F.1 Routing of cables
On passenger ships, the main- and emergency supply cables which have to be run through a common vertical main fire zone shall be laid as far apart as practicable so that, in the event of a fire in this main fire zone, supply cables passing through to main and emergency equipment in other vertical and horizontal main fire zones remains, as far as possible, unaffected.
F.2 Selection of cables
F.2.1 In areas attended by passengers and in service areas only halogen-free cables shall be used for permanent installations. Cable trays/protective casings made of plastic materials as well as mounting materials shall be halogen-free as well.
Exceptions for individual cables for special purposes have to be agreed with GL.
F.2.2 For all other areas of the ship, the use of halogen-free cables is recommended.
Section 15 Additional Rules for Tankers
Section 15 Additional Rules for Tankers
A General ... 15-1 B Oil Tankers, Cargo Flash Point above 60 °C ... 15-3 C Oil Tankers, Cargo Flash Point 60 °C or below ... 15-4 D Liquefied Gas Tankers ... 15-4 E Chemical Tankers ... 15-4
A General
A.1 Scope
These Rules apply additionally to electrical equipment on tankers for the carriage of liquids developing combustible gases or vapours.
A.2 References to other GL Rules and Guidelines A.2.1 Section 1, K.3
A.2.2 Hull Structures (I-1-1)
A.2.3 Machinery Installations (I-1-2)
A.2.4 Liquefied Gas Carriers (I-1-6), see also IGC-Code of IMO A.2.5 Chemical Tankers (I-1-7), see also IBC-Code of IMO A.2.6 IEC publication 60092-502
A.2.7 SOLAS
A.3 Hazardous areas
A.3.1 Hazardous areas in which protective measures are mandatorily required are specified in B and C and in IEC 60092-502 and Liquefied Gas Carriers (I-1-6) and IGC-Code and Chemical Tankers (I-1-7) and IBC-Code.
A.3.2 Areas on open deck, or semi-enclosed spaces on open deck, within 3 m of cargo tank ventila-tion outlets which permit the flow of small volumes of vapour or gas mixtures caused by thermal variaventila-tion are defined as Zone 1. Areas within 2 m beyond the zone specified above are to be considered as Zone 2.
A.4 Power supply systems
A.4.1 The following power supply systems are permitted:
A.4.1.1 Direct current and single-phase alternating current:
2 conductors, insulated from ship's hull A.4.1.2 Three-phase alternating current:
3 conductors, insulated from ship's hull
A.4.2 Systems with hull return, or systems with earthed neutral, or systems with earthed conductor are not permitted, except for locally limited hull return or neutral earthed systems which are located out-side of hazardous areas for
active corrosion protections
measuring circuits of starting and preheating systems of internal combustion systems
medium voltage systems without influence of hazardous areas (see Section 8, C)
A.4.3 The insulation resistance of non-earthed primary or secondary distribution systems passing through hazardous areas, or belonging to equipment in a hazardous area, shall be continuously moni-tored. Earth faults shall be alarmed (see Sections 5, E and 20, E).
A.5 Cable installation
A.5.1 In hazardous areas, cables shall be laid only for equipment whose use is permitted in these areas; cables related to other requirements of this Section may also pass through these areas. Cables shall be reliably protected against damage.
A.5.2 All cables liable to be exposed to the cargo, oil vapours or gases shall be armoured or shield-ed, and shall have an overall watertight and oil-resistant outer sheath.
A.5.3 Each intrinsically safe system shall have its own separate cable. It is not permissible for intrin-sically safe- and non-intrinintrin-sically safe circuits to lay these together in a cable bundle or pipe or to mount them under common clamps (see Section 12, C.5.7). Intrinsically safe cables shall be marked.
A.6 Electrical equipment in hazardous areas (zone 0 and 1) and extended hazardous areas (zone 2)
A.6.1 In principal electrical equipment of non-certified safe-type shall be installed outside of hazard-ous areas. Such equipment may be installed in enclosed or semi- enclosed rooms only if these are well ventilated and separated by cofferdams or equivalent spaces from the cargo tanks, and by oiltight and gastight bulkheads from cofferdams and cargo pump rooms. These rooms shall be accessible only from a non-hazardous area or through adequately ventilated air locks.
Electrical equipment of non-certified safe-type may be installed inside hazardous areas, if it belongs to an intrinsic safe circuit.
A.6.2 The use of electrical equipment in hazardous areas shall be restricted to necessary required equipment.
A.6.3 The explosion types of electrical equipment in hazardous areas shall be as mentioned
in Section 1, K.3.2 for Zone 0,
in Section 1, K.3.3 for Zone 1,
in Section 1, K.3.4 for Zone 2
and their explosion group and temperature class shall conform with the characteristics of the cargo.
A.6.4 Motors
In case of motors with an explosion protection type Ex e (increased safety) these motors shall be equipped with protective devices for over current which shut-off the motors, if the winding temperatures rise to unacceptable high levels. Monitoring of the winding temperature does not replace the motor over current protection in the motor switchgear, which is required in all cases.
A.6.5 Measuring-, signalling-, control- and intercommunication circuits
A.6.5.1 According to the classified hazardous area the construction types Ex ia or Ex ib shall be pref-ered.
Section 15 Additional Rules for Tankers
A.6.5.2 The suitability of the systems for tank level gauging, tank pressure monitoring systems, high level alarm, overflow control and for required gas detection shall be proved by a GL type approval test, Section 21, E.5.6.
A.7 Fans and ventilation
A.7.1 Fans intended for installation in hazardous areas shall be designed according to the GL Rules for Machinery Installations (I-1-2), Section 15, B.5.3.
A.7.2 Requirements for ventilation, see the GL Rules for Ventilation (I-1-21)
A.8 Integrated cargo and ballast systems
A.8.1 If the operation of cargo and/or ballast system is necessary under certain emergency circum-stances or during navigation to ensure the safety of the tanker, measures are to be taken to prevent car-go and ballast pumps becoming inoperative simultaneously due to a single failure including its control and safety system.
A.8.2 The emergency stop of the cargo and ballast systems are to be independent from the control circuits. A single failure in the control or emergency stop circuits shall not lead to an inoperative cargo and ballast system.
A.8.3 Manual emergency stops of the cargo pumps shall not make the ballast pumps inoperable.
A.8.4 The control system are to be provided with a backup power supply, which may be a second power supply from main switch board. A failure of any power supply shall cause an alarm, audible and visible at each control panel location.
A.8.5 In the event of a failure of the automatic or remote control systems, a secondary means of control shall ensure the operation of the cargo and ballast system. This shall be achieved by manual overriding and/or redundant arrangements within the control systems.
A.9 Active cathodic protection systems
A.9.1 Metallicpartsinhazardousareasshallnotbeprovidedwithimpressedcurrentcathodic protec-tion,unlessspeciallydesignedandacceptedbytheauthority.
A.9.2 Cables for active corrosion protection systems, see Section 1, K.3.3.3.
A.10 For earthing, equipotential bonding and electrostatic charging see Section 1, K.3.16.