Section 2 Bilge and Drainage Systems

201. General

1. An efficient bilge pumping system is to be provided, capable of pumping from and draining any watertight compartment other than a space permanently appropriate for the carriage of liquid and for which other efficient means of pumping are provided, under all practical conditions.

2. Where fixed pressure water-spraying fire-extinguishing systems or other systems which will supply large quantities of water are fitted, an arrangement is to be fitted in the compartment to ensure that such water is discharged directly overboard.

202. Bilge pumping system

1. At least one bilge suction which is effectively located is to be provided for every watertight compartment.

2. Arrangement is to be made whereby bilge in a watertight compartment may find its way to the bilge suctions.

3. Where, in relation to particular compartments, bilge discharge is considered difficult, the bilge pumping system may be omitted, but it is to be demonstrated that the safety of the craft will not be impaired.

4. At least two bilge suctions are to be provided in every machinery space, and all bilge suction pipes are to be provided with mud boxes which can be inspected and cleaned at easily accessible positions above the floor level of the machinery space.

5. In every watertight compartment where only portable bilge pumps are used to discharge bilge, means which are easily accessible to connect and operate bilge pumps are to be provided.

203. Prevention of flooding through bilge pipe

1. Bilge and ballast systems are to be provided with screw-down non-return valves so that water can not flow from overboard or ballast system to machinery spaces, cargo holds or other similar water-

tight compartments, or from one watertight

2. Screw-down non-return valves are to be tribution chest.

compartment to others.

provided between each branch bilge suction and dis-

204. Bilge pumps

1. All craft are to be provided with at least two bilge pumps, of which one is to be used only for bilge discharge. All available pumps, which have relevant capacity and are not intended for oil transfer on board, may be considered as the second bilge pumps. 【See Guidance】

2. Fixed or movable bilge pumps can be used, but pumps not less than 1.5 m hr, are to be pow- er-driven.

3. The capacity of each bilge pump is to be not less than required by the following formula :

【See Guidance】

: length of craft on design waterline (m ).

4. The Society may accept bilge pumps having capacity less than required by Par 3, but not less than required by the following formula or 1 m hr, whichever is the more.

: light weight (ton )

5. In bilge pumping arrangements where a bilge main is not provided then, with the exception of the forward spaces forward of public spaces and crew accommodation, at least one submersible pump is to be provided for each space. In addition, at least one portable pump is to be provided, sup- plied from the emergency supply if electric, for use on individual spaces.

6. Manual pumps, if fitted, are to be located on the bulkhead deck or upward.

7. Internal diameters of suction branches are not to be less than 25 mm , and suction branches are to be fitted with effective strainers.

8. Every valve or cock is to be fitted with open/close indicator so that can be seen at its operating place.