Lieutenant Ronan C. Grady to Admiral William S. Benson, Chief of Naval Operations
June 6, 1917
From: Lt. R.C.Grady,U.S.N.
To: Chief of Operations
SUBJECT: Recent visit to London
Upon my arrival at London I reported to Rear Admiral Sims and explained my verbal instruction. I also made a general outline of my mission, (a copy of which is attached marked “A”), which Admiral Sims submitted to Admiral Jellicoe who transmitted it to Admiral Duff, head of the Division in the Admiralty of anti-submarine affairs.
I was introduced to an officer, Lieut. Comdr. Hichens, on the staff of Admiral Duff who was to introduce me to those officers who could give me the information I wanted. I learned that the details of the mines, nets, and paravanes were all supplied and hand books used in the British service would be supplied to the United States[.] Accordingly, I made no extensive notes of these details and in this report will cover only what I could learn of the anti-submarine campaign.
Regarding this I had personal interviews with Rear Admiral Duff, then Director of Anti-Submarine Affairs and now assistant Chief of Naval Staff, Rear Admiral Fitzherbert Director of Mines and Torpedoes, Captain Spear, in charge of mines and a commander (name unremembered), who was a member of what corresponds to our planning section.
There is no special anti-submarine patrol of the North Sea. This was at first attempted, but given up on account of the danger to the ships and the number of ships required to cover the entire area, which ships were not at hand. There is a patrol maintained for obtaining information regarding the movements of the High Seas Fleet, but it is not a very strong one. There is a strong channel patrol maintained both for purposes of security and information, but it is not particularly anti-submarine. It is generally used in conveying cross channel traffic. In daytime there is a scouting patrol out in the channel. This returns to port at night unless a destroyer raid is expected; then it will remain out during the night. There are also patrols for convoy duty in the Bay of Biscay, Irish Channel and Northern Entrance to Irish Sea. The composition and numbers of these patrols I did not get, as the officers I talked with did not know them.
Nets are used now only for local defense. Towing nets were used in the North Sea for some time, but were given up after being found entirely ineffective, that is, no case of a submarine having been captured in this way has ever been recorded. An R.C. mine net is now used for... [one page is missing]
...or from Lyurig up to Fair Island, south of the Shetland Islands, thence westward and southward to St. Kilda west of Ireland. They usually made a land fall there then head south to their assigned stations.
The British Admiralty receive reports of
their the submarines which leave Germany and also get reports of their presence off Ireland or on station and so are able to estimate that the submarines travel 200 miles a day. The recent increased efforts to stop the submarines have cut this speed down to five miles an hour for the trip. I asked if the anti-submarine measures did not make the German submarines fear of taking a direct route to Fair Island and of passing through south of the Shetland Islands, but no one seemed to think so.
Air craft play practically no part in the anti-submarine campaign, excep[t] in the Channel where they do scouting duty.
As far as could be determined, the present naval strategical plans contemplate directly guarding against major operations of the High Seas Fleet, secondly to divert those craft which can be spared from the Grand Fleet to engage in the anti-submarine campaign. Occasionally one hears statements that everything is subordinated to the anti-submarine campaign, but actually this doesn’t appear to be so, for in any plan for attacking the submarines the needs of the Grand Fleet are first given con-...[one page is missing]
...question, because the base of the fleet was to the northward of that and the fleet could not be expected to pass through such a mine field. I asked if it would be practicable to have the fleet at some point farther south but he did not think so. There are so many ships of all kinds with the fleet that when it steams to sea it has a front of six or seven miles, and at its present base it can leave in that formation. The conditions at its present base are ideal for protection from submarines for the currents across the entrance are so swift that submarines could not navigate there submerged. There is also room for parts of the fleet to engage in target practice and the distractions are none, so that the personnel are not made discontented by scenes of pleasure going on around them, which the re-requirement of constant readiness would prevent them from enjoying. Altogether there was no place as suitable for the base as the present location.
There is a very strong objection on the part of all to the use of a drifting mine, for fear of it acting as a boomerang on their own ships. I explained that the intention was to use only such a mine as it could be demonstrated would be safe to surface ships, but the point did not seem to appeal very strongly to them. The magnitude of the operations of mining and patrolling the fields would practically make it impossible. The [i.e. they] would not in any case attempt to recover the mines as that would cause too much work; they would rather make the mine ineffective after a certain period. However, it is apparent that it is in the minds of many that present methods will have to be supplemented by other means, and that they are looking more and more to mines. In fact Capt. Spear had the preliminary sketch of a floating mine which he planned to use where it was too deep to anchor a mine. I left a copy of the sketch of the proposed type of floating mine I brought over with the Director of mines as they thought there was one or two points it possessed which they could employ in their mines.
The strong card they play in the anti-submarine game is the destroyer equipped with a heavy depth charge. There is no doubt that the depth charge imposes cautions on the submarine which hinder it greatly, yet this strong card is not sufficient to deter submarines from carrying on warfare on their shores almost. Admiral Duff thinks convoys will greatly help in the problem; no doubt the results of this method will soon be known.
There are now evidences of a policy to protect shipping to such an extent as to reduce shipping losses to such a minimum that the Allies can outlast Germany. This is distinct from the policy the public and the papers would like to see pursued, namely one of direct methods of attack upon submarines. The former one may be a successful policy, but in view of the increasing number of German submarines, I think it somewhat dangerous. The British Admiralty have reports that there are about 180 German submarines at present and that they are adding two a week. If the present number of surface craft are unable to check the submarine it will hardly be likely to be as good a situation one year from now when the Germans have added another hundred submarines to their fleet.
The British have recently increased their orders for mines. I asked if their present plans contemplated calling on the U.S. for large numbers of mines and Capt. Spear said he did not think so, but before I left London there were many more remarks being made about mines and in all probability great quantities of mines will be called for in this country very soon.
Another device which it is intended to employ is the hydroplane. This is similar in principle to our microphone and by using several ships at a time taking direction readings of the noise a submarine makes while under water, they hope to run the submarine down and sink it with depth charges. This will be a very slow method, all admit, and is only to be considered as one of the many efforts to be made.
Very recently the British submarines have been employed to stalk and bomb German submarines. A British Submarine will take its station in the North Sea and spend the entire day cruising slowing about with periscope up waiting for German sub, to appear, and if the chance comes will fire torpedoes at the enemy. As many as seven German submarines have been accounted for by British submarines during the war. However, British destroyers are instructed not to attempt to distinguish between an own and an enemy sub before trying to sink it and actually have bombed their own boats. This last risk is accepted however and the British subs continue their work, and upon the whole it is very satisfactory for it is entirely due to the British submarines that the spread of the Germans through the North Sea has been so largely put down. One submarine officer in the admiralty was very much interested in knowing if the U.S. would send over any subs.
There is no doubt that the submarine menace is forcing itself upon the minds of the British Admiralty, and also forcing great changes in the strategical plans.
But it is also true that in this as in any other line or enterprise that those plans will change only as fast as they are required to change. The danger is that the British will not change until too late, or that they will not be required to change until too late. Their natural tendency to regard themselves supreme in naval matters may delay the apprehension that their real danger is that the submarine may force an unsatisfactory peace.
The food situation in England is not acute, but there is necessity to guard the supply and reduce the consumption to provide for an emergency. In public restaurants, small portions of bread and sugar are issued and no one is supposed to ask for more. Potatoes are served only one day a week.
The gasoline supply is also a matter of concern. Motor traffic is largely cut down, and gasoline substitutes are generally used. This latter feature is one that is liable to cause as much concern as the food problem as the shipping decreases. One of the side problems is the transport of supplies to the forces in Greece. The force in Greece defends [i.e. depends] for its existence upon a train of ships through the Mediterranean and if this force is reduced to any extent there is danger of grave disaster to those armies. One mistake made by many is that they do not keenly realize the number of ships required for the Mediterranean transport. This line it appears must be maintained even at a great sacrifice to comfort in England, or a great defeat may be suffered. Many think that with about ten million tons of shipping England can afford to lose almost a million a month for several months until new harvests bring relief; that during the winter shipping losses will be reduced, and that new construction will supply more tonnage for the following year. I could get no clear statement which told of the conditions, but from remarks of those who returned from Greece it is plain that fuel and food are scarce in that region. This means that the Mediterranean transport is working to the limit and cannot stand much more reduction without weakening the forces in the field. So on the whole it is clear that England cannot stand much more shipping losses, and that the situation is at a critical stage.
As yet all appears satisfactory on the surface so that people are sanguine that Germany ultimately will be defeated. From talk with the naval officers including some in the admiralty one gets the impression that the Admiralty is in a dilem[m]a. They appear to be in doubt as to whether to try to squeeze through on the acceptable maximum loss theory acting along present lines, or to risk greater losses by diverting some of the present patrols to an active offensive along new lines doubtful of success. They also appear to be in doubt as to whether to sacrifice partly their present impregnable position as regards the Grand Fleet and High Seas Fleet, and divert part of the former to an active submarine offensive. One officer said “of course we are keeping the German Fleet inactive, but after all the Grand Fleet is a large force that is doing practically nothing to better present conditions”. It is very true that a force must be maintained ready to oppose the High Seas Fleet, but it is also very true that England has not got control of the seas, and that it is imperative to her position that she have it. Instead of having control of the sea England is in the position of a fleet which must fight to guard its train, and a very cumbersome train at that.
If the two big fleets are eliminated from the present problem there remains a necessary train guarded by forces unable to protect it from continual losses on one side and a constantly growing force on the other. The train may be maintained indefinitely and may not, but it is apparent that the submarine attack must be stopped, and control of the sea regained before safety is assured. The addition of one million men from the U.S. to the fighting line, imposing such an increased demand for supplies, becomes one of the extraordinary demand that fighting forces always make for supplies, above the demand made by civilian populations, is another consideration which makes it imperative to stop the submarine.
This brings the problem down to a study of the effectiveness of those measures now in force which have been generally enumerated above.
It will be noted that some measures are devoted to seeking out the submarine and to destroying it, while for the greater force is defensive, and seeks to guard the train by keeping the submarine away from it. This is the principle of convoy and the whole measure of success can be determined by the losses. The losses are generally enumerated with the total entries and clearings to show comparatively a small percentage of loss. This tends to gloss over the fact that a certain number of entries and clearings are absolutely necessary to maintain the country and that regardless of the percentage of loss that the entries must not fall below a certain figure. For instance, half the number of entries with one-half the percentage of present loss might cause an intolerable condition.
In connection with the transport of United States troops abroad it must be recognized that there is a certain amount of risk. That no matter how closely the convoy is guarded a determined submarine may sink one or two ships, and we should be nerved to withstand the shock of bad news.
Aside from the destruction of commerce the constantly growing German submarine force, presents the possibility that finally they may be used tactically in the North Sea to reduce the British fighting strength.
All the present anti-submarine measures should be vigorously pursued, but additional measure of greater effectiveness must be developed before military dominance can be secured. And in undertaking new measures care should be taken to upset as little as possible the organization of the present efforts. As it is apparent to all that the great advantage which the submarine possesses is its ability to work under water, and that under water it is protected from gunfire, it is logical that the surface ship is not the best weapon to use against the submarine. It does not appear logical that the mine located in sufficient numbers underwater will destroy the immunity the submarine enjoys underwater. Surface ships can lay those mines and then support the mine fields against mine sweeping operations. In slecting [i.e. selecting] locations for mine fields the North Sea area gives the best chance on account of its comparatively limited area. It was this theory which I presented to the officers I met abroad. I also outlined, based upon what knowledge I possessed a plan for carrying out the theory by placing a barrier across the North Sea. As previously stated there were reasons such as lack of ships, strength of tides, movements of the fleet, and mining experiences, which would modify the plan. Another plan should be worked up and as any plan would have to be on a basis of cooperation with the British in which their ideas would have to be considered and the part their fleet play in the plan decided upon, a naval commission should be sent over to London. It should be called the Anti-Submarine Commission, in order to distinguish its duties and be composed of sufficient rank to enable it to gain the proper hearings. All the necessary technical strategical and supply divisions should be represented. A preliminary study should be made on this side so that the directions of effort would be understood clearly upon arrival abroad. If such cooperation can produce nothing, we can only trust in the end.
I would finally recommend that all craft available for anti-submarine work be sent over to the other side immediately and that preparation be made to manufacture large quantities of mines.