Before loading operations begin, the pre-operational ship/shore procedures must be thoroughly discussed and carried out. Appropriate information exchange is required and the relevant parts of the Ship/Shore Safety Check List should be completed. Particular attention should be paid to:
• The setting of cargo tank relief valves and high alarm pressures
• Remotely operated valves
• Reliquefaction equipment
• Gas detection systems
• Alarms and controls, and
• The maximum loading rate
This should all be carried out taking into account restrictions in ship/shore systems.
The terminal should provide the necessary information on the cargo, including inhibitor certificates where inhibited cargoes are loaded. Any other special precautions for specific cargoes should be made known to ship personnel. This may include the lower compressor discharge temperatures required for some chemical gas cargoes. Where fitted, variable setting pressure relief valves, high tank pressure alarms and gas detection sample valves should be correctly set.
The ballast system for gas carriers is totally independent of the cargo system. Deballasting can, therefore, take place simultaneously with loading, subject to local regulations. Ship stability and stress are of primary importance during loading. Procedures for these matters are in accordance with normal tanker practice.