The news of a revival of underwater activity in the Adriatic appears to be confirmed by the announcement that the British Legation at Athens has offered a reward of £500 for information which may result in the capture or destruction of hostile submarines. It is not only that the Austrian Flotilla appears to have been augmented from German sources, but there have been statements to the effect that German boats have entered the Mediterranean through the Straits of Gibraltar. The torpedoing of the Leon Gambetta on April 27 was remarkable as showing that Austrian naval officers have been gaining in experience by practice. They have probably been advised by their German Allies that lurking tactics are the most profitable.
The boat which sank the French armoured cruiser most likely came out of Cattaro, and had been hanging about in the Straits of Otranto for some time. It was evidently known that thereabouts a patrol was likely to be stationed to guard against the exit of raiders from the Austro-Hungarian Fleet. In that Fleet there are several very fast cruisers of a type similar to those which Germany had upon the ocean trade routes. The Novara and her two sisters, which are improvements on the Admiral Spaun, are credited with a speed of 27 knots, and therefore, although they are not powerful enough to meet the Franco-British cruisers, they are the sort of vessels which could make things disagreeable if they tried to emulate the exploits of the Hamidieh during the war between Turkey and Greece. They might also, if they succeeded in getting away, act as mother ships to submarines.
There seems to be no doubt now that Germany has supplied her ally with some larger and faster submarines than she formerly possessed. The Austrian boat U5, with which Lieutenant von Trapp sunk the Leon Gambetta, was the largest submarine in the Austrian Navy, and she has only a displacement of about 280 tons, a surface speed of not more than 12 knots, and a radius of about 1,000 miles. Therefore she is comparable with the early boats of the “C” type in the British service. Since the war began there has been added the captured French boat Curie, which was caught at the mouth of Pola harbour at the end of December last, and which is quite a hundred tons larger than U5. She has been renamed the Zenta, after the light cruiser which was destroyed by the French Fleet on August 16.
BASES IN THE AEGEAN
The boats which Germany is said to have sent overland by rail are somewhat larger, and have been transported in four sections. If, also, Germany has actually sent one or more boats through the Straits of Gibraltar, it is probable that these are the heaviest she has available, and that they have a large sea-keeping capacity. All these boats could operate from the Adriatic against the ships of the Allied Fleets at the Dardanelles, but they could hardly do so with success, or for any length of time, without being provided with bases of supply. Such bases might be found in some of the out-of-the-way islands in the Aegean, but in that case it may be hoped that the reward offered would be sufficient to put the local fishermen and the crews of the small trading craft on the alert. If this were done, it ought not to be long before such bases became known.
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On the other hand, a cruiser like the Novara might prove more difficult to locate, as she certainly would be more difficult to catch. It is fairly certain that no German submarine could make the Dardanelles in one voyage and have any effective radius at the end of it. Either, therefore, these boats must find supplies awaiting them at points agreed upon in advance, or they must make for the Adriatic in order to replenish their fuel. In the latter case, it is in the Straits of Otranto that there should be a good chance of spotting them, provided an effective patrol is maintained.
THE GERMAN TORPEDO
Some doubt has been expressed as to whether the Lusitania could have been sunk by a single torpedo. The evidence certainly points to the use of more than one, but, at the same time, as long ago as February last the Scientific American stated that it had been informed on good authority that a special type of torpedo had been designed for submarines. This torpedo is only for use at short distances, and weight saved in other ways has been put into high explosives, of which each torpedo is reported to carry not less than 420lb. The effect of the explosion of this amount of TNT, especially if the torpedo forced its way through the side of the ship to any distance, would be sufficient to damage the internal structure of the vessel to such an extent as to neutralize any advantage from the special protection which might have been fitted against the danger of collision.
The variable effect of the German torpedoes has already been referred to here, and if the foregoing is accurate it would afford an explanation of the different results which have been noticed. In any case, it did not need the ingenious invention of the German naval authorities that the Lusitania was blown up by her own ammunition to explain the sudden and complete character of the torpedo explosion.
There is no problem of the war more interesting or important at the present time than the provision of an effective method of meeting the attack of the submarine and its deadly missile. If, as seems probable, the later German boats carry athwart-ship tubes as well as those in the bow, their effectiveness has been increased, and the question of the tactics employed to baffle them must be affected thereby. All the later boats, moreover, seem to be capable of firing torpedoes when running awash.