Enclosed Space Entry
Enclosed-space entry connects hazard assessment, authorisation, atmosphere testing and controls while the space is occupied. The rescue plan and two-monthly drill for personnel with entry or rescue duties prepare an organised response: an open or previously ventilated tank is not thereby safe.
Operational Explanation
Confined spaces (cargo holds, tanks, cofferdams, double-bottom spaces) present a specific and recurring risk: an atmosphere deficient in oxygen or containing toxic/flammable gases, often not detectable without instrumentation, even in spaces that appear ventilated or have already been inspected previously.
The ship’s space register and risk assessment connect geometry, access, connections to other spaces and hazards from the contents with the entry permit. Before authorisation, isolation, ventilation, test results, communications and rescue readiness are checked under the applicable procedures. Conditions may change during the work: the initial check does not replace monitoring, attendance and exit and re-entry criteria. The drill exercises these roles and practical use of the equipment, rather than merely repeating theory.
Regulatory Reference
MSC.350(92) — SOLAS III/19.3.3, 19.3.6: drills at least every two months for personnel with entry or rescue duties; covering PPE, communications, instruments, recovery and first aid/resuscitation.
MSC.380(94) — SOLAS XI-1/7: for ships subject to chapter I, portable instruments for at least O₂, flammable gases/vapours, CO and H₂S, with appropriate calibration means.
MSC.581(110) — Revised Recommendations: recommendations distinct from SOLAS obligations, to be read with applicable national requirements and SMS procedures. A.1050(27) has been revoked and replaced; MCA MIN 688 Amendment 4, §2.5 documents that COSWP correction, but is a historical reference: its official page records its withdrawal and replacement by Amendment 5.
Scope of Application
Every ship with spaces classifiable as confined (cargo holds, tanks, double-bottom tanks, pump rooms), for all personnel involved in entries or rescue operations.
Procedure / How to Complete It
- Assess the space, connections and hazards; authorize entry under the SMS permit, with isolation and rescue arrangements ready.
- Sample representative levels and locations before entry with instruments suited to expected gases, including CO₂. Follow section 7 sampling procedures and national requirements.
- Maintain ventilation, an outside attendant and communications; use suitable personal detectors and repeat tests. Leave on ventilation failure or deteriorating conditions; retest after breaks.
- In an emergency raise the alarm and activate the rescue plan. No improvised entry: only a trained, equipped team; an EEBD is unsuitable for entry.
Practical Example
Example drill: simulation of a crew member falling ill inside a double-bottom tank, with recovery using a harness and tripod, use of breathing apparatus by the rescue team, and verification of communication with the outside throughout the operation.
In this example, the recovery equipment must be selected and tested for the access and geometry of the space; a harness and tripod are not a universal arrangement. Plan the drill without exposing participants to a hazardous atmosphere.
What Typically Goes Wrong
Common Mistakes Mistake Library
| Mistake | Consequence | How to avoid it |
|---|---|---|
| Entry without instrumental verification of the atmosphere, relying only on the visual appearance of the space | An oxygen-deficient or toxic atmosphere goes undetected, a mortal risk | Test the atmosphere before entry with suitable, calibrated instruments under the procedure; check gases identified by the risk assessment |
| Immediate rescue attempt without breathing apparatus when the person inside falls ill | The rescuer becomes a second victim | Train the crew never to enter to rescue without adequate protection, even in an emergency |
| Two-monthly drill skipped or reduced to mere theory without practical exercise | The crew fails to gain real familiarity with using the equipment in an emergency | Always conduct the drill with hands-on use of PPE, instruments and rescue equipment |
What the PSCO Checks
Operational Tips
Integrate the space register and rescue plan into the SMS. A standard four-gas detector may not measure CO₂ or other cargo gases: check actual sensors and limits. Breathing apparatus alone does not make a rescue safe.
Preparation checklist
Educational checklist. This summary supports learning and preparation only. It does not replace the vessel’s approved procedures, manuals, statutory documents, company SMS, or applicable official requirements. Completing it demonstrates neither compliance nor readiness for an inspection: it shows that a list has been read, not that the ship is in order. Always verify the current documents carried on board.
- Formal permit to work issued before every entry
- Atmosphere tested instrumentally before and during the time spent inside
- Adequate ventilation ensured before and during entry
- Outside attendant present and in constant communication
- Entry and rescue drill conducted at least every 2 months for personnel with entry or rescue responsibilities (SOLAS III/19.3.3)
- Atmosphere testing instrument on board and calibrated, for O₂, flammable gases, CO and H₂S (SOLAS XI-1/7)
- Ship-specific enclosed spaces register available and up to date (MSC.581(110))
- Enclosed space emergency response plan drafted and exercised in the drills
FAQ
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Certified substantive revision: 15 October 2026 · page fingerprint 8c491109464d