Beyond the Checklist: Preventing Enclosed Space Fatalities at Sea

Introduction

Despite decades of awareness campaigns, regulatory updates, and repeated industry commitments, seafarers and shore workers continue to lose their lives in enclosed spaces on board ships, often in circumstances that were entirely preventable.

The persistence of these incidents forces us to confront a hard truth: the measures currently implemented are insufficient. To break the cycle of fatalities, the industry needs a change of mindset, move beyond the checklists and procedures, and embed a genuinely human-centric approach to safety.

 

What do the numbers tell us?

From a P&I Club perspective, enclosed space related fatalities remain one of the leading causes of loss of life at sea. According to The International Group of P&I Clubs (IG), 83 deaths occurred in enclosed spaces during the five-year period between the 2015 and 2019 policy years.

The data collated by InterManager paints a similarly troubling picture. While the annual number of recorded enclosed space accidents has remained largely unchanged, the casualty rates have worsened. In both 2022 and 2023, 14 enclosed space incidents were recorded, yet casualties rose sharply from 18 in 2022 to 34 in 2023. Alarmingly, senior officers - individuals regarded as the most experienced and well trained on board - constitute a significant proportion of those affected.

Analysis of vessel types and accident locations shows that bulk carriers account for the highest proportions of incidents (≈41%), followed by tankers (≈23%). The most common sites for fatalities are cargo holds or hold access areas (≈51%), with cargo oil tanks also presenting a significant risk (≈18%). 

Multiple-fatality accidents remain common. There were a number of cases, where rescuers instinctively rushed to aid a collapsed colleague, only to become victims themselves.

Further insight is provided in a submission by the International Bulk Terminals Association (IBTA) to the IMO (CCC 11/15/3). Between 2000 and 2024, at least 1,010 crew and shore workers lost their lives in enclosed spaces on ships of all types. Of these, 700 (69%) were crew members and 310 (31%) were shore personnel. This equates to an average of 40 deaths every year, a sobering reminder of a problem that refuses to fade.

 

Industry Responses

It is commonly noted that the standards of training and drills vary on every ship. While some companies may choose to invest in advanced training and education tools, many do not. To address this gap, the International Chamber of Shipping (ICS) has proposed amendments to the STCW Convention and Code (HTW 12/6/2) to enhance mandatory training for entering, working in, and rescuing from enclosed spaces. If adopted, this will represent a valuable step towards addressing issues repeatedly highlighted through inspections and accident investigations.

In parallel, the industry is also progressing on several enclosed space related safety enhancements. Classification Societies are actively discussing improved tank designs, including better structural layouts, improved ventilation standards and minimising maintenance items to reduce the need for human entry. Trials with drones and remote inspection technologies are also advancing, offering safer alternatives for routine tank inspections.

At the same time, organisations such as The Oil Companies International Marine Forum (OCIMF), International Parcel Tanker Association (IPTA) and International Association of Independent Tanker Owners (Intertanko) are exploring the feasibility of replacing traditional wall-wash testing on tankers with wash-water analysis, an approach that could significantly reduce enclosed space entries while maintaining cargo quality assurance.

Additionally, to deepen understanding of persistent failings, InterManager, in collaboration with The Nautical Institute and IMarEST, has launched a survey seeking first-hand feedback from those working at sea. The aim is to delve deeper into what’s going wrong and understand better what solutions are needed. The survey can be accessed here.

As part of the wider industry effort to enhance safety at sea, the UK P&I Club supports the maritime consortium ‘Together in Safety’, that has published a set of 10 ‘Golden Safety Rules’, designed as straightforward, easy-to-follow practices to help prevent the most frequent fatal incident types across shipping.  The Golden Safety Rule No. 2 provides practical steps to follow before entering inside an enclosed space.

 

Regulatory Updates

The IMO’s first recommendations for entering enclosed spaces (Resolution A.864(20)) entered into force in 1997. These were later revised via Resolution A.1050(27) in 2011.

Subsequent regulatory developments include:

• SOLAS Reg. III/19.3.6 (1 January 2015): Mandated enclosed-space entry and rescue drills every two months.
• SOLAS Reg. XI-1/7 (1 July 2016): Required portable atmosphere-testing instruments capable of measuring oxygen, flammable gases/vapours, hydrogen sulphide, and carbon monoxide.

However, despite regulation, fatalities have continued. In July 2024, following two incidents involving the deaths of stevedores during coal discharge operations at Indian ports, the Indian Directorate General of Shipping issued DGS Circular 23/2024, reinforcing safety recommendations to prevent similar incidents from happening.

Similarly, the China Maritime Safety Administration (MSA) launched a special campaign aimed at preventing enclosed space accidents onboard vessels visiting Chinese ports between 15 January and 14 October 2025. Among its findings was the unsatisfactory execution of drills, reinforcing long-standing concerns regarding training standards.

In June 2025, the IMO’s Maritime Safety Committee, at its 110th session (MSC-110), adopted Resolution MSC.581(110) (Revised Recommendations for Entering Enclosed Spaces Aboard Ship). This resolution replaces Resolution A.1050(27) and aims to address the persistent underlying issues: failure to systematically identify hazards, properly assess risks, and implement appropriate entry procedures. It also explicitly recognises that effective organisational leadership, both ashore and onboard, is essential for empowering crew to make the right decisions and ensure safe operations.

Key developments include:

1. Strengthened Ship–Shore Coordination

• A joint ship–shore risk assessment is required before any contractor, stevedore, or shore worker enters an enclosed space.
• A simple schematic plan must be posted at the gangway, highlighting which spaces are safe or unsafe to enter.
• Shore personnel must be briefed on any hazards specific to the ship.

These measures aim to bridge the gap between ship staff and visiting personnel, ensuring everyone shares the same understanding of the risks involved.

1. New and Clarified Definitions

To improve hazard recognition and ensure consistent interpretation, several critical definitions have been added or refined:

• Enclosed Space: As before, a space with limited openings, inadequate ventilation, or not designed for continuous human occupancy—now emphasising wide-ranging examples such as holds, tanks, bilges, pump rooms, chain lockers, and engine crankcases.
• Connected Space: Newly defined. Any space linked by permanent or temporary means (including manual doors) to a source space. Must be treated as hazardous until proven safe by testing.
• Adjacent Space: More clearly defined as a space sharing a boundary with a hazardous space but without any openings. Still requires precautionary consideration in case of barrier failure.
• Trapped Hazardous Atmosphere: A new concept that addresses hazardous atmospheres that linger in connected spaces even after the source space is discharged or ventilated.
• Defined Roles (Responsible Person, Competent Person, Attendant): Enhanced clarity on accountability and training expectations for each role.

1. Enclosed Space Register

One of the most consequential changes is the introduction of a ship-specific Enclosed Space Register, which must catalogue:

• Every enclosed space onboard,
• All connected and adjacent spaces,
• Associated hazards,
• Expected atmospheric changes based on cargo or tank contents,
• Required risk controls, equipment, ventilation expectations, and emergency arrangements.

This Register must be maintained both onboard and ashore and kept continuously updated—especially during voyages and cargo operations.

1. Strengthened Operational and Procedural Measures

1. Risk Assessment & Gas Testing

• The competent person’s assessment must explicitly consider the potential for CO and CO₂, in addition to other toxic or asphyxiant gases.
• CO₂ safe threshold is now clearly stated as <0.5% by volume (5,000 ppm).
• Testing must be conducted after ventilation has stabilised.
• Testing for toxicity is required where relevant—flammability or oxygen levels alone are insufficient.

1. Permit to Work

• Entry permits must not exceed eight hours and are voided if ventilation stops or conditions change.
• Additional permits (energy isolation, hot work, working aloft, etc.) may be required depending on tasks.

1. Access Control & Signage

• Entry doors and hatches to enclosed spaces must always be secured against entry unless declared safe.
• Clear “Safe to Enter” / “Unsafe to Enter” signage and sealing arrangements are now required.

1. Prohibition of Solo Entry

• For the first time, MSC.581(110) explicitly prohibits single-person entry into enclosed spaces.

1. Time Pressure and Human Factors

• Companies must ensure adequate time is allocated for enclosed space operations, acknowledging that time pressure has been a recurring causal factor in past casualties.

1. Training and Rescue Preparedness

• Crew must receive training in the operation, calibration, and maintenance of atmosphere testing equipment.
• Crew must be trained in rescue techniques, first aid, CPR, and use of recovery apparatus.
• Regular rescue drills are mandated under SOLAS, and MSC.581(110) emphasises reviewing and updating the enclosed space emergency response plan after each drill.

1. Simultaneous Operations (SIMOPS)

• Where enclosed space entry coincides with other operations, companies must set clear criteria to manage the added risks.

 

Creating a human-centric approach to workplace safety

A checklist ticked isn't a life saved. Real safety culture exists when crews are empowered to raise concerns and discuss solutions. Masters need to lead by example and embed safety as a day-to-day priority despite commercial pressures. Operators should also recognise that speed at the expense of safety undermines efficiency and creates more risk.  When safety becomes ingrained rather than imposed, when meeting requirements is not just procedure but instinct, and when every crew member looks out for the person working beside them, enclosed spaces become manageable risks rather than recurring incidents. The technology to support safer working environments exists. The regulations exist. What’s often missing is the culture and commitment to apply them effectively.

 

Conclusion

After nearly three decades of structured safety frameworks, enclosed-space fatalities should be a relic of the past. Yet they remain stubbornly prevalent. Existing procedures, while necessary, have not been sufficient on their own.

A cultural shift is essential. The long-term objective must be to eliminate the need for human entry into enclosed spaces wherever possible. Although challenging, industry bodies are increasingly aligned on driving safer standards, supported by improved regulation, technology and operational practices.

Ultimately, every life lost is one too many. By working collectively, and by embracing a more human-centric approach to safety, we can ensure that every workplace becomes a safer place for those who serve at sea.