Section 5 Sizes of bilge suction pipes

5.1.1 The diameter, d _m, of the main bilge line is to be not less than required by the following formula, to the nearest 5 mm, but in no case is the diameter to be less than that required for any branch bilge suction:

d m

=

5.2.1 The diameter, d _b, of branch bilge line suction pipes to cargo and machinery spaces is to be not less than required by the following formula, to the nearest 5 mm, but in no case is the diameter of any suction to be less than 40 mm:

d b

=

B and D are as defined in Pt 5, Ch 11, 5.1 Main bilge line 5.1.1.

5.3.1 The direct bilge suction in the machinery space required by Pt 5, Ch 11, 4.1 General 4.1.1 and referred to in Pt 5, Ch 11, 4.2 Submersible pump drainage 4.2.1. and Pt 5, Ch 11, 5.5 Separate machinery spaces 5.5.2 is to be led to the largest independent power pump, and the arrangements are to be such that the direct suction can be used independently of the main bilge suctions.

5.3.2 The size of the direct bilge suction required by Pt 5, Ch 11, 4.1 General 4.1.1 is to be not less than that determined by Pt 5, Ch 11, 5.1 Main bilge line 5.1.1 or Pt 5, Ch 11, 5.4 Main bilge line – Tankers and dry cargo ships having machinery spaces with their own bilge arrangements 5.4.1, as applicable when connected to a power pump, and by Pt 5, Ch 11, 5.2 Branch bilge suctions to cargo and machinery spaces 5.2.1 when connected to a hand pump in case of ships having engines not exceeding 220 kW.

5.4.1 In tankers and ships, where the engine room pumps do not deal with bilge drainage outside the machinery space, the diameter of the main bilge is to be not less than that required by the following formula, to the nearest 5 mm, but in no case is the diameter to exceed that required for the main bilge suction as per Pt 5, Ch 11, 5.1 Main bilge line 5.1.1:

d m

=

5.5.1 The number and position of the branch bilge suctions in auxiliary engine rooms are to be the same as for cargo holds, see Pt 5, Ch 11, 3.2 Cargo holds.

5.5.2 In addition to the branch bilge suctions, required by Pt 5, Ch 11, 5.5 Separate machinery spaces 5.5.1, at least one independent power pump direct bilge suction is to be fitted in each compartment. Similar provision is to be made in separate motor rooms of electrically propelled ships.

5.5.3 In ships other than passenger ships where a bilge main is not fitted and the auxiliary machinery space is served by fixed installed submersible pumps in accordance with Pt 5, Ch 11, 6.6 Submersible bilge pump arrangements, an additional emergency means of pumping out the compartment is to be provided, see Pt 5, Ch 11, 4.2 Submersible pump drainage 4.2.2 and Pt 5, Ch 11, 4.2 Submersible pump drainage 4.2.3.

5.5.4 In ships other than passenger ships, branch bilge suctions may be arranged as per Pt 5, Ch 11, 4.3 Branch bilge suction arrangements connected to non-isolated bilge main.

5.5.5 In passenger ships, each independent bilge pump is to have a direct bilge suction from the space in which it is situated, but not more than two such suctions are required in any one space. Where two or more suctions are provided, there is to be at least one suction at each side of the space.

5.5.6 For the number of bilge pumps to be installed in separate machinery spaces, see Pt 5, Ch 11, 6.1 Number of pumps 6.1.2.

5.6.1 The area of each branch pipe connecting the bilge main to a distribution chest is to be not less than the sum of the areas required by the Rules for the two largest branch bilge suction pipes connected to that chest, but need not be greater than that required for the main bilge line.