CAB7-4 — Page 106

Appendix No. 4.

ST. HELENA.

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Inclosure 4 in No. 13.

Memorandum on the Defences of St. Helena, by the Commanding Royal Engineer.

AS the War Office Memorandum, dated the 26th April, 1881,* issued by the Inspector-General of Fortifications, contains a statement both of the existing and also of the proposed defences of St. Helena, the present Memorandum must be considered as supplementary to the same, and to indicate the various alterations in details or additions to the proposed works which local experience has convinced me to be desirable. It will be seen that the War Office scheme will, if carried out, require very little to be added to.

Land Defences.

2. An attempt to capture the island can only succeed by first obtaining possession of the central portion of the same. All the valleys in which an enemy may land converge towards the

"the Ridge," an enemy would be favourably situated for offensive

centre.

3. Once lodged upon purposes.

He would be in absolute possession of the whole island (together with all cattle, horses, &c.), not within reach of High Knoll. He would find plenty of wood and water in convenient positions, and would obtain possession of a base of operations at Sandy Bay where he could land light guns, and move them up by the existing road to "the Ridge." The best roads in the island are grouped together in the neighbourhood, and they happen to be so laid out as most to favour an assailant's operations. The various lines of hill and ravine which run north from "the Ridge" would render an investment of“ High Knoll and Ladder Hill, and a land blockade of James' Town, practicable with a very moderate force, while a severe stress would be placed on the defence if guns were used near Alarm House to bombard the town, and which can be done from positions unseen from High Knoll, but which command a view of the long, narrow town, the whole of which would be enfiladed; so also would Rupert's Valley, in which any coal or other depôt which may be established here for naval purposes will most probably be situated.

4. So long as the ground near Halley's Mount on the east and Cason's on the west be held by the defenders, a successful land attack is considered an impossibility.

5. An inexpensive method of doing this would be by constructing on the heights near each place a tower with a gun on the top having "all round" fire. This would prevent any force which may have effected a landing from obtaining possession of "the Ridge," as one or the other of the towers would command every road in the island available to an enemy, and should it become necessary to make a final stand in advance of High Knoll, each of these towers would be a permanently fortified post on the flank of the position best suited for the purpose (according to whether the enemy's advance was from the east or from the west), and the whole of which is scen from and overlooked by the tower.

6. This particular subject has lately been fully reported on by myself, when unaware that the defences of St. Helena were to be considered specially by the present Committee, and I have recom- mended that the advanced work proposed for the north side of High Knoll be not constructed, as not being necessary, but that the amount thus saved be diverted for the towers.†

7. The various landing-places practicable to an enemy do not require any special notice here; in the estimates for 1882-83, an item has been inserted for necessary repairs to the barrier walls which block the outlets for the valleys and for scarping, &c.

8. It is, however, submitted that a few breastworks for musketry or for mountain guns, in positions suitable for opposing the passage up various ravines, would be desirable. In most cases dry stone walls would be all that is required. This would have the double advantage of determining beforehand the spots most advantageous to occupy in a hurry, and of acquainting the garrison with these localities.

9. In connection with the subject of land defence, that of distribution of garrison is intimately involved.

The infantry barracks is in James' Town, and although not at present occupied, owing to reduced garrison, it would be necessary to re-occupy it with a stronger force stationed here. But James' Town is the worst situation, both for military considerations and also those of morale, for soldiers' barracks, though it will not be possible to avoid quartering some troops there for the performance of ordinary garrison duties.

10. If some infantry were lodged near the central ridge they would be in the best position for use against an assailant, wherever he might land, and this military advantage, for a time of hostilities, would be combined with the fact, that at all times they would be in coolest and most pleasant part of the island, and removed from James' Town, which combines in a contracted space the well-known drawback of both garrison and seaport towns.

11. The central ridge corresponds, roughly speaking, to the nave of a wheel with considerable dish laid on the ground; the lines of hill running thence to the sea represent the spokes, the spaces between which are the valleys. Before an enemy can move from one hill (or spoke) to another, it is necessary for him to reach (or almost reach) the nave of the wheel, and while he would have great difficulty in toiling up the ravines which lead there, the garrison ought to be at the top (or nave) in readiness to move down to oppose hîm,

12. One rather weak company of infantry only is now stationed here; the insufficiency of this, for ordinary peace requirements, has been brought to notice on every available opportunity, and is con- sequently well known to the responsible authorities, and considering the drawbacks which attend the meagreness of the present garrison, it can be hardly doubted that the infantry here will be increased before long.

* No. 14.

+ Report, Commanding Royal Engineers, St. Helena, to Inspector-General of Fortifications, dated 9th August, 1881.

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