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.