The tragic sinking last year of the Russian submarine KURSK and its subsequent salvage recently has brought the subject of escape, rescue and salvage to the fore. This article suggests that our thinking on the matter of submarine escape and rescue may have been focused too narrowly on the problem. It outlines an alternative approach to the problem of rescuing the possible survivors aboard a sunken submarine by improving methods of empowering the surviving crew members to rescue themselves. It also considers some aspects of submarine salvage. The author is indebted to the helpful and incisive remarks of Captain F. T. (Terry) Jones, USN(Ret.), president of the Nautilus Chapter and Joe Buff, submarine enthusiast and author of three novels on submarine warfare.
We should remind ourselves that in the submarine century we have celebrated this past year, we have lost eleven submarines due to accidents with a substantial loss of lives. 1 Ever since the THRESHER disaster, in 1963, submarining risks have been substantially reduced by greater attention to sound engineering practices both in the shipyard and at sea. Nevertheless, as all submariners know, the probability of a serious casualty is not zero and can never be.
The Elements of Escape and Rescue
Escape and rescue measures have always depended on the depth of the sunken boat.
Fifty years ago, if the disabled submarine lay at a depth of up to several hundred feet, the Mccann diving bell was available to extricate surviving crew members from a sunken submarine. The diving bell was carried on the stern of a submarine rescue vessel, (an ASR), attached by block and tackle to a boom. Open to the sea at the bottom, the bell lowered from the rescue vessel and mated with one of the submarine’s escape trunks. The survivors were then transferred from the sub to the bell and brought to the surface. The sequence was repeated until everybody was rescued. The McCann bell was used in this manner in 1939 to rescue 33 crew members of the sunken submarine SQUALUS. It is equally important to remember that SQUALUS was soon raised from the bottom, repaired and went on to amass a good war record renamed SAILFISH. We will return to the subject of salvage later in this article.
Recognizing that a submarine rescue vessel carrying a diving bell may not always be able to reach the disaster scene in time to rescue surviving crew members, provision has been made in all submarines, both today’s nuclear and yesterday’s diesel electric, for survivors to leave via the escape trunk(s) provided. In fleet and guppy submarines a single escape trunk was provided in the forward torpedo room. In the after torpedo room, a steel skirt was bolted around the after torpedo room hatch. After removing the bolts, the skirt could be dropped and, by partially flooding the after torpedo room and equalizing the air pressure in the unflooded part of the room with that of the outside sea, the hatch could be opened and the survivors leave for the surface, by ducking under the skirt. In today’s nuclear submarines two escape trunks are provided.
Years ago, surviving escapees ascended to the surface by using Momsen lungs. Once on the surface, the Momsen lung doubled as a life preserver. In time, the older Momsen lung was replaced by the improved Steinke hood. In its tum, the Steinke hood is currently being replaced by the new Submarine Escape and Immersion Suit (SEIS), an adaptation of a British innovation. The new suit provides thermal protection that is essential for survival in colder climes. It also has a built-in individual life raft.
After the loss of THRESHER (SSN 593) in 1963, the SUB SAFE program was initiated. A major aim of the SUB SAFE program was, in the words of Vice Admiral Thunman:
“One major aim of the program was to correct the problems that, in all probability, contributed to the THRESHER loss. Among these, were the removal of a substantial amount of interior piping filled with sea water at pressures corresponding to the depth of the boat. The high pressure emergency blow system also was redesigned.
Another important aspect of the SUB SAFE program arose from the realization that if a submarine lay intact on the bottom at less than crush depth, but beyond the depth that could be reached by the McCann diving bell, there was no way to rescue the trapped survivors.
The deep submergence rescue vessel (DSRV) was conceived as the solution to this problem. Although twelve such rescue vessels originally were projected, only two, MYSTIC and AVALON, eventually were built.
A couple of years ago, a Submarine Escape and Rescue Steering Group was established to systematically examine all aspects of not only escape and rescue but survival as well. 3 The new SEIS suit, referred to earlier, was developed by this group. More importantly, as a direct result of the efforts of this group, the Deep Submergence Rescue Vehicles (DSRV) are being supplemented by the Submarine Rescue Chamber (SRC). 4 This chamber is completely closed, and can operate at depths of at least 850 feet. It is clearly an improvement over the McCann Diving Bell. For one thing, it can be carried by any commercial vessel to the rescue scene and does not depend on the presence of a submarine rescue vessel (ASR) to transport it to the scene of action. The SRC is designed to be mated to any submarine hatch, not just an escape trunk. As is true of the DSRV, it can be transported by air to the airfield nearest the rescue scene.
Key adjuncts to the SRC system are a greatly improved deep diving suit system and a decompression chamber called the Submarine Rescue Diving and Decompression System (SRDRS). (The SRDRS is also air-transportable.) The new atmospheric diving suit will allow divers to descend and work at depths of up to 2000 feet. Deep divers are an essential part of the SRC system. They are expected to reconnoiter the site of the sunken submarine, establish contact with survivors and attach a cable for use by the SRC itself.
An Alternative Approach to Escape and Rescue
The systems described in the preceding section are perfectly acceptable if there is sufficient time to move the SRC, the SRDRS and accompanying deep sea divers or, depending on the depth of the disabled submarine, the Deep Submergence Rescue Vehicle, to the site of the disabled sub. In either case, suitable transportation must be found to bring the right system to the scene of action. In order to buy time, the Escape and Rescue Steering Group has improved the existing life support systems to provide a survivable environment for up to four days after a disabled submarine incident.
It is quite conceivable that the time available for crew rescue is less than the time required to bring the SRC, the SRSDS and associated divers to the scene of action. While four days sounds like ample time to go anywhere on the planet, everyone knows that Murphy’s Law applies and it may not be enough time! Morever, if the crew had the ability to rescue themselves even at great depths, time would no longer be a critical factor. One possible approach to achieve that is as follows:
If the boat were disabled on the bottom at above crush depth, the first step to be taken would be to notify higher authority of the casualty. A SLOT buoy could be sent to the surface to transmit the information to them. If the seriousness of the situation warranted initiating escape procedures and not await the arrival of rescue forces, this information could be included in the transmission.
Let’s assume that both escape trunks contained an escape capsule capable of withstanding crush depth pressures. This capsule, with a slightly smaller diameter than the escape trunk, would just fit inside the trunk. The initial batch of survivors, donning the new SEIS suits could then enter the capsule from the boat and close the lower hatch of the capsule. The lower hatch of the escape trunk could be closed by either the remaining survivors or remotely from inside the capsule. Once the hatch to the boat was closed and dogged, the occupants of the escape capsule could remotely open the outer hatch of the escape trunk and the capsule could exit the boat.
As it ascended to the surface, a steel cable attached both to the capsule and to the lower door of the escape trunk would be paid out. Communications between the occupants of the capsule and the remaining crew members on the boat could be by underwater telephone or, alternatively, by using the connecting cable for telephone connections.
The main reason for maintaining communication would be to allow the occupants of the capsule to inform those remaining aboard that they were on the surface and the capsule was ready for reuse. After those on the surface exited the capsule and shut the upper hatch of the capsule, it then could be returned to the escape trunk by the reeling in of the cable by those remaining on board. The capsule, after being retrieved would seat itself inside the (larger diameter) escape trunk. The water in the trunk would be drained into the submarine’s bilges as the capsule seated itself. Each successive group of survivors could repeat the procedure until all had exited to the surface.
Potential problems with the above approach are apparent. For example, the diameter of the present escape trunks would probably have to be enlarged substantially to permit a capsule of a realistic size (i.e. capable of holding a reasonable number of people.)
Another problem area lies in how to provide power to the system. Ideally, at least two power sources should be provided, if only to provide a backup system. A battery source, self-contained within the escape capsule could be a solution.
Perhaps electric power from the ship’s battery could be used as an alternative source. (It is even conceivable that the cable up to the capsule on the surface could be reeled in by hand, by those remaining on board!)
Another problem lies in opening the upper hatch against high sea pressures at depth. One means to accomplish this is to install a sliding hatch, that after admitting sea water around the perimeter of the capsule, would be open even after the capsule left the escape trunk.
This possible alternative system is meant to be just that: An alternative approach to what we are doing today. Those of you with more extensive and recent experience than mine could undoubtedly come up with better ideas. A major reason for writing this article is to urge you to do it.
Some Thoughts on Submarine Salvage
After all survivors possible have been rescued, there remains the question of the possible salvage of the disabled submarine. Even if it has imploded, possibly scattering radioactive debris on the ocean floor, we will want to examine the debris to learn as much as we can about the cause(s) of the casualty.
At depths of up to and including 2,000 feet or so, the new atmospheric diving suit mentioned earlier should permit our divers to salvage a damaged, flooded, but intact boat lying on the ocean floor. Of course, they could also remove crew remains for decent burial.
At substantial depths, say, well beyond 2,000 feet, there are no feasible salvage methods for raising any vessel. Or are there?
One is GLOMAR EXPLORER, the recovery vessel modified under a cover story by the Central Intelligence Agency (CIA) in 1972-73. This was an attempt to raise clandestinely a Soviet Golf class ballistic missile submarine that sank in mid-Pacific in 1968. As AG-193, GLOMAR EXPLORER had been laid up in the National Defense Reserve Fleet in Suisun Bay, California. Built at cost of over a half billion dollars, the vessel was a classic example of letting existing, expensive resources go unused.
In the last several years, however, GLOMAR EXPLORER has been put back in use. It is presently on loan to the oil industry in the Gulf of Mexico assisting in drilling oil and gas wells in increasingly deeper waters by now off the continental shelf.
It is reasonable to assume that GLOMAR EXPLORER would be available for naval use in the event we had to salvage one of our submarines . The salvage to be undertaken would be at considerable depth, beyond the range of efforts by deep sea divers. Since the average ocean depth is almost two nautical miles, we could undertake salvage on vast areas of the ocean bottom. Not all the world’s oceans would be fair game for GLOMAR EXPLORER, however. She was designed to raise a submarine from a depth of 16,500 feet, or about 2.7 nautical miles. Presumably, some redesign and reconfiguration of the ship would be necessary to permit salvage at greater depths than that.
Where a submarine casualty has resulted in an implosion of the boat with a resulting debris field on the ocean bottom, there is every reason to examine the debris as closely as possible, if only to determine the cause of the casualty.
The submersible NR-1 is available at relatively shallow depths down to a few thousand feet or so for this purpose. At deeper depths, the number of available small submersibles has dwindled to just one, ALVIN, (DSV-2) , now operated by the Woods Hole Oceanographic Institution for the Office of Naval Research. AL VIN is capable of descending to depths of over two nautical miles.
There is no doubt that these submersibles are valuable for more than just scanning the ocean bottom for debris. As one example, in the fall of 1990, the submersible SEA CLIFF, (formerly DSV- 4) recovered both halves of a cargo door from a Boeing 747 at a depth of 14,000 feet. 8 (Recovery of the aircraft’s door was important in order to determine whether there was an inherent aircraft design flaw that would cause other fatal accidents.)
However, we must recognize that scanning of the bottom can be done at more reasonable cost by remote robot scanning devices, attached to long cable tethers. In the future, Unmanned Underwater Vehicles (UUVs) will replace both these remote scanning devices and the small manned submersibles, such as AL VIN and SEA CLIFF, and permit access to the deepest ocean depths, only reached heretofore by the bathyscaph TRIESTE.
1. These eleven losses, of course, do not include the 52 boats lost during World War II. Some of these wartime losses may have been due to accidents, too. Most of the eleven losses are enumerated in ADM W. J. Crowe’s banquet speech before the NSL Symposium on June 16, 2000. (Reprinted in the July 2000 issue of THE SUBMARINE REVIEW.) The losses not covered by the scope of ADM Crowe’s speech, include COCHINO, SS 345 (1949), THRESHER, SSN 593 (1963) and SCORPION, SSN 589 (1968).
2.”Thresher’s Debris Field” Submarine Review, April 1987. Capt. Frank Andrews USN (Ret.). This article quotes VADM Thunman’s remarks. Capt. Andrews was COMSUBDEVGRP 2 at the time of THRESHER’ s loss and later was in charge of the search for the remains of THRESHER in the summers of 1963 and 1964. He also discusses some of the aspects of SUB SAFE in this article.
3.See “Submarine Rescue: Ready for the Unthinkable” , Undersea Warfare, Fall 2000, Pp. 14-15. This article also discusses the Submarine Rescue Chamber.
4. AU Hands Magazine, Jan. 2001 issue, has a picture of the SRC on page 33. Unfortunately, it is mistakenly identified as MYSTIC, (DSRV – 1).
5 . In early World War II fleet boats, operation of bow and stem planes by hand was the emergency means of operation if the ship’s hydraulic system failed.
6. Ships and Aircraft of the U. S. Navy, Seventeenth edition, pp. 241-242.
7. If fitted with the personnel capsule of SEA CLIFF, (formerly DSV 4), AL VIN was capable of descending most of an additional nautical mile.
8. Ships and Aircraft of the U.S. Navy, Sixteenth 325 .