Fig:LNG carrier underway
Portable Electrical Equipment
Portable electrical equipment (self-contained or on extension cables) should not be used outside of accommodation spaces unless:
(1) The equipment circuit is intrinsically safe;
(2) The equipment is contained within an approved explosion-proof housing;
(3) Flexible cable are of a type approved for extra hard use, have an earth conductor, and are permanently attached to the explosion-proof housing in an approved manner;
(4) The compartments around and within which the equipment and/or cable are to be used are free from flammable vapour throughout the period during which the equipment is in use; and
(5) Adjacent compartments are free from flammable vapour or have been made safe by inerting or completely filling with water, and all connections with other compartments that are not free from flammable vapour are firmly closed and will remain so.
If the equipment is only to be used on the tank deck, explosion-proof and other types of certified safe equipment can be used.
Air-driven lamps of an approved type may be used in non gas-free atmospheres, although to avoid the accumulation of static electricity on the lamp it should either be earthed or the hose should have a resistance low enough to allow static dissipation.
Only approved safety torches or hand lamps should be used.
Small battery powered personal items such as watches and hearing aids are not significant ignition sources when correctly used. However portable domestic radios, electronic calculators, tape recorders, cameras and other non-approved battery powered equipment should not be used on the tank deck or wherever flammable vapour may be encountered.
When in port, reference should be made to local regulations which may totally prohibit the use of any electrical equipment. All portable electrical equipment should be carefully examined for possible defects before use. Special care should be taken to ensure that insulation is undamaged, that cables are securely attached and remain so while the equipment is in use, and that mechanical damage to cables is prevented.
Radio Transmitter, RADAR, VHF and radiating any signals
Main radio transmitters should not be used and the main aerials should be earthed during cargo operations because energy may be induced into conducting objects in the radio wave field. This energy can be sufficient to create a spark if discontinuity occurs. Heavy sparking can also occur at the insulators, particularly in humid weather. Permanently and correctly installed VFH equipment is not affected.
If it is necessary to operate the ship’s radio in port for maintenance etc., the agreement of the terminal and port authorities should be sought. The issue of a work permit may be necessary, and to ensure safety the terminal may require operation at low power, use of a dummy aerial load, or transmission only when no cargo operations are in progress.
It is advisable to consult the terminal before radar scanners or satellite communication equipment are used, because they may include non-approved equipment such as drive motors. The radiation itself is considered not to present an ignition hazard.
Follow the following items while being alongside the wharf:
(1) Ground a main antenna, and post up a notice which says that the radio transmission of the main transmitter is prohibited in the Radio Office.
(2) Prohibit the use of RADAR.
(3) Change over the output with radiating any signal down to low (1 W or under).
(4) For use of the INMARSAT and coastal telephone, obtain permission of the responsible person of the terminal.
Restriction on Private Electrical Appliances
(1) No use in private cabins
Electric appliances with built-in Nichrome wire, such as hair dryers, electric pots, and heaters. (But they may be used in the designated smoking areas with permission of the Master).
(2) Allowed in private cabins
TVs, VTRs, radios, radio cassette recorders, cameras, electric razors, and the like. But they shall not be used if inflammable gas penetrates into the accommodation. And they shall not be used on the upper deck and in areas where inflammable gas is likely to exist.
(3) No wiring without permission
Electric appliances shall be used by fixed receptacles, and no wiring shall be allowed without permission.
Maintenance of Fixed Lighting Units
Deteriorated insulation for electric cable laid on the deck, mast, and posts, and defective surface glasses, bulbs, and others of watertight lighting fixtures shall be repaired or replaced with new ones. But during liquefied gas handling operations, do not replace bulbs in areas where inflammable gas is likely to exist.
As a safety measure, crewmembers should display prominent notices near all electrical appliances, requiring the disconnection of power cord from electrical supply outlet when not in use. All old and suspect kettles should be permanently removed from use and replaced with new ones. A major fire incident was averted aboard a vessel due to timely intervention of crewmembers.
An electric kettle being used on board typically consisted of a cordless stainless steel jug fitted with a plastic base that contained the electric heating element. Power was supplied via a male-female central connector mounted on the base unit, also made of plastic. Following a mid-afternoon coffee break, the crew had left the mess room and had failed to notice that the water in the kettle was still boiling and the automatic thermostat switch had not operated and cut off the power supply to the heating coil.
Some minutes later, all the water had evaporated and without any more heat load, the temperature rose high enough for the plastic base and kettle bottom to melt and ultimately catch fire. The strong smell of burning plastic drew the attention of a passing crewmember, who, after seeing the fire and smoke at the kettle's base, quickly disconnected the power cord from the supply socket and transferred the kettle and base unit into the adjacent galley sink. Thereafter they turned on the water and successfully extinguishing the fire.
An investigation into the incident revealed that the automatic thermostatic switch was not working properly, while the crew was negligent in observing that the kettle was still boiling when they had left the mess room at the end of the coffee break.
Fuel and lubricating oil
Fuel or lubricating oils can be ignited by contact with hot surface even in the absence of the
external flame or spark. Care is to be taken to ensure that fuel or lubricating oil does not touch
hot surfaces; if leakage causes oil to spray or fall on to a hot surface, the source of oil is to be
Care is to be taken to ensure that cargo vapour (other than boiler fuel) does not enter the engine
or boiler room from any source. Particular care is necessary when LNG cargo vapour is used as a
If, as a result of malfunction of equipment, explosion, collision or grounding damage, cargo vapour
is likely to enter the machinery space, immediate consideration is to be given to its possible effect
on the operation of any equipment. Any necessary action is to be taken; e.g. isolating the source,
closing access doors, hatches and skylights, shutting down auxiliary and main machinery,
Diesel engines are liable to over-speed and destroy themselves if flammable vapour is present in
the air supply and boiler control systems rendered ineffective, even at concentrations well below
the lower flammable limit (LFL). The closing of dampers in the air supply or blocking off of the air
inlet is to be considered if this situation is suspected.
Reactivity of liquefied gas cargo
Toxicity and associated health hazards in liquefied Gas Carrier
Liquefied gases - How to remove all cargo liquid from tanks
- Precautions against Statistic Electricity
- Cargo machinery room safety
- Matters that require attention to onboard work
- Fire hazards and precautions - Atmosphere Control For Gas Carrier
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