Marine Safety Alert: Confined Spaces are "Silent Killers"

An example of a Mobile Offshore Drilling Unit (MODU). Photo: Transocean

The recent deaths of three people has prompted the Coast Guard to issue a Marine Safety Alert about the danger of confined spaces on board vessels.

Three people were asphyxiated while working on a Mobile Offshore Drilling Unit (MODU), which was laid up getting ready for a leavy lift transport to an overseas ship breaking facility. Seven crew members were dewatering the MODU’s four legs. They were experienced mariners, but lacked MODU experience, according to the Coast Guard.

Because the de-ballasting system wasn’t working in one leg, the crew rigged a portable diesel-engine-driven pump. The Coast Guard says five crew members, including the Superintendent and Captain, were on a dinner break, leaving one crew member and the Electrician overseeing the dewatering operation. The crew member didn’t tell anyone before descending into the leg to check the pump. When the Electrician didn’t see the crew member on deck, he went down into the leg to look for him, and found the crew member unconscious near the pump. The Electrician narrowly managed to escape the exhaust fumes, and went to get help. Other crew members, including the Captain and Ship Superintendent descended to help, without any safety equipment to protect themselves from the fumes. Only the ship’s Rigging Master put on a Self-Contained Breathing Apparatus, brought onboard from another vessel, before entering the leg to help.

In the end, three crew members died, while the Captain and Superintendent were airlifted to a hospital and survived.

It’s not clear what kind of Confined Space Entry training the crew had received. “Humans often miss the obvious cues of a situation while under stress and because their focus is upon another effort or action that needs to be accomplished,” the Coast Guard points out. Data indicate that over 50% of the workers in enclosed or confined space tragedies die while attempting to rescue their coworker.

In its Marine Safety Alert, the Coast Guard says, “This is a reminder that despite decades of work by to improve confined space entry by maritime safety organizations, training institutions, and vessel owners/operators, the risks have not been eliminated.”

And the confined space risk isn’t just for those working on oil rigs. Commercial fishing boats, for example, hold serious risks, too. The biggest atmospheric hazards found in confined or enclosed spaces are too low/too high oxygen levels, toxic chemicals, and flammable atmospheres, according to OSHA. One or more of those hazards can be found in ballast tanks, sewage tanks, refrigeration spaces, fuel, lube or hydraulic oil tanks, and slop tanks or holds where fish slime may decompose.

The Coast Guard is warning anyone who works on board vessels in any role, “whether they be senior shipboard officers or crew, riding crew, shore side managers, owners/operators, or other personnel,” to be sure they are trained in confined entry procedures, take part in routine emergency drills, and verify all of the required confined space entry safety equipment is on board. For more information, click here.

-Meg Walburn Viviano