Monitoring Confined Spaces to Protect Maritime Workers

For mariners there are plenty of things to worry about once they have set out on their journey to sea. These individuals deal with unpredictable climate conditions, potential piracy situations and the fickle nature of the open sea. However, it is important to note that the dangers out on water are not the only ones to be aware of. Plenty of injuries and even deaths can occur on ships or in shipyard environments if the proper precautions are not adhered to, especially in confined spaces. Proper safety training along with the right tools, technology and safe practices are all crucial in maintaining a safe work culture in a marine environment.

The Reality of Confined Space Dangers for Maritime Workers

According to The Occupational Safety and Health Administration (OSHA), the rate of injury in a shipyard environment is twice that of the general construction industry. This means that extra precautions must be taken by all workers, safety managers, operation personnel and emergency responders to ensure that a confined space is hazard free. Guy Colonna, Manager of the NFPA’s Industrial and Chemical Engineering Division reports that, “Over the course of the last five years, an average of about 92 workers annually are losing their lives in confined spaces.” The reality of this type of disaster is frighteningly real.

Confined Space 1Source: Hampshire Fire and Rescue Service

Although these types of disasters have happened in the past, it is very possible for them to be prevented in the future. Shipyard workers should look to use the same equipment as marine chemists when determining the safety of the tank or space in question. Gas monitors have the ability to detect four distinct gases: carbon monoxide, hydrogen sulfide, combustible mixtures and oxygen levels. Additionally, this type of monitor can detect volatile organic compounds that could represent a variety of hazards in a confined space.

Detecting Unsafe Conditions in a Confined Space

Until recently, shipyard chemists and marine operators have used portable gas detectors and analyzers. However wireless gas detection devices are now available providing more convenience along with 24/7 monitoring and intelligent data collection in an effort to better protect workers. For example a product such as the MultiRAE wireless multi-gas monitor allows an individual to remotely monitor for dangerous environments for the workers carrying the device. Additionally, the device features a “man down” alarm which sounds if someone goes down. This way the remote monitoring personnel or maintenance command station can be alerted and assist the individual in need.

To maintain safety, OSHA regulations require that a gas-free certificate issued by a Marine chemist be obtained before any hot work or flammable operations are carried out in certain spaces aboard a marine vessel. A certified Marine chemist must hold a valid certificate that is issued by the National Fire Protection Association (NFPA) that states that the holder can determine whether construction, alteration, repair or layup of vessels can be undertaken with safety.

Confined Space 2Source: Hampshire Fire and Rescue Service

How to Prepare For Safe Confined Space Entry

To prepare for confined space entry, it is important to designate a checklist for your team:

  • Understand and review any applicable data for hazardous substances known to affect the confined space.
  • Have a marine chemist or other competent person determine the safety of the confined space.
  • Review the system or database for the past three cargoes or materials that were in the cargo space.
  • Check the log from the marine chemist or other competent person to ensure that the space has been tested for oxygen, flammability and toxic atmospheres and that the tests are compliant with the last three cargo carries.
  • Check that the area has been properly ventilated. The air in the space should have been exchanged a minimum of three times prior to entry.
  • Review the use of proper tools and technologies before entry. Be sure to carry a multiple gas meter when entering. Additionally, keep an emergency escape breathing device if there is a potential for dynamic change in environment. Ensure that your breathing device is maintained and certified.
  • Review outlet procedures. Discuss emergency rescue procedures and verify your exit points.
  • Be sure to evacuate the space if any of the following occur: your personal monitor sounds an alarm, if you experience any dizziness or light-headedness, if forced air ventilation ceases or proves to be ineffective or if you sense any chemical that causes concern.



Lincoln, Keith. “Monitored Confined-Space Entry” Marine News. October 2014: 20-23. Print.


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