When Russia lost its nuclear-propelled submarine Kursk, the U.S. Navy was engaged in a program to increase U.S. submarine escape capabilities and to reduce submarine rescue capabilities.
The U.S. Navy has had both submarine escape and rescue systems since the early 1930s. Escape means that the crew leaves the submarine and attempts to reach the surface without outside help; rescue means that outside forces remove trapped crewmen from the submarine.
For escape, almost all U.S. submarines now are fitted with the Steinke Hood, a device invented by then-Lieutenant Harris E. Steinke in the early 1960s. Basically, it is a hood with a plastic face plate mated with a life jacket. Used in buoyant ascent, it was tested in the open sea by Steinke and other Navy personnel from a depth of 318 feet in 1961.1 They also made a simulated escape from 450 feet in a pressure chamber at Washington, D.C., that same year. Captain George Bond, a Navy medical officer, developed the physiology for using the Steinke Hood from a depth of 600 feet in an emergency situation.
The Navy adopted the device quickly following the loss of the nuclear-propelled submarine Thresher (SSN-593) in 1963. Although the Thresher's crew had no opportunity to escape, the study of the Navy's escape and rescue capabilities after her loss reported that "escape from below 50 feet is only speculative."2
The major limitations of the Steinke Hood are the depths at which it actually has been used and the limited survival capability of the hood (i.e., the flotation of the life jacket). From a practical viewpoint, some submariners in the fleet today feel that 250 feet is the practical limit for the Steinke Hood. In addition, on reaching the surface, escaping crewmen are highly vulnerable to sea conditions and cold, as demonstrated by the large loss of life in 1989, when the Soviet submarine Komsomolets (Project 685) sank in the Norwegian Sea. Of her 69 crewmen, 34 died in the water from hypothermia, heart failure, or drowning.
Accordingly, the U.S. Navy has made the decision to adopt the British-developed submarine escape immersion ensemble (SEIE) Mark 10. The SEIE covers the submariner completely, provides thermal protection, is simple to use, and in British trials has enabled escape from 600 feet. The 600-foot limitation is imposed based on the time an escapee would spend under pressure to avoid getting the bends; if one accepts the risk of getting a (probably) nonfatal bend, it is reasonable to expect safe escapes from as deep as 850 feet. An individual life raft is included in each suit, and, once afloat, the rafts can be linked together.
The U.S. Navy is purchasing some 15,000 such suits, to be carried in all U.S. submarines. To use the SEIE, however, a submarine's escape trunks must be fitted with a modification to permit air at 1.5 pounds per square inch above ambient sea pressure to inflate the suits, and this is delaying adoption. At this writing, only the USS Toledo (SSN-769) has been modified to use the new escape suits.
Significantly, the Kursk was fitted with escape-survival suits. Designated as SSPs, these suits have a closed-circuit breathing apparatus and provide flotation and warmth, but they are rated only to a depth of 328 feet.3 Russian submarines, unlike those of other navies, except the Indian Type 209 submarines, also have an escape pod or capsule (two in the Typhoon/Project 941 submarines). First installed in the Alfa (Project 705) submarines, the capsule is built into a submarine's sail structure and can accommodate the entire crew. When the Komsomolets sank, five men—including the commanding officer—were trapped in the submarine. They entered the escape capsule, which broke free as the submarine plunged to the ocean floor, a depth of 5,500 feet. Tragically, toxic gas had entered the capsule and when it reached the surface only one warrant officer was alive.
The Kursk had such a pod, but the explosions that sent her to the ocean floor obviously smashed the control room (beneath the pod); everyone in the forward portion of the submarine was dead within seconds. Those men in the rear portion of the submarine—who may have survived from a few minutes to perhaps as long as three days—were unable to use the after escape trunk, which the detonations also might have damaged.
The U.S. Navy periodically has considered an escape pod or device. In 1964, for example, one proposal called for using individual escape pods made of wound glass filament (the same material as in Polaris missile casings) that could be stacked in the submarine. A more ambitious idea posed in 1969 proposed that the entire front end of the submarine could be detached and blown to the surface. The Navy took no action on these and several other such proposals.4
Rather, following the loss of the Thresher, the Navy developed the deep submergence rescue vehicle (DSRV), which could mate with a submarine's escape hatch and recover 24 men at a time. Unlike the earlier McCann submarine rescue chamber, in U.S. Navy service since the late 1930s, the DSRV does not need a diver to attach a haul-down cable, nor does it require a surface ship to be moored over the stricken submarine.5 Indeed, the innovative DSRV—which can operate to a depth of 5,000 feet (beyond the collapse depth of any existing submarine)—can be carried, launched, and recovered underwater by a modified submarine. This makes the rescue operation fully independent of surface weather conditions and ice. A depth of some 2,000 feet currently is the practical limit for a DSRV rescue.
The Navy originally planned a fleet of 12 DSRVs, each to carry 14 rescuers plus an operator. However, redesign of the craft and its increased complexity led to provisions for two operators plus a third crewman and increased the rescue capacity to 24 men. With this increase, the number of planned DSRVs was reduced to six. But the Vietnam War caused severe funding shortfalls in the Navy, and the program was cut to two vehicles—the Mystic (DSRV-1) and the Avalon (DSRV-2), which became operational in the early 1970s.
With two vehicles available, one always was kept ready at the Naval Air Station North Island (San Diego), California, to be flown in a C-5 cargo aircraft when needed. After being taken to an allied port near a stricken submarine, the DSRV would be placed on board a modified U.S. or allied submarine or taken on board a specially built rescue ship.6 (Efforts to use the DSRV from a ship-of-opportunity did not prove overly successful.)
Periodically, one of the DSRVs was flown off for a rescue exercise with a U.S. or foreign submarine. When that occurred, the other vehicle usually would be on alert.
Prior to the loss of the Kursk, the U.S. Navy had planned to take the Avalon out of service on 1 September 2000. That would have meant potential delays in mounting rescue operations if the Mystic happened to be down for maintenance or engaged in an exercise. Although several other nations have rescue submersibles, such as the British LR5, they are launched from and recovered by surface ships and hence are limited in their operations by weather and ice conditions. Some also have depth limitations, e.g., about 1,400 feet for the British LR5. (See Don Walsh's "Oceans" on page 89 of the August 2000 Proceedings, titled "Submarine Rescue: Ready for a Worst-Case Scenario."
Admittedly, the DSRV is most efficient when operated from a nuclear-propelled submarine. The U.S. Navy now has seven submarines modified to serve as "mother" to a DSRV; four British strategic missile submarines and two French submarines are modified to carry and operate DSRVs. The vehicles also have operated with Japanese submarines.
Although the U.S. Navy would not discuss escape or rescue programs publicly following the Kursk disaster, it is reported that the Avalon now will be retained as a "backup" and for spare parts. Obviously, those two roles are not compatible, and it is unlikely she will be available for operations. Further, the Navy plans to discard the Mystic in a few years. In place of the DSRVs the Navy plans to acquire the submarine rescue diving recompression system (SRDR). This system consists of a rescue "module" lowered from a ship-of-opportunity, after a diver using an advanced diving gear reaches the submarine and attaches a haul-down cable. The advanced diving suit is expected to support rescue operations down to 2,000 feet.
Some modern surface ship should be able to maintain station over the submarine with thrusters and not need be anchored. Still, the system would be vulnerable to weather and heavy sea state conditions and could not be used under ice. Indeed, the sea-state conditions in the Barents Sea appear to have prevented Russian rescue chambers (lowered from the surface) or submersibles from being used as soon a they arrived at the site of the Kursk sinking.
The proposed SRDR system would be air transportable and would include a decompression chamber for installation on the surface ship.
In an era of reduced defense budgets and declining forces, it is difficult to maintain relatively expensive rescue forces. Since World War II the U.S. Navy has lost four submarines, two diesel-electric and two nuclear-propelled. Only one civilian technician was lost in the conventional submarines; the entire crews were lost in the two nuclear-propelled submarines. Neither escape nor rescue systems would have saved the crews of the Thresher or the Scorpion (SSN-589).
Still, both escape and rescue systems are needed. Adopting the British SEIE will provide U.S. submariners with an excellent escape system, but rescue should not be neglected. A pair of advanced DSRV-type vehicles should be developed and produced. Partial NATO sponsorship could be sought to help share costs of the project.
Submariners tend to believe that they never will need either escape or rescue systems, but they definitely favor using the latter if given a choice. Like a community maintains—and hopes never to use—fire engines, so should the U.S. Navy develop and maintain a viable, submersible-based, submarine-supported rescue system.
Mr. Polmar is a regular columnist for Proceedings and Naval History and author of Ships and Aircraft of the U.S. Fleet (Naval Institute Press, 2000). He has visited Russia nine times in the past few years to research a comparative analysis of Soviet-U.S. submarine design and construction during the Code War, planned for publication in 2001.
1. Beginning in 1930, the Navy used a succession of escape systems: the Momsen Lung, free ascent (with no escape device), buoyant ascent (using a life jacket), and then the Steinke Hood. Submarine escape was used only once in the U.S. Navy, when eight men escaped from the USS Tang (SS-306) in 1944—using the Momsen Lung—after the submarine was sunk by a circular run of one of her own torpedoes. back to article
2. Report of the Deep Submergence System Review Group, "Summary Report" (NAVEXOS P-2452, 1 March 1964), p. 3. back to article
3. Nikolai Spassky, Russia's Arms Catalog, vol. 3, Navy (Moscow: Military Parade, 1996), p. 250. back to article
4. See Ben L. Friedman, "The Submarine that Saves Its Crew," Naval Research Reviews (January 1970), pp. 23-24, and LCdr. E. S. McGinley II, USN, "For a Fail-Safe Submarine," Fathom (Naval Safety Center, Fall 1970), pp. 1-5. back to article
5. Two McCann rescue chambers remain in U.S. Navy service; they are rated to approximately 1,200 feet. back to article
6. The Navy built two rescue ships to operate DSRVs: the Pigeon (ASR-21) and the Ortolan (ASR-22); they were stricken in 1992 and 1995, respectively. back to article