Section 5 Emergency and alternative sources of electrical power

5.1.1 The requirements of this Section apply to naval ships to be classed for unrestricted service. Alternative arrangements specified in accordance with the requirements of the Naval Administration may also be acceptable.

5.1.2 A greater or lesser period than the 18 hour period specified in Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.7 may be considered in conjunction with the operational requirements as specified and any assigned Service Restriction.

5.1.3 Where it is proposed that a dedicated emergency source of electrical power and its associated transitional source of power will not be provided, the installation is to comply with the requirements of Vol 2, Pt 9, Ch 2, 5.5 Alternative sources of emergency electrical power.

5.1.4 Where the main sources of electrical power are located in two or more compartments that are not contiguous with each other, and where each source has its own independent self-contained systems, including power distribution and control systems, such that a fire or casualty in any one of the compartments will not affect the power distribution from the other(s), or to the services required by Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.7, the requirement of this section will be satisfied without an additional emergency source of electrical power and its associated transitional source of power, provided that:

1. there is at least one generating set complying with the requirements of Vol 2, Pt 9, Ch 2, 4.2 Number and rating of generators and converting equipment and of sufficient capacity to meet the requirements of Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.7 in at least two non-contiguous compartments; and

2. the generator sets referred to in Vol 2, Pt 9, Ch 2, 5.1 General 5.1.4 and their self-contained systems are installed such that one of them remains operable and readily accessible after damage or flooding in any one compartment; and

3. the generator sets referred to in Vol 2, Pt 9, Ch 2, 5.1 General 5.1.4 are capable of being automatically started on loss of the power supplied by the other main source(s) of electrical power and supplying the services required by Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.7 as quickly as is safe and practicable subject to a maximum of 45 seconds or provided with a transitional source of emergency electrical power as specified in Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.9; and

4. the number and arrangements of generators is to allow for maintenance at sea of any one generator without affecting the ability to supply electrical power to the services in Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.7 from either of at least two compartments; and

5. the requirements of this Chapter applicable to the emergency source or any associated equipment are to be applied to the main source complying with Vol 2, Pt 9, Ch 2, 4.2 Number and rating of generators and converting equipment, or any associated equipment.

5.2.1 A self-contained emergency source of electrical power is to be provided.

5.2.2 The emergency source of electrical power, associated transforming equipment, if any, transitional source of emergency power, emergency switchboard and emergency lighting switchboard are to be located above the uppermost continuous deck and be readily accessible from the open deck. They are not to be located forward of the collision bulkhead.

5.2.3 The location of:

• the emergency source of electrical power and associated transforming equipment, if any;
• the transitional source of emergency power;
• the emergency switchboard; and
• the emergency lighting switchboard;

in relation to:

• the main source of electrical power, associated transforming equipment, if any; and
• the main switchboard;

is to be such as to ensure that a fire or other casualty in spaces containing:

• the main source of electrical power, associated transforming equipment, if any, and the main switchboard; or
• in any machinery space of Category A;

will not interfere with the supply, control and distribution of emergency electrical power.

5.2.4 The space containing:

• the emergency source of electrical power, associated transforming equipment, if any;
• the transitional source of emergency electrical power; and
• the emergency switchboard;

is not to be contiguous to the boundaries of machinery spaces of Category A or those spaces containing:

• the main source of electrical power, associated transforming equipment, if any; or
• the main switchboard.

5.2.5 Where compliance with Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.3 or Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.4 is not practicable, details of the proposed arrangements are to be submitted.

5.2.6 Provided that suitable measures are taken for safeguarding independent emergency operation under all circumstances, the emergency generator may be used, exceptionally, and for short periods, to supply non-emergency circuits.

5.2.7 The electrical power available is to be sufficient to supply all those services that are essential for safety in an emergency, due regard being paid to such services as may have to be operated simultaneously. The emergency source of electrical power is to be capable, having regard to starting currents and the transitory nature of certain loads, of supplying simultaneously at least the following services for the periods specified hereinafter or for the period specified by the Naval Administration, see Vol 2, Pt 9, Ch 2, 5.1 General 5.1.2, if they depend upon an electrical source for their operation:

1. For a period of not less than three hours, emergency lighting at every lifeboat preparation station, muster and embarkation station and over the sides.

2. For a period of not less than 18 hours, emergency lighting as detailed below unless alternative arrangements are provided by lamps having accumulator batteries within the lighting unit that are continuously charged:

   1. in all service and accommodation alleyways, stairways and exits, personnel lift cars and personnel lift trunks;

   2. in the machinery spaces and main generating stations including their control positions;

   3. in all control stations, machinery control rooms, and at each main and emergency switchboard;

   4. at all stowage positions for firemen’s outfits;

   5. at the steering gear; and

   6. at the emergency fire pump, at the sprinkler pump, if any, and at the emergency bilge pump, if any, and at the starting positions of their motors.

3. For a period of not less than 18 hours:

   1. the navigation lights and other lights required by the International Regulations for Preventing Collisions at Sea in force; and

   2. The radiocommunications, as required by Amendments to SOLAS 1974, Chapter IV - Radiocommunications see also Vol 2, Pt 9, Ch 2, 5.6 Radio installation Radio installation.

4. For a period of not less than 18 hours:

   1. all internal communication equipment as required in an emergency;

   2. the navigational aids;

   3. the fire detection and fire-alarm system; and

   4. intermittent operation of the daylight signalling lamp, the ship’s whistle, the manually operated call points and all internal signals that are required in an emergency, unless such services have an independent supply for the period of not less than 18 hours from an accumulator battery, suitably located for use in an emergency;

5. For a period of 18 hours:

   1. the emergency fire pump if dependent upon the emergency source of electrical power;

   2. the automatic sprinkler pump, if any; and

   3. if any, the emergency bilge pump and all the equipment essential for the operation of electrically- powered remote controlled bilge valves.

6. The steering gear for the period of time required by Vol 2, Pt 6, Ch 1, 9 Alternative sources of power and emergency operation

7. For a period of half an hour:

   1. any watertight doors if electrically-operated together with their control, indication and alarm circuits;

   2. the emergency arrangements to bring the lift cars to deck level for the escape of persons. Personnel lift cars may be brought to deck level sequentially in an emergency.

8. Where applicable, the services required by Vol 2, Pt 9, Ch 2, 4.3 Starting arrangements 4.3.2

9. Engine cooling water and lubricating oil pumps, if independently driven.

5.2.8 The emergency source of electrical power may be either a generator or an accumulator battery, which is to comply with the following:

1. Where the emergency source of electrical power is a generator it is to be:

   1. driven by a suitable prime mover with an independent supply of fuel, having a flashpoint (closed-cup test) of not less than 43ºC;

   2. started automatically upon failure of the main source of electrical power supply unless a transitional source of emergency electrical power in accordance with Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.9 is provided; where the emergency generator is automatically started, it is to be automatically connected to the emergency switchboard; those services referred to in Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.7 are to be connected automatically to the emergency generator; and

   3. provided with a transitional source of emergency electrical power as specified in Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.9 unless an emergency generator is provided capable both of supplying the services mentioned in that paragraph and of being automatically started and supplying the required load as quickly as is safe and practicable subject to a maximum of 45 seconds.

2. Where the emergency source of electrical power is an accumulator battery it is to be capable of:

   1. carrying the emergency electrical load without recharging while maintaining the voltage of the battery throughout the discharge period within 12 per cent above or below its nominal voltage;

   2. automatically connecting to the emergency switchboard in the event of failure of the main source of electrical power;

   3. immediately supplying at least those services specified in Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.7; and

   4. remote control of fire extinguishing systems if electrical.

5.2.9 The transitional source of emergency electrical power where required by Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.8 is to consist of an accumulator battery suitably located for use in an emergency which is to operate without recharging while maintaining the voltage of the battery throughout the discharge period within 12 per cent above or below its nominal voltage and be of sufficient capacity and is to be so arranged as to supply automatically in the event of failure of either the main or the emergency source of electrical power at least the following services if they depend upon an electrical source for their operation:

1. the lighting required by Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.7.(a), Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.7.(b) and Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.7.(c) . For this transitional phase, the required emergency electric lighting, in respect of the machinery space and accommodation and service spaces may be provided by permanently fixed, individual, automatically charged, relay operated accumulator lamps; and

2. all services required by Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.7, Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.7.(d).(iii) and Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.7.(d).(iv) unless such services have an independent supply for the period specified from an accumulator battery suitably located for use in an emergency.

3. Power to operate the watertight doors at least three times, i.e. closed-open-closed against an adverse list of 15°, but not necessarily all of them simultaneously, together with their control, indication and alarm circuits as required by Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.7.

5.2.10 The emergency switchboard is to be installed as near as is practicable to the emergency source of electrical power.

5.2.11 Where the emergency source of electrical power is a generator, the emergency switchboard is to be located in the same space unless the operation of the emergency switchboard would thereby be impaired.

5.2.12 No accumulator battery fitted in accordance with this Section, unless for engine starting, is to be installed in the same space as the emergency switchboard. An indicator shall be mounted in a suitable place on the main switchboard or in the machinery control room to indicate when the batteries constituting either the emergency source of electrical power or the transitional source of electrical power are being discharged.

5.2.13 The emergency switchboard is to be supplied during normal operation from the main switchboard by an interconnector feeder which is to be adequately protected at the main switchboard against overload and short circuit and which is to be disconnected automatically at the emergency switchboard upon failure of the main source of electrical power. Where the system is arranged for feedback operation, the interconnector feeder is also to be protected at the emergency switchboard at least against short circuit.

5.2.14 In order to ensure ready availability of the emergency source of electrical power to supply circuits required to provide emergency services, arrangements are to be made, where necessary, to automatically disconnect non-emergency circuits from the emergency switchboard in the event of overloading to ensure that electrical power is available to the emergency circuits.

5.2.15 Provision is to be made for the periodic testing of the complete emergency system and is to include the testing of automatic starting arrangements.

5.3.1 Where the emergency source of power is a generator, the starting arrangements are to comply with the requirements given in Vol 2, Pt 2, Ch 1, 9.4 Starting of the emergency source of power.

5.4.1 Where the emergency source of power is a generator, the governor is to comply with Vol 2, Pt 9, Ch 2, 4.4 Prime mover governors.

5.5.1 Where it is proposed that a dedicated emergency source of electrical power and its associated transitional source of power will not be provided, the main source of electrical power and associated equipment is to meet the requirements of Vol 2, Pt 9, Ch 2, 5.5 Alternative sources of emergency electrical power 5.5.2. For such installations where the Rules specify a supply from the emergency source of power, this is to be achieved by an alternative supply meeting the requirements of Vol 2, Pt 9, Ch 2, 5.5 Alternative sources of emergency electrical power 5.5.2.

5.5.2 The main sources of electrical power are to be

1. separated and located in two or more compartments that are not contiguous with each other;

2. self-contained and arranged to be independent such that each system can operate without recourse to the other main source(s) including power distribution and any associated converting equipment and control systems;

3. arranged such that a fire or casualty in any one of the compartments will not affect the electrical power distribution from the other(s), or to the services required by Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.7.

5.5.3 The generator sets referred to in Vol 2, Pt 9, Ch 2, 5.5 Alternative sources of emergency electrical power 5.5.2 are to be capable of being started automatically on loss of the power supplied by the other main source(s) of electrical power and supplying the services required by Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.7 as quickly as is safe and practicable subject to a maximum of 45 seconds, or provided with a transitional source of emergency electrical power as specified in Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.9.

5.5.4 The number and arrangements of generators are to allow for maintenance at sea of any one generator without affecting the ability to comply with Vol 2, Pt 9, Ch 2, 5.5 Alternative sources of emergency electrical power 5.5.2.

5.5.5 Starting arrangements of main sources of electrical power are to comply with the requirements of Vol 2, Pt 2, Ch 1, 9.4 Starting of the emergency source of power.

5.5.6 Where these Rules specify that a service is required to be connected to both the main and emergency source of electrical power or is to be connected to the emergency switchboard, then these services are to be served by at least two individual circuits from the separated main sources of electrical power with arrangements to transfer between the two sources. The supplies are to be separated in their switchboard and throughout their length as widely as is practicable without the use of common feeders, protective devices, control circuits or controlgear assemblies, so that any single electrical fault will not cause the loss of both supplies.

5.5.7 Provision is to be made for periodic testing to demonstrate services required by Vol 2, Pt 9, Ch 2, 5.2 Emergency source of electrical power 5.2.7 can be supplied automatically following the loss of one main source of electrical power.

5.5.8 To demonstrate compliance with the requirements of Vol 2, Pt 9, Ch 2, 5.5 Alternative sources of emergency electrical power 5.5.2, a risk assessment of the electrical, mechanical and piping arrangements is to be carried out demonstrating that a single point failure such as a fire within a space would not render the systems incapable of supplying those services required in an emergency, see Vol 2, Pt 1, Ch 3, 18 Risk Assessment (RA).

5.6.1 Every fixed radio installation is to be provided with reliable, permanently arranged electrical lighting, independent of the main and emergency sources of electrical power, for the adequate illumination of the radio controls for operating the radio installation.

5.6.2 A reserve source or sources of energy is to be provided on every ship, for the purpose of conducting distress and safety radiocommunications, in the event of failure of the ship’s main and emergency sources of electrical power. The reserve source or sources of energy is to be capable of simultaneously operating the VHF radio installation and, as appropriate for the sea or sea area for which the ship is equipped, either the MF radio installation, the MF/HF radio installation, or the INMARSAT ship earth station and any of the additional loads mentioned in Vol 2, Pt 9, Ch 2, 5.5 Alternative sources of emergency electrical power 5.5.4, Vol 2, Pt 9, Ch 2, 5.5 Alternative sources of emergency electrical power 5.5.6 and Vol 2, Pt 9, Ch 2, 5.5 Alternative sources of emergency electrical power 5.5.7 for a period of at least one hour. The reserve source or sources of energy need not supply independent HF and MF radio installations at the same time.

5.6.3 The reserve source or sources of energy is to be independent of the propelling power of the ship and the ship’s electrical system.

5.6.4 Where, in addition to the VHF radio installation, two or more of the other radio installations, referred to in Vol 2, Pt 9, Ch 2, 5.5 Alternative sources of emergency electrical power 5.5.2, can be connected to the reserve source or sources of energy, the reserve source or sources are to be capable of simultaneously supplying, for the period specified by Vol 2, Pt 9, Ch 2, 5.6 Radio installation 5.6.2, the VHF radio installation and:

1. all other radio installations which can be connected to the reserve source or sources of energy at the same time; or

2. whichever of the other radio installations will consume the most power, if only one of the other radio installations can be connected to the reserve source or sources of energy at the same time as the VHF radio installation.

5.6.5 The reserve source or sources of energy may be used to supply the electrical lighting required by Vol 2, Pt 9, Ch 2, 5.6 Radio installation 5.6.1

5.6.6 Where a reserve source of energy consists of a rechargeable accumulator battery or batteries a means of automatically charging the batteries is to be provided which is to be capable of recharging them to minimum capacity requirements within 10 hours.

5.6.7 If an uninterrupted input of information from the ship’s navigational or other equipment to a radio installation as referred to in Vol 2, Pt 9, Ch 2, 5.6 Radio installation 5.6.2 is needed to ensure its proper performance, means are to be provided to ensure the continuous supply of such information in the event of failure of the ship’s main or emergency source of electrical power.