The Defence of Harbours against Torpedo-Boat Attack

Mr. Chairman, ladies and gentlemen, in venturing to address you upon this subject of defence against torpedo craft, I would desire at the outset to call your attention to the general obscurity that exists on the question. By this I mean not only the absence of data, but the absence of any, what I may call, "sealed pattern plan of defence."

I do not see how we could have one as things are, for we have very little to go on. The most that we can go on in the way of facts we may take from the Chino-Japanese War, which even if its results could be accepted as conclusive then, may be nullified now by the subsequent advent of the destroyer. However, let us first review the Chino-Japanese operations at Wei-hai-Wei.

There were altogether four attacks upon Wei-hai-Wei, and the defence consisted of 1 or 1½ iron steel hawsers with wooden floats every ten yards and a boom of this sort was placed at each entrance, but both booms had openings in them. The eastern entrance had two openings, there being one torpedo-boat one inshore protected by the forts that fell into the hands of the Japanese, and a larger one in the centre for big ships which was protected by mines, which the Japanese attempted to destroy, but only partially succeeded in doing. The forts guarding this entrance were already in the hands of the Japanese, and therefore from the gunners' point of view Wei-hai-Wei can hardly be regarded as any criterion whatever.

The points of interest about the attack worth noting are, that in the first attack of all, which was made on the 1st of February, when the Japanese boats came in they were sighted by the forts held by Japanese soldiers and fired at under the impression that they were Chinese boats. The boats then retreated untouched.

The second attack, which was made on the 2d of February, was again a failure, as the Chinese sighted the boats as they were coming into harbour. They again retired at once.

Then for the third attempt the scheme of attack was varied. A feint was made on one entrance by six boats, and the eastern entrance was attacked by twelve boats. It was an intensely cold night, there was no moon, it was about 3 o'clock in the morning. The Japanese lost two boats and one or two were very much damaged. Only one was hit by a 3-pr. The forts did nothing. In fact the Chinese forts, so far as could be ascertained, did not see the boats until they were more or less amongst the big ships.

On the 4th, there was another attack, which was a complete surprise, in which they lost two boats from ship fire. So that practically we have really very little to go on, so far as torpedo-boat operations in a time of war are concerned.

All we may deduce I think from the Chino- Japanese affair is that the rule with the boats seems to have been, if once sighted and fired on, to retire at once and leave everything to the chance of getting in unseen on another occasion. boats have increased very rapidly and destroyers have multiplied exceedingly, Of course if this is to be the rule, defence will be a very easy thing, because a sharp look-out and a gun or two will be all that will be required. But we have to bear in mind the sort of attack, or what is likely to be the attack on us, may not be on similar lines to that which the Chinese met. I do not think we can assume that it would be the same. The Japanese were short of torpedo-boats and they could not afford to throw away what they had. Now-a-days torpedo-boats have increased very rapidly and destroyers have multiplied exceedingly, and I think we should take it for granted that if any attack is made, it will be pushed home as long as a single boat is left. Therefore the problem with regard to defence is to account for every single boat that attacks. Say, for instance, that twelve boats attack, it will not be much good accounting for eleven if one gets through.

There might be attacks made upon us the first night of a war when the enemy would hope to find things unarranged for, and later on when attack was unsuspected because of long immunity. It is of course extremely improbable that we should have a blockaded fleet, but we should very likely have one or two injured ships. Attack is pretty sure to be pressed home as torpedo-boats are so much more plentiful now and a few can easily be spent on an off chance.

The first question in relation to defence it seems to me is to find out what has got to be defended, whether the boats are coming with a view to securing any odd ship, damaged or otherwise, that may be in a harbour or whether their intention is to try to block up the docks and dock entrances by getting inside and torpedoing these. The latter perhaps is what we might be most in fear of and must expect to see attempted.

Then if we take the various defence systems, every system seems to have its advantages and disadvantages. If we take the favorite system, No. 1 gun firing at No. 1 boat, No. 2 gun firing at No. 2 boat and so on, that in theory may be a very excellent system, but the defect of it is that in practice, No. 1 boat becomes No. 3 perhaps at one moment and No. 2 at another, and there is always the danger that No. 1 gun may be firing at No. 2 boat, and No. 2 gun at it also, leaving one boat neglected, and a practice of rushing based on the chances given by this system exists, and, if one of a dozen gets through, untold mischief may be done.

There is also of course the question of what is to happen if more boats than guns should be used.

Then take the zone system. There success depends upon doing a great deal with comparatively small armaments. If the boats, knowing that the zone system is going to be employed, come in in bunches, then again there seems to be a very good chance of one boat managing to crawl through. If the boats would each enter each zone singly, their fates would be certain; but we cannot depend on that happening. Obviously the gun that has only one boat to fire at and the gun that has a dozen in its zone are very differently situated. Still, I incline to fancy that the zone system is better than any other. But whatever system of defence is adopted, there is always grave danger in a lack of definite co-operation between the Army and the Navy, and I think there can be no doubt that if the two forces fail to act in concert, it would tend to help and assist any attacking boats more than anything else.

As things are at present, we may assume, I think, that the shore defence would be entirely in the hands of the Army, but the Navy will, by having ships in the harbour, also be conducting some defence of its own.

This defence will perhaps include picket boats and if the attacking boats realize, as they very likely will do, that there is a picket boat defence, they may manage to take advantage of it, and either our picket boats may get destroyed under the impression that they are a hostile craft or the hostile craft may slip through as picket boats; but the subject of picket boat defence I shall allude to later on.

Next to gun fire, perhaps, search-lights form the most important part in all defence operations. The value of search-lights is I think a very debatable point. From my own experience on board torpedo-boats and destroyers rushing harbours, I think there is a great deal to be said both for and against the search-light. Of course for rushing in in peace time you are not firing any shotted guns, and therefore you cannot have any data to go on, as to how easy or difficult it may be for a destroyer coming in to fire at a search-light and perhaps pick it out, and then in the sudden gloom get in easily.

Some experiments in Germany seem to have shown that it is not a difficult thing to hit the search-light. My own impression of searchlights is that when you are three or four miles out, they do not show you up, but they do show the way in, and show it tremendously clearly. This is perhaps more true of fixed beams than of searching ones; the difficulty to the attack comes in where the searching beam gets full on the boat, inasmuch as then the boat can see next to nothing, and when the light goes away or is evaded there is a sort of complete blindness; I think that the value of the search-light for defence is perhaps to flash it on to the eyes of the boat's crew and then off again. Its use thus should lead very often to the boat going ashore or running into other boats from the temporary blindness that the flash has caused. The search-lights no doubt light the way in to some extent, so much so perhaps that the real value of them to defence is only the