QUESTION 10.6.3

Planning LNG and low-flashpoint-fuel bunkering

Oil, Chemical, LPGEngine Control Room, Chief Engineer's Office, Interview - Engine Rating

What is being checked

The inspector is checking whether a low-flashpoint-fuel transfer is supported by compatibility assessment, simultaneous-operations control, exclusion zones, purging, gas detection, ESD testing and trained personnel.

Ready onboard

0/7 complete

COMPATIBILITYShip and supplier agree manifolds, hoses, pressure, temperature, rates, ESD link, communications and custody-transfer arrangements.PLANThe transfer plan defines quantity, tank limits, sequence, cool-down, purging, draining, inerting and disconnection.SIMOPSPassenger, cargo, stores, mooring, ignition and nearby-vessel activities are assessed and controlled.ZONE CONTROLSafety and security zones, access, ignition control, PPE and weather limits are established.GAS SAFETYPortable and fixed detection, ventilation and emergency escape arrangements are verified.SHIP-SHORE CHECKJoint checklist, communications and ESD tests are complete before fuel flow.TRAININGAssigned personnel hold required IGF training and vessel-specific familiarisation.

Practice questions

Answer aloud, then open the preparation point.

1What determines the safety zone?

Use the approved bunkering study, transfer conditions, dispersion or risk assessment and local authority requirements.

2Why are lines cooled down gradually?

Controlled cool-down limits thermal stress, vapour generation and pressure shock in cryogenic equipment.

3How is trapped LNG removed before disconnection?

Follow the approved drain, depressurise, purge and gas-free sequence to the designated safe system.

4Which simultaneous operations are prohibited?

State the vessel and port-specific decision from the SIMOPS assessment, not a universal list.

5What stops the operation before ESD is needed?

Monitor weather, mooring, pressure, temperature, gas detection, communication and exclusion-zone integrity against agreed stop criteria.

Where an observation may arise

NO COMPATIBILITY

Hose, manifold, ESD or operating limits are not formally matched.

SIMOPS GAP

Concurrent work introduces ignition, access or emergency-response conflict.

PURGE ERROR

Lines are disconnected without safe drain, depressurisation and atmosphere control.

ZONE BREACH

Unauthorised persons or ignition sources enter the controlled area.

WEATHER LIMIT

Transfer continues outside agreed wind, lightning or movement limits.

TRAINING

Assigned personnel lack required qualification or ship-specific knowledge.

Master's practical note

Examine the transition stages before first flow and before disconnection. Most controls focus on steady transfer, while cool-down, purging and trapped liquid create the more complex changes of state.

Equipment boundary and references

Equipment boundary: This applies only to scoped vessels using LNG or another low-flashpoint fuel. The exact process must follow the fuel type, approved IGF arrangement, port approval and supplier interface.

References

OCIMF SIRE 2.0 Question Library Part 2, Version 1.0, Question 10.6.3
IGF Code
STCW Convention regulation V/3
ISO 20519
SGMF LNG bunkering guidance

Last reviewed: 2026-09-10