III.

EXPLOSIVES:

British Naval explosive charges are indiacted in chart form on page 82.

In addition to these, heavy demolitions are sometimes accomplished by adapting Depth Charges Mk VII, Mk VIII, Mk XI, and "D" Mks I & II, and Mine Charge Case Mk V for demolition firing.

IV.

SHAPED CHARGES:

Charge, Cavity, 5 lb. RDX/TNT, Demolition, Mk I:

This charge is a linear shaped charge designed for cutting chain, steel wire rope, steel plate, etc. The charge consists of approximately five lbs. of 60/40 RDX/TNT. The primer pocket will accept either a primer C.E. Mk I, II, or III, or a 2 oz. Polar Blasting Gelatine primer. The charge has been designed for use with detonators Briska No. 6, and is not suitable for use with No. 21 or No. 25 detonators. An ICI No. 1 Gasless Delay detonator may be used when the charge is fitted with a Mk III C.E. primer.

The thin sheet steel case encloses the water-tight cavity, and the case and primer tube bung are watertight, allowing the charge to be used in depths up to 3 fathoms.

Two cleats and 6 ft. lanyards attached to the charge enable it to be quickly se-cured to its target.

V.

Fuse, Safety No. 9 Mk IV:

This is a standard service fuse, frequently known as "Bickford's", used for detonators No. 25. The rate of burning is approximately 2 ft/min. This fuse is of larger diameter then No. 11, or No. 100, and when used with Briska No. 6 deto-nators, the outer layer must be peeled back before the fuse can be inserted in the detonator.

Fuse, Safety, No. 11 Mk II:

See page 81.

Fuse, Safety, No. 100:

This fuse is smaller in diameter than Service safety fuse and can be used only with Briska No. 6 detonators. Burning rate is approximately 2 ft/min. The fuse is weather-proofed, not water-proofed, but will burn under water not ex-ceeding 10 fathoms, provided it has not been immersed for than 15 minutes.

Cordtex: