QUESTION 10.2.6

Emergency air compressor and starting-air reserve

Oil, Chemical, LPG, LNGEngine Room

What is being checked

The inspector is checking whether the independent emergency air compressor and reservoir can restore starting-air capability after loss of the normal system and are maintained ready for immediate use.

Ready onboard

0/6 complete

INDEPENDENCEThe compressor has the approved independent power or manual drive and can operate after loss of main electrical supply.RESERVOIRThe emergency receiver, pressure gauge, relief valve, drains and isolating valves are in satisfactory condition.START PROCEDUREEngineers know the valve line-up and sequence to charge the correct receiver or main starting-air system.OPERATIONAL TESTPeriodic testing demonstrates pressure build-up within a reasonable or specified time.AIR QUALITYCondensate is drained and compressor oil, cooling and filters are maintained.ACCESSThe unit and instructions remain accessible under the casualty conditions for which it is intended.

Practice questions

Answer aloud, then open the preparation point.

1How would you regain starting air after a blackout?

Isolate losses, start the independent emergency compressor, line up the approved receiver and restore sufficient pressure before attempting machinery start.

2What powers this compressor?

Identify the actual independent source and how it remains available when the main plant is dead.

3How is performance verified?

Show the latest operational test with initial pressure, final pressure, elapsed time and defects.

4Why must receiver drains be controlled?

Water and oil accumulation reduces capacity, promotes corrosion and can create dangerous carryover or ignition risk.

5Which valves must remain in normal readiness position?

Use the vessel diagram and tagged line-up; do not rely on a generic answer.

Where an observation may arise

DEPENDENCY

The emergency compressor depends on power unavailable during the intended casualty.

NO BUILD-UP TEST

The unit runs but pressure recovery has not been demonstrated.

VALVE LINE-UP

Crew cannot identify the correct receiver and isolation arrangement.

POOR CONDITION

Leakage, corrosion, low oil, defective gauge or inaccessible equipment compromises use.

NO RECORD

Required inspection and test evidence is absent or incomplete.

Master's practical note

Ask an engineer to trace the actual air path from compressor to the machinery that must be restarted. A free-running compressor is not useful if the receiver cannot be charged after blackout.

Equipment boundary and references

Equipment boundary: The approved design may use a manual compressor, independent engine or emergency-powered unit. Apply the ship's drawings, class requirements and maker instructions.

References

OCIMF SIRE 2.0 Question Library Part 2, Version 1.0, Question 10.2.6
SOLAS Chapter II-1 regulation 26
Class rules for starting-air systems
Manufacturer instructions

Last reviewed: 2026-09-10