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liquefied gas cargoes are transported at or close to their boiling point the boiling temperatures of these cargoes range from 162 °C for methane to 0 “R for butane low temperatures can cause cold burns, which may damage skin and tissue when ...Read more

liquefied gas cargoes are transported at or close to their boiling point

the boiling temperatures of these cargoes range from 162 °C for methane to 0 “R for butane

low temperatures can cause cold burns, which may damage skin and tissue when in direct contact with cold liquid or vapour

these low temperatures can cause brittle fracture if cold cargo comes in sudden contact with metals

liquefied gas cargoes give off vapour readily because they are boiling

cargo vapour can be flammable, toxic or both

polymerization may, under some circumstances, be dangerous

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hazardsliquefied gas
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– ship movements alongside must be restricted by adjusting moorings – all pipelines, joints and valves must be kept under observation whilst handling cargo – catchment trays must be fitted or placed at vulnerable points (hose connections, for example) – ...Read more

– ship movements alongside must be restricted by adjusting moorings
– all pipelines, joints and valves must be kept under observation whilst handling cargo
– catchment trays must be fitted or placed at vulnerable points (hose connections, for example)
– strict control must be exercised whilst loading to prevent tanks overflowing
– all scuppers must be closed to prevent a discharge of oil from the deck overboard
– all valves and blanks must be checked prior to cargo operations
– valves not used should be secured if possible
– sea valves not in use should be closed by double valves or blanked off
– if oil is spilt, cargo operations must be stopped and warnings given to all involved

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marine pollutionoil tankersoil tankers in port
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I think life is about sharing and teaching and this is the best way to share knowledge and be able to educate our maritime family all around the world, so lets talk about ideas worth spreading!

I think life is about sharing and teaching and this is the best way to share knowledge and be able to educate our maritime family all around the world, so lets talk about ideas worth spreading!

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Tank atmosphere evaluation lists circumstances when the atmosphere in cargo tanks and enclosed spaces must be tested as: – prior to entry by personnel – to establish that there is a gas-free condition prior to repair work, entry to a ...Read more

Tank atmosphere evaluation
lists circumstances when the atmosphere in cargo tanks and enclosed spaces must be tested as:
– prior to entry by personnel
– to establish that there is a gas-free condition prior to repair work, entry to a shipyard or dry-docking
– during inerting, gas-freeing and purging operations
– as a quality control before loading/changing cargo
an evaluation is the only way to get correct information about the composition of the tank atmosphere
information essential to evaluation of the tank atmosphere as:
– the nature of the constituent gases
– flammability
– toxicity/oxygen deficiency
– reactivity
he atmosphere in tanks or enclosed spaces must be considered dangerous unless proper checks prove otherwise
the importance of taking measurements of the atmosphere at several positions within a tank
before entry in enclosed spaces:
– oxygen content must be 21% by volume
– hydrocarbon content must be less than 1% LFL
– toxic gas concentration must be less than its TLV
after tank washing, manual removal of residue may be necessary
residue removal generates more hydrocarbon gas
gas-freeing operations must therefore be continuous
adjacent bulkheads and pipelines may constitute additional sources of hydrocarbon gas
the inert gas supply to the tank should be shut off
a gas-free certificate is needed from a qualified chemist before contractor’s work can be carried out
an additional hot work permit is required for hot work
such certificate and permit must be reissued every day that work is carried out, or such lesser period as the port authority stipulates

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enclosed spacesprotection of personnelsafety equipmentsafety precautions and measurestank
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accommodation is located outside the cargo area – states that superstructures for accommodation are designed to minimize the possibility of entry of cargo vapour and that this design feature should not be impaired in any way – states that no ...Read more

accommodation is located outside the cargo area
– states that superstructures for accommodation are designed to minimize the possibility of entry of cargo vapour
and that this design feature should not be impaired in any way
– states that no entrances, air inlets or openings to the accommodation are facing the cargo area
– states that accommodation portholes and windows facing the cargo area, and those within a certain distance from
the cargo area, are of the non-opening type
– states that all doors, portholes or windows in accommodation should be kept closed during cargo operations
– states that mechanical ventilation and air-conditioning units supply air to accommodation spaces
all ventilation systems should be stopped or operated on closed cycle if there is any possibility of cargo vapour being drawn into accommodation spaces
air intakes for accommodation and forijje engine- room are subject to requirements with respect to
minimum distance from ventilation outlets of gas-dangerous spaces
access to accommodation or to the engine-room is subject to requirements with respect to the minimum
distance from the forward bulkhead of the accommodation
for the safety barrier concept to be successful it is essential that the ship’s staff follow the safe
operational practices

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accommodationoperational practicesprotection of personnelsafety equipment
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for the purpose of discharging slops containing cargo residues into the sea, Annex II divides noxious cargoes on chemical tankers into four categories – these categories are X, Y, R and D, and a cargo of category A represents the ...Read more

for the purpose of discharging slops containing cargo residues into the sea, Annex II divides noxious cargoes on
chemical tankers into four categories
– these categories are X, Y, R and D, and a cargo of category A represents the most dangerous pollutant and a cargo of
category D the least dangerous
– all operations on board involving cargo, ballast and bunkers should be done in accordance with the applicable pollution Regulations
– carrying out operations in accordance with the ship’s Procedures and Arrangements (P and A) Manual ensuresthat
pollution regulations are complied with
– care should be taken to avoid cargo spillage during cargo transfer, ballasting or tank-cleaning operations
– pollution-prevention procedures during the operations include keeping a watch on:
• levels in cargo, slop or ballast tanks
• cargo or ballast hoses or hard arms
• pumps, valves, gaskets, connections and hatches
• spill pans and scuppers
• alarms and instrumentation
• co-ordination of operation signals
– personnel on watch should be present at all times during operations and regularly carry out the inspections on the pollution-prevention procedures

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chemical tankerschemical tankers at sea and in portmarine pollutionprevention