“The Secretary of the Admiralty.”
Quick-firing guns of the 3-inch and 6-inch type are certainly the best weapons for an attack on submarines. In combination with “sharp look-outs,” they could be used with effect from the elevated positions on the fore part of warships. The periscopic-tube of the submarine always proves a target for gun-fire; but a grey steel tube, 3 inches in diameter, at a distance of 1,000 yards requires “excellent” marksmanship to hit. That it can be done is proved by the sinking of the German submarine U.15 by the British Cruiser Birmingham in the North Sea. The effect of a shot carrying away the periscope is to blind the submarine, at least in one eye, she can then be run-down by the surface warship or destroyed by rapid gun-fire at close range.
Of course, if submarines were caught napping on the surface the guns of surface warships could quickly sink them; but another incident, similar to that which opened the naval engagements of the Russo-Japanese War, cannot be looked for in the naval engagements to come.
For a fleet engaged in bombarding or blockading, one of the best methods of defence would be to lower the torpedo nets, not close round each vessel, but suspended from “picket-boats” at a distance from the bombarding or blockading fleet. “Picketing” is also considered a good defence during daylight, but neither of these methods are reliable. A submarine might be able to dive unobserved under, or past, the destroyers acting as pickets, and it is this chance which causes these under-water craft to be a source of constant anxiety.
The torpedo-boat destroyer should prove a nasty enemy to the submarine. In warfare it is the duty of these 30-knot vessels to look after their under-water opponents.
It has been suggested that internal armour could be fitted to warships below the water-line, which would render the hulls able to withstand mine or torpedo explosions. At present this is practically impossible, as the great weight of this additional armour, combined with the ever-increasing size of guns and weight of above-water protection, would necessitate a vessel of such enormous displacement as to be quite impossible, if the important factor—high speed—has also to be maintained.
The defence of harbours against submarines is a problem which does not present nearly so many difficulties as the defence of moving ships. Portsmouth, for example, is closed by means of a submarine boom-defence, which is stretched across the mouth of the harbour. The entrance to the River Elbe (leading to the Kaiser Wilhelm Canal) is effectively closed to British submarines by boom-defences, mines, and submerged wire entanglements. Narrow waterways, such as the Straits of Dover, can be closed by the laying of contact-mines, and even broader seas can be made dangerous to submarines by the same method. An example of this is afforded by the laying of a British mine-field somewhere between the Goodwin Sands and the Dutch Coast, to prevent German submarines from penetrating into the English Channel.
There are so many reliable means of defending harbours and narrow waterways against submarines that it is unnecessary to say anything further here. But to protect moving ships at sea, under all conditions, certainly presents a most profound puzzle.
CHAPTER X
THE SUBMARINE TORPEDO
The submarine torpedo has become one of the principal naval arms. Not only does it supply the chief offensive power of the submarine, the torpedo-boat and the destroyer, but it is also carried as a separate arm, with a special highly-trained crew, by almost every warship afloat. At the beginning of hostilities the Naval Powers engaged owned considerably over 80,000 of these weapons, and one factory in England alone can make them at the rate of two a day. During the first few weeks of the Great War the torpedo was responsible for the sinking of warships to the value of over one million sterling. Had the German Fleet been on the high seas instead of in harbour and protected from torpedo raids by carefully-prepared submarine defences, there is little doubt but what several more of the enemy’s ships would have been sunk by this weapon. The fact that at first the British light cruisers suffered rather heavily—though in total loss of ships and men less than the German Navy—does not point to any advantage derived either from the type of torpedo used or from skill in this mode of warfare possessed by the Germans, but clearly to the timidity of the German main fleet, which was at the very beginning of hostilities withdrawn from the zone of war and placed behind fortifications, where it was safe from torpedo attack. The British Fleet, true to the policy of “attack and not defence,” began operations the moment war was declared, with results so brilliantly successful, and of such far-reaching and world-wide importance, that enumeration is well-nigh impossible. But while all these operations were in progress the British Fleet was more or less exposed to torpedo attack by any hostile submarines or fast surface craft which might succeed in getting past the cordon of protecting destroyers, while the German Fleet was safe, but ignominiously impotent. That the naval losses of Great Britain, with all her fleets at sea, have not been far greater than they have is in itself a victory of the greatest magnitude—a victory due entirely to consummate naval skill.