Detailed information in preparation of vessel for Gas-Free Inspection with pursuant to MPA Regulations.
Definition on the classification of petroleum cargo; and compartments of the vessel that will be inspected.
(a) Prior to the inspection of a vessel, which has carried Class A or Class B petroleum in bulk, the master is required to certify that all empty cofferdams and all the compartments, pumps and pipelines which contained petroleum have since the last discharge of such petroleum been thoroughly cleansed (to state the method of washing) and that the vessel is to the best of his knowledge and belief free from flammable vapour.
(b) All compartments (including cargo tanks, pump-rooms, cofferdams, and void spaces) to be opened and freed from liquid petroleum and petroleum vapour. As far as possible they must also be freed from water, sediment, scale and rust or anything which might retain petroleum or its vapour.
(c) All valves on cargo lines (including vapour lines if available), both in the tanks and on deck should be opened and blank flanges removed.
(d) Consistent with docking requirements, permanent segregated ballast tanks are allowed to be in ballast before issuing the gas free certificate.
(e) All slops on board have been discharged and that the slop tanks and any available residue tank onboard are thoroughly cleaned, ventilated and free from flammable vapour.
(f) The bunker tanks must not be contaminated with low flash-point petroleum such as Class “A” or Class “B” petroleum.
(a) Gas-Freeing of cofferdams (the fact that a cofferdam is normally kept full of water does not mean that it is gas-free).
(b) Available vapour line openings on deck were not opened at the time of inspection.
(c) Washing of pipelines, including crossovers and other possible ‘dead ends’ and complete draining thereof.
(d) Removal of sediment, sludge and scale (especially on stringers and similar places).
(e) Cleaning of heating-coils.
(f) Cleaning of manifold lines (including the drip trays).
(g) Emptying of pump-room bilges.
(i) Pipeline including vapour line openings on deck;
(ii) All empty cargo tanks;
(iii) Cofferdams or void spaces;
(v) Ballast tanks (if not fully filled with water);
(vi) Slop tanks, residue tank; and
(vii) Bunker tanks (if the vessel is to enter a shipyard).
Q1: Can the cargo tanks remain in ballast conditions when arranging for gas-free inspection with the MPA’s Port Chemist?
A1: No. The cargo tanks must be emptied and gas-freed before arranging for gas-free inspection.
Q2: Can tank cleaning be conducted at Singapore port waters?
A2: No, tank-cleaning operation can only be carried out when written permission had been obtained from Port Master, MPA. Further information can be referred to Maritime And Port Authority of Singapore (Dangerous Goods, Petroleum And Explosives) Regulations 2005, Regulation 13.