Section 4 Drainage of machinery spaces
Clasification Society 2024 - Version 9.40
Clasifications Register Rules and Regulations - Rules and Regulations for the Classification of Naval Ships, January 2023 - Volume 2 Machinery and Engineering Systems - Part 7 Piping Systems - Chapter 2 Ship Piping Systems - Section 4 Drainage of machinery spaces

Section 4 Drainage of machinery spaces

Parent topic: Chapter 2 Ship Piping Systems

4.1 General

4.1.1 The dewatering arrangements in the machinery spaces are to comply with Vol 2, Pt 7, Ch 1, 3.1 Design and construction, except that the arrangements are to be such that any water which may enter these compartments can be drained through at least two dewatering suctions when the ship is on an even keel, and is either upright or has a list of not more than 5º. The two means of drainage are to be capable of being operated independently of each other.

4.1.2 The drainage arrangements are to be such that machinery spaces can be pumped out under all practical conditions after a casualty, whether the ship is upright or listed.

4.1.3 In ships propelled by electrical machinery, special means are to be provided to prevent the accumulation of bilge water under the main propulsion generators and motors.

4.2 Separate machinery space

4.2.1 The two means of drainage required by Vol 2, Pt 7, Ch 1, 4.1 Metallic materials 4.1.1 are to be located in no fewer than two watertight compartments.

4.3 Machinery space — Emergency drainage

4.3.1 In addition to the dewatering suctions detailed in Vol 2, Pt 7, Ch 2, 4.1 General, an emergency suction is to be provided in each main machinery space. This suction is to be fitted with a screwdown non-return valve having the spindle so extended that the hand wheel is not less than 460 mm above the bottom platform.

4.3.2 The emergency suction is to be led to the largest available power pump, or an eductor which is not a dewatering unit required by Vol 2, Pt 7, Ch 2, 4.1 General 4.1.1. The emergency drainage suction is to be the same size as that of the pump suction branch.

4.3.3 One suction from one of the two independent means of drainage required by Vol 2, Pt 7, Ch 2, 4.1 General 4.1.1 may be omitted on the same side of the ship where the emergency suction is fitted.

4.3.4 Emergency drainage suction valve nameplates are to be marked ‘For emergency use only’.

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