QUESTION 10.7.4

Fire protection for hydraulic power packs

Oil, Chemical, LPG, LNGEngine Room

What is being checked

The inspector is checking whether high-pressure hydraulic units inside the main machinery space are screened, contained and protected so a pinhole leak cannot atomise oil onto an ignition source and escalate undetected.

Ready onboard

0/7 complete

ENCLOSUREWhere required, the power pack is enclosed or effectively screened with suitable fire-resistant construction.LEAK CONTAINMENTDrip trays, drainage and leak collection prevent oil spreading to hot surfaces or bilges.SPRAY CONTROLFlexible hoses, flanges and high-pressure connections are shielded from nearby ignition sources.DETECTIONLeak, low-level, fire or local detection and alarm arrangements are functional as fitted.REMOTE STOPPower and oil flow can be stopped promptly from a safe position where required.MAINTENANCEHose age, condition, clamps, pressure, relief devices and cleanliness are controlled in the PMS.FIRE RESPONSESuitable local firefighting protection and clear access are maintained.

Practice questions

Answer aloud, then open the preparation point.

1Where would oil travel after a hose rupture?

Trace the spray and drainage path to nearby exhausts, electrical equipment, bilges and escape routes.

2How is the power pack stopped from outside the hazard area?

Identify the actual remote electrical or hydraulic isolation and the consequence for dependent machinery.

3What evidence supports hose condition?

Use maker life limits, installation date, close inspection, pressure rating and replacement history rather than appearance alone.

4Why is a fine hydraulic leak particularly dangerous?

High pressure can create an ignitable mist that travels beyond the visible leak and reaches hot or electrical ignition sources.

5What must remain clear around the unit?

Enclosure doors, remote stops, detectors, extinguishers, drainage and escape access.

Where an observation may arise

UNSHIELDED SPRAY

A high-pressure connection can spray onto an ignition source.

OIL ACCUMULATION

Drip trays or enclosure drainage contain standing oil.

AGED HOSE

Hose life, rating or replacement history is unknown.

REMOTE STOP

Safe shutdown is inaccessible, unlabelled or defective.

DETECTION

Leak or fire alarm protection is isolated or untested.

POOR ENCLOSURE

Required screens or doors are missing, open or damaged.

Master's practical note

Look beyond the power pack itself and map the spray cone. A small pinhole at operating pressure can reach an ignition source that is not directly adjacent to the unit.

Equipment boundary and references

Equipment boundary: Required enclosure, detection and shutdown depend on system pressure, oil quantity, location, vessel construction date and approved design. Apply class drawings and SOLAS requirements.

References

OCIMF SIRE 2.0 Question Library Part 2, Version 1.0, Question 10.7.4
SOLAS Chapter II-2 regulation 10.5.6
IMO MSC.1/Circ.1321
IACS class requirements
Hydraulic equipment manufacturer instructions

Last reviewed: 2026-09-10