Section 14 Additional requirements for tankers intended for the carriage in bulk of oil cargoes having a flash point of 60°C and below (closed cup test)

14.1.1 Sub-Sections Pt 6, Ch 2, 14.2 Below deck cargo zones define the electrical equipment permitted in dangerous zones or spaces.

14.2.1  Cargo tank. Intrinsically safe electrical equipment.

14.2.2 Cofferdams adjoining cargo tanks:

1. Intrinsically safe electrical equipment.

2. Electric depth-sounding devices hermetically enclosed located clear of the cargo tank bulkhead, with cables installed in heavy gauge steel pipe with gastight joints up to the main deck.

3. Where it is necessary for cables to pass through spaces, other than those supplying the equipment described in this paragraph, they are to be installed in heavy gauge steel pipes with gastight joints.

14.2.3 Cargo pump-rooms:

1. Electrical equipment as defined in Pt 6, Ch 2, 14.2 Below deck cargo zones 14.2.2.

2. Lighting. Pump-rooms immediately adjoining an engine room or similar non-dangerous space may be lit through permanently fitted glass lenses or ports fitted in the bulkhead on deck, so arranged as to maintain integrity of the structure. The externally mounted lighting fixture may be designed so that the gastight flanged port forms part of the fixture. The lighting fixtures and wiring are to be located in the non-dangerous space.

3. Alternatively, flameproof lighting fittings (symbol d) may be fitted. The fittings are to be arranged on at least two independent final branch circuits to permit light from one circuit to be retained while maintenance is carried out on the other.

4. Lighting fittings of the air driven type, see Pt 6, Ch 2, 13.8 Certified safe type equipment 13.8.2.

5. Motors. Electrical motors driving equipment located in cargo pump-rooms are to be separated from the pump-room by a gastight bulkhead or deck. Flexible couplings or other means of maintaining alignment are to be fitted in the shafts between the motors and the driven unit. In addition, suitable stuffing boxes are to be fitted where shafts pass through gastight bulkheads or decks.

6. Cables. Where it is necessary for cables other than those supplying lighting to pass through cargo pump-rooms, they are to be installed in heavy gauge steel pipes with gastight joints.

14.2.4 Spaces other than cofferdams adjoining and below the top of a cargo tank e.g. holds:

1. Intrinsically safe equipment.

2. Safe type lighting fittings, see Pt 6, Ch 2, 13.8 Certified safe type equipment.

3. Through runs of cable.

4. Special consideration is to be given to the mechanical protection of electrical equipment in such spaces.

14.3.1 Safe type equipment, see Pt 6, Ch 2, 13.8 Certified safe type equipment. Such equipment is to be suitably protected for use on deck.

14.3.2 Through runs of cable.

14.4.1 Safe type equipment, see Pt 6, Ch 2, 13.8 Certified safe type equipment. Such equipment is to be suitably protected for use on deck.

14.4.2 Through runs of cable.

14.5.1 Safe type equipment, see Pt 6, Ch 2, 13.8 Certified safe type equipment. Such equipment is to be suitably protected for use on deck where necessary.

14.5.2 Through runs of cable.

14.6.1 Intrinsically safe equipment.

14.6.2 Safe type lighting fittings, see Pt 6, Ch 2, 13.8 Certified safe type equipment.

14.6.3 Through runs of cable.

14.7.1 Independent 1^st stage and 2^nd stage high level alarms are to be provided for cargo tanks. The 2nd stage high level alarm is to be set at a maximum tank level of 97.5%. Level indication is also to be provided locally to each tank.

14.7.2 ‘Fail-safe’ arrangements (see Pt 6, Ch 1, 2.4 Safety systems – General requirements 2.4.6) are to be provided to shutdown loading and discharging pumps and compressors to operate in the event of activation of either high cargo tank level alarm required by Pt 6, Ch 2, 14.7 Cargo tank level, pressure and temperature measurement 14.7.1.

14.7.3 The high cargo tank level alarms required by Pt 6, Ch 2, 14.7 Cargo tank level, pressure and temperature measurement 14.7.1 are to be both audible and visual and are to be provided on the wheelhouse and on the tank deck.

14.7.4 Indication of cargo tank pressure and temperature on an analogue display is to be provided in the wheelhouse and at the tank deck for all fluids and gasses where dangerous situations may arise, for example venting resulting from environmental effects causing heating of tanks.

14.7.5 To determine where the dangerous situations referred to in Pt 6, Ch 2, 14.7 Cargo tank level, pressure and temperature measurement 14.7.4may arise, reference is to be made to the A.D.N. and the relevant requirements of the appropriate National, International or Local Authorities. The applicability of Pt 6, Ch 2, 14.7 Cargo tank level, pressure and temperature measurement 14.7.4 is to be identified in the in the plans required by Pt 6, Ch 2, 1.2 Plans 1.2.2.

14.8.1 Cargo pumps are to be provided with means to stop the pumps in an emergency in the wheelhouse and at appropriate locations for the pump on the tank deck.

14.9.1 Systems providing inert gas to cargo spaces are to be provided with a loss of pressurization and an overpressure alarm (minimum setting 3,5 kPa underpressure and 7 kPa overpressure, see also Pt 5, Ch 13, 9 Inert gas systems) for the relevant cargo spaces. The alarms are to be both audible and visual and are to be provided on the wheelhouse.

14.10.1 Where a cargo control room is provided for the monitoring and control of cargo operations, the arrangements are to comply with Pt 6, Ch 2, 14.10 Cargo control rooms 14.10.2.

14.10.2 The applicable alarms and indications required by Pt 6, Ch 2, 13 Special requirements for tankers intended for the carriage in bulk of oil and other hazardous liquids(including those for cargo tank level, temperature and pressure) are, additionally, to be provided in the cargo control room.

14.10.3 Where means to control cargo valves remotely are provided, these are to permit control from the cargo control room.

14.10.4 Cargo pump room ventilation outlets are to be situated at least 6 m from accommodation entrances.

14.11.1 Pump rooms below the upper deck are to be provided with a system of gas detection that satisfies the requirements of Pt 6, Ch 2, 13.13 Spaces maintained at overpressure 13.13.4, as applicable.

14.11.2 The gas detection system is to automatically isolate electrical equipment that does not satisfy the constructional requirements of Pt 6, Ch 2, 13.13 Spaces maintained at overpressure 13.13.4 and provide audible and visual alarms in the pump room and in the wheelhouse to indicate detection of gas when a gas concentration of 10 per cent of the lower explosive limit (LEL) of the gas resulting from leakage from the intended cargoes is detected. The arrangements are to prevent automatically isolated electrical equipment being energized until the atmosphere within the space is made safe.

14.11.3 Gas detection heads are to be located at the entrances to the cargo pump rooms and in appropriate lower positions in the space.

14.12.1 Where thermal oil or hot water cargo tank heating arrangements are provided that includes equipment located outside of dangerous zones and spaces, arrangements are to be provided to activate an audible and visual alarm in the event of loss of heating system overpressure required to prevent cargo fluids entering heating system piping as a result of leaks in the heating system coils or other components located in the tank. Alarms are to be activated at an appropriate pressure taking into account, as necessary, the heating system operating pressures and design cargo static head.

14.13.1 Sprinkler systems installed on tank deck are to be provided with means of control in the wheelhouse and locally.