Man has established anniversaries to remind us of things past both good and bad. Through this method we can celebrate the good and recall the unpleasant insuring that if mistakes were made they will not be repeated.
Rear Admiral J.B. Mooney, Jr., recalled his personal memories on the 20th anniversary of the Thresher’s loss (“The Submarine Review” of July 1983) and concluded by saying ” . . . between then and now our Navy and our Nation were moved to action not only to make our submarines safer, but also to develop the ocean science and technology which offers far better opportunities to find and rescue submariners in peril.”
The most significant contribution to improved rescue methods since the disaster was the development and activation (approximately 15 years after the Thresher loss) of two Deep Submergence Rescue Vehicles (DSRVs). It would seem that the DSRV, with an operating depth of 5, 000 feet, is the ultimate system for rescuing crew members trapped in a submarine on the ocean floor when onboard conditions permit waiting for its arrival. Other rescue methods with considerable less operating depth include the McCann chamber with operational require~ents similar to the DSKV, and free ascent, which involves some risk to personnel at shallow depths and affords no protection from exposure once the surface is reached.
The only significant factor challenging any remote system and the men who may be trapped is . . . time. Time to locate the casualty, time to alert the system, time to transport the system and time, weather permitting, to mate with the stricken submarine. Time is the enemy, especially when on board condi tiona may involve toxic gases, limited life support systems, cold temperature, or flooding. If a survival chamber were installed onboard, the crew of the distressed submarine could, after accurately evaluating the conditions onboard, decide to reach the surface at any time without the aid of remote systems. Life support on the surface (protection from exposure and predators) would depend on the equipment cycled to the surface and the use of the chamber itself. Once the surface has been reached, the crew could radio their location for rescue by aircraft or by ship of opportunity, while pinpointing the exact location of the submarine for possible salvage operations. Simply stated, the on board chamber would give the crew a highly reliable alternative to waiting for the DSRV system to arrive.
The concept of a submarine onboard chamber is far from new. Several patents have been granted dating back to 1926. All such devices use a cable and winch to raise and/or lower the chamber. The Federal German Navy has recently installed an on board capsule on their Type 2000 submarine. Because of the Type 2000’s small size of 2370 tons, its entire crew of twenty four can be evacuated at one time. In addition to small chambers requiring repeated trips to the surface, preliminary designs are also presently available for escape chambers capable of transporting entire crews of approximately one hundred crewmen to the surface. The chambers whatever their size or number on board the submarine, should be designed to serve as part of a ship’s access. The illustration shown suggests the use of a 3-part chamber to carry an entire crew to the surface. This onboard chamber system would fit in the superstructure above an escape hatch.
Obviously an onboard chamber could not replace the DSRV system until such time as all submarines have onboard chambers. This could take as long as twenty years. Backfitting is a possibility however on FBMs because of the chambers’ adaptability to the superstructure.
The primary reason for considering a chamber at this time is because a new submarine design is under consideration, affording the opportunity to evaluate and shortly install such an onboard system – or something similar. Naturally the reliability of the on board chamber would have to be proven. Noise, vibration and hydrodynamic requirements would be critical if the chamber was to be installed forward of the sail. (The onboard chambers shown could be carried in a flooded condition and then blown when put to use — compensation being effected by flooding into the room from which escape was made.) Problems similar to those encountered with the no longer used messenger buoys would have to be resolved. But taken in today’s context of significant technological advances, there should be little doubt that an onboard personnel survival chamber can be designed, installed and working within a relatively short time.