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(a.) The mean range of the higher tides being 8 feet, it would be impossible to arrange the mines so as to prevent the entrance of torpedo- boats or vessels of similar draught. Moreover, the attempt to arrange the electro-contact mines with such an object would require a very large increase of mines (about double the present number) to defend a passage of 4,400 yards, such as the western entrance.
(b.) The application of such a system to the Lyemun Pass would be still more difficult, owing to the depth of water and the irregularity of the bottom. (c.) The increase of labour that would be thrown on the Harbour- master's Department by the necessity which would arise for restricting the junk traffic to the friendly channel, through which it would have to be towed, would be very great.
(C.)—Defence against Torpedo Craft.
Owing to the great width of the western entrance and the impossibility of narrowing it owing to the nature of the bottom, the Committee find that at the very least it would be necessary to employ three fixed post vessels with quick-firing guns and five 16° lights in each vessel, in addition to a large number of shore lights, that even this would only light up a depth of 1,200 yards through which a torpedo-boat could pass in two minutes, while the fixed post vessels would, in such open water, have an unsteady platform, and the quick-firing guns from the shore would be over 2,000 yards from the centre of the channel. The personnel required for such a system would be unduly large, and the strain on them very great, while in dirty weather even these lights would not cover the channel.
Under these circumstances, the Committee have felt compelled to abandon the idea of rendering the "man-of-war anchorage absolutely safe" from the attack of torpedo-boats by this means, and, while recommending their adoption to a limited extent, as hereafter described, for the purpose of deterring torpedo-boats from entering, and to assist in the general defence, they consider that absolute safety for men-of-war inside the harbour can only be insured by withdrawing them to a protected area close to the shore. This might be provided in connection with the long pier, which is already projected, to run out from the Victoria Dockyard into water which will be dredged to a depth of 30 feet, by surrounding the pier with piles from which specially made torpedo nets would be hung. A plan is annexed, marked A, showing the general features of the Scheme.
Quick-firing Guns.
The Committee nevertheless consider that the following additions to and redistribution of the quick-firing armament should be made, as shown in the annexed tracings B and C :-
At Belcher's.-The two 6-pr. quick-firing guns now mounted to be remounted according to latest instructions, on sites in front of and to the westward of their present position. They will thus obtain greatly increased lateral range.
Two 12-pr. quick-firing guns to be mounted near the water. The site that seems best adapted is on the salient corner of the Praya, where a building plot might be bought for that purpose and these guns mounted.
At Stonecutter's Island. Two 6-pr. quick-firing guns to be mounted on the north side at point D. One of these to be taken from Stonecutter's west (the present position, 218 feet above the water, being too high), and one from Lyemun.
Two 12-pr. quick-firing guns to be mounted in South Shore Battery, in lieu of the three 64-pr. now mounted there.
At Lyemun.-Two 6-pr. quick-firing guns to be mounted as near as may be to the water at the south-west corner of the mine-field. These will command the whole of the Pass and a considerable amount of water inside.
Two 12-pr. quick-firing guns to be mounted at the south-east corner of the mine-field to command the Pass, the Examination Anchorage, and all the water to the cast.
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