CHAPTER III
THE ADOPTION OF THE CONVOY
I
All this time that we were seeking a solution for the submarine problem we really had that solution in our hands. The seas presented two impressive spectacles in those terrible months of April, May, and June, 1917. One was the comparative ease with which the German submarines were sinking merchant vessels; the other was their failure materially to weaken the Allied fleets. If we wish a counter-picture to that presented by the Irish Sea and the English Channel, where merchant shipping was constantly going down, we should look to the North Sea, where the British Grand Fleet, absolutely intact, was defiantly riding the waves. The uninformed public explained this apparent security in a way of its own; it believed that the British dreadnoughts were anchored behind booms, nets, and mine-fields, through which the submarines could not penetrate. Yet the fact of the matter was that the Grand Fleet was frequently cruising in the open sea, in the waters which were known to be the most infested with submarines. The German submarines had been attempting to destroy this fleet for two and a half years. It had been their plan to weaken this great battle force by "attrition"; to sink the great battleships one by one, and in this way to reduce the fighting power of the fleet to such a point that the German dreadnoughts could have some chances of success. Such had been the German programme, widely heralded at the beginning of the war; nearly three years had now passed, but how had this pretentious scheme succeeded? The fact was that the submarines had not destroyed a single dreadnought. It was certainly a profitable study in contrasts—that of merchant ships constantly being torpedoed and that of battleships constantly repelling such attacks. Certainly a careful study of this situation ought to bring out facts which would assist the Allies in solving the most baffling problem of the war.
Yet there was no mystery about the immunity which these great fighting vessels were enjoying; the submarine problem, so far as it affected the battle fleet, had already been solved. The explanation was found in the simple circumstance that, whenever the dreadnoughts went to sea, they were preceded by a screen of cruisers and destroyers. It almost seemed as though these surface craft were serving as a kind of impenetrable wall against which the German U-boats were beating themselves in vain. Yet to the casual observer there seemed to be no reason why the submarines should stand in any particular terror of the destroyers. Externally they looked like the least impressive war vessels afloat. When they sailed ahead of the battle squadrons, the destroyers were ungraceful objects upon the surface of the water; the impression which they conveyed was that of fragility rather than of strength, and the idea that they could ever be the guardians of the mighty battleships which sailed behind them at first seemed almost grotesque. Yet these little vessels really possessed the power of overcoming the submarine. The war had not progressed far when it became apparent that the U-boat could not operate anywhere near this speedy little surface vessel without running serious risk of destruction.
Until the reports of submarine fighting began to find their way into the papers, however, the destroyer was probably the one type of warship in which the public had the smallest interest. It had become, indeed, a kind of ugly duckling of the Navy. Our Congress had regularly neglected it; year after year our naval experts had recommended that four destroyers be built for every battleship, and annually Congress had appropriated for only one or two. The war had also found Great Britain without a sufficient number of destroyers for the purpose of anti-submarine warfare. The Admiralty had provided enough for screening the Grand Fleet in cruising and in battle, but it had been called upon to divert so many for the protection of troop transportation, supply ships, and commerce generally that the efficiency of the fleet had been greatly undermined. Thus Britain found herself without enough destroyers to meet the submarine campaign; this situation was not due to any lack of foresight, but to a failure to foresee that any civilized nation could ever employ the torpedo in unrestricted warfare against merchant ships and their crews.
The one time that this type of vessel had come prominently into notice was in 1904, when several of them attacked the Russian fleet at Port Arthur, damaging several powerful vessels and practically ending Russian sea power in the Far East. The history of the destroyer, however, goes back much further than 1904. It was created to fulfil a duty not unlike that which it has played so gloriously in the World War. In the late seventies and early eighties a new type of war vessel, the torpedo boat, caused almost as much perturbation as the submarine has caused in recent years. This speedy little fighter was invented to serve as a medium for the discharge of a newly perfected engine of naval warfare, the automobile torpedo. It was its function to creep up to a battleship, preferably under cover of darkness or in thick weather, and let loose this weapon against her unsuspecting hulk. The appearance of the torpedo boat led to the same prediction as that which has been more recently inspired by the submarine; in the eyes of many it simply meant the end of the great surface battleship. But naval architects, looking about for the "answer" to this dangerous craft, designed another type of warship and appropriately called it the "torpedo boat destroyer." This vessel was not only larger and speedier than its appointed antagonist, but it possessed a radius of action and a seaworthiness which enabled it to accompany the battle fleet. Its draft was so light that a torpedo could pass harmlessly under the keel, and it carried an armament which had sufficient power to end the career of any torpedo boat that came its way. Few types have ever justified their name so successfully as the torpedo boat destroyer. So completely did it eliminate that little vessel as a danger to the fighting ships that practically all navies long since ceased to build torpedo boats. Yet the destroyer promptly succeeded to the chief function of the discarded vessel, that of attacking capital ships with torpedoes; and, in addition to this, it assumed the duty of protecting battleships from similar attack by enemy vessels of the same type.
It surprises many people to learn that the destroyer is not a little boat but a warship of considerable size. This vessel to-day impresses most people as small only because all ships, those which are used for commerce and those which are used for war, have increased so greatly in displacement. The latest specimens of the destroyer carry four-or five-inch guns and twelve torpedo tubes, each of which launches a torpedo that weighs more than a ton, and runs as straight as an arrow for more than six miles. The Santa Maria, the largest vessel of the squadron with which Columbus made his first voyage to America, had a displacement of about five hundred tons, and thus was about half as large as a destroyer; and even at the beginning of the clipper ship era few vessels were much larger.
Previous to 1914 it was generally believed that torpedo attacks would play a large part in any great naval engagement, and this was the reason why all naval advisers insisted that a large number of these vessels should be constructed as essential units of the fleet. Yet the war had not made much progress when it became apparent that this versatile craft had another great part to play, and that it would once more justify its name in really heroic fashion. Just as it had proved its worth in driving the surface torpedo boat from the seas, so now it developed into a very dangerous foe to the torpedo boat that sailed beneath the waves. Events soon demonstrated that, in all open engagements between submarine and destroyer, the submarine stood very little chance. The reason for this was simply that the submarine had no weapon with which it could successfully resist the attack of the destroyer, whereas the destroyer had several with which it could attack the submarine. The submarine had three or four torpedo tubes, and only one or two guns, and with neither could it afford to risk attacking the more powerfully armed destroyer. The U-boat was of such a fragile nature that it could never afford to engage in a combat in which it stood much chance of getting hit. A destroyer could stand a comparatively severe pounding and still remain fairly intact, but a single shell, striking a submarine, was a very serious matter; even though the vessel did not sink as a result, it was almost inevitable that certain parts of its machinery would be so injured that it would have difficulty in getting into port. It therefore became necessary for the submarine always to play safe, to fight only under conditions in which it had the enemy at such a disadvantage that it ran little risk itself; and this was the reason why it preferred to attack merchant and passenger ships rather than vessels, such as the destroyer, that could energetically defend themselves.
The comparatively light draft of the destroyer, which is about nine or ten feet, pretty effectually protects it from the submarine's torpedo, for this torpedo, to function with its greatest efficiency, must take a course about fifteen feet under water; if it runs nearer the surface than this, it comes under the influence of the waves, and does not make a straight course. More important still, the speed of the destroyer, the ease with which it turns, circles, and zigzags, makes it all but impossible for a torpedo to be aimed with much chance of hitting her. Moreover, the discharge of this missile is a far more complicated undertaking than is generally supposed. The submarine commander cannot take position anywhere and discharge his weapon more or less wildly, running his chances of hitting; he must get his boat in place, calculate range, course, and speed, and take careful aim. Clearly it is difficult for him to do this successfully if his intended victim is scurrying along at the rate of thirty or forty miles an hour. Moreover, the destroyer is constantly changing its course, making great circles and indulging in other disconcerting movements. So well did the Germans understand the difficulty of torpedoing a destroyer that they practically never attempted so unprofitable and so hazardous an enterprise.
Torpedoes are complicated and expensive mechanisms; each one costs about $8,000 and the average U-boat carried only from eight to twelve; it was therefore necessary to husband these precious weapons, to use them only when the chances most favoured success; the U-boat commander who wasted them in attempts to sink destroyers would probably have been court-martialled.
But while the submarine had practically no means of successfully fighting the destroyer, the destroyer had several ways of putting an end to the submarine. The advantage which really made the destroyer so dangerous, as already intimated, was its excessive speed. On the surface the U-boat made little more than fifteen miles an hour, and under the surface it made little more than seven or eight. If the destroyer once discovered its presence, therefore, it could reach its prey in an incredibly short time. It could attack with its guns, and, if conditions were favourable, it could ram; and this was no trifling accident, for a destroyer going at thirty or forty miles could cut a submarine nearly in two with its strong, razor-like bow. In the early days of the war these were the main methods upon which it relied to attack, but by the time that I had reached London, another and much more frightful weapon had been devised. This was the depth charge, a large can containing about three hundred pounds of TNT, which, if it exploded anywhere within one hundred feet of the submarine, would either destroy it entirely or so injure it that the victim usually had to come to the surface and surrender.
I once asked Admiral Jellicoe who was the real inventor of this annihilating missile.
"No man in particular," he said. "It came into existence almost spontaneously, in response to a pressing need. Gunfire can destroy submarines when they are on the surface, but you know it can accomplish nothing against them when they are submerged. This fact made it extremely difficult to sink them in the early days of the war. One day, when the Grand Fleet was cruising in the North Sea, a submarine fired a torpedo at one of the cruisers. The cruiser saw the periscope and the wake of the torpedo, and had little difficulty in so manœuvring as to avoid being struck. She then went full speed to the spot from which the submarine had fired its torpedo, in the hope of ramming it. But by the time she arrived the submarine had submerged so deeply that the cruiser passed over her without doing her any harm. Yet the officers and crew could see the submerged hull; there the enemy lay in full view of her pursuers, yet perfectly safe! The officers reported this incident to me in the presence of Admiral Madden, second in command.
"'Wouldn't it have been fine,' said Madden, 'if they had had on board a mine so designed that, when dropped overboard, it would have exploded when it reached the depth at which the submarine was lying?'"
"That remark," continued Admiral Jellicoe, "gave us the germinal idea of the depth charge. I asked the Admiralty to get to work and produce a 'mine' that would act in the way that Admiral Madden had suggested. It proved to be very simple to construct—an ordinary steel cylinder filled with TNT; this was fitted with a simple firing appliance which was set off by the pressure of the water, and could be so adjusted that it would explode the charge at any depth desired. This apparatus was so simple and so necessary that we at once began to manufacture it."
The depth charge looked like the innocent domestic ash can, and that was the name by which it soon came to be popularly known. Each destroyer eventually carried twenty or thirty of these destructive weapons at the stern; a mere pull on a lever would make one drop into the water. Many destroyers also carried strange-looking howitzers, which were made in the shape of a Y, and from which one ash can could be hurled fifty yards or more from each side of the vessel. The explosion, when it took place within the one hundred feet which I have mentioned as usually fatal to the submarine, would drive the plates inward and sometimes make a leak so large that the vessel would sink almost instantaneously. At a somewhat greater distance it frequently produced a leak of such serious proportions that the submarine would be forced to blow her ballast tanks, come to the surface, and surrender. Even when the depth charge exploded considerably more than a hundred feet away, the result might be equally disastrous, for the concussion might distort the hull and damage the horizontal rudders, making it impossible to steer, or it might so injure the essential machinery that the submarine would be rendered helpless. Sometimes the lights went out, leaving the crew groping in blackness; necessary parts were shaken from their fastenings; and in such a case the commander had his choice of two alternatives, one to be crushed by the pressure of the water, and the other to come up and be captured or sunk by his surface foe. It is no reflection upon the courage of the submarine commanders to say that in this embarrassing situation they usually preferred to throw themselves upon the mercy of the enemy rather than to be smashed or to die a lingering and agonizing death under the water. Even when the explosion took place at a distance so great that the submarine was not seriously damaged, the experience was a highly disconcerting one for the crew. If a dozen depth charges were dropped, one after the other, the effect upon the men in the hunted vessel was particularly demoralizing. In the course of the war several of our own submarines were depth-charged by our own destroyers, and from our crews we obtained graphic descriptions of the sensations which resulted. It was found that men who had passed through such an ordeal were practically useless for several days, and that sometimes they were rendered permanently unfit for service. The state of nerves which followed such an experience was not unlike that new war psychosis known as shell-shock. One of our officers who had had such an adventure told me that the explosion of a single depth charge under the water might be compared to the concussion produced by the simultaneous firing of all the fourteen-inch guns of a battleship. One can only imagine what the concussion must have been when produced by ten or twenty depth charges in succession. Whether or not the submarine was destroyed or seriously injured, a depth-charged crew became extremely cautious in the future about getting anywhere in the neighbourhood of a destroyer; and among the several influences which ultimately disorganized the moral of the German U-boat service these contacts with depth charges were doubtless the most important. The hardiest under-water sailor did not care to go through such frightful moments a second time.
This statement makes it appear as though the depth charge had settled the fate of the submarine. Yet that was far from being the case, for against the ash can, with its 300 pounds of TNT, the submarine possessed one quality which gave it great defensive power. That was ability to make itself unseen. Strangely enough, the average layman is inclined to overlook this fairly apparent fact, and that is the reason why, even at the risk of repeating myself, I frequently refer to it. Indeed, the only respect in which the subsurface boat differs essentially from all other war vessels is in this power of becoming invisible. Whenever it descries danger from afar, the submarine can disappear under the water in anywhere from twenty seconds to a minute. And its great advantage is that it can detect its enemy long before that enemy can detect the submarine. A U-boat, sailing awash, or sailing with only its conning-tower exposed, can see a destroyer at a distance of about fifteen miles if the weather is clear; but, under similar conditions, the destroyer can see the submarine at a distance of about four miles. Possessing this great advantage, the submarine can usually decide whether it will meet the enemy or not; if it decides that it is wise to avoid an encounter, all it has to do is to duck, remain submerged until the destroyer has passed on, entirely unconscious of its presence, and then to resume its real work, which is not that of fighting warships, but of sinking merchantmen. The chief anxiety of the U-boat commander is thus to avoid contact with its surface foe and its terrible depth charge, whereas the business of the destroyer commander is to get within fighting distance of his quarry.
Ordinarily, conditions favour the U-boat in this game, simply because the ocean is so large a place. But there is one situation in which the destroyer has more than a fighting chance, for the power of the submarine to keep its presence secret lasts only so long as it remains out of action. If it makes no attempt to fight, its presence can hardly ever be detected; but just as soon as it becomes belligerent, it immediately reveals its whereabouts. If it comes to the surface and fires its guns, naturally it advertises to its enemy precisely where it is; but it betrays its location almost as clearly when it discharges a torpedo. Just as soon as the torpedo leaves the submarine, a wake, clearly marking its progress, appears upon the surface of the water. Though most newspaper readers have heard of this tell-tale track, I have found few who really understand what a conspicuous disturbance it is. The torpedo is really a little submarine itself; it is propelled by compressed air, the exhaust of which stirs up the water and produces a foamy, soapy wake, which is practically the same as that produced by the propeller of an ocean liner. This trail is four or five feet wide; it is as white and is as distinct as a chalk line drawn upon a blackboard, provided the weather is clear and the sun is in the right direction. Indeed, it is sometimes so distinct that an easily manœuvred ship, and even sometimes a merchantman, can avoid the torpedo which it sees advancing merely by putting over the helm and turning out of its course. But the chief value of this wake to the submarine hunters is that it shows the direction in which the submarine was located when the torpedo started on its course. It stands out on the surface of the water like a long, ghostly finger pointing to the spot where the foe let loose its shaft.
As soon as the destroyer sees this betraying disturbance, the commander rings for full speed; and one of the greatest advantages of this type of vessel is that it can attain full speed in an incredibly short time. The destroyer then dashes down the wake until it reaches the end, which indicates the point where the submarine lay when it discharged its missile. At this point the surface vessel drops a depth charge and then begins cutting a circle, say, to the right. Pains are taken to make this circle so wide that it will include the submarine, provided it has gone in that direction. The destroyer then makes another circle to the left. Every ten or fifteen seconds, while describing these circles, it drops a depth charge; indeed, not infrequently it drops twenty or thirty in a few minutes. If there is another destroyer in the neighbourhood it also follows up the wake and when it reaches the indicated point, it circles in the opposite direction from the first. Sometimes more than two may start for the suspected location and, under certain conditions, the water within a radius of half a mile or more may be seething with exploding depth charges.
It is plain from this description that the proceeding develops into an exceedingly dangerous game for the attacking submarine. It is a simple matter to calculate the chances of escaping which the enemy has under these conditions. That opportunity is clearly measured by the time which elapses from the moment when it discharges its torpedo to the moment when the destroyer has reached the point at which it was discharged. This interval gives the subsurface boat a certain chance to get away; but its under-water speed is moderate, and so by the time the destroyer reaches the critical spot, the submarine has advanced but a short distance away from it. How far has she gone? In what direction did she go? These are the two questions which the destroyer commander must answer, and the success with which he answers them accurately measures his success in sinking or damaging his enemy, or in giving him a good scare. If he always decided these two points accurately, he would almost always "get" his submarine; the chances of error are very great, however, and that is the reason why the submarine in most cases gets away. All that the surface commander knows is that there is a U-boat somewhere in his neighbourhood, but he does not know its precise location and so he is fighting more or less in the dark. In the great majority of cases the submarine does get away, but now and then the depth charge reaches its goal and ends its career.
If only one destroyer is hunting, the chances of escape strongly favour the under-water craft; if several pounce upon her at once, however, the chances of escaping are much more precarious. If the water is shallow the U-boat can sometimes outwit the pursuer by sinking to the bottom and lying there in silent security until its surface enemy tires of the chase. But in the open sea there is no possibility of concealing itself and so saving itself in this fashion, for if the submarine sinks beyond a certain depth the pressure of the water will crush it.
While the record shows that the U-boat usually succeeded in evading the depth charges, there were enough sunk or seriously damaged or given a bad shake-up to serve as a constant reminder to the crews that they ran great danger in approaching waters which were protected by destroyers. The U-boat captains, as will appear, avoided such waters regularly; they much preferred to attack their merchant prey in areas where these soul-racking depth charges did not interfere with their operations.
It is now becoming apparent why the great battle fleet, which always sailed behind a protecting screen of such destroyers, was practically immune from torpedo attack. In order to assail these battleships the submarine was always compelled to do the one thing which, above all others, it was determined to avoid—to get within depth-charge radius of the surface craft. In discharging the torpedo, distance, as already intimated, is the all-important consideration. The U-boat carries a torpedo which has a much shorter range than that of the destroyer; it was seldom effective if fired at more than 2,000 yards, and beyond that distance its chances of hitting became very slight. Indeed, a much shorter distance than that was desirable if the torpedo was to accomplish its most destructive purpose. So valuable were these missiles and so necessary was it that every one should be used to good advantage, that the U-boat's captain had instructions to shoot at no greater distance than 300 yards, unless the conditions were particularly favourable. In the early days, the torpedoes which were fired at a greater distance would often hit the ships on the bow or the stern, and do comparatively little damage; such vessels could be brought in, repaired in a short time, and again put to sea. The German Admiralty discovered that in firing from a comparatively long distance it was wasting its torpedoes; it therefore ordered its men to get so near the prey that it could strike the vessel in a vital spot, preferably in the engine-room; and to do this it was necessary to creep up within 300 yards. But to get as close as that to the destroyers which screened the battleships meant almost certain destruction. Thus the one method of attack which was left to the U-boat was to dive under the destroyer screen and come up in the midst of the battle fleet itself. A few minutes after its presence should become known, however, a large number of destroyers would be dropping depth charges in its neighbourhood, and its chances of escaping destruction would be almost nil, to say nothing of its chances of destroying ships.
The Germans learned the futility of this kind of an operation early in the war, and the man who taught them this lesson was Commander Weddingen, the same officer who had first demonstrated the value of the submarine in practical warfare. It was Otto Weddingen who, in September, 1914, sank the old British cruisers, the Hogue, the Cressy, and the Aboukir, an exploit which made him one of the great popular heroes of Germany. A few months afterward Commander Weddingen decided to try an experiment which was considerably more hazardous than that of sinking three unescorted cruisers; he aspired to nothing less ambitious than an attack upon the Grand Fleet itself. On March 18th a part of this fleet was cruising off Cromarty, Scotland; here Weddingen came with the U-29, dived under the destroyer screen and fired one torpedo, which passed astern of the Neptune. The alarm was immediately sounded, and presently the battleship Dreadnought, which had seen the periscope, started at full speed for the submarine, rammed the vessel and sent it promptly to the bottom. As it was sinking the bow rose out of the water, plainly disclosing the number U-29. There was not one survivor. Weddingen's attempt was an heroic one, but so disastrous to himself and to his vessel that very few German commanders ever tried to emulate his example. It clearly proved to the German Admiralty that it was useless to attempt to destroy the Grand Fleet with submarines, or even to weaken it piecemeal, and probably this experience had much to do with this new kind of warfare—that of submarines against unprotected merchant ships—which the Germans now proceeded to introduce.
The simple fact is that the battle fleet was never so safe as when it was cruising in the open sea, screened by destroyers. It was far safer when it was sailing thus defiantly, constantly inviting attack, than when it was anchored at its unprotected base at Scapa Flow. Indeed, until Scapa Flow was impregnably protected by booms and mines, the British commanders recognized that cruising in the open sea was its best means of avoiding the German U-boats. No claim is made that the submarine cannot dive under the destroyer screen and attack a battle fleet, and possibly torpedo one or more of its vessels. The illustration which has been given shows that Weddingen nearly "got" the Neptune; and had this torpedo gone a few feet nearer, his experiment might have shown that, although he subsequently lost his own life, crew, and ship, he had sunk one British battleship, a proceeding which, in war, might have been recognized as a fair exchange. But the point which I wish to emphasize is that the chances of success were so small that the Germans decided that it was not worth while to make the attempt. Afterward, when merchant vessels were formed into convoys, a submarine would occasionally dive under the screen and destroy a ship; but most such attacks were unsuccessful, and experience taught the Germans that a persistent effort of this kind would cause the destruction of so many submarines that their campaign would fail. So the U-boat commanders left the Grand Fleet alone, either because they lacked nerve or because their instructions from Berlin were explicit to that effect.
II
Having constantly before my eyes this picture of the Grand Fleet immune from torpedo attack, naturally the first question I asked, when discussing the situation with Admiral Jellicoe and others, was this: "Why not apply this same principle to merchant ships?"
If destroyers could keep the submarines away from battleships, they could certainly keep them away from merchantmen. It is clear, from the description already given, precisely how the battleships had been made safe from submarines; they had proceeded, as usual, in a close formation, or "convoy," and their destroyer screen had proved effective. Thus logic apparently indicated that the convoy system was the "answer" to the submarine.
Yet the convoy, as used in previous wars, differed materially from any application of the idea which could possibly be made to the present contest. This scheme of sailing vessels in groups, and escorting them by warships, is almost as old as naval warfare itself. As early as the thirteenth century, the merchants of the Hanseatic League were compelled to sail their ships in convoy as a protection against the pirates who were then constantly lurking in the Baltic Sea. The Government of Venice used this same device to protect its enormous commerce. In the fifteenth century the large trade in wool and wine which existed between England and the Moorish ports of Spain was safeguarded by convoys, and in the sixteenth century Spain herself regularly depended upon massing her ships to defend her commerce with the West Indies against the piratical attacks of English and French adventurers. The escorts provided for these "flotas" really laid the foundation of the mighty Spanish fleet which threatened England's existence for more than a hundred years. By the time of Queen Elizabeth the convoy had thus become the all-prevailing method of safeguarding merchant shipping, but it was in the Napoleonic wars that it had reached its greatest usefulness. The convoys of that period were managed with some military precision; there were carefully stipulated methods of collecting the ships, of meeting the cruiser escorts at the appointed rendezvous, and of dispersing them when the danger zone was passed; and naval officers were systematically put in charge. The convoys of this period were very large; from 200 to 300 ships were not an unusual gathering, and sometimes 500 or more would get together at certain important places, such as the entrance to the Baltic. But these ships, of course, were very small compared with those of the present time. It was only necessary to supply such aggregations of vessels with enough protecting cruisers to overwhelm any raiders which the enemy might send against them. The merchantmen were not required to sail in any particular formation, nor were they required to manœuvre against unseen mysterious foes. Neither was it absolutely essential that they should keep constantly together; and they could even spread themselves somewhat loosely over the ocean. If an enemy raider appeared on the horizon, the escorting cruiser or cruisers left the convoy and began chase; a battle ensued, the convoy meanwhile passing on its voyage unharmed. When its protecting vessels had disposed of the attackers, they rejoined the merchantmen. No unusual seamanship was demanded of the merchant captains, for the whole responsibility for their safety rested with the escorting cruisers.
But the operation of beating off an occasional surface raider, which necessarily fights in the open, is quite a different procedure from that of protecting an aggregation of vessels from enemies that discharge torpedoes under the water. As part protection against such insidious attacks both the merchant ships and the escorting men-of-war of to-day had in this war to keep up a perpetual zigzagging. This zigzag, indeed, was in itself an efficacious method of protection. As already said, the submarine was forced to attain an advantageous position before it could discharge its torpedo; it was its favourite practice to approach to within a few hundred yards in order to hit its victim in a vital spot. This mere fact shows that zigzagging in itself was one of the best methods of avoiding destruction. Before this became the general rule, the task of torpedoing a vessel was comparatively easy. All it was necessary for the submarine to do was to bring the vessel's masts in line; that is, to get directly ahead of her, submerge with the small periscope showing only occasionally, and to fire the torpedo at short range as the ship passed by. Except in the case of very slow vessels, she could of course do this only when she was not far from the course of her advancing prey when she first sighted her. If, however, the vessel was zigzagging, this pretty game was usually defeated; the submarine never knew in what direction to go in order to get within torpedoing distance, and she could not go far because her speed under water is so slow. The same conditions apply to a zigzagging convoy. This explained why, as soon as the merchant vessel or convoy entered the submarine zone, or as soon as a submarine was sighted, it began zigzagging, first on one side and then on the other, and always irregularly, its course comprising a disjointed line, which made it a mere chance whether the submarine could get into a position from which to fire with any certainty of obtaining results. A vessel sailing alone could manœuvre in this way without much difficulty, but it is apparent that twenty or thirty vessels, sailing in close formation, would not find the operation a simple one. It was necessary for them to sail in close and regular formation in order to make it possible to manœuvre them and screen them with destroyers, so it is evident that the closer the formation the fewer the destroyers that would be needed to protect it. These circumstances make the modern convoy quite a different affair from the happy-go-lucky proceeding of the Napoleonic era.
It is perhaps not surprising that the greatest hostility to the convoys has always come from the merchant captains themselves. In old days they chafed at the time which was consumed in assembling the ships, at the necessity for reducing speed to enable the slower vessels to keep up with the procession, and at the delay in getting their cargoes into port. In all wars in which convoys have been used it has been very difficult to keep the merchant captains in line. In Nelson's day these fine old salts were constantly breaking away from their convoys and taking their chances of running into port unescorted. If the merchant master of a century ago rebelled at the comparatively simply managed convoy of those days it is not strange that their successors of the present time should not have looked with favour upon the relatively complicated and difficult arrangement required of them in this war. In the early discussions with these men at the Admiralty they showed themselves almost unanimously opposed to the convoy.
"The merchantmen themselves are the chief obstacle to the convoy," said Admiral Jellicoe. "We have discussed it with them many times and they declare that it is impossible. It is all right for war vessels to manœuvre in close formation, they say, for we spend our time practising in these formations, and so they think that it is second nature to us. But they say that they cannot do it. They particularly reject the idea that when in formation they can manœuvre their ships in the fog or at night without lights. They believe that they would lose more ships through collisions than the submarines would sink."
I was told that the whole subject had been completely threshed out at a meeting which had been held at the Admiralty on February 23, 1917, about six weeks before America had entered the war. At that time ten masters of merchant ships had met Admiral Jellicoe and other members of the Admiralty and had discussed the convoy proposition at length. In laying the matter before these experienced seamen Admiral Jellicoe emphasized the necessity of good station-keeping, and he described the close formation which the vessels would have to maintain. It would be necessary for the ships to keep together, he explained, otherwise the submarines could pick off the stragglers. He asked the masters whether eight merchant ships, which had a speed varying perhaps two knots, could keep station in line ahead (that is, in single file or column) 500 yards apart, and sail in two columns down the Channel.
"It would be absolutely impossible," the ten masters replied, almost in a chorus.
A discouraging fact, they said, was that many of the ablest merchant captains had gone into the navy, and that many of those who had replaced them could not be depended on to handle their ships in such a formation.
"We have so few competent deck officers that the captain would have to be on the bridge the whole twenty-four hours," they said. And the difficulty was not only with the bridge, but with the engine-room. In order to keep the ships constantly the same distance apart it would be necessary accurately to regulate their speed; the battleships could do this because they had certain elaborate devices, which the merchant vessels lacked, for timing the revolutions of the engines. The poor quality of the coal which they were obtaining would also make it difficult to maintain a regular speed.
Admiral Jellicoe then asked the masters whether they could sail in twos or threes and keep station.
"Two might do it, but three would be too many," was the discouraging verdict. But the masters were positive that even two merchantmen could not safely keep station abreast in the night-time without lights; two such vessels would have to sail in single file, the leading ship showing a stern light. The masters emphasized their conviction that they preferred to sail alone, each ship for herself, and to let each one take her chances of getting into port.
And there the matter rested. I had the opportunity of discussing the convoy system with several merchant captains, and in these discussions they simply echoed the views which had been expressed at this formal conference. I do not believe that British naval officers came in contact with a single merchant master who favoured the convoy at that time. They were not doubtful about the idea; they were openly hostile. The British merchant captains are a magnificent body of seamen; their first thought was to serve their country and the Allied cause; their attitude in this matter was not obstinacy; it simply resulted from their sincere conviction that the convoy system would entail greater shipping losses than were then being inflicted by the German submarines.
Many naval officers at that time shared the same view. They opposed the convoy not only on these grounds; its introduction would mean immediately cutting down the tonnage 15 or 20 per cent., because of the time which would be consumed in assembling the ships and awaiting escorts and in the slower average speed which they could make. Many ship owners and directors of steamship companies expressed the same opinions. They also objected to the convoy on the ground that it would cause considerable delay and hence would result in loss of earnings. Yet the attitude of the merchant marine had not entirely eliminated the convoy from consideration. At the time when I arrived the proposal was still being discussed; the rate at which the Germans were sinking merchantmen made this inevitable. And there seemed to be two schools among Allied naval men, one of which was opposed to the convoy, while the other insisted that it should be given a trial. The convoy had one irresistible attraction for the officer which seemed to counterbalance all the objections which were being urged against it. Its adoption would mean taking the offensive against the German submarines. The essential defect of the patrol system, as it was then conducted, was that it was primarily a defensive measure. Each destroyer cruised around in an assigned area, ready to assist vessels in distress, escort ships through her own "square" and, incidentally, to attack a submarine when the opportunity was presented. But the mere fact that a destroyer was patrolling a particular area meant only, as already explained, that the submarine had occasionally to sink out of sight until she had passed by. Consequently the submarine proceeded to operate whenever a destroyer was not in sight, and this was necessarily most of the time, for the submarine zone was such a big place and the Allied destroyer fleet was so pitifully small that it was impossible to cover it effectively. Under these conditions there were very few encounters between destroyers and submarines, at least in the waters south and west of Ireland, for the submarines took all precautions against getting close enough to be sighted by the destroyers.
But the British and French navies were not the only ones which, at this time, were depending upon the patrol as a protection against the subsurface boat. The American navy was committing precisely the same error off our Atlantic coast. As soon as Congress declared war against Germany we expected that at least a few of the U-boats would cross the Atlantic and attack American shipping; indeed, many believed that some had already crossed in anticipation of war; the papers were filled with silly stories about "submarine bases" in Mexican waters, on the New England coast, and elsewhere; submarines were even reported entering Long Island Sound; nets were stretched across the Narrows to keep them out of New York Harbour; and our coasting vessels saw periscopes and the wakes of torpedoes everywhere from Maine to Florida. So prevalent was this apprehension that, in the early days of the war, American destroyers regularly patrolled our coast looking for these far-flung submarines. Yet the idea of seeking them this way was absurd. Even had we known where the submarine was located there would have been little likelihood that we could ever have sighted it, to say nothing of getting near it. We might have learned that a German U-boat was operating off Cape Cod; we might have had the exact latitude and longitude of the location which it was expected that it would reach at a particular moment. At the time the message was sent the submarine might have been lying on the surface ready to attack a passing merchantman, but even under these conditions the destroyer could never have reached her quarry, for as soon as the U-boat saw the enemy approaching it would simply have ducked under the water and remained there in perfect safety. When all danger had passed it would again have bobbed up to the surface as serenely as you please, and gone ahead with its appointed task of sinking merchant ships. One of the astonishing things about this war was that many of the naval officers of all countries did not seem to understand until a very late date that it was utterly futile to send anti-submarine surface craft out into the wide ocean to attack or chase away submarines. The thing to do, of course, was to make the submarines come to the anti-submarine craft and fight in order to get merchantmen.
I have made this point before, and I now repeat the explanation to emphasize that the patrol system was necessarily unsuccessful, because it made almost impossible any combats with submarines and afforded very little protection to shipping. The advantage of the convoy system, as its advocates now urged, was precisely that it made such combats inevitable. In other words, it meant offensive warfare. It was proposed to surround each convoy with a protecting screen of destroyers in precisely the same way that the battle fleet was protected. Thus we should compel any submarine which was planning to torpedo a convoyed ship to do so only in waters that were infested with destroyers. In order to get into position to discharge its missile the submarine would have to creep up close to the rim that marked the circle of these destroyers. Just as soon as the torpedo started on its course and the tell-tale wake appeared on the surface the protecting ships would immediately begin sowing the waters with their depth charges. Thus in the future the Germans would be compelled to fight for every ship which they should attempt to sink, instead of sinking them conveniently in waters that were free of destroyers, as had hitherto been their privilege. Already the British had demonstrated that such a screen of destroyers could protect merchant ships as well as war vessels. They were making this fact clear every day in the successful transportation of troops and supplies across the Channel. In this region they had established an immune zone, which was constantly patrolled by destroyers and other anti-submarine craft, and through these the merchant fleets were constantly passing with complete safety. The proposal to convoy all merchant ships was a proposal to apply this same system on a much broader scale. If we should arrange our ships in compact convoys and protect them with destroyers we would really create another immune zone of this kind, and this would be different from the one established across the Channel only in that it would be a movable one. In this way we should establish about a square mile of the surface of the ocean in which submarines could not operate without great danger, and then we could move that square mile along until port was reached.
The advantages of the convoy were thus so apparent that, despite the pessimistic attitude of the merchant captains, there were a number of officers in the British navy who kept insisting that it should be tried. In this discussion I took my stand emphatically with these officers. From the beginning I had believed in this method of combating the U-boat warfare. Certain early experiences had led me to believe that the merchant captains were wrong in underestimating the quality of their own seamanship. It was my conviction that these intelligent and hardy men did not really know how capable they were at handling ships. In my discussions with them they disclosed an exaggerated idea of the seamanly ability of naval officers in manœuvring their large fleets. They attributed this to the superior training of the men and to the special manœuvring qualities of the ship. "Warships are built so that they can keep station, and turn at any angle at a moment's notice," they would say, "but we haven't any men on our ships who can do these things." As a matter of fact, these men were entirely in error and I knew it. Their practical experience in handling ships of all sizes, shapes, and speeds under a great variety of conditions is in reality much more extensive than naval officers can possibly enjoy. I learned this more than thirty years ago, when stationed on the Pennsylvania schoolship, teaching the boys navigation. This was one of the most valuable experiences of my life, for it brought me in every-day contact with merchant seamen, and it was then that I made the discovery which proved so valuable to me now.
It is true that merchant captains had much to learn about steaming and manœuvring in formation, but I was sure they could pick it up quickly and carry it out successfully under the direction of naval officers—the convoy commander being always a naval officer.
The naval officer not only has a group of vessels that are practically uniform in speed and ability to turn around quickly, but he is provided also with various instruments which enable him to keep the revolutions of his engines constant, to measure distances and the like. Moreover, as a junior officer, he is schooled in manœuvring these very ships for some years before he is trusted with the command of one of them, and he, therefore, not only knows their peculiarities, but also those of their captains—the latter very useful information, by the way.
Though it was necessary for the merchantmen, on the other hand, to bring their much clumsier ships into formation with perhaps thirty entirely strange vessels of different sizes, shapes, speeds, nationalities, and manœuvring qualities, yet I was confident that they were competent to handle them successfully under these difficult conditions. Indeed, afterward, one of my most experienced destroyer commanders reported that while he was escorting a convoy of twenty-eight ships they kept their stations quite as well as battleships, while they were executing two manœuvres to avoid a submarine.
Such influence as I possessed at this time, therefore, I threw in with the group of British officers which was advocating the convoy.
There was, however, still one really serious impediment to adopting this convoy system, and that was that the number of destroyers available was insufficient. The British, for reasons which have been explained, did not have the necessary destroyers for this work, and this was what made so very important the participation of the United States in the naval war—for our navy possessed the additional vessels that would make possible the immediate adoption of the convoy system. I do not wish to say that the convoy would not have been established had we not sent destroyers for that purpose, yet I do not see how otherwise it could have been established in any complete and systematic way at such an early date. And we furnished other ships than destroyers, for besides providing what I have called the modern convoy—that which protects the compact mass of vessels from submarines—it was necessary also to furnish escorts after the old Napoleonic plan. It was the business of the destroyers to conduct the merchantmen only through the submarine zone. They did not take them the whole distance across the ocean, for there was little danger of submarine attack until the ships had arrived in the infested waters. This would have been impossible in any case with the limited number of destroyers. But from the time the convoys left the home port there was a possibility that the same kind of attack would be launched as that to which convoys were subjected in Nelsonian days; there was the danger, that is, that surface war vessels, raiders or cruisers, might escape from their German bases and swoop down upon them. We always had before our minds the activities of the Moewe, and we therefore deemed it necessary to escort the convoys across the ocean with battleships and cruisers, just as was the practice a century ago. The British did not have ships enough available for this purpose, and here again the American navy was able to supply the lack; for we had a number of pre-dreadnoughts and cruisers that were ideally adapted to this kind of work.
III
On April 30th I received a message from Admiral Jellicoe requesting me to visit him at the Admiralty. When I arrived he said that the projected study of the convoy system had been made, and he handed me a copy of it. It had been decided to send one experimental convoy from Gibraltar. The Admiralty, he added, had not yet definitely decided that the convoy system should be adopted, but there was every intention of giving it a thorough and fair trial. That same evening at dinner I met Mr. Lloyd George, Sir Edward Carson, and Lord Milner, and once more discussed with them the whole convoy idea. I found the Prime Minister especially favourable to the plan and, in fact, civilians in general were more kindly disposed toward the convoy than seamen, because they were less familiar with the nautical and shipping difficulties which it involved.
Naval officers were immediately sent to Gibraltar to instruct the merchant masters in the details of assembling and conducting vessels. Eight-knot ships were selected for the experiment, and a number of destroyers were assigned for their protection. The merchant captains, as was to be expected, regarded the whole enterprise suspiciously, but entered into it with the proper spirit.
On May 20th that first convoy arrived at its English destination in perfect condition. The success with which it made the voyage disproved all the pessimistic opinions which the merchant sailors had entertained about themselves. They suddenly discovered, as I had contended, that they could do practically everything which, in their conferences with the Admiralty, they had declared that they were unable to do. In those meetings they had asserted that not more than two ships could keep station; but now they discovered that the whole convoy could sail with stipulated distances between the vessels and keep this formation with little difficulty. They were drilled on the way in zigzagging and manœuvring—a practice carried out subsequently with all convoys—and by the time they reached the danger zone they found that, in obedience to a prearranged signal, all the ships could turn as a single one, and perform all the zigzag evolutions which the situation demanded. They had asserted that they could not sail at night without lights and that an attempt to do so would result in many collisions, but the experimental convoy proved that this was merely another case of self-delusion. Naturally the arrival of this convoy caused the greatest satisfaction in the Admiralty, but the most delighted men were the merchant captains themselves, for the whole thing was to them a complete revelation of their seamanly ability, and naturally it flattered their pride. The news of this arrival naturally travelled fast in shipping circles; it completely changed the attitude of the merchant sailors, and the chief opponents of the convoy now became its most enthusiastic advocates.
Outside shipping circles, however, nothing about this convoy was known at that time. Yet May 20th, the date when it reached England safely, marked one of the great turning-points of the war. That critical voyage meant nothing less than that the Allies had found the way of defeating the German submarine. The world might still clamour for a specific "invention" that would destroy all the submarines overnight, or it might demand that the Allies should block them in their bases, or suggest that they might do any number of impossible things, but the naval chiefs of the Allies discovered, on May 20, 1917, that they could defeat the German campaign even without these rather uncertain aids. The submarine danger was by no means ended when this first convoy arrived; many anxious months still lay ahead of us; other means would have to be devised that would supplement the convoy; yet the all-important fact was that the Allied chiefs now realized, for the first time, that the problem was not an insoluble one; and that, with hard work and infinite patience, they could keep open the communications that were essential to victory. The arrival of these weather-beaten ships thus brought the assurance that the armies and the civilian populations could be supplied with food and materials, and that the seas could be kept open for the transportation of American troops to France. In fine, it meant that the Allies could win the war.
On May 21st the British Admiralty, which this experimental convoy had entirely converted, voted to adopt the convoy system for all merchant shipping. Not long afterward the second convoy arrived safely from Hampton Roads, and then other convoys began to put in from Scandinavian ports. On July 21st I was able definitely to report to Washington that "the success of the convoys so far brought in shows that the system will defeat the submarine campaign if applied generally and in time."
But while we recognize the fact that the convoy preserved our communications and so made possible the continuation of the war, we must not overlook a vitally important element in its success. In describing the work of the destroyer, which was the protecting arm of the convoy, I have said nothing about the forces that really laid the whole foundation of the anti-submarine campaign. All the time that these destroyers were fighting off the submarines the power that made possible their operations was cruising quietly in the North Sea, doing its work so inconspicuously that the world was hardly aware of its existence. For back of all these operations lay the mighty force of the Grand Fleet. Admiral Beatty's dreadnoughts and battle cruisers, which were afterward supplemented by a fine squadron of American ships, kept the German surface vessels penned in their harbours and in this way left the ocean free for the operations of the Allied surface craft. I have already said that, in April, 1917, the Allied navies, while they controlled the surface of the water, did not control the subsurface, which at that time was practically at the disposition of the Germans. Yet the determining fact, as we were now to learn, was that this control of the surface was to give us the control of the subsurface also. Only the fact that the battleships kept the German fleet at bay made it possible for the destroyers and other surface craft to do their beneficent work. In an open sea battle their surface navies would have disposed of the German fleet; but let us suppose for a moment that an earthquake, or some other great natural disturbance, had engulfed the British fleet at Scapa Flow. The world would then have been at Germany's mercy and all the destroyers the Allies could have put upon the sea would have availed them nothing, for the German battleships and battle cruisers could have sunk them or driven them into their ports. Then Allied commerce would have been the prey, not only of the submarines, which could have operated with the utmost freedom, but of the German surface craft as well. In a few weeks the British food supplies would have been exhausted. There would have been an early end to the soldiers and munitions which Britain was constantly sending to France. The United States could have sent no forces to the Western Front and the result would have been the surrender which the Allies themselves, in the spring of 1917, regarded as not a remote possibility. America would then have been compelled to face the German power alone, and to face it long before we had had an opportunity of assembling our resources and of equipping our armies. The world was preserved from all these calamities because the destroyer and the convoy solved the problem of the submarine and because back of these agencies of victory lay Admiral Beatty's squadrons, holding at arm's length the German surface ships while these comparatively fragile craft were saving the liberties of the world.