InterManager on Enclosed Spaces: What 354 Accidents Say About Your Safety Management System

Ship management association InterManager has recorded 354 enclosed space accidents between 1996 and 2026, across tankers, bulk carriers, containerships, passenger vessels, and other types. Thirty years of campaigns, training requirements, and regulatory attention, and the same problems keep appearing.

A new survey of more than 900 seafarers, published this month, identifies what those problems actually are. Crews report overly complicated procedures, insufficient time and manpower, commercial pressure, and inadequate practical training. Respondents also said inspections often focus more on paperwork than on whether safety measures work on board.

“Enclosed spaces have been killing seafarers for decades,” said Captain Kuba Szymanski, InterManager’s secretary general. “The industry does not need more paperwork for the sake of paperwork, it needs practical measures that work onboard.”

For an operator, that finding has a sharper edge than it first appears. A procedure that cannot be followed is not a defense. It is a document a plaintiff’s lawyer will read back to you.

Why This Is an Insurance Problem

Enclosed space entry sits at the intersection of three exposures that rarely get considered together:

Crew Injury and Death Liability: For a vessel owner, covered crew injury and death liabilities ordinarily fall within P&I. Where the worker is a Jones Act seaman and the claim is brought in the United States, that is negligence litigation before a jury rather than a compensation claim on a schedule.

Regulatory Enforcement: Shoreside and in U.S. shipyards, OSHA. At sea, flag state and port state. Both produce findings that then travel into the civil case.

The Documentary Record: Everything InterManager’s survey describes, the gap between written procedure and actual practice, becomes the exhibit list. Procedural deficiencies go to notice, foreseeability, and negligence. A safety management system specifying controls the vessel cannot deliver establishes that the operator knew what was required and did not provide it.

Szymanski’s framing is the one to hold onto. “If a procedure cannot realistically be completed with the time, people and equipment available, then we need to question the system, not blame the seafarer.”

In a courtroom, the system is the defendant.

What SOLAS Already Requires of Vessels

Enclosed space training at sea is not a matter of voluntary recommendations, and this is the requirement most often confused with the shoreside standards discussed below.

SOLAS Regulation III/19 requires an enclosed space entry and rescue drill on board at least once every two months. The requirement was introduced by IMO Resolution MSC.350(92), adopted in May 2013 and in force from 1 January 2015. Crew members with enclosed space entry or rescue responsibilities must participate.

Each drill must include the checking and use of four things:

(1) The personal protective equipment required for entry,

(2) communication equipment and procedures,

(3) instruments for measuring the atmosphere in enclosed spaces,

(4) and rescue equipment and procedures.

It must also include instruction in first aid and resuscitation techniques. Details must be recorded in the official logbook.

Separately, all crew members must be instructed on the risks associated with enclosed spaces and the procedures for safe entry, not just those with assigned duties.

The logbook requirement is worth dwelling on. It means the record of whether you complied exists in a document a port state inspector, a flag state investigator, and a plaintiff’s lawyer can all obtain. A gap in that record is not an administrative oversight. It is the first thing anyone looks at after a casualty.

Two points of scope matter:

SOLAS does not reach every vessel. The Convention applies principally to ships engaged on international voyages, subject to exceptions including cargo ships of less than 500 gross tons. Passenger ships are treated differently, and national regulations may extend equivalent requirements to smaller vessels or to domestic operations. Establish applicability by vessel type, service, and flag requirements rather than by tonnage alone.

Applicability turns on a risk assessment. U.S. Coast Guard guidance addresses operators who conclude the drill requirement does not apply to their ship. The position is that a risk assessment should be conducted to identify all enclosed spaces on board, and that the exemption is available only where no crew member has enclosed space entry or rescue responsibilities at any time, including in an emergency. Where crew need to enter or have routine duties to do so, the regulation applies in its entirety, the safety management system should be updated, and the required drills performed. The requirement applies to vessels in operation rather than during a shipyard period.

That last point creates a handover problem. Coast Guard guidance for vessels in U.S. drydocks and shipyards distinguishes the operational SOLAS drill requirements from OSHA’s shipyard employment standards, which take precedence for covered yard work. The two regimes carry different intervals, different responsible parties, and different documentation. Outside U.S. jurisdiction, the applicable flag state and local occupational safety requirements apply instead and need establishing separately.

The Direction of Travel

The IMO adopted revised recommendations for entering enclosed spaces aboard ships in June 2025, replacing Resolution A.1050(27). They address hazard identification, risk assessment, and safe entry procedures. The organization is separately reviewing the STCW Convention, with enclosed space training among the issues under consideration.

That matters for two reasons. The revised recommendations become the reference point against which an operator’s procedures are judged, whether or not they are mandatory in themselves, and SOLAS III/19 directs that drills take account of the recommendations developed by the Organization. And an STCW change would eventually reach manning and certification.

An operator rebuilding procedures this year should build toward the revised recommendations rather than the ones they replaced.

What U.S. Law Requires Ashore and in the Yard

For shipyard employment, the standard is 29 CFR Part 1915 Subpart B. Its scope covers vessels, vessel sections, and land-side operations regardless of geographic location, which means it can reach work aboard a vessel outside a traditional shipyard, provided that work falls within OSHA’s geographical jurisdiction. It should not be assumed to apply to ordinary vessel operations, marine terminal employment, or general industrial facilities, which fall under different standards including 29 CFR 1910.146 for general industry, Part 1917 for marine terminals, and Part 1926 Subpart AA for construction.

Within its scope, the standard is more prescriptive than most operators realize, and it is worth knowing in outline because it sets a benchmark a plaintiff’s expert will measure against.

Testing follows a fixed sequence. Oxygen content, then flammability, then toxicity. Not whichever order the meter is set to.

The thresholds are numbers, not judgments. For a space to be classified Safe for Workers, oxygen must be at least 19.5 percent and below 22.0 percent by volume, flammable vapor must be below 10 percent of the lower explosive limit, and any toxic materials must be within permissible concentrations. The regulation contains narrow exceptions for emergency rescue and for short-duration entry to install ventilation equipment, each with its own conditions including continuous monitoring.

Entry begins earlier than people think. Under the regulation, entry occurs as soon as any part of the entrant’s body breaks the plane of an opening into the space. Leaning in to look is entry.

Adjacent spaces count. The definition reaches spaces bordering the subject space in all directions, including corners, diagonals, decks, tank tops, and bulkheads. Testing the tank and not what surrounds it misses the mechanism in a significant share of casualties.

Conditions must be maintained, not just established. A competent person must inspect and test as often as necessary to confirm the atmosphere is holding. Where a change occurs that could alter conditions, work stops and may not resume until the space is retested. The regulation’s own examples are opening a manhole and adjusting a valve.

Pipelines must be positively isolated. Disconnected, blanked off, or otherwise blocked by a positive method to prevent hazardous materials discharging into a certified space.

Rescue capability is mandatory. The employer must establish a shipyard rescue team or arrange an outside team that will respond promptly. In-house teams must practice at least once every 12 months, using mannequins and rescue equipment in conditions approximating the real thing, and at least one member must hold current first aid certification including CPR.

Note the gap. Twelve months for a shipyard rescue team, two months for crew aboard a SOLAS vessel. They govern different populations doing different work, and an operator who applies the shipyard interval to a ship’s crew is non-compliant by a factor of six.

Hot work in the highest-risk spaces needs a Marine Chemist. Hot work within, on, or immediately adjacent to spaces that contain or have contained flammable or combustible liquids or gases, and on fuel tanks and their connected pipework, requires certification as Safe for Hot Work by an NFPA-certificated Marine Chemist or a Coast Guard authorized person. The certificate must be posted in the immediate vicinity while work is in progress and kept on file for at least three months.

Training must be certified. The employer must certify that required training has been delivered, with the employee’s name, the certifier’s name, and the dates, available for inspection.

Contractors must exchange hazard information. Each employer whose people enter must ensure available information on hazards, safety rules, and emergency procedures is exchanged with any other employer whose people may enter the same spaces. On a multi-contractor repair job, that is a mutual obligation most parties never discharge.

What the Survey Says Is Actually Failing

InterManager’s findings describe a specific set of failures, and each maps to something an operator controls.

Procedures are too complicated. A permit system that takes forty minutes to complete for a routine entry will be completed retrospectively or not at all. Complexity is not rigor.

There is not enough time or manpower. This goes straight to commercial decisions. If the schedule assumes an entry that properly requires four people and two hours can be done by two people in twenty minutes, the procedure is not the control. The schedule is.

Commercial pressure. Reported by crews as a direct factor. Where a vessel is on a tight turnaround and the entry is on the critical path, the pressure is real and it comes from ashore.

Training is inadequate and front-loaded. InterManager’s conclusion is that regular practical training is needed rather than reliance on exercises completed early in a seafarer’s career. Worth measuring against the two-month SOLAS drill requirement, which exists precisely to prevent that.

Inspections measure the wrong thing. Respondents said inspections emphasize paperwork over whether measures work on board. That is a direct challenge to how most operators verify their own systems.

Reporting and sharing are poor. InterManager criticized delayed and incomplete investigations, which make it harder for the industry to learn. The internal version of that problem is a near-miss system nobody uses.

The association’s recommendations are more frequent drills, refresher training, reliable gas detection equipment, and effective rescue arrangements, with technology offering further gains through wearable gas monitors, digital entry permits, hands-free communications, and remotely operated inspection equipment. It also points to ship design, where better equipment placement, improved coatings, and more durable piping would reduce the need to enter at all.

Where the Liability Falls

Three scenarios, and they produce different answers:

A crew member dies in a tank aboard a vessel. For a vessel owner, liability to crew for injury, illness, and death ordinarily falls within P&I cover. Where the worker is a Jones Act seaman and the claim is brought in the United States, the employer faces negligence litigation under the Jones Act and general maritime law rather than a scheduled compensation claim. Those damages are not subject to a general statutory cap, though a qualifying vessel owner may seek limitation under the federal Limitation of Liability Act, which carries its own conditions and exceptions. Maritime employers liability cover is a distinct product, and it matters most where an employer’s people work aboard vessels that are not entered in that employer’s own P&I, which is a common position for contractors, surveyors, and technical service providers.

A shipyard worker dies in a vessel under repair. OSHA Part 1915 Subpart B applies directly. The worker is almost certainly covered by the Longshore Act rather than the Jones Act. The yard faces citations and the vessel owner may face third-party liability, with the hazard information exchange obligation becoming a live question about who told whom what.

A terminal or facility worker dies in a shoreside tank. State workers’ compensation, potentially concurrently with Longshore cover for qualifying land-based maritime employment, as the Supreme Court held in Sun Ship. Plus OSHA under whichever standard applies to the operation, plus any third-party claims.

In all three, the documentary position is what moves the number. An operator with a procedure nobody could follow, drills that did not happen on the required interval, meters that were not calibrated, and a rescue arrangement that existed only on paper is not defending a claim. It is negotiating one.

What to Actually Do

Confirm your drill interval against the right regulation. For SOLAS vessels, every two months for crew with entry or rescue responsibilities, plus instruction for all crew. For U.S. shipyard rescue teams, at least annually. Applying the wrong one is a compliance failure before it is a safety failure.

Document the risk assessment if you think the SOLAS drill requirement does not apply. Coast Guard guidance expects a risk assessment identifying all enclosed spaces on board, and the exemption is narrow. Concluding it does not apply without that assessment is the worst of both positions.

Test your procedure against the resources on board. Take the written entry procedure, count the people it requires, time it honestly, and compare against the manning and the schedule. If it does not fit, you have found the problem and it is not the crew.

Simplify the permit and strengthen the training together. Remove administrative steps that control nothing, without removing hazard checks, authorization requirements, or rescue controls. A shorter permit that gets completed properly beats a longer one that gets completed afterward.

Verify by observation, not by file review. InterManager’s finding about inspections applies to internal audits too. Watch an entry and watch a drill. Do not read about them.

Check that rescue is real. Who responds, how long do they take, have they drilled on the required interval, and with what equipment. If the answer is the local fire service and nobody has spoken to them, there is no rescue arrangement.

Calibrate and maintain the gas detection. A meter that has not been bump tested is a meter that reads whatever it reads.

Run the adjacent space question. Most procedures test the space. The regulation reaches everything bordering it in all directions, and a significant number of casualties come from something next door.

For contractors, document the hazard exchange. Both directions, in writing, before the work.

Manage the yard handover. For vessels entering U.S. shipyards, Coast Guard guidance separates the operational SOLAS drill requirements from OSHA’s shipyard standards, which govern covered yard work. Establish who is responsible for enclosed space entry, rescue arrangements, and hazard communication during the yard period. Outside U.S. jurisdiction, work out which flag state and local occupational safety requirements apply.

Treat near misses as the leading indicator. With 354 recorded accidents over thirty years, the industry has no shortage of lagging data. What an individual operator needs is the entry that nearly went wrong last month, and most reporting systems do not capture it.

Put it in front of your underwriter. As we covered in the piece on how underwriters assess small fleets, documented loss prevention is one of the few things a smaller operator can show that genuinely moves a judgment call. A credible enclosed space program, demonstrated rather than filed, is exactly that kind of evidence.

The Bottom Line

Three hundred and fifty-four accidents over thirty years. Mandatory two-monthly drills since 2015. Revised IMO recommendations last year. And crews surveyed this month are still describing procedures too complex to follow, too few people, too little time, and training that happened once a long time ago.

Szymanski’s closing question is the right one. “Enclosed space deaths are not inevitable. The industry has the knowledge to prevent them so why isn’t it doing it already?”

For an operator, there is a narrower version of that question with a direct commercial answer. If your written procedure cannot be performed with the people, time, and equipment your vessel actually has, you do not have a safety management system. You have a document that will be read aloud in a deposition.

InterManager and The Nautical Institute are discussing the survey findings in a joint webinar on 27 October.