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But meanwhile, how can life be preserved with a hope of rescue from those operations? Of course, you can not conserve life except by getting air and food to the men. One of the points regarding salvaging is the affording facilities by the use of straps built into the submarine, of very highly alloyed material, and lifting rings, as distinguished from the method of passing chains under the submarine and burrowing through the mud to get at them.

As to the particular point of getting air into the submarine, I felt immediately at the time of that accident that if there had been some access to individual compartments as well as connection from compartment to compartment, these means of connection to the various compartments being opened or closable both from inside and outside, and proper valve connections being made for a through line, it would have been possible to have made connections from the outside with any one of those compartments, and especially a compartment in which life existed, and to have gotten air and food there, to have preserved life for a sufficient time for salvage operations to possibly have been conducted on some improved plan, and the submarine either raised, or some means gotten at through access to that compartment, so that the men could have been gotten out.

It is my belief that if the lives of the men could have been continued for a week or 10 days there would have been found means to get into that compartment and get the men out even if the submarine itself could not have been raised.

I can not feel that the officers on duty were in any way at fault. I think they did everything that was possible in accordance with the spirit of naval officers and men engaged in operations of that kind, knowing that human life is at stake, which is infinitely more important than the salvage of equipment-I can not believe that they would not work every hour of the 24 and do all that was humanly possible to bring those men to the surface. What leads me to my conclusion is my experience and my acquaintance with naval officers.

But there is a big gap sometimes between things that can be made and are recommended, both by men who are operating submarines and those in command, and the acceptance by those who are responsible for design.

Of course, I know that when different propositions are put up to a designing engineer, who must go ahead to a certain extent on his own responsibility, but with the experience of years back of him and with the advice pro and con as to whether a thing shall be done or not, he must to a certain extent compromise in his decisions; and ordinarily he will compromise on what he believes to be the best thing.

I do not think, however, that our submarine development has been under as good-I will not say as good, I should say under as extended critical engineering supervision as it ought to be. That is, I mean in this country there is an enormous available potential power which can be brought into play, and it seems to me that that could be used to a greater extent than it is. Some people say that is the fault of the Navy Department. I will say that is the fault of every great institution. There is not an industrial organization in the country in which, as it grows larger and larger, you do not find difficulty, on account of the inertia of things, to get things new into operation, and to get them adopted; and yet in the industrial field

there is an even greater incentive from a commercial standpoint, because there they are trying to build something that is in competition with somebody else, and the men themselves continue on their duties; it is a continuing job of the heads of departments.

It is not so in the naval service. Every officer is supposed to be anything, from a naval officer to a paymaster, a gunnery officer or perhaps a commanding officer, or on duty ashore, perhaps in the department. He is in the department for a certain period of time, but by the time he gets interested he is shifted to something else. Continuity of practice along a particular direction is more difficult in a military organization, where you have got to shift the personnel, than it is in any other great organization. It is bad enough in industrial enterprises, and it is unnecessarily so in the Navy and the Army. I believe the best results will be gotten, not only in the Navy but in any other military organization, if men are more specialized in their duty and are given greater opportunity to follow out their specialized lines. I recommended that point of view to Secretary Daniels some years ago, and was convinced at that time that instead of trying to make every officer, as I say, a superman, capable of doing anything and everything, and applying the very highest degree of intelligence in carrying out his work, many should be specialized; that they should be given certain duties and encouraged to develop along those lines instead of along universal lines; yet perhaps a good many naval officers would not care to have that situation, because it might interfere with their future prospects.

I understand that there have come in to the Navy Department between 3,000 and 4,000 propositions as the result of this accident. I recall there were over 100,000 propositions that came in to the Naval Consulting Board for various things which might be used to shorten the war. Scores of them were duplicates. Hundreds of them were merely the reiteration of propositions which had been made long ago, carefully considered and set aside; and I think it is difficult for anyone who is not on the job all the while to pass really a justifiable opinion as to the sufficiency or lack thereof, in regard to anything which has been proposed for submarine safety.

If there is no objection I should like to call attention-particularly to the copy of the naval institute proceedings referred to, because I think it has, stated in a pretty concise manner, comments which are worth while as a matter of record. I suppose that every engineer who has been connected with the naval service feels that if he were given free rein to sit down in a submarine, he might make some proposals that might be constructive. Perhaps I have somewhat of that conceit myself, but I must confess I would not think of doing a thing of that kind except in consultation with those who are responsible for the construction, and likewise considering the whole history back of it. I would not be justified in doing such a thing. I want to reiterate that in my opinion, so far as the officers of the S-4 were concerned, it is my belief that they lived up to the traditions of the service, and did all that was humanly possible. A craft that goes under water is always subordinate to things above. They may come to the surface and look around with a periscope; and that periscope ought to be a perfectly recognizable thing to any craft engaged in prohibition enforcement or any other craft of that character on the

coast. If it is not, they ought not to be on that duty. The Nayy ought not to be sacrificed to it.

I do believe, however, that it is the duty of the department to make the most rigid examination of the plans and the construction so far as carried out, of any submarine that is now afloat, or which is now under consideration or authorized, to see if with not only the advice of their own people, but such outside advice as may be brought into coordinate judgment with them, something can not be done to make this kind of a disaster-not impossible, if you please, but at least to minimize its possibility; and I think I speak for the Naval Consulting Board, as will Doctor Hutchison, who likewise is one of the Board, here when I say that individually and collectively they have at all times been ready, and are now ready, to cooperate in any way which is within the proprieties.

It is a little hard to volunteer expressions of opinion about anything; sometimes one can reply more specifically or a little more directly to direct questions, and if there is any information I can possibly give to the committee, I shall be very glad to do so.

Senator ODDIE. You have covered the matter very carefully and thoroughly along the lines that you have discussed, and your suggestions will be helpful.

Mr. SPRAGUE. I intend, of course, to give this a good deal more thought. It has been brought home to me now perhaps a little more forcibly than before.

Senator ODDIE. On behalf of the committee I thank you very much for appearing and giving us your opinion.

(The article submitted by Mr. Sprague is here printed in the record as follows:)

MISCELLANEOUS

SUBMARINE SAFETY AND SALVAGE DEVICES

[Mechanical Engineering, February]

There have been very many devices proposed for the salvage of submarines. Some of these are too impractical to call for serious consideration-for example, the use of huge magnets to lift the submarine from the bottom. Other devices, however, are in one way or another worthy of notice.

There are certain technical limitations with which the submarine designer has to contend, and those must be most carefully taken into consideration when it comes to the installation of any device whatsoever on a submarine. In the first place, submarines are now built so as to be capable of submersion to increasingly great depths. Where formerly 100 feet or 150 feet was considered good, the modern submarine should be capable of freely submerging to a depth of 300 feet, which means roughly a water pressure of 145 pounds to the square inch. This requires a very great increase in the strength of the hull with a consequent increase in weight. Any addition of weight to the outside of the hull of a submarine requires an increase in size to provide the increased displacement necessary to carry this weight. The result is that when one ton is added to the weight of a submarine in the form of some fixture or attachment, such an increase in size is made necessary as will increase the total weight to the extent of 2.7 tons.

The next great limitation is that of space. A submarine has to carry about three times as much equipment for the power developed as does a surface ship. The propelling plant of the latter is what might be called a single-acting unit, say, steam or Diesel. A submarine carries a Diesel engine which drives it on the surface and also charges the storage batteries. To do this it has to have a powerful generator. The drive under surface is by electric motor from the storage battery. A three-step arrangement therefore becomes necessary, in addition to which the submarine has to carry water tanks, a supply of air, and for its size an inordinate amount of military equipment. It is therefore about

as full of machinery as an ordinary watch case, and every square inch of space is utilized to the utmost degree. None of this can be given up to any additional gadget without taking it away from something else.

SAFETY WEIGHTS OR DROP KEELS

One of the earliest methods of submarine salvage was the use of the so-called "safety weights," which consisted of huge blocks of iron or lead so attached to the bottom of the submarine that they could be released from the inside. The purpose of this was to decrease very rapidly the specific weight of the submarine and permit it to rise to the surface. Such weights were fairly regularly employed up to about the time of the World War, but the recent trend of opinion is against their use. In the first place, it has been found that the working of this device is neither rapid nor reliable enough for practical purposes. In the next place, the additional load reduces the speed of the submarine and its cruising radius to such an extent as to affect very materially the military value of the device. Finally, with the great increase in the size of submarines the weights that could have been used would have had to be inordinately large and, moreover, would have complicated the important problem of balancing when submerged. On the whole, therefore, the present tendency in design is to dispense with their use.

In one instance during the World War the drop keel was accidently knocked off an English submarine by contact with the sea bottom. The vessel was unable to submerge after the accident and ran the danger of being sunk by the enemy, getting back to England by mere fortune. A step in the direction of abandoning this scheme was the adoption of safety tanks. These tanks were filled with water, thus providing an extra weight, and when necessary could be very quickly emptied by introducing very high-pressure air carried for this purpose in special cylinders.

DETACHABLE CHAMBERS

The next device from which great things were expected was the detachable chamber. The idea was to provide in the hull of the submarine small compartments with double doors working something like the Servidor device used in hotels. Double doors were to be provided so that a person could pass into this detachable chamber, close the doors after him, have the chamber detached from the submarine, and float up to the surface. One of the suggestions was to make the entire conning tower act as such a chamber, so that in case of necessity the whole crew of the submarine might save themselves in this way. The problem of designing such a device so that it will withstand when detached the considerable pressures met at substantial depths is not an easy one. Moreover, with the present large submarines carrying a crew of some 85 perople, the device would have to be of a very considerable size. The question of placing these detachable chambers is also not an easy one. If they were located inside the hull they would occupy most valuable space, and space is what the designer of a submarine can least spare. If the chambers were located outside the hull, somewhat like warts on a frog's back, they would materially reduce the submerged speed of the vessel.

DIVING SUITS

It has been suggested many times-but not by submarine designers-that diving suits be provided for the crew, the idea being that in case of accident the crew could don these suits, open doors, and serenely walk out on to the ocean floor. The trouble with this scheme is, first, that in case of an accident, particularly where the hull is ripped open, there is seldom time for the rather elaborate operation of donning a diving suit. Next, not many men employed on a submarine are physically suited for work at substantial depths in an ordinary diving suit. On the other hand, however, in several European navies the so-called "oxylite" masks are carried. These masks have a chemical which is capable of absorbing moisture from the human breath and evolving oxygen in proportion thereto, so that a man can live in an oxylite mask for as long as three-quarters of an hour without breathing any ouside air.

The main value of these masks is in case sea water should accidentally penetrate into the storage batteries. Because of the reaction between the sodium and magnesium chloride in sea water and the sulphuric acid in the batteries, such an accident would result in the evolution of chlorine. Should this happen when the submarine was submerged, time would be needed to bring the vessel to the

surface and either ventilate it thoroughly or permit the crew to get outside For such a purpose masks of the oxylite type are quite valuable, and being comparatively light and small they are not in the way.

THE EXTENSIBLE TUBE

This device has been suggested on numerous occasions, the idea being to provide a tube of a diameter sufficient for a man of ordinary girth to pass through. This tube is supposed to be collapsed under ordinary conditions, somewhat like a traveler's aluminum drinking cup. In case of necessity it is to be extended so as to reach the surface and thus provide a means of egress for men trapped in a submarine. The device has never been adopted in practice by any navy, and the reasons for this are fairly obvious. Such a tube would have to be at least 25 inches in diameter. For a hollow tube to withstand water pressure at a depth of, say, 300 feet, it would have to be made very strong, particularly at the joints, which means that it would have to be quite heavy. It would occupy a lot of room, require quite an elaborate arrangement for extending it, and then would provide egress only to men trapped in the one compartment with which the tube communicated.

SAFETY TANKS

All submarines of the United States Navy are fitted with an automatic device which may be set to operate at a predetermined depth. Several different types of valves have been used, all of which operate on the same principle; i. e., the unbalancing of forces previously in equilibrium by sea pressure due to the depth of submergence. The tripping of such a valve opens the 100-pound air line to one or more of the main ballast tanks, usually forward of amidships, and allows air to be blown into the tank, forcing the water out through the Kingston valve, and thereby bringing the boat to the surface. These valves are not of an automatic repeating type, but require to be reset by hand after each operation. Valves of this type have generally proved satisfactory, being capable of arresting the descent of the vessel to within 5 feet of the intended depth, and criticism mainly has been directed to the capacity of the reducing valve which supplies air from the 100-pound line. No standard valve has been adopted. Two varieties have been installed on contract-built submarines, both of which are covered by United States patents. A special type of automatic valve has been designed by the Portsmouth yard and installed on the "S" vessels built by that yard, but has not been thoroughly tested as yet. Automatic control of the diving planes has been suggested and has been considered in a tentative way at various times, but no definite action along these lines has been taken, as it is believed that the complications involved would not be warranted by the advantage gained. The practicability of providing automatic arrangements for controlling the regulating or adjusting pump has been investigated, but in view of the complications involved it is not believed that the arrangement is practicable or would serve any useful purpose.

SIGNALING BUOYS

Many of the European submarines are equipped with signaling buoys which in case of accident can be released by the submarine and will indicate its position. In the German Navy, for example, these buoys are equipped with telephones, and at times attempts have been made to equip them at night with flares and in the daytime with smoke or sounding devices. These buoys were formerly quite extensively used in the American Navy, but of late have been discarded. The reason for this appears to be to be the possibility that in war time the concussion produced by depth bombs might release the buoy and thus indicate the position of the submarine to the enemy. It would seem to be quite feasible to use these buoys in peace time, and either batten them down or cut them off completely in war time.

If properly used and equipped these buoys constitute a valuable auxiliary, in particular by indicating immediately the location of the submarine and possibly giving information as to the condition of the vessel, the condition of the crew, and the degree of necessity for prompt action. The design of these buoys is, however, as yet in a very crude state, and no facilities are provided for the men in all of the water-tight compartments to communicate with the outside world by the telephone apparatus inclosed in the buoy. It may be stated in this connection that the whole subject of submarine safety devices is in an inchoate

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