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Appendix No. 4. waters of Half Die, its parapet need not necessarily be strengthened to the same extent as those of the six- and three-gun batteries, but concrete work forming an exterior slope of 1 in 1 should be GAMBIA.
built up against the 3 feet thick circular parapet to lessen the chance of its becoming damaged by the concussions in firing the gun, and bomb-proof shelter ought to be provided close by to hold the neces- sary ammunition. This, on account of the swampy nature of the ground, must be brick-lined (in cement) all round, also top and bottom, and covered with asphalte and a thick layer of concrete below the sand; 150%. are sufficient to defray the cost of strengthening the battery as above described, but to construct a small bomb-proof magazine of 10 × 8 × 7 feet inside dimensions, with a secure passage, air- space, means of ventilation, and all necessary fittings, will cost about 6507.
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13. Before proceeding to give a description and estimate of proposed new works of defence, I beg to suggest that instead of building a separate and isolated barracks for an additional garrison, some of the available spaces within the boundary walls of the existing barracks and the so-called military hospital be made use of for providing the necessary accommodation. To effect this it would only be necessary to erect inner walls, parallel to and some 20 feet from the boundary walls, connecting both by partition walls some 30 feet apart, and covering the inclosed spaces by flat roofs, resting either on arches- or girders. The floors may consist of flags, tiles, or bricks laid on concrete. The brickwork partitions would strengthen the outer and inner walls, and consequently the whole building, while, in the event of a shell bursting through the outer wall, its effect would become more or less localized by them. By raising suitable portions of the boundary walls 3 feet higher, two tiers of loop-holes may be used simultaneously, the lower row (8 feet above the external ground) from the here-proposed additional barrack-rooms, and the upper row from the flat roofs above those rooms.
14. At the barracks are 600 feet run, and at the military hospital 750 feet run of boundary wall available for forming the outer walls of forty-five additional barrack-rooms of 30 × 12 × 11 feet each. They could well accommodate 540 additional men. The moderate-sized rooms at the military hospital and at the barracks might be reserved for the use of officers, while the more sheltered parts outside the boundary walls of those buildings could be used for hospital sheds and stabling, and connected, where necessary, by doorways with the barracks inside the boundary walls.
15. In case this plan should be approved of, the cost of providing such additional accommodation for 540 men would be 6,5007. if the roofs are made to rest on girders, but if vaulted roofing be applied the cost will be 9,000l. Hospital sheds for fifty men and stabling for fifty horses can be built against the above-named boundary walls for 5001. each. Both the military hospital and barrack buildings already contain a fair amount of cooking accommodation, which can, moreover, be easily augmented by the use of improved appliances. Both places have also good wells, besides which there is an underground rain-water tank at the barracks.
16. To re-roof in the ordinary way, and repair the various buildings within Fort Bullen, so as to make them habitable, will cost 7501. The accommodation within the fort cannot well be increased for a permanency, although covered shelter (irrespective of the barracks) can be found for temporary occupation of an additional twenty men, under arches which run along the north and west curtains, and also beneath the officers' quarters in the fort. Should it be decided to make roofs bomb-proof, it would also be necessary to strengthen some of the masonry which would have to support them, and to provide and fix extra beams and pillars, and allowing for this, the additional outlay on account of bomb-proof roofing being estimated at 8s. per square foot covered, would amount to 1,2007., bringing the cost of builder's work at Fort Bullen to about 2,0007.
17. In reference to Fort James, I am not able at present to give an estimate of the cost of making appropriate alterations and improvements with accuracy, as I have no measurements of the existing works, but judging from what I saw on the spot, I believe that an outlay of 5,000l. would be sufficient to make the fortifications suitable to the purposes suggested in paragraph 8 of this Report.
18. Proceeding now to deal with the proposition of new works of defence, it may be appropriate to point out the desirability of making them as effective and as safe as possible, as in the first place it may happen that more than one of an enemy's war-vessels may enter the river at the same time, and steaming at the rate of, say, 12 knots per hour, they could, within the space of ten minutes, pass through the range of fire from the north-east battery and Fort Bullen without even coming within reach of fire from the proposed south-east battery; and secondly, as it may be reasonably presumed that such war-vessels would deal out a liberal supply of shells against the batteries, the men working the guns in those batteries ought to be well protected, to enable them to keep up a rapid and well- directed fire.
19. I believe that turret batteries are best suited to combine the advantages of rapid and accurate fire, and great security against counter-attack; and taking into consideration that such batteries are specially well adapted for situations where a large sweep of range is desirable, as at Fort Bullen, or the projecting point near the three-gun battery, I am led to think their usefulness in the event of an attack by sea would fully compensate for the extra outlay, if at all greater, than that on elongated batteries.
20. Having since my arrival here in 1874 frequently seen the higher part of St. Mary's Shoal above water, and having had frequent opportunities of noticing the accumulation of sand wherever brushwood revetments have been applied for the protection of our river beach, I may safely express the opinion that to form an island of part of St. Mary's Shoal will not be so difficult or expensive as it may at first appear. The shoal itself is of very old standing, probably as old as the sandbank on which Bathurst lies, and there seems to be no reason why it should not be as lasting. An island formed there by causing a large accumulation of sand by means of brushwood revetments, which could be placed and renewed at a trifling cost, would form an excellent site for a turret battery, as it would give an extensive command of range considerably in advance of the proposed north-east battery. No. 2 of the appended plans and sections* shows at a glance the advantageous position which can be * Not printed.
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