Tests of a new immersion suit developed by safety gear manufacturer Stearns have shown the suit to dramatically increase a wearer’s survival time. The key to the suit is capturing the warm breath of the wearer and recirculating it.
Under current standards, a suit must protect the wearer for at least six hours to win certification from the U.S. Coast Guard. The recently-introduced Stearns I950 Thermashield 24+ Immersion Suit has been shown in tests to protect wearers for more than 24 hours, according to the company.
The tests were conducted in September 2013 at Simon Fraser University near Vancouver, British Columbia, using members of the Canadian Coast Guard as test subjects. They wore the suits in 32-degree water with air temperatures 10 inches above the water of 32 degrees.
“At 24 hours and 15 minutes, we ended the testing. We felt there wasn’t a need for additional data,” said Darin Webb, global senior director, product development with Stearns. “Several of the people were more than willing to stay in the suit. They were holding up quite nicely. Basically they had no cold water issues to deal with.”
The suits are expected to go on sale in March with a suggested retail price of about $1,500.
The suit is the brainchild of Bob Duncan, an Alaska Airlines pilot and inventor. He brought the idea of a breath-warmed immersion suit to Stearns about three years ago. Duncan created a liner that circulates the wearer’s warm breath through the immersion suit. Stearns then took two and a half years figuring out how to convert that core concept into a marketable product. The company came up with refinements including treaded boots, removable gloves and a breath-heated cuff at the waist for re-warming hands.
The key element of the design is the crush-proof fibrous liner that extends along the back of the suit, down the arms to the wrist cuffs and down the legs into the boots. When the wearer breathes into a mouthpiece, the warm air is propagated by the liner, providing warmth to the wearer’s core and extremities.
“It’s like sitting on a breath-powered radiator,” Webb said. “It is a unique product. It opens up a whole new realm of possibilities. Our whole goal is to keep people alive longer.”
But the suits do more than just increase the chances of survival. During long exposure to cold water, the body conserves its heat in the body’s core, leaving the extremities susceptible to damage from frostbite. By circulating warmth to the feet and the hands, the suit should also reduce injuries to extremities.
Typically, mariners don their immersion suits only when it has become clear that they will have to abandon ship. Once they put on their suits, they are pretty much committed to going over the side, since the traditional “Gumby” suit does not give the wearer the mobility to move around the vessel or the manual dexterity to perform vessel operations.
By incorporating a treaded boot into its design, Stearns has created a suit that allows the wearer to move more steadily about the vessel.
“This is a real boot integrated into the systems,” Webb said.
And by incorporating gloves along with the hand-warming cuff, the Stearns design allows wearers to remove the gloves and to use their bare hands to operate controls and perform manual tasks, knowing that the cuff can be used to re-warm the hands. The cuff has a valve that allows warm air to enter.
“That’s something you’re not going to be able to do in any other suit,” Tyler Winthers, Stearns’ global category manager, flotation, said of the cuffs.
These design elements mean a mariner can put on the suit before the order to abandon ship is issued. Consequently, the suit can be put on in a more controlled atmosphere, increasing the chance that it will be donned carefully in a way that ensures its integrity and proper performance. And this design may give the crew a bit more time to get the emergency under control.
“It’s obviously a revolutionary immersion suit,” said Winthers. By being more “user friendly,” the suit allows the crew to “address the emergency, not just flee from it.”