Section 3 Systems for broadcasting safety information

3.1.1 This Section states requirements for safety systems which broadcast warning of existing and potential hazards present on the unit and advise personnel on board of necessary actions they need to take.

NOTE

The requirements for the sound pressure levels to be provided by the public address system and audible alarms should be determined by reference to the LSA Code - International Life-Saving Appliance Code – Resolution MSC.48(66) and the Code on Alerts and Indicators, 2009.

3.2.1 The requirements for public address systems are given in Pt 6, Ch 2, 18.3 Public address system of the Rules for Ships, which are to be complied with where applicable. Additions or amendments to these requirements are given in the following paragraph(s) of this sub-Section.

3.2.2 Additional requirements with respect to unit types as indicated in this Section should also be complied with as applicable. In machinery spaces and other locations with high ambient noise levels, whether continuous or intermittent, audible alarms should be supplemented by visual alarms.

3.2.3 A public address (PA) system is to be provided which is to be audible in all parts of the unit. The PA microphones are to be located at the main control station and at the fire-control station and/or navigating bridge, if fitted. Additional microphones may be provided at other suitable locations, e.g. in the Unit Manager’s office.

3.2.4 Where it is proposed that a dedicated emergency source of electrical power and its associated transitional source of power will not be provided, see Pt 6, Ch 2, 3.7 Alternative sources of emergency electrical power.

3.2.5 For mobile offshore drilling units reference also needs to be made to the various requirements within the 2009 MODU Code - Code for the Construction and Equipment of Mobile Offshore Drilling Units, 2009 – Resolution A.1023(26) 5.7 Alarms and internal communication for public address systems.

3.3.1 The requirements for general emergency alarm systems are given in Pt 6, Ch 2, 18.2 General emergency alarm system of the Rules and Regulations for the Classification of Ships, July 2022, which are to be complied with where applicable. Additions or amendments to these requirements are given in the following paragraph(s) of this sub-Section.

3.3.2 A general alarm (GA) system is to be provided which is to be audible in all parts of the unit. Alarm signal devices are to produce a distinctive and strong note. The IMO Code on Code on Alerts and Indicators, 2009 should be referenced.

3.3.3 Where it is proposed that a dedicated emergency source of electrical power and its associated transitional source of power will not be provided, see Pt 6, Ch 2, 3.7 Alternative sources of emergency electrical power.

3.3.4 The alarm signal used should be limited to: general emergency, toxic gas (hydrogen sulphide etc. if a credible risk exists), combustible gas, fire and abandon unit.

3.3.5 For mobile offshore drilling units reference also needs to be made to the various requirements within the 2009 MODU Code - Code for the Construction and Equipment of Mobile Offshore Drilling Units, 2009 – Resolution A.1023(26)5.7 Alarms and internal communication for general alarm systems.

3.4.1 Where it is required that alarms be provided to warn of the release of a fire-extinguishing medium, and these are electrically operated, they are to be provided with an emergency source of electrical power, as required by Pt 6, Ch 2, 3.1 General, and also connected to the main source of electrical power, with automatic changeover facilities located in or adjacent to the fire-extinguishing medium release panel. Failure of any power supply is to operate an audible and visual alarm, see also Pt 6, Ch 2, 1.14 Alarms and Pt 6, Ch 2, 3.7 Alternative sources of emergency electrical power.

3.5.1 Escape route or low level location lighting (LLL), in the form of either electrically powered systems or photo-luminescent strip indicators, is to be provided in accordance with the requirements of 3.2 Means of escape in passenger ships .2.15. Where electrically powered systems are used the arrangements are to comply with the requirements of this sub-Section.

3.5.2 Where an electrically powered system is used, the LLL system is to be provided with an emergency source of electrical power as required by Pt 6, Ch 2, 3.1 General and also connected to the main source of electrical power, with automatic changeover facilities located adjacent to the control panel. See also Pt 6, Ch 2, 3.7 Alternative sources of emergency electrical power. For Accommodation Units the LLL system is to be provided with an emergency source of electrical power as required by Pt 3, Ch 4, 2 Structure and also connected to the main source of electrical power, with automatic changeover facilities located adjacent to the control panel. The system is to be capable of being operated under fire conditions, see also IEC 61892-2:2012, Mobile and fixed offshore units – Electrical installations – Part 2: System design, Section 12.12.2.4 and Pt 6, Ch 2, 1.16 Operation under fire conditions of the Rules for Ships.

3.5.3 The power supply arrangements to the LLL are to be arranged so that a single fault or a fire, in any one fire zone or deck, does not result in loss of the lighting in any other zone or deck. This requirement may be satisfied by the power supply circuit configuration, use of fire-resistant cables complying with Pt 6, Ch 2,10.5.3 of the Rules for Ships, and/or the provision of suitably located power supply units having integral batteries adequately rated to supply the connected LLL, for a minimum period of 60 minutes. If the accommodation or part of the accommodation is classified as the Temporary Refuge, the LLL integral batteries are to have a minimum supply capacity of 60 minutes or a period in excess of 60 minutes if the Temporary Refuge is to be rated to maintain integrity for a period in excess of 60 minutes. Where these units are installed within cabins for crew or offshore personnel, or within associated corridors, the batteries are to be of the sealed type, see Pt 6, Ch 2, 11.2 Testing.

3.5.4 The performance and installation of lights and lighting assemblies are to comply with ISO 15370: Ships and marine technology – Low location lighting on passenger ships – Arrangement.

3.6.1 For mobile offshore drilling units a suitable audible and visual alarm to indicate significant increase or decrease in the level of the contents of the mud pit is to be provided at the control station for drilling operations and at the mud pit. Equivalent means to indicate possible abnormal conditions in the drilling system may be considered by LR.