Vice Admiral William S. Sims, Commander, United States Naval Forces Operating in European Waters, to American Newspaper Editors
THE FOLLOWING QUESTIONS WERE ASKED BY VARIOUS MEMBERS OF A PARTY OF AMERICAN EDITORS VISITING THE ALLIED COUNTRIES AND, AT THEIR REQUEST, ANSWERED BY VICE ADMIRAL SIMS, U.S. NAVY.
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What is the speed of submarines under water and on the surface?
What is the speed of a torpedo?
An ordinary submarine has a speed of about 12 or 13 knots on the surface and submerged has a speed of 8 to 10 knots. The cruising submarines of the Deutschland class, the latest type, have a speed reported to be about 16 knots on the surface and probably 10 or 11 submerged. The original Deutschland submarines have a speed of 9 knots on the surface and probably not more than 6 or 7 submerged.
The speed of a torpedo is about 30 nautical miles an hour, or 35 land miles. They can fire a torpedo a distance of about 3 miles, but the chance of hitting would be very small. They usually seek to fire from a distance of a few hundred yards.
Is there any estimate of the number of submarines the Germans now have in commission?
They have about 170.
Are the submarines which operate on the American coast of some special design different from the others?
These submarines are of the large Deutschland class. The boats of the Deutschland class were designed for commercial purposes but, not being successful, were transformed into military submarines, by placing two 5.9-inch guns on deck and fitting them with torpedoes and mines. A subsequent class, somewhat larger and designed for military purposes, had the same characteristics except that they have a greater speed both on the surface and submerged. They carry somewhat more torpedoes and mines and are armed with 5.9 inch guns.
The displacement of these submarines is about two thousand to three thousand tons, about twice that of a destroyer. They are not efficient for ordinary submarine work, as they take much longer to submerge than the small submarines and are very unhandy in making an attack. Their method of procedure is to operate well off shore where they are not in much danger of encountering destroyers. They have been known to stop vessels at sea, which they are enabled to do by their superior gunfire. They open fire on a vessel that has smaller guns and force the crew to abandon the ship on pain of being sunk. They have been known to keep possession of a vessel for two or three weeks using her as a base and getting supplies from her. They have quite sufficient oil capacity to remain at sea three or four months.
The object of submarines visiting our coast is not because the advantage they derive is chiefly a military one. That is, they cannot expect to encounter vessels as readily coming from our ports, all the way from Boston to Florida, as on this side of the ocean where commerce necessarily converges towards the English Channel and the coasts of France. Doubtless their object is to oblige the American Government to keep destroyers and other anti submarine craft in the western Atlantic which would otherwise be more effectively employed in protecting commerce on this side. It is of course recognised that the force of public opinion would require a certain number of anti submarine craft to be kept in American waters. There is, of course, an idea in the public mind that anti submarine craft patrolling a coast can prevent merchant vessels being sunk by a submarine. This is a misapprehension. Patrol craft would have little effect unless they were so numerous and so close together that a submarine could not come up within the area covered by them without being seen and fired upon. It would take literally thousands of craft to accomplish this. The few craft that can be assigned to such an area can have very little influence in interfering with the attack of submarines against merchant vessels. The reason of this is that the submarine, being a relatively small object, can be seen only at a relatively small distance, whereas the destroyer, with its four smoke pipes, mast, and so forth, can be seen at a distance three or four times greater. This amounts to giving the submarine the quality of invisibility. As she sees the destroyer long before the destroyer can see her, she has only to submerge to escape all danger, and remain submerged until the danger is past. If, therefore, the number of patrol craft is relatively small, they are really wasting their time dispersed along the coast hunting for submarines or with the object of preventing them attacking merchant vessels.
An example of the manner in which patrol craft can be used efficiently is afforded by the conditions in the Channel between Folkestone and Boulogne, and so forth. There have been transported across this band of water about fourteen or fifteen million military passengers, practically without any loss of life. This is due to the fact that this area is not only so intimately patrolled that a submarine could not come to the surface without being in sight of one or more patrol vessels, but also to the fact that the transports making the passage are accompanied by destroyers. If this group of patrol vessels were moved to any other similar area that area would similarly be immune to submarines. It would be suicidal for any submarine to come to the surface within such an area.
It follows that if you place such an intimately patrolled area round a battle fleet, the fleet may go where it pleases accompanied by this patrolled area, and similarly, will be immune to attack by submarines. It is for this reason that the Grand Fleet is able to cruise round the North Sea wherever it pleases with practically no danger of torpedo attack. This illustrates, incidentally, the fact that the submarine is not an effective offensive weapon. If the Germans had thousands of submarines, and confined the efforts of these submarines to purely naval warfare, i.e. if they did not molest merchant shipping, they would have very little effect in opposition to the naval activities of the Allies. It follows, of course, that if we had thousands of submarines of our coast, but a relatively small battle fleet, and enemy having a more powerful battle fleet could proceed to any part of our coast, notwithstanding the presence of the submarines, and make an attack at any particular place. This is something which it is important should be understood because a great many people have the idea that if we built plenty of submarines you do not need to build any other type of craft. If, however, we have a stronger battle fleet that that of the enemy, we may be sure that he will not approach out [i.e., our] coast, as the result would that his battle fleet would be destroyed by ours.
The above remarks illustrate also the effectiveness of escorted convoys. The convoy is a group of vessels in regular formation, steaming as close to each other as safety will permit, and surrounded by a screen of anti-submarine vessels. For the purpose of escorting either a battle fleet or a mercantile convoy the destroyer is by far the most efficient vessel. The reason of this is that the destroyer can increase her speed from a cruising speed of, say, 15 knots, to 25 or 30 in a very short time. This enables her quickly to reach the position where the submarine has been seen to go down. She carries 30 or 40 depth charges each with several hundred pounds of high explosive. These are arranged so that they will explode after sinking to any required depth. The consequence is that it is a very dangerous thing for a submarine to approach a convoy that is escorted by destroyers. If she hopes to destroy some of the merchant vessels she must approach close enough to have a reasonable chance of making a hit with the torpedo, and at this distance she runs a grave risk of being seen and attacked with depth charges.
How long can a submarine remain away from its base?
How large a supply of torpedoes does a submarine carry?
A submarine of the Deutschland, or cruiser, class can, as previously stated, remain away from its base three or four months. In order that a submarine may submerge she fills certain ballast tanks full of water so as to decrease her buoyancy. When a submarine starts out on a cruise against commerce, she has her ballast tanks filled with fuel oil. With this supply, in addition to what is in her oil bunkers, she can remain out three or four months. A submarine of this type can carry 36 mines. She can substitute torpedoes for some of these mines.
The ordinary submarine has also a very long radius of action, but the limitation of the time she remains out is determined by the number of torpedoes she carries. If the hunting is good and she fires her torpedoes away in a week or so, she must return to her base as she is no longer dangerous to commerce. These smaller submarines frequently remain out as long as a month. They carry from 8 to 12 torpedoes. There are others of a still smaller class which carry 4 to 5 torpedoes and 18 mines. Improved U mine layers carry 45 mines and 8 - 10 torpedoes.
Has the submarine as demonstrated in the present war, changed the principles of sea power laid down by Admiral Mahan?
Is the submarine, with other defences, an invincible means of defensive sea power?
This question has been answered under question No. 3. The submarine has not changed the principles of sea power as laid down by Mahan, and this for the reasons given in the answers to No.3. It is not an invincible means of defensive sea power, because it cannot operate within an area that is sufficiently patrolled by efficient surface craft. No matter how numerous the submarines, they cannot prevent a battle fleet going where it pleases, provided this battle fleet is accompanied by a sufficient number of efficient patrol craft. As previously stated, the most efficient craft for this purpose is the powerful modern destroyer.
Do the submarines ever operate in groups?
No. The reason is a very simple one, and that is that Allied submarines are used to hunt German submarines. The consequence is that if two or more German submarines attempt to operate together they would be in continuous danger of torpedoing each other. It has been explained above that a submarine can always escape observation by a surface craft, because she sees the surface craft long before the surface craft sees her. This is not true as concerns an enemy submarine, because if two submarines approach each other each has an equal chance of seeing the other first, and getting in the first shot. The submarine recognises that its most dangerous opponent is an enemy submarine. A German submarine operating against commerce spends most of its time on the surface. She submerges only when necessary to escape observation or when necessary to make an attack. A submarine must come up on the surface in order to use her oil engines for charging her storage batteries with which she propels herself when submerged. If she is chased by surface craft carrying depth charges she can only escape by steaming in various directions, and sometimes for a considerable distance, below the water. Safety, therefore, requires that she keep her storage batteries always as fully charged as possible. Submarines of the Allies when hunting for German submarines remain submerged during the whole of daylight, only putting the periscopes up for a few seconds at intervals. If they see a German submarine on the surface they are sometimes able to manouevre so as to get within torpedo range and destroy her. Submarines are the most successful vessels in destroying enemy submarines. There are often reports in the papers on “Submarines operating in Groups”. It is more or less common for merchant vessels to report that they have been attacked by a number of submarines. This is largely due to the excitement caused on such occasions, and by inexperience.
Would it be possible for the Germans, by devoting all their shipbuilding facilities to submarines, and by making a maximum effort, to succeed yet in crippling our transports?
It would not be possible for them to do so to any considerable extent. In the answers to some of the questions above it has been explained that a battle fleet surrounded by an efficiently patrolled area of anti-submarine vessels can go where it pleases. The same is also true of a troop or merchant convoy. If the escort of a convoy is efficient it means that a submarine cannot attack the convoy successfully, and it therefore follows that it makes little difference to the convoy whether it encounters during a passage one or half a dozen submarines. This illustrates the rather curious fact that doubling the number of the enemy submarines does not double the power of these submarines to sink merchant shipping. To put the extreme case, it may be stated that if we had enough destroyers to make our convoys wholly immune to the attack of submarines, it would not make any material difference to us how many submarines the enemy have. Unfortunately, we have not enough destroyers to make our convoys entirely safe from attack. It may be said that they are reasonably safe from an attack which will be successful, or rather from an attack which can be made without great danger to the submarine. They can, however, always fire a shot from such a distance that the submarine itself is reasonably safe from observation and attack, but such shots have little chance of hitting. If, however, they do hit, they do as much damage as if they had been fired from a short range. The answer to this question illustrates the extreme importance of an increase in the number of destroyers in the dangerous zones through which our transports have to be brought.
For the purpose of the present war on commerce what further ought to be done by America in the way of naval activity? What types of vessels are most needed?
The answer to previous questions has, I believe, made it clear that for the purpose of the present war we need more destroyers. There are other types of vessels, such as mine sweepers, and so forth, which are needed, but there is no such urgent necessity as for additional destroyers, not only to render the transport of our troops safer, but also in order to enable us to carry a more extensive and offensive war against the submarine. We would like to use many groups of destroyers, fitted with listening devices, in hunting submarines whenever their positions are determined, but we are unable to do so to any considerable extent because of the necessity of using these vessels to safeguard our troops and the merchant shipping that is necessary to bring their supplies.
Has Germany increased the strength of her Navy other than in submarines since the war began?
She has to a considerable extent. She has completed vessels that were on the stocks when the war began and she has laid down a certain number of battle cruisers since that time. This is also true of Great Britain; so that the relative strength of the German Fleet has not been materially increased.
Did Germany acquire any addition to her naval strength through the collapse of Russia?
Yes. She acquired certain Russian battleships and destroyers in the Black Sea. A number of these battleships and destroyers were sunk or disabled by the Russians. Germany may also acquire certain vessels in the Baltic, though it is likely that these would be disabled rather than let them fall into her hands. It is possible that she may man the vessels that have been seized in the Black Sea. The Allied forces in the Mediterranean are, however, of greater strength than any forces that the Germans can bring to bear in that area through the vessels above mentioned.
Is there any available information, of reasonable accuracy, with regard to the difficulty which Germany is reported to have experienced in getting submarine crews?
It is not believed that there has been any material difficulty in this respect, but it is believed that the crews of submarines have decreased in efficiency. As recently stated in the British Press, 150 submarines have been destroyed and 150 submarine captains have been interned, taken prisoners, or killed. Among these are doubtless the majority of more experienced captains. It is believed that in the beginning of the submarine warfare the German submarines were manned by volunteer crews. It is now believed that few, if any, of the men are volunteers[.] Their attacks are not as successful as they used to be. It is believed that the morale of the crews has considerably decreased. It would be remarkable if this were not so, considering the greater numbers that are being destroyed and the greater strain that is brought on the crews by the multiplication of minefields and the multiplication of the means of offence.
Why are transports west bound not so well protected as transports east bound?
Contrary to the general impression, all transports west bound are given as much protection as practicable. If there were no particular hurry about getting American troops to Europe it would be possible to give the outgoing transports as much protection as inbound ones. This would, however, involve all of the vessels of an incoming convoy remaining in port until all of them had been unloaded, repaired and so forth. Then all of them could be taken off the European coast with the same escort that brought them in. As, however, some vessels must wait their opportunity to unload, and as some must be repaired, it follows that great delays would be caused by all remaining in port until the last vessel was ready to sail. It is therefore the practice to send them off in smaller groups as soon as they are ready. This necessitates, of course, a less powerful escort than if they all went together. This point is not always clear to the civilian, and it is not very easy to explain the technical reasons upon which it depends. I may, however, explain briefly, that a convoy of eight transports protected by eight destroyers is much safer than two groups of four transports each protected by four destroyers. The reason of this is that a large (wide) convoy is seldom attacked in its centre on account of the danger to the submarine, so that if the flanks of the convoy are well protected all the vessels in the centre of the group enjoy similar protection. Whenever the military authorities concerned decide that the flow of troops can be decreased sufficiently, it would be possible to give the same protection to outgoing transports as is now given to inbound ones.
What would you lay down as the best future policy for the United States Government?
I am sure this will be recognised as a question which should be answered only by the United States Government. I might express an opinion on this subject, but I could not feel much confidence therein because the naval policy of the United States must necessarily depend very largely, if not chiefly, upon the Government’s general policy.
There have been some reports of friction between American and British sailors. Is there any basis for these rumors?
There is no basis for these rumors in the sense in which I am sure this question is meant. No cases of friction have come to me except such as might be expected between the individuals of a large group of men who associate together in more or less restricted ports. There have been no cases whatever of a political complexion. There have been cases of purely personal friction that have been caused by purely personal reasons. There have been cases, I have no doubt where an American sailor has “cut out” a British sailor in the effections of his girl. There have no doubt been cases where the British sailor has been successful in this respect. In either case, the difference would probably be settled in more or less boisterous manner, and possibly by personal conflict. This has doubtless been somewhat aggravated by the fact that our men, coming from a country where in normal times living is more expensive, receive higher pay, and this higher pay doubtless has its attractions, by reason of the superior purchasing power of ice cream soda, and so forth.
The following are some additional questions which were not asked by the editors of the American press, but which will doubtless be asked later by others who come over on a similar mission.
Why is it that instead of trying to protect commerce against the submarine, or in trying to run down the submarines after they are out in the ocean, the Allied navies do not attack the bases where the submarines are fitted out and from which they operate?
This is a question which has been very frequently asked,though not so often now as in the beginning of the war. Unfortunately, the idea was put into the people’s mind by a statement attributed to Mr. Winston Churchill, then First Lord of the Admiralty, that if the German Fleet would not come out and fight, the British Navy would “dig the rats out of their holes.” Of course it seems perfectly reasonable to untechnical people that the most effective way of suppressing the submarines is to destroy their bases. It seems a perfectly reasonable argument that it is better to stop up the hole in a wasps’ nest rather than try and catch the wasps after they are out.
It is more than a little unfortunate that explanation should have to be given as to why certain military operations are not carried out. Any educated civilian should know the requirements of secrecy during a war must necessarily preclude his having the information necessary to form a sound military judgment, even assuming he had the military knowledge and experience necessary to form a correct judgment. It would therefore seem reasonable for such a man to say to himself; “If the Allied navies have not attacked the bases of the submarines it must be because there are very good reasons of which I am not informed.” Unfortunately neither the civilian, nor the naval officer who is so situated that he cannot have full information, always refrain from uttering drastic criticisms of those who are responsible for the operations. In the naval clubs on both sides of the ocean sanguinary verbal battles have been fought by uninformed officers of all grades, explaining just how the submarine campaign could be brought to a speedy end. I suppose that such criticisms have always been, and will always be, made during a war. There can be no doubt as to the harm which they do in destroying public confidence in the chosen military leaders and the services they represent.
As a matter of fact, all possible phases of the submarine campaign are necessarily very carefully and very earnestly discussed by the responsible officials. The “rats” would promptly be dug out of their holes if it were possible to do so. It would take very long to explain all of the elements of such operations, but a few of the principal reasons why they are not practicable may be given.
One is that the modern sea coast defence gun is wholly invisible from the sea. Such guns are placed either in pits or behind elevations. Their aiming is indirect. Such guns have a range quite fifty per cent greater than any guns mounted on any battleships in the world. The battleship is clearly outlined against the sky and is a perfect target. The gun on shore can be aimed with perfect accuracy, because the earth remains quite still. The gun on the battleship is always in motion and never can be aimed with such accuracy. The relative chances of success between guns of similar calibre mounted on a battleship and guns mounted as above described on shore may be compared to the relative chances of success between two pugilists, one of whom is blind and has arms only half as long as the other one. In a word, it may be said that an attack by battleships against ports adequately defended by heavy guns would be suicidal - not to mention the danger from mines, torpedoes and heavy bombs. There can be no doubt whatever as to the result. It is hardly necessary to state that German naval ports are adequately defended.
It has frequently been stated by amateur critics (many of them naval officers) that if there were any Nelsons among the Allies they would have taken Heligoland long ago, and by the possession of this island have prevented the German fleet from taking the sea. It is quite possible that if there were any Nelsons, Heligoland might have been taken, provided however, conditions now were the same as in Nelson’s time. But present conditions differ in certain respects quite fundamentally from those of Nelson’s time. Heligoland is only about thirty miles away from the German coasts and it could therefore be bombed with thousands of bombs every night bombs carrying from 250 to 2000 pounds of high explosives. Experience has shown that there is no adequate defence against such night attacks, and this for the simple reason that enemy planes can seldom be seen at night in time to prevent them dropping their bombs. The situation may perhaps be made clear by the statement that if the Germans should turn over Heligoland to the Allies with all of its batteries and defences, the Allies could not use it as a base for any of their shipping, air planes, etc., because the shipping and planes would promptly be bombed out of existence. Moreover, they could not even maintain their personnel on the island because every square yard of it could be bombed within a short time.
Of course, the natural reply is that if the Germans could bomb the Allies out of Heligoland so easily, the latter should be able to bomb the Germans out, though perhaps not so easily. The Allies would be glad to do so, and would do so were it not that the development of bombing planes is not yet such as to permit sending them such a great distance with any considerable weight of bombs - and getting them back again. It is about ten times as far from Dunkirk or England to Heligoland as it is from Germany to Heligoland.
By reason of the conditions described above it is recognised by military authorities that a properly defended naval port cannot be taken without an attack from the land. If the German armies are driven back into Germany so as to uncover the German naval ports the latter will fall into our hands. When the German lines are driven back from Ostend and Zeebrugge these ports will also come into the possession of the Allies. Even the very gallant attack on these ports from the sea succeeded in maintaining a landing only for an hour or so, and blocking the ports so they could not be used for a few weeks.
Why is that, if it is not possible to “dig the rats out of their holes,” they cannot be blocked in by mines?
It would take too long to explain such a matter in detail, but it may be made clear by a few statements.
A minefield could be placed before an enemy’s port which would prevent any enemy vessel coming out of the port on pain of being blown up. The difficulty is to keep the minefield in place. In a few hours the enemy’s mine-sweepers can sweep a channel through the minefield and in a few days they can sweep up all the mines of a field of very considerable area. Therefore a minefield is of no use unless it can be continuously defended to keep the enemy from destroying it. Such a defence at such a short distance from the enemy’s port is impracticable, because the defending vessels would be subject to continuous night attack by torpedo craft, and so forth. It is well known that the Heligoland Bight for one hundred miles out is pretty well filled with mines. Some of these are German mines to embarrass the Allied operations in the Bight, and some are Allied mines to similarly embarrass the Germans. There is a war of mine laying and mine dragging that has been going on both sides in this area since shortly after the beginning of the war. In this warfare many vessels have been lost on both sides. Sometimes exits from the German ports are blocked for a few days until they can be dragged out. Various channels have been opened by the Germans and closed again by the British, but it is impracticable for the Germans to keep their channels continuously open or for the British to keep them continuously closed. It may be taken for granted that if either operation were practicable it would have been carried out long ago.
There has been published in the press within the past few months the fact that a mine barrage is being laid from the coast of Norway to the Orkney Islands. The position of this minefield was given at the time that the area was publicly declared. The attack or defence of a minefield in this position is quite a different matter from that of a minefield in the Heligoland Bight not far from the German coast. To attack the former the Germans would have to send out their attacking vessels to such a distance from their base that they would be in great danger of being cut off by the superior British Fleet. It is not probable that this minefield can be successfully attacked. On the other hand the laying of such a minefield is a tremendous undertaking and is surrounded by many difficulties.
Are many Allied merchant and other vessels destroyed by mines?
There are comparatively few vessels destroyed by mines.
Why, then, do the Germans persist in planting mines along the coast of the British Isles and along the coast of France?
These mines are planted by submarines of a well known type. The number planted is not great. The mine planting submarines carry from 18 to 40 mines according to the size of the vessel, and they can seldom be prevented from planting their mines in any place they please where the area is sufficiently open and the water sufficiently deep. As they work unseen, the Allies can never be sure that any particular channel is clear except immediately after it has been swept by mine sweepers. The consequence is that, though relatively few mines are being laid by the enemy, all channels must be continuously swept to make sure that they are clear. The result is that the laying of this small number of mines obliges the Allies to keep continuously employed some hundreds of vessels sweeping the various ports and channels. All this sweeping is rendered more difficult because mines have been devised of such a nature that they can be adjusted so that after they are planted they will remain on the bottom for any determined length of time from one to several days. This obliges the Allies to do much more sweeping than otherwise would be the case with simple mines. For example, a field may be thoroughly swept with the result that a few mines are found, but there is no assurance that a number of others will not come up from the bottom at any time within the next few hours.
Cy, DLC-MSS, William S. Sims Papers, Box 24.