Safe Operational Practice on Oil and Chemical Tankers
This domain tests cargo transfer, line-up, segregation, tank cleaning and permit control on oil and chemical tankers. The exam rewards a sequence: plan, check, communicate, monitor and record.
Before transfer
Complete the ship/shore safety checklist, agree loading rates, tank allocation, line-up and emergency shutdown. Confirm overfill alarms, vapour vents and scuppers. For chemical cargoes, check compatibility, inhibitor requirements, tank coating and segregation according to the IBC Code.
During transfer
Maintain a continuous watch, monitor ullages and pressures, avoid opening gauge ports, and keep communication with the terminal. Use closed sampling where required. Stop immediately for leaks, overpressure or unexplained readings. After transfer, drain lines, confirm valve positions and record cargo quantities.
Tank cleaning and gas freeing
Crude oil washing and tank cleaning need inerting, permits and static precautions. Gas freeing requires ventilation and repeated testing. Hot work is a separate high-risk permit and is not authorised by a cargo permit.
Worked example
Two chemical parcels are to be loaded: one is toxic and one is water-reactive. Use separate tanks, separate pumps and dedicated lines; verify segregation against the IBC Code; confirm the water-reactive cargo tank is dry and inhibited as required. Reasoning: shared lines can transfer moisture or residues and create a reaction or contamination.
Traps that cost marks
Opening a gauge port during loading; skipping the ship/shore checklist; mixing incompatible cargoes through a common line; assuming a cargo permit covers hot work; ignoring inhibitor monitoring.