QUESTION 8.6.1

Gas-carrier cargo-tank overfill alarms

LPG, LNGCargo Control Room, Main Deck

What is being checked

The inspector is checking whether independent gas-carrier high-level and overfill protection matches the approved arrangement, is physically ready, is tested through its complete operating path and is understood by responsible personnel.

Ready onboard

0/6 complete

APPROVED BASISPlans, manuals and certificates identify sensor identity, independence, alarm and ESD set points, tank assignment, power supply and test connection.PHYSICAL CONDITIONInspection confirms the fitted arrangement is complete, labelled and accessible, with none of these defects or unsafe conditions: wrong tank, common sensor dependence, delayed shutdown, incorrect set point, failed alarm or untested channel.FUNCTION TESTThe approved test method proves each channel from test input to CCR alarm and required shutdown, including set-point verification.ALARM AND INDICATIONLocal and remote indications, alarms, trips, interlocks and power supplies agree with the actual equipment condition.MAINTENANCEPMS tasks, calibration, service limits, defects and authorised repairs are traceable to the specific equipment.USER KNOWLEDGEResponsible personnel can locate the controls and explain sensor identity, independence, alarm and ESD set points, tank assignment, power supply and test connection, limitations and failure response.

Practice questions

Answer aloud, then open the preparation point.

1What is the purpose and operating limit of independent gas-carrier high-level and overfill protection?

Explain the protection provided by sensor identity, independence, alarm and ESD set points, tank assignment, power supply and test connection, including the condition that requires intervention.

2How is the complete operating path tested?

Use the approved safe test method to prove each channel from test input to CCR alarm and required shutdown, including set-point verification, including the final alarm, trip, movement or indication.

3What happens if the equipment is unavailable?

Notify the Master and terminal as applicable, stop or restrict the affected operation, establish approved compensating controls and obtain repair or formal authority.

4Show the latest maintenance and defect history.

Match the physical identity to PMS, calibration or service records and verify that any temporary control has been closed.

5Which indication proves the equipment is in its safe condition?

Identify the local and remote indication, its source, alarm set point and how a false or frozen signal would be detected.

Where an observation may arise

ARRANGEMENT CONFLICT

The fitted system, drawing, manual or certificate did not agree.

PHYSICAL DEFECT

Inspection identified wrong tank, common sensor dependence, delayed shutdown, incorrect set point, failed alarm or untested channel.

INCOMPLETE TEST

Records did not prove each channel from test input to CCR alarm and required shutdown, including set-point verification through the complete operating path.

ALARM DEFECT

An alarm, trip, interlock or indication was isolated, incorrect, overdue for test or not understood.

MAINTENANCE GAP

PMS, calibration, service or repair evidence was missing, overdue or not traceable to the item.

KNOWLEDGE GAP

Responsible personnel could not explain sensor identity, independence, alarm and ESD set points, tank assignment, power supply and test connection, operating limitations or failure response.

Master's practical note

Trace one signal or flow path from the field device to the CCR or ECR and back to the final protective action. A successful local test alone may not prove the full system.

Equipment boundary and references

Equipment boundary: Use approved test modes and maker instructions. Do not bypass an interlock, release cargo or defeat protection merely to satisfy an inspection demonstration.

References

OCIMF SIRE 2.0 Question Library Part 2, Version 1.0, Question 8.6.1
IMO IGC Code Chapters 13 and 18

Last reviewed: 2026-09-14