

(1) Sidescuttles, gangway, cargo and coaling ports, and other means for closing openings in the ship's sides above the margin line shall be of efficient design and construction and of sufficient strength having regard to the spaces in which they are fitted and their positions relative to the deepest subdivision loadline.

(2) The bulkhead deck or a deck above it shall be weathertight in the sense that in ordinary sea conditions water will not penetrate in a downward direction. All openings in the exposed weather deck shall have coamings of ample height and strength, and shall be provided with efficient means for expeditiously closing them weathertight.

(3) Freeing ports and/or scuppers shall be fitted as necessary for rapidly clearing the weather deck of water under all weather conditions.

REGULATION XVIII.-Exits From Watertight Compartments.

(1) In passenger and crew spaces, practicable means of exit to the open deck shall be provided for the occupants from each watertight compartment.

(2) Practicable means of escape for the crew shall be provided from each engine room, shaft tunnel, stokehold compartment, and other working spaces, independent of watertight doors.

REGULATION XIX.-Pumping Arrangements (Steamships).

(1) Ships shall be provided with an efficient pumping plant capable of pumping from and draining any watertight compartment under all

practicable conditions after a casualty whether the ship is upright or listed. For this purpose wing suctions will generally be necessary except in narrow compartments at the ends of the ship. Where close ceiling is fitted over the bilges, arrangements shall be made whereby water in the compartment may find its way to the suction pipes. Efficient means shall be provided for draining water from insulated holds.

(2) In addition to the ordinary bilge pump, worked by the main engines, or its equivalent engine-room pump, two independent power bilge pumps shall be provided, except that in ships less than 300 feet (91.5 meters) in length, having a criterion numeral less than 30, either two efficient hand pumps of the crank type, fitted one forward and one aft, or a portable power pump, may be substituted for one of the additional independent power bilge pumps.

In all cases an additional independent power pump shall be fitted when the criterion number exceeds 30 (51 Stat. L. 15).

Sanitary, ballast, and general service pumps may be accepted as independent power bilge pumps if fitted with the necessary connections to the bilge pumping system.

(3) Where two or more independent power pumps are required, the arrangement shall be such that at least one power pump will be available for use in all ordinary circumstances in which a vessel may be flooded at sea. One of the power pumps shall, therefore, be an emergency pump of a reliable submersible type. A source of power situated above the bulkhead deck shall be available for this pump in any case of emergency.

(4) Where practicable, the power bilge pumps shall be placed in separate watertight compartments so arranged or situated that these compartments will not readily be flooded by the same damage. If the engines and boilers are in two or more watertight compartments, the pumps available for bilge service shall be distributed through these compartments as far as is possible.

(5) With the exception of pumps which may be provided for peak compartments only, each bilge pump, whether operated by hand or by power, shall be arranged to draw water from any hold or machinery compartment in the ship.

(6) Each independent power bilge pump shall be capable of giving a speed of water through the main bilge pipe of not less than 400 feet (122 meters) per minute, and it shall have a separate direct suction, to the compartment in which it is situated, of a diameter not less than that of the bilge main. The direct suctions from each independent power bilge pump shall be arranged to pump from either side of the ship.

(7) Main circulating pumps shall have direct suction connections, provided with nonreturn valves, to the lowest drainage level in the machinery space, and of a diameter at least two-thirds that of the main sea inlet. Where the fuel is, or may be, coal, and there is no watertight bulkhead between the engines and boilers, a direct discharge overboard shall be fitted from at least one circulating pump, or, alternatively, a bypass may be fitted to the circulating discharge. (8) (a) All pipes from the pumps which are required for draining cargo or machinery spaces shall be entirely distinct from pipes which may be used for filling or emptying spaces where water or oil is carried.