Enclosed Space Entry for a Cargo Hold Bilge Inspection
A coastal general cargo vessel has completed discharge. The chief officer wants an engineer to inspect a hold bilge line and a sounding pipe inside the forward cargo hold. The hold has been closed since discharge; the hatch covers were opened briefly yesterday for cleaning. The atmosphere has not been tested. A permit-to-work system exists on board but the permit has not been raised. The deck crew say the hold smells of cargo residue but is probably fine. The vessel sails in 6 hours and the chief officer wants the job done now.
1. Identify the safety issues and state what must happen before anyone enters the hold.
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The situation has several serious problems:
- The atmosphere is untested, and a cargo hold after discharge can be oxygen-deficient or contain flammable or toxic residues, especially with organic cargoes.
- No permit to work has been raised, so the formal control is missing.
- The informal "probably fine" judgement is not evidence.
- A schedule pressure of 6 hours is being used to justify skipping controls.
Before entry:
- Raise the permit to work and have it authorised by the master or responsible officer.
- Test the atmosphere with a calibrated meter at several levels for oxygen, flammable gas, and any relevant toxic gas; record the results.
- If the atmosphere is not proven safe, ventilate continuously and retest until acceptable.
- Identify and isolate any machinery or systems that could affect the space.
- Brief the entry team, position a standby person at the entrance, and confirm rescue arrangements and communications.
If these cannot be met, the inspection should be deferred or done another way.
2. The test shows 19.5 percent oxygen and no flammable gas. How would you interpret this and what would you do?
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19.5 percent oxygen is at or below the usual acceptance threshold for entry and is not a comfortable margin. It may reflect incomplete ventilation, consumption by cargo residue or rusting steel, or displacement by another gas. The absence of flammable gas does not rule out toxic gas or a continuing oxygen demand.
Actions:
- Do not enter on this result.
- Increase ventilation and retest after a suitable period, checking oxygen at top, middle, and bottom of the hold.
- If oxygen remains low despite ventilation, treat the space as suspect and investigate the cause rather than assuming the meter is wrong.
- Consider toxic gas testing appropriate to the cargo.
- If the space cannot be made safe, defer the inspection and report to the master.
A reading at the threshold is a stop signal, not a pass.
3. Draft the key points you would insist on in the entry procedure and the rescue plan.
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Entry procedure key points:
- Authorised permit with defined task, duration, and personnel.
- Atmosphere tested and recorded before entry and monitored during the job.
- Continuous ventilation while occupied.
- Adequate lighting, including intrinsically safe equipment where required.
- Communications tested between entrant and standby person.
- Entrants briefed on the task, the hazards, and the exit signal.
Rescue plan key points:
- Standby person at the entrance at all times, in communication, never entering alone.
- Rescue equipment at the entrance: harness, lifeline, and suitable breathing apparatus.
- Trained rescuers identified and available; untrained personnel must not attempt rescue.
- A means to raise the alarm and summon help.
- A clear instruction that the standby person raises the alarm rather than entering unprotected.
The 6-hour sailing target is not a reason to shorten these controls; the master should be told if the schedule cannot be met safely.