S.L. 499.12 Art. 27Conditionsofentry to Grand Harbour for a tanker certified fully gas-free and/or inert.

A tanker which is certified fully inert or gas free, or with some compartments certified gas free and the remainder inert, may enter Grand Harbour for the purposes of proceeding to a repair facility, provided that the following additional safety checks have also been conducted by a competent person:

(a) the gas-tightness of the inert gas distribution system and cargo tanks is confirmed, and that, attested to by the Master’s written declaration, all tanks have been in a continuously inert condition for at least four hours prior inspection and will so remain throughout a tanker’s stay in Grand Harbour. In exceptional cases the Authority may approve lesser periods of prior inertion, under the requirement that the competent person undertakes immediate and frequent monitoring of such a ship's subsequent I.G. status and record full details of such monitoring, which shall be provided to the Authority as required;

(b) the gas-tight seals of all cargo compartment openings are effective and tight;

(c) all inert gas system Pressure/Vacuum Breakers or other approved devices and Pressure/Vacuum valves appear to be regularly maintained and that for those which are liquid-filled, the correct fluid and level has been used and is maintained;

(d) the water level in the deck water seal is satisfactory;

(e) both the inert gas pressure indicators and the fixed and portable oxygen analysers are of an approved type and have been properly calibrated.