CO129-205 - Public Offices - 1882 — Page 539

Appendix N°2

Colonel Crossman's letter.

th November 1881

to J.9.7. N°53 dated 244

Secret,

534

SUBMARINE MINING DEFENCE OF SINGAPORE.

Number of Mines and where stored.

1. The number of mines at present set apart for the defence of Singapore is 16 300-th ground mines und 38 electro contact aniues--7 of which can be used us mechanical mines.

These are stored, in time of peace, at Pulo Brani, where special stores and a pier have been built.

The stores are in charge of one officer and five men, but this force, in time of war, would have to be largely increased. (Vide Special Report attached.)

The Defence,

2. The defence, as arranged at present, consists of 8 500-1 mines and 32 E. C. for the Eastern entrance und 8 500-15 and 6 E. C. for the Western entrance.

The Eastern Entrance.

3. The mine field in this entrance is placed under the heaviest fire of the batteries of Mount Palmer and Blakang Mali East, which are each 1,500 yards distant, on opposite sides of the channel.

This distance is rather beyond that laid down in Manual of S. M. M. defence, but cannot be avoided. The mine field, however, is well retired, so that its Hanks cannot be easily attacked by small boats with giapnels and creepers. The distance across the on- trance defended by mines is 1,100 yards.

Arrangement of E. C. Mines,

4. The 32 E. C. mines for the defence of this pas- sage are arranged in groups of four, and each group of four is again grouped to a multiple junction box, and thence, by two multiple four-core armoured cables, they are led to the firing station.

By this arrangement a saving is effected in cable, and not more than four mines cone on one shutter in the test room.

The 500-th ground mines are placed in two lines of four mines, all the wines in a line are fired simulta- neously by un observer from the firing station.

In this way a channel of 40' is left for the pas- of ships desiring to enter and leave the barbour.

Bagd

Firing Station.

5. The firing station is placed behind the break- water at Tanjong Pagar and is proposed to be built in accordance with the accompanying drawing, which is the same as in the approved S. 3. M. Manual, with the addition of an arrangement for firing locomotive ter- pedoes from a tube.