Enclosed spaces on sea-going vessels

New Regulation: Enclosed spaces on vessels

New regulations concerning enclosed spaces on sea-going vessels were made on 14th Feb 2022. These regulations come into full force this May (2023). Here's an overview of what you need to know.

Examples of enclosed spaces on vessels are:

  • cargo holds
  • pipe tunnels
  • ballast tanks
  • pump rooms
  • peak tanks
  • void spaces
  • bunker tanks
  • cofferdams
  • fresh water tanks
  • chain lockers
  • battery lockers
  • bottom tanks
  • paint / chemical lockers
  • boiler furnaces
  • engine crankcases

Any of these spaces may be dangerous. If a person is injured or unconscious in an enclosed space, do not enter immediately. Sound the alarm and then organise safe entry.

Enclosed spaces can change and special consideration needs to be given to cargo that may give off hazardous vapours. Even little amounts of harmful gas can cause harm and kill. In enclosed spaces, there may not be enough oxygen to breathe adequately and there may be a concentration of hazardous gases that would cause asphyxiation. An number of factors could cause lack of oxygen, such as corrosion (rusting), paint drying or organic matter. Dangerous gases can come from a wide range or sources.

Incidents often involve more than one person and can cause death. A second person coming to the rescue may  become unconscious also, without proper precautions. Therefore, DO NOT ENTER an enclosed space unless you are certain it is safe to do so.

A range of equipment is available to help manage the risks of enclosed spaces, enabling safe access and rescue. Globestock's range covers a wide range of solutions that may be deployed on sea-going vessels, covering temporary or fixed anchor points and vertical or lateral / horizontal entries.

Gov.uk's summary of the regulations gives the following instructions for reducing the risks:

How to reduce risk

1. Identify your enclosed spaces

  • identify the hazard of any contents of the space
  • ensure the spaces have hazardous warning signage and permit only access
  • all enclosed space access doors, hatches or manholes should be secured
  • avoid entering closed spaces if possible

2. Carry out risk assessments and familiarise yourself with guidance

Familiarise yourself with the advice provided in the Code of Safe Working Practices for Merchant Seafarers (COSWP).

This is the simplest way to establish company procedure for entry into enclosed spaces.

In addition, you must carry out a risk assessment and issue a permit to work.

3. Precautions to take when entering an enclosed space

No enclosed space should be entered without proper precautions.

 Before entry:

  • a competent person should undertake a risk assessment and identify any potential hazards
  • prepare the space
  • secure the space for entry
  • ensure persons undertaking the work are trained and have participated in appropriate drills
  • test the atmosphere of the space
  • complete a permit to work
  • make a contingency plan in case things go wrong
  • review risk assessment

On entry:

  • ensure you have a person assigned on standby for each entry
  • the standby person should be equipped with rescue equipment including self-contained breathing apparatus and radio
  • wear protective clothing and boots
  • the standby person should ensure they maintain radio contact with the bridge or engine control room, or in port with someone who can help in case of emergency
  • ensure the space is well ventilated - ventilation should continue during the period that the space is occupied and during temporary breaks

If things go wrong

  • if you see someone lying motionless do not rush to carry out a rescue by yourself - an unplanned rescue is likely to end in tragedy as personnel rush into lethal atmospheres under the misconception that they will be able to save colleagues
  • stop, think – why are they unconscious, could this be an enclosed space?
  • should an emergency occur, the general (or crew) alarm should be sounded so that back-up is immediately available to the rescue team
  • never enter the space before help has arrived and a plan for rescue confirmed


  • do not enter the space without the authorisation of the master or a nominated responsible person
  • do not enter the space without testing the atmosphere
  • rescue equipment including breathing apparatus should be immediately available
  • if the atmosphere is unsafe, do not enter unless it is an emergency - if it is an emergency, you must wear breathing apparatus
  • emergency escape breathing devices (EEBDs) are NOT safe to use in enclosed space entries including for rescue
  • self-contained breathing apparatus should be used for rescue
  • rescue procedures should be established before entry - the rescue procedure should be specific for each type of enclosed space
  • drills on enclosed space entry must include rescue procedures - they should be practiced frequently enough to provide a level of proficiency that eliminates life-threatening rescue attempts and ensures an efficient and calm response to any emergency

Failure to follow this advice may result in multiple fatalities.

More information can be found here.