The Victory At Sea Part 7

II

The headquarters of the convoy system was a room in the British Admiralty; herein was the mainspring of the elaborate mechanism by which ten thousand s.h.i.+ps were conducted over the seven oceans. Here every morning those who had been charged with the security of the Allies'

lines of communication reviewed the entire submarine situation.

Vice-Admiral Sir Alexander L. Duff, R.N., bore this heavy responsibility, ably a.s.sisted by a number of British officers. Captain Byron A. Long, U.S.N., a member of my staff, was a.s.sociated with Admiral Duff in this important work. It was Captain Long's duty to co-ordinate the movements of our convoys with the much more numerous convoys of the Allies; he performed this task so efficiently that, once the convoy organization was in successful operation, I eliminated the whole subject from my anxieties and requested Captain Long not to inform me when troop convoys sailed from the United States or when they were due to arrive in France or England. There seemed to be no reason why both of us should lose sleep over the same cause.

The most conspicuous feature of the convoy room was a huge chart, entirely covering the wall on one side of the office; access to this chart was obtained by ladders not unlike those which are used in shoe stores. It gave a comprehensive view of the North and South American coast, the Atlantic Ocean, the British Isles, and a considerable part of Europe and Africa. The ports which it especially emphasized were Sydney (Cape Breton), Halifax, New York, Hampton Roads, Gibraltar, and Sierra Leone and Dakar, ports on the west coast of Africa. Thin threads were stretched from each one of these seven points to certain positions in the ocean just outside the British Isles, and on these threads were little paper boats, each one of which represented a convoy. When a particular convoy started from New York, one of these paper boats was placed at that point; as it made its way across the ocean, the boat was moved from day to day in accordance with the convoy's progress. At any moment, therefore, a mere glance at this chart, with its mult.i.tude of paper boats, gave the spectator the precise location of all the commerce which was then _en route_ to the scene of war.

But there were other exhibits on the chart which were even more conspicuous than these minute representations of convoys. Little circles were marked off in the waters surrounding the British Isles, each one of which was intended to show the location of a German submarine. From day to day each one of these circles was moved in accordance with the ascertained positions of the submarine which it represented, a straight line indicating its course on the chart. Perhaps the most remarkable fact about the Allied convoy service was the minute information which it possessed about the movements of German submarines. A kind of separate intelligence bureau devoted its entire attention to this subject.

Readers of detective stories are familiar with the phenomenon known as "shadowing." It is a common practice in the detective's fascinating profession to a.s.sign a man, known as a "shadow," to the duty of keeping a particular person under constant observation. With admirable patience and skill an experienced "shadow" keeps in view this object of his attention for twenty-four hours; he dogs him through crowded streets, tracks him up and down high office buildings, accompanies him to restaurants, trolley cars, theatres, and hotels, and un.o.btrusively chases him through dense thoroughfares in cabs and automobiles. "We get him up in the morning and we put him to bed at night" is the way the "shadow" describes the a.s.siduous care which he bestows upon his unsuspecting victim. In much the same fas.h.i.+on did the Allied secret service "shadow" German submarines; it got each submarine "up in the morning and put it to bed at night." That is to say, the intelligence department took charge of Fritz and his crew as they emerged from their base, and kept an unwearied eye upon them until they sailed back home.

The great chart in the convoy room of the Admiralty showed, within the reasonable limits of human fallibility, where each submarine was operating at a particular moment, and it also kept minute track of its performances.

Yet it was not so difficult to gather this information as may at first be supposed. I have already said that there were comparatively few submarines, perhaps not more than an average of eight or nine, which were operating at the same time in the waters south and west of Ireland, the region with which we Americans were most concerned. These boats betrayed their locations in a mult.i.tude of ways. Their commanders were particularly careless in the use of wireless. The Germanic pa.s.sion for conversation could not be suppressed even on the U-boats, even though this national habit might lead to the most serious consequences.

Possibly also the solitary submarine felt lonely; at any rate, as soon as it reached the Channel or the North Sea, it started an almost uninterrupted flow of talk. The U-boats communicated princ.i.p.ally with each other, and also with the Admiralty at home; and, in doing this, they gave away their positions to the a.s.siduously listening Allies. The radio-direction finder, an apparatus by which we can instantaneously locate the position from which a wireless message is sent, was the mechanism which furnished us much of this information. Of course, the Germans knew that their messages revealed their locations, for they had direction finders as well as we, but the fear of discovery did not act as a curb upon a naturally loquacious nature. And we had other ways of following their movements. The submarine spends much the larger part of its time on the surface. Sailing thus conspicuously, it was constantly being sighted by merchant or military s.h.i.+ps, which had explicit instructions to report immediately the elusive vessel, and to give its exact location. Again it is obvious that a submarine could not fire at a merchantman or torpedo one, or even attempt to torpedo one, without revealing its presence. The wireless operators of all merchant vessels were supplied at all times with the longitude and lat.i.tude of their s.h.i.+ps; their instructions required them immediately to send out this information whenever they sighted a submarine or were attacked by one.

In these several ways we had little difficulty in "shadowing" the U-boats. For example, we would hear that the _U-53_ was talking just outside of Heligoland; this submarine would be immediately plotted on the chart. As the submarine made only about ten knots on the surface, in order to save fuel oil, and much less under the surface, we could draw a circle around this point, and rest a.s.sured that the boat must be somewhere within this circle at a given time. But in a few hours or a day we would hear from this same boat again; perhaps it was using its wireless or attacking a merchantman; or perhaps one of our vessels had spotted it on the surface. The news of this new location would justify the convoy officers in moving this submarine on our chart to this new position. Within a short time the convoy officers acquired an astonis.h.i.+ngly intimate knowledge of these boats and the habits of their commanders. Indeed, the personalities of some of these German officers ultimately took shape with surprising clearness; for they betrayed their presence in the ocean by characteristics that often furnished a means of identifying them. Each submarine behaved in a different way from the others, the difference, of course, representing the human element in control. One would deliver his attacks in rapid succession, boldly and almost recklessly; another would approach his task with the utmost caution; certain ones would display the meanest traits in human nature; while others--let us be just--were capable of a certain display of generosity, and possibly even of chivalry. By studying the individual traits of each commander we could often tell just which one was operating at a given time; and this information was extremely valuable in the game in which we were engaged.

"Old Hans is out again," the officers in the convoy room would remark.

They were speaking of Hans Rose, the commander of the _U-53_; this was that same submarine officer who, in the fall of 1916, brought that boat to Newport, Rhode Island, and torpedoed five or six s.h.i.+ps off Nantucket.

Our men never saw Hans Rose face to face; they had not the faintest idea whether he was fat or lean, whether he was fair or dark; yet they knew his military characteristics intimately. He became such a familiar personality in the convoy room and his methods of operation were so individual, that we came to have almost a certain liking for the old chap. Other U-boat commanders would appear off the hunting grounds and attack s.h.i.+ps in more or less easy-going fas.h.i.+on. Then another boat would suddenly appear, and--bang! bang! bang! Torpedo after torpedo would fly, four or five s.h.i.+ps would sink, and then this disturbing person would vanish as unexpectedly as he had arrived. Such an experience informed the convoy officers that Hans Rose was once more at large. We acquired a certain respect for Hans because he was a brave man who would take chances which most of his compatriots would avoid; and, above all, because he played his desperate game with a certain decency. Sometimes, when he torpedoed a s.h.i.+p, Rose would wait around until all the lifeboats were filled; he would then throw out a tow line, give the victims food, and keep all the survivors together until the rescuing destroyer appeared on the horizon, when he would let go and submerge. This humanity involved considerable risk to Captain Rose, for a destroyer anywhere in his neighbourhood, as he well knew, was a serious matter. It was he who torpedoed our destroyer, the _Jacob Jones_. He took a shot at her from a distance of two miles--a distance from which a hit is a pure chance; and the torpedo struck and sank the vessel within a few minutes.

On this occasion Rose acted with his usual decency. The survivors of the _Jacob Jones_ naturally had no means of communication, since the wireless had gone down with their s.h.i.+p; and now Rose, at considerable risk to himself, sent out an "S.O.S." call, giving the lat.i.tude and longitude, and informing Queenstown that the men were floating around in open boats. It is perhaps not surprising that Rose is one of the few German U-boat commanders with whom Allied naval officers would be willing to-day to shake hands. I have heard naval officers say that they would like to meet him after the war.

We were able to individualize other commanders; the business of acquiring this knowledge, learning the location of their submarines and the characteristics of their boats, and using this vital information in protecting convoys, was all part of the game which was being played in London. It was the greatest game of "chess" which history has known--a game that exacted not only the most faithful and studious care, but one in which it was necessary that all the activities should be centralized in one office. This small group of officers in the Admiralty convoy room, composed of representatives of all the nations concerned, exercised a control which extended throughout the entire convoy system.

It regulated the dates when convoys sailed from America or other ports and when they arrived; if it had not taken charge of this whole system, congestion and confusion would inevitably have resulted. We had only a limited number of destroyers to escort all troops and other important convoys arriving in Europe; it was therefore necessary that they should arrive at regular and predetermined intervals. It was necessary also that one group of officers should control the routing of all convoys, otherwise there would have been serious danger of collisions between outward and inward bound s.h.i.+ps, and no possibility of routing them clear of the known positions of submarines. The great centre of all this traffic was not New York or Hampton Roads, but London. It was inevitable, if the convoy system was to succeed, that it should have a great central headquarters, and it was just as inevitable that this headquarters should be London.

On the huge chart already described the convoys, each indicated by a little boat, were shown steadily making their progress toward the appointed rendezvous. Eight or nine submarines, likewise indicated on the chart, were always waiting to intercept them. On that great board the prospective tragedies of the seas were thus unfolding before our eyes. Here, for example, was a New York convoy of twenty s.h.i.+ps, steaming toward Liverpool, but steering straight toward the position of a submarine. The thing to do was perfectly plain. It was a simple matter to send the convoy a wireless message to take a course fifty miles to the south where, according to the chart, there were no hidden enemies.

In a few hours the little paper boat, which represented this group of s.h.i.+ps and which was apparently headed for destruction, would suddenly turn southward, pa.s.s around the entirely unconscious submarine, and then take an un.o.bstructed course for its destination. The Admiralty convoy board knew so accurately the position of all the submarines that it could almost always route the convoys around them. It was an extremely interesting experience to watch the paper s.h.i.+ps on this chart deftly turn out of the course of U-boats, sometimes when they seemed almost on the point of colliding with them. That we were able constantly to save the s.h.i.+ps by sailing the convoys around the submarines brings out the interesting fact that, even had there been no destroyer escort, the convoy in itself would have formed a great protection to merchant s.h.i.+pping. There were times when we had no escorting vessels to send with certain convoys; and in such instances we simply routed the s.h.i.+ps in ma.s.ses, directed them on courses which we knew were free of submarines, and in this way brought them safely into port.

III

The Admiralty in London was thus the central nervous system of a complicated but perfectly working organism which reached the remotest corners of the world. Wherever there was a port, whether in South America, Australia, or in the most inaccessible parts of India or China, from which merchantmen sailed to any of the other countries which were involved in the war, representatives of the British navy and the British Government were stationed, all working harmoniously with s.h.i.+pping men in the effort to get their cargoes safely through the danger zones. These danger zones occupied a comparatively small area surrounding the belligerent countries, but the safeguarding of the s.h.i.+ps was an elaborate process which began far back in the countries from which the commerce started. Until about July, 1917, the world's s.h.i.+pping for the most part had been unregulated; now for the first time it was arranged in hard and fast routes and despatched in accordance with schedules as fixed as those of a great railroad. The whole management of convoys, indeed, bore many resemblances to the method of handling freight cars on the American system of transcontinental lines. In the United States there are several great headquarters of freight, sometimes known as "gateways," places, that is, at which freight cars are a.s.sembled from a thousand places, and from which the great acc.u.mulations are routed to their destinations. Such places are Pittsburg, Buffalo, St. Louis, Chicago, Minneapolis, Denver, San Francisco--to mention only a few.

s.h.i.+pping destined for the belligerent nations was similarly a.s.sembled, in the years 1917 and 1918, at six or eight great ocean "gateways," and there formed into convoys for "through routing" to the British Isles, France, and the Mediterranean. Only a few of the s.h.i.+ps that were exceptionally fast--speed in itself being a particularly efficacious protection against submarines--were permitted to ignore this routing system, and dash unprotected through the infested area. This was a somewhat dangerous procedure even for such s.h.i.+ps, however, and they were escorted whenever destroyers were available. All other vessels, from whatever parts of the world they might come, were required to sail first for one of these great a.s.sembling points, or "gateways"; and at these places they were added to one of the constantly forming convoys. Thus all s.h.i.+pping which normally sailed to Europe around the Cape of Good Hope proceeded up the west coast of Africa until it reached the port of Dakar or Sierra Leone, where it joined the convoy. s.h.i.+pping from the east coast of South America--ports like Rio de Janeiro, Bahia, Buenos Aires, and Montevideo--instead of sailing directly to Europe, joined the convoy at this same African town. Vessels which came to Britain and France by way of Suez and Mediterranean ports found their great stopping place at Gibraltar--a headquarters of traffic which, in the huge amount of freight which it "created," became almost the Pittsburg of this mammoth transportation system. The four "gateways" for North America and the west coast of South America were Sydney (Cape Breton), Halifax, New York, and Hampton Roads. The grain-laden merchantmen from the St.

Lawrence valley rendezvoused at Sydney and Halifax. Vessels from Portland, Boston, New York, Philadelphia, and other Atlantic points found their a.s.sembling headquarters at New York, while s.h.i.+ps from Baltimore, Norfolk, the Gulf of Mexico, and the west coast of South America proceeded to the great convoy centre which had been established at Hampton Roads.

In the convoy room of the Admiralty these aggregations of s.h.i.+ps were always referred to as the "Dakar convoy," the "Halifax convoy," the "Hampton Roads convoy," and the like. When the system was completely established the convoys sailed from their appointed headquarters on regular schedules, like railroad trains. From New York one convoy departed every sixteen days for the west coast of England and one left every sixteen days for the east coast. From Hampton Roads one sailed every eight days to the west coast and one every eight days to the east coast, and convoys from all the other convoy points maintained a similarly rigid schedule. The dates upon which these sailings took place were fixed, like the arrivals and departures of trains upon a railroad time-table, except when it became necessary to delay the sailing of a convoy to avoid congestion of arrivals. According to this programme, the first convoy to the west coast left New York on August 14, 1917, and its successors thereafter sailed at intervals of about sixteen days. The instructions sent to s.h.i.+pmasters all over the world, by way of the British consulates, gave explicit details concerning the method of a.s.sembling their convoys.

Here, for example, was a s.h.i.+p at New York, all loaded and ready to sail for the war zone. The master visited the port officer at the British consulate, who directed him to proceed to Gravesend Bay, anchor his vessel, and report to the convoy officers for further instructions. The merchant captain, reaching this indicated spot, usually found several other vessels on hand, all of them, like his s.h.i.+p, waiting for the sailing date. The commander of the gathering convoy, under whose instructions all the merchantmen were to operate, was a naval officer, usually of the rank of commodore or captain, who maintained constant cable communication with the convoy room of the Admiralty and usually used one of the commercial vessels as his flags.h.i.+p. When the sailing day arrived usually from twenty to thirty merchantmen had a.s.sembled; the commander summoned all their masters, gave each a blue book containing instructions for the management of convoyed s.h.i.+ps, and frequently delivered something in the nature of a lecture. Before the aggregation sailed it was joined by a cruiser or pre-dreadnought battles.h.i.+p of the American navy, or by a British or French cruiser. This s.h.i.+p was to accompany the convoy across the Atlantic as far as the danger zone; its mission was not, as most people mistakenly believed, to protect the convoy from submarines, but to protect it from any surface German raider that might have escaped into the high seas. The Allied navies constantly had before their minds the exploits of the _Emden_; the opportunity to break up a convoy in mid-ocean by dare-devil enterprises of this kind was so tempting that it seemed altogether likely that Germany might take advantage of it. To send twenty or thirty merchant s.h.i.+ps across the Atlantic with no protection against such a.s.saults would have been to invite a possible disaster. As a matter of fact, the last German raider that even attempted to gain the high seas was sunk in the North Sea by the British Patrol Squadron in February, 1917.

On the appointed day the whole convoy weighed anchor and silently slipped out to sea. To such spectators as observed its movements it seemed to be a rather limping, halting procession. The speed of a convoy was the speed of its slowest s.h.i.+p, and vessels that could easily make twelve or fourteen knots were obliged to throttle down their engines, much to the disgust of their masters, in order to keep formation with a s.h.i.+p that made only eight or ten; though whenever possible vessels of nearly equal speed sailed together. Little in the newly a.s.sembled group suggested the majesty of the sea. The s.h.i.+ps formed a miscellaneous and ill-a.s.sorted company, rusty tramps shamefacedly sailing alongside of spick-and-span liners; miserable little two-or three-thousand ton s.h.i.+ps attempting to hold up their heads in the same company with other s.h.i.+ps of ten or twelve. The whole ma.s.s was sprawled over the sea in most ungainly fas.h.i.+on; twenty or thirty s.h.i.+ps, with s.p.a.ces of nine hundred or a thousand yards stretching between them, took up not far from ten square miles of the ocean surface. Neither at this stage of the voyage did the aggregation give the idea of efficiency. It presented about as desirable a target as the submarine could have desired. But the period taken in crossing the ocean was entirely devoted to education. Under the tutors.h.i.+p of the convoy commander, the men composing the twenty or thirty crews went every day to school. For fifteen or twenty days upon the broad Atlantic they were trained in all the evolutions which were necessary for coping with the submarine. Every possible situation that could arise in the danger zone was antic.i.p.ated and the officers and the crews were trained to meet it. They perfected themselves in the signal code; they learned the art of making the sudden manoeuvres which were instantaneously necessary when a submarine was sighted; they acquired a mastery in the art of zigzagging; and they became accustomed to sailing at night without lights. The crews were put through all the drills which prepared them to meet such crises as the landing of a torpedo in their engine-room or the sinking of the s.h.i.+p; and they were thoroughly schooled in getting all hands safely into the boats. Possibly an occasional scare on the way over may have introduced the element of reality into these exercises; though no convoys actually met submarines in the open ocean, the likelihood that they might do so was never absent, especially after the Germans began sending out their huge under-water cruisers.

The convoy commander left his port with sealed orders, which he was instructed not to open until he was a hundred miles at sea. These orders, when the seal was broken, gave him the rendezvous a.s.signed by Captain Long of the convoy board in London. The great chart in the convoy room at the Admiralty indicated the point to which the convoy was to proceed and at which it would be met by the destroyer escorts and taken through the danger zone. This particular New York convoy commander was now perhaps instructed to cross the thirtieth meridian at the fifty-second parallel of lat.i.tude, where he would be met by his escort.

He laid his course for that point and regulated his speed so as to reach it at the appointed time. But he well knew that these instructions were only temporary. The precise point to which he would finally be directed to sail depended upon the movement and location of the German submarines at the time of his arrival. If the enemy became particularly active in the region of this tentative rendezvous, then, as the convoy approached it, a wireless from London would instruct the commander to steer abruptly to another point, perhaps a hundred miles to north or south.

"Getting your convoy" was a searching test of destroyer seamans.h.i.+p, particularly in heavy or thick weather. It was not the simplest thing to navigate a group of destroyers through the tempestuous waters of the North Atlantic, with no other objective than the junction point of a certain meridian and parallel, and reach the designated spot at a certain hour. Such a feat demanded navigation ability of a high order; and the skill which our American naval officers displayed in this direction aroused great admiration, especially on the part of the merchant skippers; in particular it aroused the astonishment of the average doughboy. Many destroyer escorts that went out to meet an incoming convoy also took out one which was westward bound. A few mishaps in the course of the war, such as the sinking of the _Justicia_, which was sailing from Europe to America, created the false notion that outward-bound convoys were not escorted. It was just as desirable, of course, to escort the s.h.i.+ps going out as it was to escort those which were coming in. The mere fact that the inbound s.h.i.+ps carried troops and supplies gave stronger reasons, from the humane standpoint, for heavier escorts, but not from the standpoint of the general war situation. The Germans were not sinking our s.h.i.+ps because they were carrying men and supplies; they were sinking them simply because they were s.h.i.+ps. They were not seeking to destroy American troops and munitions exclusively; they were seeking to destroy tonnage. They were aiming to reduce the world's supply of s.h.i.+ps to such a point that the Allies would be compelled to abandon the conflict for lack of communications. It was therefore necessary that they should sink the empty s.h.i.+ps, which were going out, as well as the crowded and loaded s.h.i.+ps which were coming in.

For the same reason it was necessary that we should protect them, and we did this as far as practicable without causing undue delays in forming outward-bound convoys. The _Justicia_, though most people still think that she was torpedoed because she was unescorted, was, in fact, protected by a destroyer escort of considerable size. This duty of escorting outward-bound s.h.i.+ps increased considerably the strain on our destroyer force. The difficulty was that the inbound convoy arrived in a body, but that the s.h.i.+ps could not be unloaded and sent back in a body without detaining a number of them an undue length of time--and time was such an important factor in this war that it was necessary to make the "turn-around" of each important transport as quickly as possible. The consequence was that returning s.h.i.+ps were often despatched in small convoys as fast as they were unloaded. The escorts which we were able to supply for such groups were thus much weaker than absolute safety required, and sometimes we were even forced to send vessels across the submarine zone with few, if any, escorting wars.h.i.+ps. This explains why certain homeward-bound transports were torpedoed, and this was particularly true of troop and munition convoys to the western ports of France. Only when we could a.s.semble a large outgoing convoy and despatch it at such a time that it could meet an incoming one at the western edge of the submarine zone could we give these vessels the same destroyer escort as that which we always gave for the loaded convoys bound for European ports.

As soon as the destroyers made contact with an inward-bound convoy, the ocean escort, the cruiser or pre-dreadnought, if an American, abandoned it and started it back home, sometimes with a westbound convoy if one had been a.s.sembled in time. British escorts went ahead at full speed into a British port, usually escorted by one or more destroyers. This abandonment sometimes aroused the wrath of the pa.s.sengers on the inbound convoy. Their protector had dropped them just as they had entered the submarine zone, the very moment its services were really needed! These pa.s.sengers did not understand, any more than did the people at home, that the purpose of the ocean escort was not to protect them from submarines, but from possible raiders. Inside the danger zone this ocean escort would become part of the convoy itself and require protection from submarines, so that its rather summary departure really made the merchantmen more secure. As the convoy approached the danger zone, after being drilled all the way across the ocean, its very appearance was more taut and business-like. The s.h.i.+ps were closed up into a much more compact formation, keeping only such distances apart as were essential for quick manoeuvring. Generally the convoy was formed in a long parallelogram, the distance across the front of which was much longer than the depth or distance along the sides. Usually the formation was a number of groups of four vessels each, in column or "Indian file," at a distance of about five hundred yards from s.h.i.+p to s.h.i.+p, and all groups abreast of each other and about half a mile apart. Thus a convoy of twenty-four vessels, or six groups of four, would have a width of about three miles and a depth of one. Most of the destroyers were stationed on the narrow sides, for it was only on the side, or the beam, that the submarines could attack with much likelihood of succeeding. It was usually necessary for a destroyer to be stationed in the rear of a convoy, for, though the speed of nearly all convoys was faster than that of a submarine when submerged, the latter while running on the surface could follow a convoy at night with a fair chance of torpedoing a vessel at early daylight and escaping to the rear if unhampered by the presence of a rear-guard destroyer. It was generally impracticable and dangerous for the submarine to wait ahead, submerge, and launch its torpedoes as the convoy pa.s.sed over it. The extent to which purely mechanical details protected merchant s.h.i.+ps is not understood, and this inability to attack successfully from the front ill.u.s.trates this point. The submarine launches its torpedoes from tubes in the bow or stern; it has no tubes on the beam. If it did possess such side tubes, it could lie in wait ahead and shoot its broadsides at the convoy as it pa.s.sed over the spot where it was concealed. Its length in that case would be parallel to that of the merchant s.h.i.+ps, and thus it would have a comparatively small part of its area exposed to the danger of ramming. The mere fact that its torpedo tubes are placed in the bow and stern makes it necessary for the submarine, if it wishes to attack in the fas.h.i.+on described, to turn almost at right angles to the course of the convoy, and to manoeuvre into a favourable position from which to discharge its missile--a procedure so altogether hazardous that it almost never attempts it. With certain reservations, which it is hardly necessary to explain in detail at this point, it may be taken at least as a general rule that the sides of the convoy not only furnish the U-boats much the best chance to torpedo s.h.i.+ps, but also subject them to the least danger; and this is the reason why, in the recent war, the destroyers were usually concentrated at these points.

I have already compared the convoy system to a great aggregation of railroads. This comparison holds good of its operation after it had entered the infested zone. Indeed the very terminology of our railroad men was used. Every convoy nearly followed one of two main routes, known at convoy headquarters as the two "trunk lines." The trunk line which reached the west coast of England usually pa.s.sed north of Ireland through the North Channel and down the Irish Sea to Liverpool. Under certain conditions these convoys pa.s.sed south of Ireland and thence up the Irish Sea. The convoys to the east coast took a trunk line that pa.s.sed up the English Channel. Practically all s.h.i.+pping from the United States to Great Britain and France took one of these trunk lines. But, like our railroad systems, each of these main routes had branch lines.

Thus s.h.i.+pping destined for French ports took the southern route until off the entrance to the English Channel; here it abandoned the main line and took a branch route to Brest, Bordeaux, Nantes, and other French ports. In the Channel likewise several "single-track" branches went to various English ports, such as Plymouth, Portsmouth, Southampton, and the like. The whole gigantic enterprise flowed with a precision and a regularity which I think it is hardly likely that any other transportation system has ever achieved.

IV

A description of a few actual convoys, and the experiences of our destroyers with them, will perhaps best make clear the nature of the mechanism which protected the world's s.h.i.+pping. For this purpose I have selected typical instances which ill.u.s.trate the every-day routine experiences of escorting destroyers, and other experiences in which their work was more spectacular.

One day in late October, 1917, a division of American destroyers at Queenstown received detailed instructions from Admiral Bayly to leave at a certain hour and escort the outward convoy "O Q 17" and bring into port the inbound convoy "H S 14." These detailed instructions were based upon general instructions issued from the Admiralty, where my staff was in constant attendance and co-operation. The symbols by which these two groups of s.h.i.+ps were designated can be easily interpreted. The O Q simply meant that convoy "No. 17"--the seventeenth which had left that port--was Outward bound from Queenstown, and the H S signified that convoy "No. 14" was Homeward bound from Sydney, Cape Breton. Queenstown during the first few months was one of those places at which s.h.i.+ps, having discharged their cargoes, a.s.sembled in groups for despatching back to the United States. Later Milford Haven, Liverpool, and other ports were more often used for this purpose. Vessels had been arriving here for several days from ports of the Irish Sea and the east coast of England. These had now been formed into convoy "O Q 17"; they were ready for a destroyer escort to take them through the submarine zone and start them on the westward voyage to American ports.

This escort consisted of eight American destroyers and one British "special service s.h.i.+p"; the latter was one of that famous company of decoy vessels, or "mystery s.h.i.+ps," which, though to all outward appearances unprotected merchantmen, really carried concealed armament of sufficient power to destroy any submarine that came within range.

This special service s.h.i.+p, the _Aubrietia_, was hardly a member of the protective escort. Her mission was to sail about thirty miles ahead of the convoy; when observed from the periscope or the conning-tower of a submarine, the _Aubrietia_ seemed to be merely a helpless merchantman sailing alone, and as such she presented a particularly tempting target to the U-boat. But her real purpose in life was to be torpedoed. After landing its missile in a vessel's side, the submarine usually remained submerged for a period, while the crew of its victim was getting off in boats; it then came to the surface, and the men prepared to board the disabled s.h.i.+p and search her for valuables and delicacies, particularly for information which would a.s.sist them in their campaign, such as secret codes, sailing instructions, and the like. The mystery s.h.i.+p had been preparing for this moment, and as soon as the submarine broke water, the gun ports of the disguised merchantman dropped, and her hitherto concealed guns began blazing away at the German. By October, 1917, these special service s.h.i.+ps had already accounted for several submarines; and it had now become a frequent practice to attach one or more to a convoy, either ahead, where she might dispose of the submarine lying in wait for the approaching aggregation, or in the rear, where a U-boat might easily mistake her for one of those stragglers which were an almost inevitable part of every convoy.

Trawlers and mine-sweepers, as was the invariable custom, spent several hours sweeping the Queenstown Channel before the sailing of convoy "O Q 17" and its escort. Promptly at the appointed time the eight American s.h.i.+ps sailed out in "Indian file," pa.s.sing through the net which was always kept in place at the entrance to the harbour. Their first duty was to patrol the waters outside for a radius of twelve miles; it was not improbable that the Germans, having learned that this convoy was to sail, had stationed a submarine not far from the harbour entrance.

Having finally satisfied himself that there were no lurking enemies in the neighbourhood, the commander of the destroyer flags.h.i.+p signalled to the merchant s.h.i.+ps, which promptly left the harbour and entered the open sea. The weather was stormy; the wind was blowing something of a gale and head seas were breaking over the destroyers' decks. But the convoy quickly manoeuvred into three columns, the destroyers rapidly closed around them, and the whole group started for "Rendezvous A"--this being the designation of that spot on the ocean's surface where the fourteenth meridian of longitude crosses the forty-ninth parallel of lat.i.tude--a point in the Atlantic about three hundred miles south-west of Queenstown, regarded at that time as safely beyond the operating zone of the submarine. Meanwhile, the "mystery s.h.i.+p," sailing far ahead, disappeared beneath the horizon.

Convoying s.h.i.+ps in the stormy autumn and winter waters, amid the fog and rain of the eastern Atlantic, was a monotonous and dreary occupation.

Only one or two incidents enlivened this particular voyage. As the _Parker_, Commander Halsey Powell, was scouting ahead at about two o'clock in the afternoon, her lookout suddenly sighted a submarine, bearing down upon the convoy. Immediately the news was wirelessed to every vessel. As soon as the message was received, the whole convoy, at a signal from the flags.h.i.+p, turned four points to port. For nearly two hours the destroyers searched this area for the submerged submarine, but that crafty boat kept itself safely under the water, and the convoy now again took up its original course. About two days' sailing brought the s.h.i.+ps to the point at which the protecting destroyers could safely leave them, as far as submarines were concerned, to continue unescorted to America; darkness had now set in, and, under its cover, the merchantmen slipped away from the wars.h.i.+ps and started westward. Meantime, the destroyer escort had received a message from the _c.u.mberland_, the British cruiser which was acting as ocean escort to convoy "HS 14."

"Convoy is six hours late," she reported, much like the announcer at a railroad station who informs the waiting crowds that the incoming train is that much overdue. According to the schedule these s.h.i.+ps should reach the appointed rendezvous at six o'clock the next morning; this message evidently moved the time of arrival up to noon. The destroyers, slowing down so that they would not arrive ahead of time, started for the designated spot.

Sometimes thick weather made it impossible to fix the position by astronomical observations, and the convoy might not be at its appointed rendezvous. For this reason the destroyers now deployed on a north and south line about twenty miles long for several hours. Somewhat before the appointed time one of the destroyers sighted a faint cloud of smoke on the western horizon, and soon afterward thirty-two merchantmen, sailing in columns of fours, began to a.s.sume a definite outline. At a signal from this destroyer the other destroyers of the escort came in at full speed and ranged themselves on either side of the convoy--a manoeuvre that always excited the admiration of the merchant skippers.

This mighty collection of vessels, occupying about ten or twelve square miles on the ocean, skilfully maintaining its formation, was really a beautiful and inspiring sight. When the destroyers had gained their designated positions on either side, the splendid cavalcade sailed boldly into the area which formed the favourite hunting grounds for the submarine.

As soon as this danger zone was reached the whole aggregation, destroyers and merchant s.h.i.+ps, began to zigzag. The commodore on the flags.h.i.+p hoisted the signal, "Zigzag A," and instantaneously the whole thirty-two s.h.i.+ps began to turn twenty-five degrees to starboard. The great s.h.i.+ps, usually so c.u.mbersome, made this simultaneous turn with all the deftness, and even with all the grace of a school of fish into which one has suddenly cast a stone. All the way across the Atlantic they had been practising such an evolution; most of them had already sailed through the danger zone more than once, so that the manoeuvre was by this time an old story. For ten or fifteen minutes they proceeded along this course, when immediately, like one vessel, the convoy turned twenty degrees to port, and started in a new direction. And so on for hours, now a few minutes to the right, now a few minutes to the left, and now again straight ahead, while all the time the destroyers were cutting through the water, every eye of the skilled lookouts in each crew fixed upon the surface for the first glimpse of a periscope. This zigzagging was carried out according to comprehensive plans which enabled the convoy to zigzag for hours at a time without signals, the courses and the time on each course being designated in the particular plan ordered, all s.h.i.+ps' clocks being set exactly alike by time signal. Probably I have made it clear why these zigzagging evolutions const.i.tuted such a protective measure. All the time the convoy was sailing in the danger zone it was a.s.sumed that a submarine was present, looking for a chance to torpedo. Even though the officers might know that there was no submarine within three hundred miles, this was never taken for granted; the discipline of the whole convoy system rested upon the theory that the submarine was there, waiting only the favourable moment to start the work of destruction. But a submarine, as already said, could not strike without the most thorough preparation. It must get within three or four hundred yards or the torpedo would stand little chance of hitting the mark in a vital spot. The commander almost never shot blindly into the convoy, on the chance of hitting some s.h.i.+p; he carefully selected his victim; his calculation had to include its speed, the speed of his own boat and that of his torpedo; above all, he had to be sure of the direction in which his intended quarry was steaming; and in this calculation the direction of the merchantman formed perhaps the most important element. But if the s.h.i.+ps were constantly changing their direction, it is apparent that the submarine could make no calculations which would have much practical value.

In the afternoon the _Aubrietia_, the British mystery s.h.i.+p which was sailing thirty miles ahead of the convoy, reported that she had sighted a submarine. Two or three destroyers dashed for the indicated area, searched it thoroughly, found no traces of the hidden boat, and returned to the convoy. The next morning six British destroyers and one cruiser arrived from Devonport. Up to this time the convoy had been following the great "trunk line" which led into the Channel, but it had now reached the point where the convoys split up, part going to English ports and part to French. These British destroyers had come to take over the twenty s.h.i.+ps which were bound for their own country, while the American destroyers were a.s.signed to escort the rest to Brest. The following conversation--typical of those that were constantly filling the air in that area--now took place between the American flags.h.i.+p and the British:

_Conyngham_ to _Achates_: This is the _Conyngham_, Commander Johnson. I would like to keep the convoy together until this evening. I will work under your orders until I leave with convoy for Brest.

_Achates_ to _Conyngham_: Please make your own arrangements for taking French convoy with you to-night.

_Achates_ to _Conyngham_: What time do you propose leaving with French convoy to-night?

_Conyngham_ to _Achates_: About 5 P.M. in order to arrive in Brest to-night.

Devonport Commander-in-chief to _Conyngham_: Proceed in execution Admiralty orders _Achates_ having relieved you. Submarine activity in Lat. 48.41, Long. 4.51.

The _Aubrietia_ had already given warning of the danger referred to in the last words of this final message. It had been flas.h.i.+ng the news in this way:

1.15 P.M. _Aubrietia_ to _Conyngham_: Submarine sighted 49.30 N 6.8 W. Sighted submarine on surface. Speed is not enough.

Course south-west by south magnetic.

1.30 P.M. _Conyngham_ to _Achates_: Aubrietia to all men-of-war and Land's End. Chasing submarine on the surface 49.30 N 6.8 W, course south-west by south. Waiting to get into range. He is going faster than I can.

2.00 P.M. _Aubrietia_ to all men-of-war. Submarine submerged 49.20 N 6.12 W. Still searching.

The fact that nothing more was seen of that submarine may possibly detract from the thrill of the experience, but in describing the operations of this convoy I am not attempting to tell a story of wild adventure, but merely to set forth what happened ninety-nine out of a hundred times. What made destroyer work so exasperating was that, in the vast majority of cases, the option of fighting or not fighting lay with the submarine. Had the submarine decided to approach and attack the convoy, the chances would have been more than even that it would have been destroyed. In accordance with its usual practice, however, it chose to submerge, and that decision ended the affair for the moment. This was the way in which merchant s.h.i.+ps were protected. At the time this submarine was sighted it was headed directly for this splendid aggregation of cargo vessels; had not the _Aubrietia_ discovered it and had not one of the American destroyers started in pursuit, the U-boat would have made an attack and possibly would have sent one or more s.h.i.+ps to the bottom. The chief business of the escorting s.h.i.+ps, all through the war, was this unspectacular one of chasing the submarines away; and for every under-water vessel actually destroyed there were hundreds of experiences such as the one which I have just described.

The rest of this trip was uneventful. Two American destroyers escorted H.M.S. _c.u.mberland_--the ocean escort which had accompanied the convoy from Sydney--to Devonport; the rest of the American escort took its quota of merchantmen into Brest, and from that point sailed back to Queenstown, whence, after three or four days in port, it went out with another convoy. This was the routine which was repeated until the end of the war.