NEDU’s investigation of the triple fatalities at Aberdeen Proving Ground

• Bad maintenance can turn a good regulator into a killer
• Use of non-US Navy approved cold water regulators is risky
• Differences between EN-250 and U.S. Navy testing
• Physics of free flow on ascent
• Antarctic regulator testing - diving experiences and ORM

Navy SEAL Divers encountering difficult breathing

•  Sodalime friability (softness) problems
•  Two ways to make breathing resistance too high, and consequences
•  Sodalime powdering
•  Wrong size granules for deep missions

 

This presentation will share the lessons learned from Navy Experimental Diving Unit’s (NEDU’s) accident investigations. The role of oxygen control and carbon dioxide absorbent in rebreather accidents, and the role of regulator maintenance in cold water diving will be highlighted. The physics of regulator free flow and differences between EN-250 and U.S. Navy cold water regulator testing procedures will be described. Careful regulator maintenance by certified repairmen is critical to safe regulator performance, especially in cold water. The selection of the proper sodalime absorbent and proper storage and handling of sodalime can make the difference between a routine dive and a potentially fatal dive.