A volunteer Navy diver dressed in a submarine escape immersion equipment (SEIE) suit being tested in the Doriot Climatic Chambers at the U.S. Army Soldier Systems Center.

Researchers from the Naval Submarine Medical Research Laboratory (NSMRL) in Groton, Conn., used the Doriot Climatic Chambers at the U.S. Army Soldier Systems Center (SSC) in Natick, Mass., to begin an evaluation of two different designs of submarine escape immersion equipment (SEIE) suits. Participating in the study are four volunteer Navy divers divided into groups of two; each group is in the SEIE in an inflatable pool within the chambers."They are trying to simulate an emergency evacuation from a disabled submarine and waiting for rescue," said Josh Bulotsky, an SSC electrical engineer.

According to Lt. Jon Vanderweele, NSMRL undersea medical officer, the Navy is looking at two competing designs of SEIE to possibly replace the current generation aboard submarines. Both consist of a dry suit with inflatable hood and air pockets that also have an inflatable raft attached. The idea is to evaluate the two different designs to see the pros and cons of each, including which design provides the best thermal protection.

"Rescue is always preferable to escape, but if the crew on a disabled submarine is forced to escape by swimming out the escape trunk, this equipment is designed to keep them afloat on the surface until they are picked up. We want to evaluate its ability to keep them warm in an arctic sea environment," Lt. Venderweele said. "After escaping, the submariners may end up scattered over a large area, and they may be waiting a day or two before rescue. We want to prevent hypothermia while they are waiting."

In test conditions, the chambers are kept at 35 degrees Fahrenheit with a constantly blowing 15 mile-per-hour wind. In addition, the water in the pools is chilled to 37 degrees Fahrenheit, and water is periodically poured on the volunteers to simulate waves or rain. "We want to see if heat gets pulled away from the SEIE suit," noted Lt. Venderweele.

Eleven different sensors monitor the volunteers' core and skin temperatures. Although the idea was to have the volunteers sit in the pools for 24 hours straight, the divers needed to stop this first test after approximately eleven and one-half hours. Even after about three and one-half hours, the divers said their hands and feet were beginning to get cold. The goal is to have five iterations of the test.

"We will take the data and evaluate it to see if one design is better than the other or if there is some combination that might be best," Lt. Venderweele said. "For instance, based on the hands and feet comment, maybe there is a need for better gloves or booties."

After learning about the test, the Combat Feeding Directorate (CFD) provided some rations for evaluation. They supplied shortbread bars, a previously approved ration component, and the volunteers are going to evaluate the packaging and ease of use in a wet, cramped environment. The bars are a current component of the food packet survival package and have a proven shelf life beyond the current requirement of five years. The Navy has expressed the need for a product with a seven-year shelf life, she said. The participants will eat one shortbread bar every six hours during the study and, after testing, divers will be asked to complete a brief questionnaire to gather information on product acceptability. For upcoming iterations of the testing, Lt. Vanderweele is working with the CFD to investigate the possibility of evaluating reverse osmosis water purification systems to convert sea water into potable water for inclusion in the SEIE system. CFD will be providing NSMRL some information on these types of systems.

Both Bulotsky and Lt. Vanderweele agree that this collaboration between the Army and the Navy has been beneficial. Lt. Vanderweele pointed out that testing with manikin simulations is not the same as human volunteers; and although the original thought was to do this testing at sea, the Doriot Climatic Chambers provides more controlled test conditions and is safer for the volunteers.