Professional Notes

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ASW: Some Surface Views 99 By Lieutenant W. T. Btamlett, II, U. S. Navy Surface Effect Vehicles: A Perspective 101 By J. E. Sladky, Jr.

"For Those in Peril . .            105

By W. Robert Bryant

ASW: Some Surface Views

By Lieutenant W. T. Bramlett II, U. S. Navy, former ASV7 Officer, USS Pursons (DDG-33)

The effectiveness of surface directed antisubmarine warfare is underrated by aviators, submariners, and surface war­fare officers alike. In the case of aviators and submariners, their false impressions of surface ASW initially are exaggerated by faulty analysis of surface ASW capa­bilities and, later, by the rivalry for force development and support dollars. In the case of surface warfare officers, the false impressions are generated by inadequately trained or inexperienced officers who approach ASW with a fatal­istic attitude. The "silent service” is hardly silent, submariners have attempted to brainwash the Navy and the Con­gress into accepting the submarine as invincible. Captain Holland’s article* is an ingredient of the brainwashing program.

It must be understood that U. S. Navy submarines are not designed to shoot or stop U. S. Navy surface war­ships. Conversely, U. S. Navy surface forces are not designed to combat U. S. Navy submarines. Therefore it serves little purpose to compare the merits and demerits of U. S. submarines against U. S. surface forces. Instead, compare their missions: «See W. J. Holland, "ASW: Some Submerged Views,” pp. 97-99, September 1975 Proceedings.

►  U. S. surface forces exist to keep the sea lanes of communications open eco­nomically over large areas of ocean high­ways.

►  "Enemy” submarines exist to interdict these sea lanes.

►  U. S. attack submarines exist to deny the enemy effective use of his subma­rines, covertly in special ocean areas.

No one will dispute the submarine’s capability or advantage in fighting enemy submarines in the enemy’s coastal waters. But what defending capa­bilities does the submarine have for convoy escort duties?

Submarines can attack submarine and surface targets but not aerial targets. Airplanes can attack all three threats (submerged, surface, and aerial), but one aircraft cannot handle them all at once. Only the surface warship can engage all three threats simultaneously. While it is unlikely that a warship would encounter a simultaneous triple threat attack, all three modes of attack have, could, and would be used to interdict sea lanes of communications.

The surface warship equipped with a passive variable depth sonar capability equal to that of a submarine, combined with the rapid mobility of LAMPS, and the electromagnetic spectrum with which to vector, with security, support­ing forces, is an attractive alternative to an attack submarine in an open ocean engagement. The surface ship can be built and operated more economically than an attack submarine. With less restrictions on compactness, a 4,000-ton displacement surface ship can carry more sensors and more weapons for less cost than a 4,000-ton displacement subma­rine. Granted, the surface ship cannot arrive on station covertly, but when the mission is convoy or amphibious escort duty, covert presence is not required.

With the advent of V/STOL (vertical or short take-off and landing), PHM (missile-equipped patrol hydrofoil), and SES (surface effect ship) platforms on the horizon, the partial or complete combi­nation of these platforms will enhance further the mobility and quick reaction capability of the surface forces. Carrier and amphibious strike forces escorted by such surface vessels are capable of an invasion across any shore in the world.

Many people question how such forces fare, against submarines designed for their destruction, but as the stand­off range of submarine weapons in­creases so does the time of flight, the target’s reaction time, and the proba­bility of a miss. The greater the distance, the more difficult the classification and fire control problem becomes. All things considered, the advantages and disad­vantages are on a sliding scale. To in­crease hit probability, the submarine

Of the three main weapon types in the Navy’s arsenal, aircraft, submarines, and surface ships, only the latter, such as the USS Talbot (FFG-4) shown here, can engage air, surface, and subsurface targets simultaneously.

The proposed 2,000-ton surface effect ship, with advanced helicopter launching and retrieval systems and a speed better than 70 knots, will further enhance the capability of U. S. Navy antisubmarine forces.

commander must do things which sys­tematically reduce his options. High speeds decrease sonar capability and increase the probability of passive sonar counter-detection. An alert surface force has a chance of detecting a submarine’s electronic emissions which may indicate her attack intentions. Conversely, a sub­marine commander’s first detection of an attack against his submarine may be a report of hydrophone effects from a 40-knot torpedo less than 30 seconds away. This prospect alone will act as a deterrent against all but the most ag­gressive submarine skippers. To effec­tively fight his submarine, the submarine commander must attack, which makes the surface ship’s ASW job simpler: deny the enemy effective use of his subma­rine. This can be accomplished by any one of several ways: avoid enemy sub­marines or, if unavoidable, compound the submarine’s options by confusing the anticipated or perceived situation.

Deception is the primary measure used to compound the submarine’s op­tions. Deception can be in several forms: visual, electromagnetic, audio, and sonic measures. Altering the formation to put the high value target in the screen on

one or two screws and replace it with two escorts steaming alongside each other is an example of combined de­ceptions. Radio silence and Em Con (emis­sion control) is a condition seldom used by the surface forces, but, when em­ployed, it greatly compounds the sub­marine’s classification problem. Darken ship and deceptive lighting measures are additional options that submarines are not used to encountering. In short, anything which causes the submarine commander to wonder will eventually lead him to risk counter-detection or miss contact with the main body.

Captain Holland’s charges that ASW exercises (ASWEXS) are not conducted in a realistic fashion are correct and reflect poorly on all communities. This prob­lem mainly stems from the readiness criterion laid on surface combatants to be "Charlie-One” in ASW. Currently, a certain number of hours must be spent pinging away madly day and night in what is affectionately known as "dual ships.” This exercise is intended ostensi­bly to be the surface ship exercise which builds the skills necessary to conduct coordinated dual ship attacks, tactics which were great in World War II but which are hardly applicable today. While the CIC personnel are frantically trying to trace the "big picture” on the NC-2 plot, the bridge wants to know where in blazes the submarine is, and why isn’t the ship going there? This exercise, con­trived as it is to teach ASW, only re­inforces the submariners’ notion that surface ships are more likely to kill each other than a submarine.

The exercise is not completely with­out merit, but it must be commenced with a trained set of plotters, evaluators, and conning officers. Any ASW officer worth his salt always has his sonar gang up to speed on tracking targets by

means of the performance monitor equipment (PME) tapes. The PME tapes serve two functions. They provide the sonar operator with basic tracking skills and sharpen his acoustic recognition skills. Because the submariner requires fewer men on his tracking detail than the destroyer, the destroyer has more chances for a plotting error. In a real scenario, little time will be available for the varsity ASW training team to man up; the least trained man will determine the might of the team.

Captain Thomas Truxton’s advice,

"Practice daily with guns,” did not re­quire sled services on a daily basis. Still, surface commanders name the paucity of "services,” sleds, sleeves, subs, torpedoes, and retrievers, as excuses for the mar­ginal readiness status of their units. When the Seventh Fleet was operating at its highest post-World War II tempo in 1972, surface commanders com­plained that their material condition suffered because of excessive operating time. Today, commanders complain about the lack of underway time. There probably never will be a day when the balance is correct for any given ship. This "never ready” attitude must be corrected and serious thought must be given to ways in which surface com­manders teach themselves and their crews how to fight the ship while in port so that underway training benefits are maximized. Commanding officers’ presence at in port training sites must become the norm.

The surface warfare community must enhance its own professionalism. Surface Warfare Officers School (SWOS) is just part of the solution.

Surface Effect Vehicles: A Perspective

By J. F. Sladky, Jr., faculty member, Aerospace Engineering Department, U. S. Naval Academy

History has shown that societies pos­sessing mobility have grown and pros­pered while those devoid of ease of transportation have withered and col­lapsed. However, the degree of mobility and ease of transportation is dependent upon the conditions of the terrain in question. From the earliest times the seas, lakes, and rivers were the basic transportation routes. These generally were the smoothest and provided the least obstacles to the transfer of goods. Man, however, continuously desires more; he wants to move more material and at a faster rate; he himself wants to travel faster; and he needs to recover natural resources from progressively more remote areas. All of these factors drive to increase the demand on the capacity of transportation systems. It is this drive and desire that has begotten flight and the multibillion dollar avia­tion industry. The history of surface effect vehicles (SEV) must be viewed in this broad perspective.

To increase the capacity of his trans­portation systems, man has two choices: either increase vehicle size or increase speed. Each, of course, has its advantages and disadvantages. For reasons of versa­tility and quick returns man has, in the majority of cases, opted for increasing speed. To increase speed two choices again present themselves. The first is to increase power and move at speed by sheer force. The second choice is to decrease or eliminate resistive or drag forces. It is perhaps in this last choice that the idea of surface effect vehicles is founded.

The history of surface effect vehicles can be traced through three distinct and separate paths. One trend develops in the marine vehicle field.

The retarding effect of frictional forces on a craft was well known to man at the earliest times. Many scientists as well as inventors have invested consid­erable time and effort in eliminating or, at least, reducing this frictional drag. The efforts of Gustaf de Laval in 1882 led to the construction of a ship the hull of which was "lubricated” by a stream of air bubbles introduced through the hull. It was hoped that the ship would ex­perience a reduction in drag due to the lubricating qualities of the air-water mixture.

The stability problems of the air sheet experienced by de Laval were tackled by Culbertson. His 1897 patent consisted of a hull fitted with multiple keels which formed a series of longitudinal cham­bers. Feed holes at the front of each chamber were to supply compressed air, and, thus, it was hoped that an air interface could be established and main­tained in the intra-keel region. There are many other records of attempts at drag reduction where a gas is introduced between a hull and the water in which it moves. However, these schemes attempt to reduce drag by altering only the boundary layer.

The next marked step in the history of SEV was in 1916 when Dagobert Muller von Thomamhul designed a tor­pedo boat for the Austrian Navy. In general appearance, it resembled another attempt at boundary layer manipulation. However, closer examination reveals that for the first time an effort had been made to introduce significant amounts of air into the hull-water region and, thus, physically separate the craft hull from the water surface. The craft was essentially riding on a captured bubble. This vehicle achieved a speed of 40 knots.

Experiments and inventions in the direction of the confined bubble fol­lowed. In 1921, Gambin in France dis­closed information on a barge-type craft fitted with side boards and supported in part by a bubble of confined higher pressure air. These craft, while demon­strating some desirable qualities, were nevertheless plagued by many opera­tional problems. The air lubricated boat suffered from the tendency of the air to

separate from the hull and coalesce into large bubbles. The air-supported barges, because of their geometry, were re­stricted to relatively calm inland waters. Development along these lines contin­ued sporadically until the early 1950s. At that point it was realized that the entire craft could be lifted above the water, and the waves allowed to pass under the craft. Only rigid sidewalls were im­mersed to provide cushion air seals on both sides. Bow and stern seals were configured initially as hinged plates and later as flexible material skirts or seals. The seals accommodate the passage of waves in and out of the cushion while at the same time they prevent the loss of supporting air.

One of the earliest commercially suc­cessful captured air bubble, or sidewall, craft was the British Hovermarine HM2, a 20-ton craft propelled by waterscrews driven by Cummins marine diesel en­gines. This craft, still in operation, is capable of speeds of 35 knots. In the United States, where the sidewall hover­craft are more commonly known as surface effect ships (SES), work spon­sored by the U. S. Navy is continuing on two 100-ton craft. The SES tooA is built by Aerojet General and is propelled by waterjets while the SES 100B is con­structed by Bell Aerospace Company and driven by semi-submerged propel­lers. These craft are test vehicles de­signed to explore the performance and stability envelopes of surface effect ships. Presently design studies are under way on 2,000-ton SES.

A second historical path can be traced for the air cushion vehicle (ACV) itself. The air cushion vehicle, as we know it today, perhaps had its birth in 1716 in the hands of a Swedish minister and inventor Emanuel Swedenborg. His pro­posal consists of a device resembling an inverted dish which encloses, over a surface, a volume of air. This volume was to be continuously supplied with air by a man-powered, oar-configured, fan device. The purpose of the machine was to "fly” and, as such, its connection to the present air cushion vehicles concept may be only through geometrical simi­larity.

In 1955, Sir Christopher Cockerell patented the peripheral jet concept of cushion sealing. Considerable effort was then devoted in England to the develop

ment of the peripheral jet seal. The culmination of this undertaking was the English Channel crossing of SRN-i. Vari­ations of this concept have been pro­posed and are continuously evolving. Weiland, in 1957, patented a system of labyrinth seals, and Avro-car was con­structed in Canada. The latter is a hy­brid. The craft obtains its lift from a peripheral jet contained air cushion at low speed and from aerodynamic lift at high speed.

Some controversy exists about the next major breakthrough in air cushion vehicles. A patent describing flexible extensions of the ACV periphery was issued to Latimer-Needham in 1958. At the same time, or slightly earlier, Bertin of France developed the terraplane con­cept, which employs flexible trunks for support and cushion air sealing. The development of these flexible extensions has made the ACV a truly viable trans­portation alternative. The actual day­light clearance, the open air gap, has been reduced to very low values, thus saving on cushion power while obstacle

At left is the HM2 Mk III 60-passenger rigid sidewall hovercraft. Below her is the prototype Navy surface effect ship 100B, produced by Bell Aerospace, cruising across the surface of the water during a test run. In the bottom photo a helicopter perches on the deck of the Canadian Voyageur air cushion vehicle on Lake Ontario.

clearance capability has been retained and, in many cases, increased. This de­velopment increased the ACV’s rough terrain capability; but, it has not been without penalties. The problems of skirt wear, power requirements to overcome skirt drag, and skirt stability did, at times, look insurmountable. However, solutions have been found in some cases, while in others alternatives are being evaluated and answers sought. It should be remembered that to reach the same tonnage capacities, ACV technology has developed in 20 years, while aviation has taken six decades.

Of all the surface effect vehicles, the fully skirted hovercraft enjoys the great­est popularity. Not only is the ACV being developed by major corporations, but a proliferation of amateur built and sporting types exists throughout the world. To date the largest air cushion vehicle is the 200-ton SRN-4 produced by British Hovercraft Corporation. This craft can carry up to 254 passengers and 30 cars at 65 knots. Perhaps the most commercially successful ACVs are the

British Hovercraft Corporation SRN-5 and the Bell Aerospace license-built SK-5. The SRN-5 and its stretched version, the SRN-6, are operational as passenger fer­ries and coast guard vessels in the United States, Canada, and throughout the world. The SK-5 outfitted with ar­mament saw action in the Mekong Delta on interdict and search and de­stroy missions with the U. S. Armed Forces. Its amphibious capability and rapid traverse of swamp and rice paddies make the traditional guerilla tactics of strike and run more difficult.

Indicative of the tempo of surface effect vehicle technology is the Voyageur by Bell Aerospace of Canada. The craft is essentially a skirted modular barge fitted with SRN-5-type propulsion packages. Projected uses include arctic transport and coast guard duties, such as icebreak­ing. The deck area lends itself to various modifications and modular superstruc­ture installations. A smaller version of the same design philosophy is the Vik­ing craft also by Bell Aerospace of Can­ada.

Presently the U. S. Navy is pursuing the design of a large amphibious assault landing craft. It is the aim of this craft to rapidly transfer material from a sup­ply ship to inland points, thus avoiding beach accumulation of cargo and associ­ated exposure to enemy action. Two prototypes are under construction, one by Bell Aerospace Company and one by Aerojet General.

The third historical path leads into the wing-in-ground effect (WIG) cate­gory of surface effect vehicles. The con­cept was first utilized in the late 1920s by American D. K. Warner. Warner’s lack of success in racing high speed hydroplanes in general and confined air bubble craft, in particular, led him into ram wing technology. He reasoned that by lifting the craft clear of the water by aerodynamic means he would eliminate the high drag forces of the water and the discomfort of high speed intimate contact with a wavy water surface. Other early work was done by T. J. Kaario in the middle and late 1930s. Kaario’s work was done in Finland and met with considerable success. However, neither Warner’s nor Kaario’s develop­ments are now being pursued.

In the United States considerable in-

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T/>A hybrid surface effect vehicle is only a dream now for engineers and for the artist who produced this sketch. Someday, however, she or some variation may become a commonplace reality. If so, it will be because the hybrid is able to eliminate the undesirable characteristics of various systems while retaining their desirable features.

terest existed in the early 1960s in the ram wing and wing-in-ground effect vehicles. Prototypes and manned models were constructed by a number of com­panies; however, a series of unfortunate accidents due to craft instabilities and/or lack of funding has resulted in the shelving of these projects. The only active development of a wing-in-ground effect machine is Lippisch’s single place test craft. It is operating, and larger designs are under consideration. There also appears to be interest in the ram wing and wing-in-ground effect in the U.S.S.R. Recent reports indicate that a 500-ton wing-in-ground effect vehicle is under construction. However, little is known of the vehicle’s progress and development stages.

In concluding this brief look into the history of the development of surface effect vehicles a number of observations are in order. The earlier fervor and belief that the surface effect vehicle would be an answer to all of man’s transportation problems have been tempered by realis­tic technical evaluations. It has been realized that surface effect craft are spe­cialized vehicles, and they can perform certain missions very well. However, pushed beyond their designed missions, their performance decays rapidly. The situation is analogous to the helicopter. It is the only aircraft capable of sus­tained hovering flight and thus, in order to justify the high capital and operating costs, vertical flight must be a stringent platform requirement. For the surface effect vehicle, all-terrain or amphibious capability and high speed must be im­portant mission requirements before these craft show an advantage over existing modes of transport.

In recent years there has been a trend toward the hybridization of surface effect vehicles. Combinations of wings- in-ground effect, air cushion, hydrofoils, and ram wings have appeared in various proposals. A hybrid craft is now being studied by the U. S. Navy. The thrust of hybridization is to eliminate undesirable characteristics of various lift systems while retaining their advantageous qual­ities. It may very well be that the future of surface effect vehicles lies in the hybrid concept not only in lift gener­ation but in propulsion systems as well.

"For Those in Peril . .

By W. Robert Bryant, Vice-President, Perry Oceanographies, Inc.

A century ago, danger and distress dogged the mariner on the surface of the sea. But, with the recent coming of age of the small commercial submersible, man must cope with a new kind of danger under the sea. And, as it has throughout its storied past, the U. S. Coast Guard must be prepared to rescue survivors of underwater accidents.

Two definitions are in order at the outset. A "small submersible” usually weighs less than 30 tons and is capable of supporting personnel in a one- atmosphere environment at varying depths. With few exceptions thus far, the vehicles require the support of a surface ship. Because it is a work vehicle that is used in a predetermined location to accomplish one or more specific tasks, it is rarely, if ever, operated in areas where water depth exceeds its maximum operating depth capacity.

A "military submarine” is a highly sophisticated system that must operate in the oceans of the world—regardless of the extremity of water depth.

The important difference between the two is that the submersible’s pressure boundary will almost always be intact following an accident. It follows, then, that its personnel will almost always be alive, trapped, and in urgent need of rescue.

Some submersibles can ",lock out” divers who can do their work while being sustained by umbilicals.

In years past, the operation of small submersibles was minuscule. Compared to other areas of responsibility of the U. S. Coast Guard, they hardly deserved any attention. This situation has changed. While most of us see the submersible as a scientific tool in sup­port of basic research in the oceans, the largest percentage of today’s submersible activity is in support of the offshore oil industry.

In the turbulent North Sea area alone some 30 vehicles now operate, each vehicle carrying a minimum crew of two and operating approximately 100 days per year. Economically, it is not feasible to operate a small submersible system less than those 100 days.

Some companies, through the use of well-designed support systems, have extended their North Sea operating season to ten months, and very soon submersibles will operate year-round. However, if used only the minimum 100 days, about 36,000 manhours would be spent in submersibles in the North Sea alone this year. The North Sea is used as an example since it is presently the most active area for submersibles. As a result of this country’s current energy pro­grams, however, the oil and gas lease/ sale activity of many domestic areas is increasing. Within the next two years, we will see more extensive use of sub­mersibles in the Gulf of Mexico, the

Gulf of Alaska, and off both the U. S. East and West coasts.

The time has come to develop a rescue system to meet the threat to the commercial small submersible industry. There are only four major categories of failure incidents which will ultimately require a rescue plan. These areas are:

►  Flooding of external hard tanks

►  Flooding of secondary compartments in a multi-compartment vehicle

►  Total loss of power in a restricted area, such as under ice

►  Entanglement

Note: Failure of the main pressure boundary can be excluded from the list since the vehicle would be at a depth beyond which man can make a free ascent, and, as a result, the effort re­quired would be salvage, not rescue. This kind of failure, however, is highly unlikely with pressure vessels built to today’s rules, such as those established by the American Bureau of Shipping and Lloyds.

There are a number of steps which can be taken to reduce the risks associa­ted with these failures. Consider, as an example, the Perry PC-15-class submarine. This sub has several external hard tanks which could be subjected to flooding. Two long pressure-proof pods down each side of the vehicle contain the main power source: lead-acid batteries carried at one atmosphere. Two smaller tanks under the center of the vehicle are high pressure air containers used for blowing the main ballast tanks. There are also high pressure oxygen containers and a pressure-proof pod for electronics when a Doppler navigation system is included. There is a forward compartment for observers and pilot, a lockout compart­ment for divers, and a motor room aft. Each of these compartments can be isolated from the others.

When any one or more of these tanks or compartments is flooded, the neu­tral buoyancy of the system has been destroyed, and another means of positive buoyancy must be created. Several safety features have been built into this partic­ular vehicle. Both battery pods are droppable, instantly creating an addi­tional several tons of buoyancy. In addi­tion, sufficient high pressure air is car­ried to dewater the ballast tanks at depth, creating another 1,000 pounds of buoyancy. The combination of these steps would overcome the flooding of any external tanks or unmanned com­partments and allow the vehicle to re­surface. A failure in the emergency system, such as the battery pod drop mechanism, would precipitate a require­ment for rescue.

The Perry submersible "Shelf Diver” is an example of a craft with a droppable front cage that has tools attached.

The next area of concern could be

total loss of power in a restricted area. Because most of the vehicles operating today have primary and secondary sources of power, loss of one complete battery pod does not result in a total loss of power. If, however, a series of inci­dents occurred in which the result was total loss of power, a rescue effort would be necessary.

The last failure category is entangle­ment. A review of all submarine acci­dents quickly reveals this to be the most common accident associated with en­trapment. How does it happen, and what can be done to reduce the hazard?

All submarine designers would like to see the vehicles’ exteriors completely free of protuberances and attachments. Un­fortunately, the work tasks of these vehicles make that impossible. The ve­hicles have a number of features— mechanical arms, external thrusters, lights, etc.—which could become en- snarled in a wire, cable, or bit of debris.

Ideally, as many of the external ap­pendages as possible should be drop­pable. This can be accomplished by dropping individual items or in some cases by dropping the entire front cage with the working tools attached.

The last and most important factor cannot be accomplished on the vehicle; it must be performed by the pilot—good seamanship. While most submersible entrapments are the result of entangle­ment, errors in judgment and seaman­ship have been the cause of almost every accident.

If a rescue system were available, how much time would it take to respond to an emergency? And, if there is time to effect a rescue, what kind of rescue system would be required?

As a result of recent technological developments in the industry, it is now possible to provide emergency life sup­port on small observation submersibles for periods of 80 to 160 hours. This life support can be provided even when there has been a total loss of power.

In the one-atmosphere environment of a small observation submersible there are two major requirements: (1) to provide oxygen, and (2) to eliminate C0₂. The provision of oxygen has never been a problem, since very large quanti­ties, as compared to human require­ments, can be carried in small containers at high pressure. The problem has al­ways been the elimination of C0₂. During normal operations this is accom­plished with a device called a C0₂ scrub­ber, generally a simple canister of chem­icals, such as lithium hydroxide, with an electric fan to move the compartment air through the chemical bed. The problem has always been that electrical power is required. In an emergency situ­ation, electrical power may be very limited or, depending upon the accident, not available at all.

A new Perry development is a C0₂ scrubber package with a full face mask. The chemical bed has been packaged in such a manner that there is very little back pressure on the lungs and the wearer simply exhales through the chemical bed. The mask can be worn when sleeping and is efficient enough to allow removal for extended periods devoted to eating, etc.

The stated 80 to 160 hour emergency life-support range specifically refers to observation submersibles. The prob­lems could either be simplified or mag­nified if an accident involves a diver- lockout submersible. The rescue attempt could be simplified if the divers on board could lock out and clear away an en­tanglement problem. However, on the other hand, one may have a more serious problem.

Consider a mission which is nearing completion. A diver has been locked out of the vehicle to perform a specific work task. He returns to the submersible, reenters, and secures the hatches. As it is about to surface at the conclusion of the mission, the submersible has an accident which prevents it from reaching the surface.

The two divers are now in grave danger. They are or soon will be in a saturated condition. In addition to the problems of providing oxygen and C0₂ scrubbing services as described earlier, an additional service now becomes critical- heat.

While occupants of a small observa­tion submersible can survive cold tem­peratures for extended periods as long as they are properly clothed, this is not the case with a saturated diver. It is the nature of most inert gases used in mixed gas diving to remove the natural body heat rather quickly. As long as electrical power remains, this heat can be provided by the normal C0₂ scrubber heater pro­vided in the system. The complete loss of electrical power, however, could re­duce the survival period of divers to a few hours.

The rescue system itself must be sim­ple and easily and quickly deployable. It must require a minimum of support and be as universal as possible.

The first choice that must be made is whether to rescue the personnel or the entire vehicle. There are several methods possible when discussing rescue of the personnel—submarine, McCann cham­ber, or personnel escape equipment.

The U. S. Navy has done considerable work toward the rescue of personnel in a distressed submarine with the use of a smaller submarine such as the deep submergence research vehicle (DSRV). The DSRV was developed for the purpose of transferring personnel from a dis­tressed military submarine into a smaller transfer vehicle for transport to the sur­face. The basic concept is quite simple.

A small submarine capable of trans­ferring a number of personnel in one trip is deployed from a support ship in the area of the distressed submarine. By the use of electronic pingers and sonar, the distressed vehicle is located. The rescue vehicle then proceeds to mate to one of the standard hatches of the dis­tressed vehicle. The ambient pressure between the two vehicles is transferred to a special holding tank, a seal is made, and transfer at one atmosphere is then made.

There are numerous problems with a system of this type. The rescue vehicle will be a minimum of 15-18 tons dis­placement, which means that it is not easily and quickly deployed. It requires a specific support boat with the capability to handle such a vehicle in difficult sea conditions, and the mating can only take place with a special flange over a hatch in the distressed vehicle. This means that the downed submersible must also be in a reasonably upright position. Finally, a system of this type will become extremely complex and ex­pensive if it is also to solve the problem of transferring divers under pressure.

For those not familiar with a McCann chamber, it is quite simply a diving bell with a mating capability similar to the rescue submarine that is lowered from a ship in a fixed position. So, in addition

Operating Depth: Weight in Air: Overall Size:

Speed:

Inspection

Capability:

Work Capability:

to the problems associated with the rescue submarine, we have the added requirement of a ship with dynamic positioning or four-point moor capabil­ity.

The final personnel rescue method is personnel escape equipment. This, how­ever, can be dismissed as impractical in the water depths that are involved in today’s submersible operations. There simply is no equipment available that can safely accomplish this task.

In view of the foregoing, the most

desirable rescue technique is to recover the entire vehicle intact. The basic res­cue alternatives that can be used to recover the entire vehicle are by: subma­rine, divers using mixed gas diving gear, and an unmanned tethered vehicle.

The submarine can be eliminated for

the reasons given earlier; quite simply, it is not easily and quickly deployed. Div­ers using mixed gas diving gear might provide a solution in some cases. How­ever, generally the equipment that is required to support saturation diving is large, expensive, and even more difficult to transport and set up than the subma­rine.

This leaves the unmanned tethered

vehicle, which has the greatest rescue capability and could be developed in the shortest time at the least expense. Devel­opment engineering shows that an un­manned tethered vehicle can be pro­duced and operational in six to eight months that would meet the following specifications:

1,500 feet 500 pounds

72" length, 36" width, 24" height

3 knots at 1,500 feet On board video system and lighting Hydraulic manipulators with cable cutter and abil­ity to attach lift lines to a distressed vehicle

A system such as this would be helicopter-transportable, able to operate from ships of opportunity, and easily deployed.

How should such a system be devel­oped?

In the United States, the Coast Guard has the legal responsibility for civilian search and rescue on, under, and over the high seas and waters subject to the jurisdiction of the United States. At present, in the area of submersible res­cue, this responsibility is carried out by relying on the capabilities and expertise of the U. S. Navy. This is not an ade­quate solution. While the Navy has been extremely helpful in the past, it does not have a civilian search and res­cue responsibility. Navy equipment has other important priorities and the assets required for commercial submersibles may or may not be available when needed.

(The Naval Institute will pay S25.00 for each anecdote published in the Proceedings.)

--------------------------------------------  Bully for George

When the USS Charles E. Brannon (DE-446) was mobilized for the Berlin Crisis in 1961, the wardroom was composed mostly of senior lieutenants. A letter was duly written to the Bureau of Naval Personnel which said in part, "Every ship in the fleet should have at least one ensign to be trained, among other things, in the traditional duties of 'George.’ Therefore, it is requested that at least one ensign be transferred to this ship.” The letter continued that there would be a better distribution of rank if two ensigns could be assigned so that one of them would have the unique privilege of being "bull ensign.”

In about two weeks we received a reply from BuPers:

"The Chief of Naval Personnel heartily concurs that the lack of a suitably inexperienced ensign would be sorely felt, both in the effect upon the morale of the ship and the absence of a suitable nucleous upon which to base the ships’ long-range training program. Accordingly, orders are being prepared to assign Ensign George E. Tuttle to USS Charles E. Brannon." The letter went on to say that due to the exigencies of the service it would be necessary for Ensign Tuttle to wear the hats of "George” and "Bull Ensign” simultaneously.

Lieutenant Commander Fred F. Sima, USNR (Retired)

May I, then, strongly urge the Coast Guard to participate in the development of a tethered unmanned submersible rescue system. If such a program were started today, we could have the hard­ware and the trained personnel required within 12 months. Second, a major effort must be directed toward establish­ment of a set of qualifications for person­nel operating submersibles. We have enough rules, regulations, guidelines, and committees devoted to the design and fabrication of these vehicles—we must now provide for their proper opera­tion and, when necessary, the rescue of those in peril under the sea.

San Diego

Navy Town

From its vantage point on Point Loma, the stone likeness of Portuguese explorer Juan Rodriguez Cabrillo has been watching the comings and goings of the U. S. Navy since 1913. This month, a small footnote will be added to Cabrillo’s log as, for the first time in the 103-year history of the U. S. Naval Institute, the Navy’s own and only professional society will hold its annual meeting in a setting other than Annapolis, Maryland. Many sites were considered, but San Diego was chosen. In the four and a half centuries since Cabrillo, in the service of Spain, became the first European to step ashore on this sun-drenched sand spit, what once was the most remote of Spain’s New World colonies has become one of America’s great naval bases. What follows, then, is a brief look at some of the reasons why, in this bicentennial year, the Naval Institute has chosen San Diego as both a site and a symbol of the Institute’s resolve to expand its

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110 U. S. Naval Institute Proceedings, April 1976

As the sun begins its descent into the Pacific Ocean these ships sail upon, the USS Henry B. Wilson (DDG-7) approaches her berth at the Naval Station, known to generations of Navy men simply as "52nd Street. ” At right is the USS Hoel (DDG- 13). Established in 1922 as the "U. S. Destroyer Base, San Diego, ” 32nd Street is now the major logistics base for the operating forces. It serves as host to 35 tenant activities varying from Commander, Surface Force, Pacific Fleet, to the Fleet Maintenance Assistance Group Pacific.

Ballast Point’s Submarine Support Facility, facing page, covers 288 acres at the foot of Point Foma and is home for "diesel boat, ” "nuke, ” and "boomer” alike. Two submarine tenders, the USS Dixon (AS-37) and USS Sperry (AS-12), support these boats as well as the staffs of Submarine Group Five and Submarine Squadron Three. The submarine facility occupies most of what once was the A rmy's Fort Rosecrans.

A medium-sized warship sports a very big gun at the Naval Station. The Forrest Sherman-r/<ws destroyer USS Hull (DD-945) trains her prototype 8-inch main battery to port for maintenance. On the opposite side of the 32nd Street pier is the 35-year-old destroyer tender Prairie (AD-15).

Representing one facet of the extremely varied naval aviation activities in the San Diego area, a Lockheed S3A Viking antisubmarine aircraft, below, rolls to a stop at North Island Naval Air Station. Home port for three carriers, North Island hosts not only an ASIV wing but also several helicopter squadrons, the Naval Air Rework Facility, Commander Naval Air Force, Pacific, and a host of smaller commands.

Text and photographs by William M. Powers