In the case of tankers engaged in the carriage of crude
oil it is essential that the cargo tanks be maintained in the inerted
condition to avoid the hazard of pyrophoric iron sulphide ignition.
If it is assessed that the tanks cannot be maintained in an inerted
condition before the inert gas system can be repaired, an external
supply of inert gas should be connected to the system through the
arrangements required by regulation 62.11.5 as
soon as practicable, to avoid air being drawn into the cargo tanks.