Section 3 Additional requirements for units with drilling and/or production and process plant or pipe-laying system

3.1.2 The arrangements of the pumps, sea suctions and sources of power are to be such as to ensure that a fire, explosion, gas release, flood or any other credible significant event in any one space would not put more than one required pumping unit out of action. There are to be at least two water supply sources (sea chests, valves, strainers and pipes, firewater pump risers directly from the sea) provided and so arranged that one supply source failure will not put all supply sources out of action dependent upon the requirements of Pt 7, Ch 3, 3.3 Fire pumps 3.3.10 with regards to firewater pump redundancy.

3.1.3 Suitable provision is to be made for the automatic start-up of the fire pumps, when any fire-fighting appliance supplied with water from the fire main is operated. Provision is also to be made for the start-up of the pumps locally and remotely from a continuously manned space or fire-control station. Once activated the pumps are to be capable of continuous unattended operation for at least 18 hours.

3.2.1 The diameter of any fire-water main and individual service pipes is to be sufficient for the effective distribution of the maximum required discharge from the required pumps operating simultaneously.

3.2.2 With the required pumps operating simultaneously, the pressure maintained in a fire-water main is to be adequate for the safe and efficient operation of all equipment supplied therefrom. The arrangements are to be such that the handheld fire-fighting equipment supplied from the main may be safely used by one person.

3.2.3 Where practicable, fire-water mains are to be routed clear of hazardous areas and be arranged in such a manner as to make maximum use of any thermal shielding or physical protection afforded by the structure of the offshore installation or unit.

3.2.4 Fire-water mains are to be provided with isolating valves, located so as to permit optimum utilisation of the main in the event of physical damage to any part of the main.

3.2.5 Fire-water mains are not to have connections other than those necessary for fire-fighting purposes.

3.2.6 Where applicable, all practicable precautions consistent with having water readily available are to be taken to protect the fire main against freezing.

3.2.7 Materials readily rendered ineffective by heat, are not to be used for fire-water mains unless adequately protected. The pipes and hydrants are to be so placed that the fire hoses may be easily coupled to them.

3.3.1 Any diesel-driven power source is to be capable of being readily started in its cold condition down to a temperature of 0°C, except where agreed otherwise with LR. If this is impracticable, or if lower temperatures are likely to be encountered, consideration will be given to the provision and maintenance of heating arrangements, so that ready starting will be assured. The engine is to be equipped with an approved starting device (e.g. starting battery), independent hydraulic system, or independent starting air system, having a capacity sufficient for at least six starts of the emergency fire pump within a 30 minute period with at least two starts within the first 10 minutes.

3.3.2 Any service fuel tank is to contain sufficient fuel to enable the pump to run on full load for at least 18 hours.

3.3.3 Under both normal and emergency conditions any compartment in which a pump unit is located is to be accessible, properly illuminated and efficiently ventilated.

3.3.4 Every centrifugal pump which is connected to a fire water main is to be fitted with a non-return valve.

3.3.5 Relief valves are to be provided in conjunction with all pumps connected to a fire-water main if the pumps are capable of developing a pressure exceeding the design pressure of the main, hydrants and hoses or other fire-fighting equipment connected to the main. Such valves are to be so placed and adjusted as to prevent excessive pressure in any part of the fire-water main system.

3.3.6 Means are to be provided for testing the output capacity of each fire pumping unit, in accordance with NFPA (20) or an equivalent Standard.

3.3.7 The provision of surge relief devices is also to be considered at the fire pumps, to prevent over-pressurisation of the mains on fire pump start-up. Such devices are to reset automatically once the excess pressure has been relieved.

3.3.8 The fire-water pump stop should be local only. Except during testing, any alarms from pump-monitoring systems should not automatically stop a running fire pump with the exception of engine overspeed for fire-water pump engine drive units. Fire detection at the fire-water pump should not stop the pump or inhibit the start of the fire-water pump driver. Confirmed hydrocarbon detection in the air inlet of the driver should inhibit the pump start but should not trip a running fire-water pump.

3.3.9 With reference to Pt 7, Ch 3, 3.3 Fire pumps 3.3.8, the design of the fire-water pump drive system shall ensure, so far as practical, that the fire-water pump drive set does not constitute an ignition source for potential hydrocarbon gas which may migrate to the pump drive enclosure on a hydrocarbon release incident. As such, the fire-water pump drives should be located in a non-hazardous area of the installation or unit and housed in a non-hazardous enclosure with ventilation designed to be maintained at an overpressure of at least 50 Pa in relation to adjacent external spaces. The fire-water pump drive enclosure is to be constructed with suitable fire-rated and gastight barriers, suitable fire-rated and gastight doors, and suitable fire-rated and gas-rated dampers. The design of the fire-water pump drive is to be such that, on gas detection on the enclosure ventilation air intakes, the drive is capable of continued operation with the enclosure ventilation shut down, ventilation fire and gas dampers closed and all entrances to the enclosure closed.

3.3.10 The installation design should incorporate a suitable allowance for fire-water pump redundancy. This redundancy is to allow for failure of a fire-water pump on demand or loss of a fire-water pump for maintenance without incurring potential lost production on the installation due to the loss of fire-water supply. Permanently manned hydrocarbon installations and mobile offshore drilling units typically have two 100 per cent or three 50 per cent fire-water pumps designed to meet the installation’s defined largest credible fire-water demand scenario (i.e. the installation’s 100 per cent fire-water demand). However, other configurations of fire-water pump supply redundancy may be acceptable for an installation, subject to suitable demonstration (for example, normally unmanned installations often do not have any dedicated fire-water pumps). 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) Chapter 9 - Fire Safety.

3.4.2 Water deluge systems and water monitors are to be connected to a continuously pressurised water main supplied by at least two pumps, capable, with any one pump out of action, of maintaining a supply of water at a pressure sufficient to enable the system or monitors to operate at the required discharge rates to meet the water demand of the largest single area requiring protection in accordance with the FEE.

3.4.3 The quantity of water supplied to any part of the production and process plant facility is to be at least sufficient to provide exposure protection to the relevant equipment within that part, and where appropriate, local principal load-bearing structural members. ‘Exposure protection’ means the application of water spray to equipment or structural members to limit absorption of heat to a level which will reduce the possibility of failure.

NOTE

Water monitors may only be used for the protection of equipment sited in essentially open areas.

Each monitor is to have sufficient movement in the horizontal and vertical planes to permit the monitor to be brought to bear on any part protected by it. Means are to be provided to lock the monitor in any position. Each monitor is to be capable of discharging under jet and spray conditions.

3.4.8 Any additional requirements for foam type fire protection systems to the topsides process modules and associated plant are to be evaluated within the unit's FEE Report. The specific requirements for foam systems are to be designed to provide extinguishing capabilities in areas where hydrocarbon pool fires may occur. Consideration shall also be given to bunding/drainage arrangements in these areas to ensure that system functionality is not compromised due to lack of hydrocarbon containment.

3.4.9 With regard to the performance requirements for foam systems (concentration levels, discharge time, method of induction, etc.), particular attention is to be given to the design criteria outlined in NFPA 16 or Chapter 6 - Fixed Foam Fire-Extinguishing Systems of the IMO FSS Code - Fire Safety Systems – Resolution MSC.98(73) or in the case of Fixed Deck Foam Systems, Chapter 14 - Fixed Deck Foam Systems of the IMO FSS Code - Fire Safety Systems – Resolution MSC.98(73). Alternatively, reference is to be made to an acceptable equivalent standard.

3.4.10 With reference to the above requirements for water deluge and water monitor coverage, it may be possible to utilise passive fire protection in place of fire-water cover over certain facilities dependent upon the finding of the FEE, see Pt 7, Ch 3, 3.6 Passive fire protection.

3.4.12 Fixed fire extinguishing systems on a mobile offshore drilling units mud processing area for active mud (i.e. mud mixed with hydrocarbon reservoir fluid) or mud capable of generating a pool fire risk is to consist of a suitable deluge / foam system. The fixed deluge / foam system is to be capable of delivering foam solution at a rate of at least 10 litres / minute over each square metre of exposed surface requiring protection (via solution made up from either Aqueous Film Forming Foam or Film-Forming Fluoroprotein Foam) for 15 minutes application. Alternatively, a gas fixed fire extinguishing system may be used for enclosed mud processing spaces with a determined pool fire risk.

3.4.13 For the electrical safety of electrical and electronic equipment in areas protected by fixed water-based local application fire-fighting systems and adjacent areas exposed to direct spray, the exposed equipment are to have a degree of protection not less than IP44.

3.5.1 The number and position of the hydrants are to be such that at least two jets of water, not emanating from the same hydrant, one of which is to be from a single length of fire hose, may reach any part of the installation or unit normally accessible to those on board. A hose is to be provided for every hydrant.

3.5.2 A cock or valve is to be fitted to serve each fire hose so that any fire hose may be removed while the fire pumps are operational.

3.5.3 Fire hoses are to be of type approved material and be sufficient in length to project a jet of water to any of the spaces in which they may be required to be used. Their length in general is not to exceed 18 m. Every fire hose is to be provided with a nozzle and the necessary couplings. Fire hoses together with any necessary fittings and tools are to be kept ready for use in conspicuous positions near the water service hydrants or connections.

3.5.4 Standard nozzle sizes are to be 12 mm, 16 mm and 19 mm or as near thereto as possible. Larger diameter nozzles may be permitted if required as a result of special considerations.

3.5.5 For exterior locations, the nozzle size is to be such as to obtain the maximum discharge possible from two jets at the pressure specified in Pt 7, Ch 3, 3.1 General requirements for fire-water mains and pumps 3.1.1.(d) provided that a nozzle size greater than 19 mm need not be used.

3.5.6 The jet throw at any nozzle is to be about 12 m.

3.5.7 All nozzles are to be of an approved dual purpose type (i.e. spray/jet type) incorporating a shut-off.

3.5.8 Mobile Offshore drilling units should be provided with at least one international shore connection complying with Chapter II-2 - Construction - Fire protection, fire detection and fire extinctionand the FSS Code - Fire Safety Systems – Resolution MSC.98(73). Facilities should be available enabling such a connection to be used on any side of the unit.

3.6.1 As outlined in Pt 7, Ch 3, 1.2 Submission of documentation 1.2.1, Pt 7, Ch 3, 1.2 Submission of documentation 1.2.2 and Pt 7, Ch 3, 3.4 Water deluge systems, water monitors and foam systems 3.4.10, the additional requirements for passive type fire protection systems to the topsides process modules and associated plant are to be evaluated within the unit’s FEE Report. The specific requirements for passive fire protection (PFP) systems are to be designed to provide adequate hydrocarbon containment to prevent escalation and enable safe evacuation of personnel to the ‘Temporary Refuge’.

3.6.2 With regard to the performance requirements for PFP systems, particular attention is to be given to the potential thermal and erosive effects of hydrocarbon jet-fires in the initial phase of a topsides incident. Consideration is also to be given to the ongoing thermal effects from pool fires. The duration of these events is to be examined in the project FEE in conjunction with the process system blowdown capabilities.

3.6.3 For fire rated divisions, bulkhead and decks, further reference should also be made to the guidance given in SOLAS - International Convention for the Safety of Life at Sea, Chapter II-2 - Construction - Fire protection, fire detection and fire extinction, Part C - Suppression of fire - Regulation 9 - Containment of fire, as applicable to the design intent of the unit. 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) Chapter 9 - Fire Safety.

3.7.1 Where included and assessed in the FEE Report (see Pt 7, Ch 3, 1.2 Submission of documentation 1.2.4) additional consideration will be given to the installation of other fixed fire-extinguishing systems (which may include, but may not be limited to, Fixed Pressure Water Spraying and Water-Mist fire-extinguishing systems, High Expansion Foam systems, Clean Agent fire-extinguishing systems) within internal machinery spaces, accommodation and service spaces, such as cabins and low risk areas. Specific functionality requirements for these systems should be evaluated and clearly defined within the FEE Report.

3.7.2 With regard to the performance requirements for Fixed Pressure Water Spraying and Water-Mist fire-extinguishing systems, particular attention should be given to the requirements of Chapter 7 - Fixed Pressure Water-Spraying and Water-Mist Fire-Extinguishing Systems and Chapter 8 - Automatic Sprinkler, Fire Detection and Fire Alarm Systems respectively, and of testing standards referred to therein. Reference can also be made to an acceptable equivalent standard (such as NFPA 750) for project-specific applications.

3.7.3 With regard to the performance requirements for fixed gaseous fire-extinguishing systems, particular attention should be given to the requirements of IMO FSS Code - Fire Safety Systems – Resolution MSC.98(73) Chapter 5 - Fixed Gas Fire-Extinguishing Systems. Reference can also be made to an acceptable equivalent standard (such as NFPA 12 for Carbon Dioxide systems and NFPA 2001 for ‘Clean Agent’ fixed gaseous fire-extinguishing systems) for project-specific applications.

3.7.4 Where a low-pressure CO₂ system is fitted, the piping system is to be designed in such a way that the CO₂ pressure at the nozzles is not less than 1 N/mm².

3.7.5 For the electrical safety of electrical and electronic equipment in areas protected by fixed water-based local application fire-fighting systems (i.e. a water mist system) and adjacent areas exposed to direct spray, the exposed equipment are to have a degree of protection not less than IP44. Alternatively other measures are to be considered (e.g. utilising only de-ionised water in the water mist system). Evidence is required to demonstrate the safe and effective operation of the overall arrangements in the event of system operation. This evidence is to demonstrate that exposure to system spray and/or water:

• cannot result in loss of availability of emergency services;
• will not affect the continued safe and effective operation of electrical and electronic equipment required to operate during the required period of system operation;
• does not present additional electrical or fire hazards; and
• would require only identified readily replaceable components to be repaired or replaced.

3.8.1 Installations with liquefied gas storage in bulk and/or vapour discharge and loading manifolds/facilities are, in general, to comply with the requirements of Chapter 11 Fire Protection and Fire Extinctionof the IMO International Code for the construction and Equipment of Ships carrying Liquefied Gases in Bulk (IGC Code) and Chapter 11 of the associated LR’s Rules and Regulations for the Construction and Classification of Ships for the Carriage of Liquefied Gases in Bulk. However, specific reference is to be made to the requirement stipulated within Pt 11, Ch 11 Fire Prevention and Extinction .

3.9.1 Fire-fighting facilities for helidecks and any helicopter refuelling equipment should be in compliance with a recognised standard (i.e. UK CAA CAP 437 or SOLAS - International Convention for the Safety of Life at Sea Chapter II-2 - Construction - Fire protection, fire detection and fire extinction, Part G - Special requirements, Regulation 18 - Helicopter facilities, Chapter 17 - Helicopter Facility Foam Firefighting Appliances of the FSS Code - Fire Safety Systems – Resolution MSC.98(73)). 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)Chapter 9 - Fire Safety for fire-fighting facilities.

3.9.2  At least one fire extinguisher on the helideck should be a gaseous agent type provided with a suitable applicator for use on engine fires.

3.9.3 Helidecks markings and lights should be in compliance with a recognised standard (i.e. UK CAA CAP 437). 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) Chapter 13 - Helicopter Facilities1. Other standards, for example relevant national standards where the unit is operating, may also be applicable. As such, other relevant standards may need to be complied with, rather than CAP 437 and the MODU Code.