When the allied fleets had started their bombardment of the Turkish forts at the Dardanelles they were breaking certain well-defined rules which had been axiomatic with naval authorities. The greatest of modern battleships were designed to fight with craft of their like, but not to take issue with land fortifications. For weeks, while the fleets succeeded in silencing for a time some of the Turkish forts, it was thought that this rule no longer held good. But when, after March 19, 1915, the fleets ceased attempting to take the passage without military cooperation, the worth of the rule was reestablished. The ease with which the bombarding ships were made victims of hostile submarines was greatly instrumental in making the rule again an axiom.
The naval supremacy of the allied powers brought them certain advantages—advantages which they had without winning a decisive victory. Germany and Austria were cut off from the Western Hemisphere, and were troubled, in consequence, by shortage in food for their civilian populations to a greater or lesser degree. This was perhaps a negative benefit derived by the Allies from their naval supremacy; the affirmative benefit was that their own communications with the Western Hemisphere were maintained, enabling them not only to get food for their civilian populations, but arms and munitions for their armies; and even financial arrangements, which, if their emissaries could not pass back and forth freely could not have been made, depended on their control of the high seas.
They were able to keep the Channel clear of submarines long enough to permit the passage of the troops, which England from time to time during the first year of the war sent to the Continent, and permitted the participation of the troops of the British overseas dominions, the troops from Canada joining those in France, and the troops from New Zealand and Australia taking their places in the trenches along the Suez Canal and on the Gallipoli Peninsula. Thus, to a certain extent, the advantage of continuous railroad communication which was enjoyed by the Teutonic allies "inside" the arena of military operations was offset by the naval communication maintained by the Entente Powers "outside" the arena of military operations.[Back to Contents]
CHAPTER XXXIII
FIGHTS OF THE SUBMARINES
When, on the 5th of February, 1915, the German admiralty proclaimed a "war zone" around the British Isles and announced that it would fight the sea power of the Allies with submarines, a new era in naval warfare had opened. In all previous wars, and in the earlier months of the Great War, submarines were employed as auxiliaries to the larger naval units. The Germans were the first to use them as separate units. The idea of sending a fleet of submarines out on to the high seas was a new one, and had been impossible in the last war in which they had been used—that between Russia and Japan. But the improvements which had been made in their design and equipment since then had made an actual cruising submarine possible, and made possible the new phase of naval warfare inaugurated by the German admiralty.
While Germany was the last great sea power to adopt the submarine as a weapon, both England and Germany, in the years immediately preceding the war, had spent the same amounts of money on this sort of craft—about $18,000,000—but while the Germans had later given as much attention to them as to any other sort of naval craft, the British authorities did not figure on employing the submarine as a separate offensive tactical unit being sufficiently equipped in large ships carrying large guns. And being weaker in capital ships Germany was compelled to rely upon underwater warfare in her campaign of attrition. Not only were the naval authorities of the rest of the world uninformed about the improvements that German submarines carried, but they were fooled even as to the actual number which Germany had built.
The most modern of the German submarines at the time had a length of 213 feet and a beam of twenty feet, these dimensions giving them sufficient deck space to mount thereon two rapid-fire guns, one of 3.5 inches and another of 1.4 inches. Their displacement was 900 tons, and they could make a speed of 18 knots when traveling "light" (above water), and 12 knots when traveling submerged. These speeds made it possible for them to overtake all but the fastest merchantmen, though not fast enough to run away from destroyers, gunboats, and fast cruisers. Their range of operation was 2,000 miles, and in the early months of 1915, it was possible for Germany to send two or three of them from their base in the North Sea to the Mediterranean. Germany was at the same time experimenting with a larger type, with a displacement of 1,200 tons and an operating distance of 5,000 miles.
The ordinary submarine in service at the beginning of the war could remain below the surface for twenty-four hours at least. Reserve amounts of air for breathing were carried in tanks under pressure, and in the German type there were also chemical improvements for regenerating air. Contrary to the opinion of laymen, submerging was accomplished both by letting water into ballast tanks, and also by properly deflecting a set of rudders; every submarine had two sets of rudders, one of which worked in vertical planes and pointed the prow of the ship either to the left or the right; the other pair worked in horizontal planes and turned the prow either upward or downward. A pair of fins on the sides of the hull assisted action in both rising and diving. The action of water against the fins and rudders when the ship was in motion was exactly the same as that of the air against the planes of a kite; to submerge one of the craft it was necessary to have it in motion and to have its horizontal rudders so placed that the resistance of the water would drive the ship downward; the reverse operation drove it upward. And here lay a danger, for if the engines of a diving submarine stopped she was bound to come to the surface. Her presence, while moving entirely submerged could be detected by a peculiar swell which traveled on the water above; if submerged only so much as to leave the tip of her periscope still showing, the latter left an easily discernible wake.
The periscope was merely a tube in which there were arranged mirrors so that anything reflected in the first mirror, the one above the surface of the water, was again reflected till it showed in a mirror at the bottom of the tube, within the hull of the vessel, where its commander could observe it safely. A crew of about twenty-five men was necessary to operate one of these crafts, and theirs was an unpleasant duty, first because of the danger that accompanied each submergence of their vessel; second because of the discomforts aboard. The explosive engines which drove the craft, whether burning oil or the lighter refinements such as gasoline, gave off gases that caused headaches and throbbing across the forehead; and it was almost impossible to heat the interior of the craft.