The Submarine War

THE present basic strategy of the United Nations appears to have two chief goals. It aims to contain Japan -- that is, to hold her in check so that she cannot overwhelm the Chinese or launch an offensive against Russia, India or Australia, meanwhile preventing her from recouping her dwindling economic strength by drawing on the resources of territories she has occupied. And it aims, while doing this with the minimum force required, to concentrate all remaining forces for the destruction of the armed power of Germany. This strategy is dictated by the fact that by far the largest single force on the side of the United Nations, the Red Army, is committed to the struggle against Germany and cannot be shifted elsewhere. That being so, sound military judgment demands that all additional strength be concentrated to bring the fight with Germany to a conclusion, leaving Japan to be dealt with later, or as opportunity may offer.

In our operations against Japan, the submarine is a most important weapon, if indeed it is not the most important one in our armory. In our fight to bring the war with Germany to an immediate decision, it is probably the strongest and most dangerous weapon at the disposal of the enemy.

I think it may fairly be said that Hitler and his High Command now have little if any hope of being able to achieve victory in this war -- victory, that is, in the sense of conquering any one of their principal foes, the British Commonwealth of Nations, the Soviet Union or the United States. They now center their hopes on a very different objective. They hope to drag out the war until we all sicken of the strain and the slaughter, and then make peace with us on terms which will allow them to retain some modicum of power, some modicum of prestige and standing with the German people. The Nazi leaders and the Prussian military caste, as joint custodians of the "sacred" ideals of German world domination, are well aware that for the time being the game is up. Their remaining hope is to be left in such a position, however enfeebled they may be temporarily, that later on when opportunity smiles again, when their opponents have gone back to sleep, they can resume the game. Let us not make the mistake of supposing that these German leaders are fools. They know perfectly well that the blitzkrieg phase of the war is over. They are now waging a war of attrition -- of moral and psychological as well as physical attrition. To such a war, to such a purpose, no weapon could be better adapted than the submarine.

In these circumstances, the immediate objectives of the United Nations may be very simply stated: to bring to bear against the vital centers of Germany, and against Germany's armed forces wherever found, a crushing weight of superior armament, and to do this as quickly as possible, not only to end the war, but because Japan cannot be contained forever with minimum forces. Only one of the United Nations has an army in the field on the Continent of Europe -- Russia. Hence, the United States and Britain must give Russia all possible support. The Germans must be driven out of Africa, in order that its whole north shore may become a base of Allied operations against Europe and in order that the Mediterranean short-cut may be available for Allied shipping. The air offensive against Germany's communications and production centers must be intensified. Finally, the "fortress of Europe" must be directly assaulted by American and British armies, working in close coördination with their Russian allies. For the accomplishment of these objectives, Russian power alone, or Russian power plus British power, is insufficient. The full weight of America is demanded in addition. The greater the American strength, and the quicker it comes, the quicker the decision will be attained. This is mainly a matter of shipping, of sea power.

The United States is, to all intents and purposes, fully mobilized. If we could suddenly be moved to the geographical position of France, the German case would be instantly hopeless. But we must make a 3,000-mile sea passage to reach Europe or Africa. Britain is an island and must likewise use ships to move men and supplies to Europe or Africa, save within the very definite limitations of air transport. All Anglo-American help to Russia must go by sea.

Germany cannot strike directly at the United States. She has struck directly at Russia, and been worsted. She cannot invade Britain; and she has been soundly beaten in an attempt to subdue that indomitable island from the air. But Germany can still strike at the lines of communication by which American and British power is distributed to the various theaters of war, by which British power is itself sustained and the British people fed, by which in the end the United States will put its decisive weight into the European battle. The more ships Germany can destroy, the longer she can defer the day of reckoning. That is the significance of the U-boat campaign.

Quite different were the conditions at the time of the great submarine crisis of the last war. In the early months of 1917, Germany was seemingly in the full tide of victory. Actually, she was feeling the strain of war, though Russia was slowly crumbling and the Western Front held fast. Germany's leaders deliberately assumed the risk of American entry into the war in order to gamble on the U-boat being able to starve out the British before unprepared America could make her weight felt. The German hope that the U-boat might bring complete and decisive victory came within an ace of fulfilment. Germany was beaten by the introduction, at the fifty-ninth minute of the eleventh hour, of the convoy system. In all probability it will be the convoy system, on modern lines, which will deny her in this war the lesser but still considerable advantages which she hopes to obtain from her submarines.

The situation in the Atlantic may be described as a double blockade. The British and American navies, commanding the surface of the sea, are able to deny that surface to German merchant vessels. Germany can receive nothing from any transoceanic source save by means of an occasional lucky blockade runner. This has an increasingly serious effect on Germany's economy, and therefore on her ability to wage war. On the other hand, by means of submarines and long-range aircraft Germany seeks to deny the movement of troops and supplies to and from the island of Great Britain, which not only is a springboard for American power to be launched against Europe, but possesses great fighting power of its own. Likewise, Germany seeks to stop the movement of American and British ships to and from Africa, now to become another base for attack on Europe. This undersea blockade cannot be as effective as the surface blockade because of the nature of the chief instrument it employs, the submarine, whose tactics must always be those of stealth and evasion rather than of the forthright exercise of power. But if the submarine can destroy a sufficiently high percentage of United Nations ships in transit across the Atlantic, it can so reduce the margin of available fighting power and supplies reaching Britain and Africa that, when minimum defensive needs and minimum rations for the British people have been taken care of, there will not be enough left over to permit the accumulation of sufficient forces for an offensive against Germany.

Strategically, Germany of 1943 has many advantages which Germany of 1917 did not possess. Chief among these is the possession of the French and Norwegian bases on the open Atlantic. In 1914 all her submarine bases were within the North Sea. To reach their ocean hunting grounds, the U-boats leaving Wilhelms-haven, Emden or Zeebrugge either had to pass through the netted and mined and patrolled bottleneck of the English Channel or had to make the long voyage around Scotland, passing out to sea through the narrow waters between the coasts of Scotland and Norway. Today all the Norwegian and French coasts are in German hands, while much of the coast of Ireland and all the coast of Portugal, as well as the Portuguese islands, are denied to the Allies. This gives the Germans a tremendous advantage in economy of operation and freedom of action. Moreover, it makes coöperation between German aircraft and submarines much easier.

In the technical field, the German U-boat of today is a much more formidable vessel than its predecessor of 1917. In the first place, it is tougher, harder to kill. The 1917 U-boat could hardly dive to depths of over 200 feet; below that, the pressure became dangerous. Today, pressure hulls are strong enough to withstand submersion to 600 or 700 feet. This enables the modern submarine to lie on the bottom, engines stopped, in many places where this would have been impossible a few years ago. It also complicates immensely the problem of the destroyer attacking with depth charges. The depth charge must be aimed in two dimensions; it must take the right direction, and it must be set to explode at the right depth. When the latter factor was limited to 200 feet, the task of laying a "pattern" which was sure to bag a given submarine was much simpler than it is now when the depth factor is extended to 700 feet. Moreover, in 1917 a depth charge or a mine needed only to explode within 100 or 150 feet of a submarine to be reasonably certain of doing it fatal injury; whereas today 15 to 25 feet is none too close.

Next, the 1943 submarine is much faster than its predecessor. Built on sleeker lines, and with more powerful engines, it is capable of attaining speeds of 20-22 knots on the surface, whereas 12-14 knots was good speed in 1917. The average speed of merchant convoys is not much over 10 knots. This means that when a scouting submarine or an airplane locates a convoy it can call other submarines in the vicinity; these can run ahead of the convoy, on parallel or converging courses, take up position, and waylay the convoy at a moment when conditions of sea, visibility and weather are most favorable for attack. Moreover, the submarine can run away from many types of escort vessels, especially converted yachts and the old-style sub-chasers. As a result, more expensive and powerful engines, taking longer to build, must be installed in the new escort ships.

The modern submarine also carries more dangerous weapons than did that of 1917. Its principal sting is still the torpedo; but the torpedo of today is more accurate, has longer range, and has greater destructive power than in former times. Some German torpedoes are propelled by electric batteries, eliminating the telltale trail of bubbles which used to arise on the surface from the old compressed air propulsion. This was one of the best means of locating the submarine when it attacked a convoy. The Germans also use torpedoes which are directed to their targets by magnetic and acoustic devices, thus insuring a greater degree of accuracy. The magnetic type has been in part discounted by the invention of the "de-gaussing" gear, but this is expensive and requires highly skilled personnel both for its manufacture and installation. Submarines no longer always have to raise their periscopes before firing torpedoes. The course of a torpedo may be directed by the use of sound devices, though visual bearings still are more accurate if they can be taken without undue risk.

Improvements in Diesel engines have given the modern submarine enormous radius of action. Most of the present larger German U-boats can cruise 15,000 miles without refueling. Indeed, their endurance is limited less by fuel capacity than by the human factor -- the ability of the crew to stand up under the gruelling trials of a war cruise. This is mitigated by the fact that there are more comforts and more living space in the modern U-boats than in the older ones. Moreover, submarine supply ships now bring out fresh food and mail as well as fuel and torpedoes to the cruising subs.

At best, however, a submarine must return to base at regular periods in order to give the crew a run on shore and a change from the cramped and wearing conditions under which they live at sea. A submarine crew is a highly trained fighting team. Each man has specific duties which he must learn to perform with accuracy and dispatch; he must know what to do, how to do it, and why he is doing it. The lives of every officer and man are in the hands of every other. The submarine service is one service where mistakes are not condoned. At sea in hostile waters there is no letup from the constant strain. An enemy airplane may dive out of any passing cloud; every vessel sighted may be an armed foe; every channel may be mined. There is never a moment on the surface when it may not be necessary to send the ship down in a "crash dive" to avoid sudden attack; and when submerged there is never a moment when it is assuredly safe to show the periscope. Human nerves can stand this sort of thing for a time, but only for a time; then there must come either rest or a collapse.

The heaviest burden of all rests upon the commanding officer. His personal responsibility is greater than in any other branch of the naval service. He it is who must make every decision, meet every emergency; hour by hour and minute by minute, the safety of the ship and the lives of all on board are in his hands. His officers and men must have the utmost confidence in his skill, courage and ability, and he in turn must have complete confidence in every one of his subordinates. Otherwise there will be disaster, born of hesitation and uncertainty in the split seconds of decision and action upon which may hang a submarine's success or her destruction. The commanding officer must personally conduct his ship to the best position for attacking her prey; he must choose the course, lay off the torpedo heading, and fire the torpedoes. When this is done, he must make the decision whether to dive and withdraw in order to avoid counterattack or attempt to attack another victim. In time of trouble he must be steadfast and cool, calculating chances, taking wise action, inspiring all by his bearing and good judgment. The ideal submarine captain is a composite of character, ability and experience. No navy has any surplus of such men; even a large navy cannot have very many submarine captains of the first rank. Such leaders, with the special qualities required by the submarine service, are not to be made out of every graduated midshipman. That this is true is attested by the fact that in the last war nearly two-thirds of the total British shipping sunk by German submarines fell prey to 25 submarine captains, each of whom averaged about 160,000 tons. The Germans used a total of about 250 submarine captains during the war. The average "kill" of the other nine-tenths of these officers was only about 12,000 tons.

Here is one great weakness of the submarine which the Germans have not been able to overcome, and never will be able to overcome. When one of their good captains goes down with his ship, he is gone forever, and it may take years to replace him. Moreover, the crew he has trained is gone too. The gradual dilution of submarine crews with green men, the weeding out of key petty officers to train new crews, produces, in any rapid expansion of submarine strength such as is now taking place in Germany, a general decrease in the average quality of the crews which can be made good only by experience under active war conditions. And in the submarine service an inexpert crew is likely to pay for experience with their lives.

There are two other inherent weaknesses of the submarine which the Germans have not been able to eliminate. The first is vulnerability. A submarine on the surface, holed by a single shell, cannot dive; if it is any distance from base, it is done for. The second is the submarine's low speed and low endurance when submerged. On the surface, it uses Diesel engines for the most part; but submerged it is propelled by electric motors, which draw their current from storage batteries. These batteries have a sufficient capacity to keep the submarine moving at two or three knots for a day and a half, perhaps a little more; but at any higher speed the batteries are much more quickly exhausted. The top speed, submerged, is ten or eleven knots, and this can be maintained for just about one hour. This means that a submarine manœuvring to attack a convoy must move to its position on the surface; it may dive to attack, but if it misses it has no chance of overtaking its victim without again coming to the surface.

All these characteristics of submarines must be kept in mind if one is to understand the problem now facing the United Nations in combatting this menace. We must determine where and how the submarine can best be attacked, and what means out of our total resources we can afford to apportion to this task. In considering the priorities to be assigned to anti-submarine measures, we must apply the principle of "first things first." It is of little avail to train soldiers and produce tanks and artillery and machine guns unless we have the means to transport them to the places where they can be used against the enemy. Nor is it much use trying to build ships faster than the enemy can sink them, without at the same time providing adequate protection for the ships already afloat. Experience has shown that it is far more efficient, from the point of view of tonnage continuously in service, to build eighty merchant ships and twenty high-seas escort vessels rather than a hundred merchant ships and no escort vessels. One finds patience with difficulty for the current discussions in which certain of the disputants seek higher priorities for valves, fittings, small motors and electrical appliances for the production of synthetic rubber, high-octane gasoline and other things, at the expense of escort ships. As Admiral Lord Jellicoe remarked at the height of the crisis of 1917, military history is replete with examples of the disastrous consequences of attempting large-scale operations at the farther end of insecure lines of communication. The Germans have just had a lesson in that respect at Stalingrad, and another in Libya. It does seem that we might learn from experience, and not have to be taught the hard way, at the price of the blood of our bravest and best.

The German submarine can be attacked in four general areas:

It may be attacked, first, at the plants which manufacture engines and appliances and in the shipyards where the hulls are fabricated. This task lies, for the present, entirely in the hands of our bombing squadrons, and they are performing it well; but it is idle to hope that they can do more than cut down the output.

Secondly, it may be attacked at the operating bases where it goes to be refueled and overhauled and where damages are repaired. At the larger German bases, such as Lorient, the submarines are kept in covered pens, with roofs of concrete a number of feet thick. Thus it is difficult to injure the submarines themselves even by direct hits from bombs; but damage can be done to the workshops, oil storage tanks, warehouses, barracks and approaches. Much greater damage could be done by commando raids which might afford opportunities for the systematic demolition of all facilities. If trained engineer troops could be given full freedom of action in a base area for only three or four hours, they could do more damage than is likely to be accomplished in a dozen air raids.

Thirdly, it may be attacked while it journeys to and from its allotted cruising grounds. Here the principal weapons at our disposal are aircraft and mines. Aircraft can now patrol wide areas of ocean, and the German submarine bases are so located that no U-boat can leave a base either in France or Norway, let alone Germany, and reach a station in the open Atlantic without passing through a patrol area of Allied aircraft. The most difficult area to patrol is the Bay of Biscay, because of German fighter opposition and because the patrolling aircraft in the farther reaches of the Bay are in the outer zone of their radius of action. German U-boats leaving Lorient at nightfall and steering a generally southwesterly course have a good chance of escaping observation, especially in the long winter nights. Their chances will grow less as the nights shorten; on the other hand, the chances of the patrol planes evading attack by German fighters will be similarly affected. Our ability to use bases in Southern Ireland would substantially improve this situation; an Allied air base in the northwestern corner of Spain would probably put an end to the usefulness of Lorient and Saint Nazaire as German submarine bases for good and all. But the chances of obtaining bases in either of these localities seem, at this writing, remote. As for mining operations, the chief difficulty is the enormous amount of material required to obtain really worthwhile effects. In the last war, both sides laid extensive minefields, but it was not until the industrial resources of the United States could be called upon that it was found possible to lay the great North Sea mine barrage between Norway and Scotland. Even so, the mine destroyed more German submarines than any other weapon in World War I. Now that we have acoustic and magnetic mines, and are able to lay mines from airplanes, the idea of "mining in" the German submarine bases is, in theory, highly attractive; but before we adopted it there would have to be evidence to show that the material and labor necessary for such an effort could not be better expended on escort craft or air bombing. Vast areas of the North Sea were closed off by mines in the last war, but the Germans contrived to keep channels swept clear in most cases. It is always possible for the enemy to sweep channels in minefields laid close to his bases, though the very fact that he is required to expend resources in men and material to do so is something of a gain. Other means of attacking submarines in waters through which they must pass to reach their hunting grounds are nets (sometimes equipped with explosive charges) and surface patrols.

But when all is said and done, these three methods combined are not as likely to produce casualties amongst the enemy's U-boat fleet (and at the same time directly protect the merchant shipping he is seeking to attack) as the convoy system. The aim of the convoy system is to insure that no submarine can attack a merchant vessel without itself encountering the attack of an armed escort craft fitted to deal with it. The convoy system places these submarine-killers where the submarine must come if it is to fulfil its mission -- in the vicinity of the prey.

As I have already remarked, it was the convoy system which beat the submarine in the last war. Yet for a long time the British naval authorities resisted its introduction, partly from innate conservatism, partly because certain well-reasoned objections seemed to more than offset the advantages to be obtained. It was urged that deliveries would be reduced because of delays in assembling convoys, because the speed of a convoy is necessarily that of the slowest ship, and because of congestion in ports of arrival. Doubts were entertained as to whether merchant ships could "keep station" in the manner required for the orderly handling of a convoy. It was further argued that to bring so many ships together in one place afforded the U-boats a larger target.

None of these objections, as the event proved, had much real substance. The question of speed was disposed of by forming convoys of ships possessing relatively similar speeds. Thus at one period there were five convoy sailings from New York during each eight-day "cycle," two being 8-knot convoys, two being composed of ships capable of doing 10 knots, and one of faster ships which could do 12½ knots. Still faster ships usually sailed without escort and depended on their speed to bring them safe to port. Port congestion was cared for by a better organization of port facilities, by the formation of movable battalions of dock workers who could be hurried from one port to another as need arose, and by dispersing convoys to several ports when well within waters protected by coastal patrol flotillas. Practice showed that merchant officers had no difficulty in keeping station; and as for the "larger target" argument, it was really somewhat ludicrous to contend that a given submarine would be more likely to find a close-packed convoy of, say, twenty ships than to find at least one of them if they were scattered over hundreds of miles of ocean. In fact, when convoys were introduced, the U-boat captains actually supposed for many days that all British shipping had been re-routed around the North of Ireland and that none was entering the Channel at all. From an area of sea formerly swarming with fat prey, all shipping seemed to them to have disappeared.

The immediate success of the first convoys must have been a revelation to those who opposed the system. Yet opposed it was until continuance of the situation was plainly bringing Britain and the Allied cause face-to-face with defeat. Even then, the naval chiefs did not give way until Prime Minister Lloyd George announced his intention of paying a personal visit to the Admiralty for a full-dress investigation of the whole problem.

The immediate falling off in the rate of destruction is the best index of the convoy system's success. In February, March and April of 1917 each operating U-boat accounted for over 800 tons of shipping per day of operation. In May, with the introduction of convoys, the figure fell to 717 tons; in June it fell to 669; by December it had reached 284, and the submarine was beaten.

The method used in convoying was simple. Merchant ships were generally organized in convoys of 20 or 24 ships, and sailed at stated intervals from the assembly ports -- New York, Hampton Roads, Sydney (Nova Scotia), Gibraltar and Dakar. For the first part of the voyage they were accompanied by the so-called "ocean escort," usually an old cruiser, whose duty it was to keep off attacks by the roving surface raiders which occasionally slipped out to sea. About two days out from a British port the destroyer escort met the convoy. The predetermined rendezvous was the outer limit of the danger zone, fixed by the known radius of action of existing submarines from German bases. Normally the destroyer escort consisted of from 8 to 14 destroyers, though it sometimes included patrol-boats and sloops. The proportion of escort ships to merchant ships thus was between one to three and one to two, or better. When the destroyer escort had brought the convoy well within coastal waters, the ships dispersed to their various ports of destination under the escort of trawlers and small patrol craft, while the destroyer escort turned about and took under its protection an outward-bound convoy of ships returning to the United States or other places. In those days there was no air problem; and the submarine problem did not exist outside the "danger zone," except in the form of a comparatively few German cruiser-submarines of long range.

The results speak for themselves. Of 9,354 ships in homeward convoys, 9,250 arrived safely; only 61 were lost while actually under escort, the others being attacked after parting company, or being lost as a result of marine perils. Of 7,339 ships in outward convoys, 7,289 made port safely, and only 41 were torpedoed while under escort. Thus the convoy system delivered safely no less than 99.08 percent of the ships committed to its care; and only .62 percent were torpedoed while in convoy. It would be difficult indeed to find a better record for any military plan or system in all the long history of warfare. If we could do as well today, we could finish off Germany before snow flies this coming winter.

But it should be emphasized again that in those days there was no air peril, and especially that the escorts were sufficient in number from the very beginning in proportion to the number of ships to be protected.

The situation in 1943 is very different in detail, though the solution to be applied is undoubtedly the same in principle. First of all, escort must be provided over the whole distance, but particularly in areas where we cannot maintain a constant air patrol (roughly speaking, beyond a 500-mile radius from established bases on one side or other of the Atlantic). The middle of the ocean is therefore the real danger zone in this war. The vigilance of the Coastal Command of the Royal Air Force, commanded by Air Marshal J. C. Slessor (under whom are placed all anti-submarine operations in British coastal waters) is such that no German U-boat has dared operate within 300 miles of the island of Great Britain for many months. Our own Eastern Sea Frontier Command, under Vice Admiral Adolphus Andrews, has now made American coastal waters similarly dangerous for enemy submarines. But the increased radius of action of the U-boats enables them to evade these dangers by operating far out at sea.

The air factor must also be taken into account. Within the radius of operations of German aircraft, the U-boat captain enjoys the enormous advantage of having an "eye in the air" to help him locate his prey. But this is becoming rarer due to the growth of Allied air superiority. Where aircraft assistance is lacking, the signal to gather for an attack on a convoy is given by any one of the patrolling submarines which spots it first. The best defense against this "wolf pack" system is vigilant air patrol around each convoy for a distance of 200 miles in all directions. If no U-boat can come to the surface by daylight within this distance of the convoy, there can be no catching up with it by night. Such a system would require either that all convoys sail only through waters patrolled by land-based aircraft, which is at present impossible, or that each convoy be accompanied, beyond the patrolling range of land-based aircraft, by a converted carrier equipped with enough planes to maintain the daily patrol. How many carriers this would require is a point on which I can offer no opinion, but certainly it is a number which we do not yet possess.

Next as to surface escort. The surface escort, composed of destroyers, special escort ships and corvettes, comes into action as a rule only after the convoy is actually attacked. The job of the air escort is to prevent an attack from taking place at all; the job of the surface escort is to punish the enemy submarines after the attack has taken place, and so in the end to make attacks too expensive for the enemy to keep them up. For escort duties, there is required a type of ship faster than any submarine at its surface speed. It must have good sea-keeping qualities, be highly manœuvrable, be well armed with guns and depth charges, and be fitted with all the various radio and sound devices known to science for detecting the presence and following the course of hostile submarines. These have been vastly improved since the last war.

When the submarines of a German "wolf pack" are notified of the approach of a convoy they run at full speed, on the surface, to get ahead of it, and then lie in wait to attack at a favorable time and place. Most attacks now take place at night. The day is spent in manœuvring for position. The usual procedure is for one or two submarines to attack on one side of the convoy; having fired their torpedoes, they do their best to get away, hoping to draw off the bulk of the escort in pursuit. The convoy is then attacked by all the remaining submarines. The advantages of the method are obvious. By day, the track of the torpedoes or at any rate the "impulse bubble" of escaping air from the torpedo tube may disclose the position of the submarine to a vigilant escort; at night, the submarines operate largely on the surface, can use their high speed to get away in the darkness, and can always submerge if too closely pressed. The answers are more aircraft, to prevent surface runs and scouting in the daytime and to provide more complete air observation, and more escorts to deal with attackers at night.

The tactics of the escort must be based on the careful group training of the escort as a whole, including the air component. The escorting surface ships must be numerous enough to permit a certain number to be left permanently with the convoy, while others are detached in pursuit of any enemy which may appear. One of our main troubles so far has been that we have not had enough escorts to give proper protection. As a result, convoys have been larger, and escort groups smaller, than in the last war.

When an attack is delivered, the ships told off by the escort commander for the purpose must immediately make it their job to locate each submarine and stay with it until it is destroyed or has definitely made its escape. At the least it must be driven below the surface and compelled to stay there. The devices now at the disposal of escort-ship commanders for locating and tracking submarines are usually adequate for this purpose, if the submarine can be located approximately well at the start. In case of "wolf-pack" attacks, several hunting ships may have to be detached, yet the convoy must not be left unprotected. This emphasizes the need for a numerous escort. The ideal situation is attained when every enemy submarine captain has learned by experience that to attack one of our convoys means beyond question that he must immediately submerge and prepare to dodge depth charges; also that he will not have a chance to surface again during the night, and that there will be hostile aircraft overhead when daylight comes. It is when this point is reached that the U-boat game begins to be no longer worth the candle. It is then that the rate of submarine losses begins to go up and of merchant ships down. It is then that the morale of the crews begins to crack, as it did in the German submarine service toward the end of the last war.

In addition, experience has shown the necessity for organizing special "killer groups," composed ideally of large destroyers with great radius of action, based at convenient points from which they can quickly reach all parts of the submarine-infested zone. As concentrations of enemy submarines are detected by our aircraft or surface patrols, or are made manifest by attacks in a given locality, a killer group proceeds to the indicated area, accompanied by long-range patrol planes, and systematically hunts down the "wolf pack."

The arming of merchant vessels is not of great importance in the actual destruction of submarines, yet it is a useful part of an anti-submarine system. An armed ship can add a certain volume of gunfire to the efforts of the escort in case a submarine can be located on the surface; and the possession of a gun gives at least a fighting chance to a ship which becomes separated from her convoy or is proceeding without escort. The provision of anti-aircraft armament for merchant shipping is also of importance, especially in the case of ships operating on the Murmansk run, where long days are at hand again and where the ice will soon be creeping south to narrow the available channel.

The various measures outlined above must be coördinated and controlled according to a master plan. This plan must be devised by men with the technical experience to know what they are doing but with a sufficiently open mind toward new and even radical suggestions. Scope must be given to the full resources of American ingenuity; conservatism must stand aside.

All this can be achieved, in time. It will take time to turn out the escorts and the aircraft; it will take time to provide additional bases;^[i] it will take time to train officers and crews; it will take time to develop our bombing of enemy bases and factories, our commando raids, our mining operations, our patrol of inshore waters; it will take time to work out new ideas and devices. All these things can be done. Indeed, they must be done if the war is to be won, if the enemy is to be defeated in his last hope of wearing us down. We have learned in the North African expedition, and otherwise, that when there is complete protection of the modern type, which means both in the air and on the surface of the sea, convoys can get through submarine infested zones with little or no loss. Our problem is to provide this full protection to every convoy at the same time that we keep up and intensify all the other phases of our anti-submarine effort.

We must be prepared for the most desperate and savage efforts on the part of the enemy. In the last war, the Germans never had more than 175 submarines at any given time, and the number in actual operation at sea rarely exceeded 50. This spring they will probably have in the neighborhood of 400, of which perhaps 125 or 150 can be operating at once; and these will have the advantage of operating from Atlantic bases. When the last war closed, the Allies possessed over 700 destroyers and literally thousands of patrol craft. Today we may doubt whether, in the Atlantic Ocean, the British and American Navies together have more than 250 destroyers, though the number of corvettes is possibly greater than this. Deliveries on our new escort craft program have been much delayed; they must be accelerated. Nor must we forget the danger that the enemy, in desperation, may cut loose all his remaining battleships and cruisers in a final attempt to smash our shipping.

The protection of our shipping is our first need, our first responsibility. It should have number one priority in all our efforts. It is good to know that special study is being given to all phases of the problems involved by a joint Anglo-American committee of experienced officers. It is greatly to be hoped that from this will evolve a joint anti-submarine command under a single capable head. But just as civilian pressure was needed to force the adoption of the convoy system in 1917, so now the pressure of an aroused and vigilant public opinion ought to be brought to bear on all concerned to speed up the production and perfection of anti-submarine weapons and measures. The crystallization of such a public opinion both here and in Great Britain is being retarded by what I believe is the unwise refusal of the authorities to permit the publication of tonnage figures of ships lost. The contention is that this would give useful information to the enemy. It is hard to see how this can be so, since the enemy knows what his submarines do with approximate accuracy; whereas the one sure means of bringing the anti-submarine program to an early state of high efficiency is to arouse the people and get them behind it.

The quicker the public realizes the seriousness of the submarine problem the quicker we shall solve it. The enemy's motto is, "While there's life there's hope." Our purpose must be to shorten both his hope and his life. Every day the war is prolonged is a day in which American men must die. The submarine can be beaten, just as it was beaten before. No guerre de course directed against merchant shipping has ever been decisively victorious, though it has often been attempted. The blitzkrieg has failed. Attrition must not be allowed to serve the enemy any better, nor as well.

^[i] If we could use the Azores, we could cover a vast area of sea now closed to our planes.