Section 3 Bilge systems and cross-flooding arrangements for accommodation units
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Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Offshore Units, July 2022 - Part 3 Functional Unit Types and Special Features - Chapter 4 Accommodation and Support Units - Section 3 Bilge systems and cross-flooding arrangements for accommodation units

Section 3 Bilge systems and cross-flooding arrangements for accommodation units

Parent topic: Chapter 4 Accommodation and Support Units

3.1 Application

3.1.1 The requirements of this Section are only applicable to units with accommodation for more than 12 persons who are not crew members. For self-elevating units, see also Pt 3, Ch 4, 1.1 Application 1.1.1.

3.2 Location of bilge main and pumps

3.2.1 The general requirements of Pt 5, Ch 12 Piping Design Requirements and Pt 3, Ch 13 Buoys, Deep Draught Caissons, Turrets and Special Structures are to be complied with as applicable unless otherwise specified in this Section.

3.2.2 The bilge main is to be arranged so that no part is situated nearer to the side of the unit than the damage penetration zone.

3.2.3 Where any bilge pump or its pipe connection to the bilge main is situated outboard of the damage penetration zone, a non-return valve is to be fitted at the pipe connection junction with the bilge main.

3.2.4 The emergency bilge pump and its connections to the bilge main are to be situated inboard of the damage penetration zone.

3.2.5 At least three power bilge pumps are to be provided. Where practicable, these pumps are to be placed in separate watertight compartments which will not be readily flooded by the same damage. In units where engines and auxiliary machinery are located in two or more watertight compartments, the bilge pumps are to be distributed throughout these compartments.

3.2.6 The bilge pumping units are to be such that at least one power pump will be available in all circumstances in which the unit may be flooded after damage. This requirement will be satisfied if:
  1. one of the pumps is an emergency pump of the submersible type having a source of power situated above the bulkhead deck or maximum anticipated damage load line; or
  2. the pumps and their power sources are located throughout the length of the unit so that, under any conditions of flooding that the unit is required to withstand by Statutory Regulation, at least one pump in an unaffected compartment will be available.

3.3 Arrangement and control of bilge system valves

3.3.1 The valves and distribution boxes associated with the bilge pumping system are to be arranged to enable any one of the bilge pumps to pump out any compartment in the event of flooding. All the necessary valves for controlling the bilge suctions are to be capable of being operated from above the bulkhead deck or maximum anticipated damage load line. The controls for these valves are to be clearly marked and a means provided at their place of operation to indicate clearly whether they are open or closed.

3.3.2 Where, in addition to the main bilge pumping system, an emergency bilge pumping system is provided, it is to be independent of the main system and so arranged that a pump is capable of pumping out any compartment under flooding conditions. In this case, only the valves necessary for the operation of this emergency system need to be operable from above the bulkhead deck or maximum anticipated damage load line.

3.4 Prevention of communication between compartments in the event of damage

3.4.1 Provision is to be made to prevent any compartment served by a bilge suction pipe being flooded in the event of the pipe being damaged by collision or grounding in any other compartment. For this purpose, where any part of the pipe is situated outboard of the damage penetration zone, or in a duct keel, a non-return valve is to be fitted to the pipe in the compartment containing the open end.

3.5 Cross-flooding arrangements

3.5.1 Cross-flooding arrangements are not permitted as a means of attaining the damage stability criteria in accordance with Pt 4, Ch 7 Watertight and Weathertight Integrity and Load Lines.

3.5.2 Cross-flooding arrangements may be used under control to restore a situation after damage. Such arrangements are not to be automatic or self-acting. Controls are to be situated above the worst anticipated damage waterline.

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