Figure 4-10. M700 time fuse.

TM 9-1300-277

consists of a core of PETN or RDX in a textile tube

coated with a thin layer of asphalt. On top of this is an

outer textile cover finished with a wax gum composition

or plastic coating. It transmits a detonating wave from

one point to another at a rate of between 20,000 to

21,000 feet per second (partially submerged

watersoaked detonating cord will detonate if initiated

from a dry end). Although it does not lose its explosive

properties by exposure to low temperatures, the

covering becomes stiff and cracks when bent. Thus,

great care is required in using detonating cord primers in

arctic conditions. Detonating cord is issued in a variety

of types and classes including commercial types.

Plastic reinforced and wirebound types are available.

Detonating cord is used to prime and detonate other

explosive charges.

When its explosive core is

Figure 4-9. Safety fuse.

detonated by blasting cap or other explosive devices, it

will transmit the detonation wave to an unlimited number

of explosive charges.

Figure 4-10. M700 time fuse.

This fuse is similar to safety fuse and may be used

interchangeably with it. The fuse is a dark green cord

0.2 inches in diameter with a plastic cover. Depending

upon the time of manufacture, the cover may be smooth

or have single bands around the outside at 12 or 18 inch

intervals and double bands at 5foot or 90-inch intervals.

These bands are provided for easy measuring purposes.

The burning rate is approximately 40 seconds per foot.

However, the burning rate always must be tested in the

same manner as that for safety fuse.

At arctic

temperatures, the outside covering becomes brittle and

cracks easily.

d. Detonating cord (fig. 4-11). Detonating cord

(also known as primer and commercial type Primacord)

Figure 4-11. Detonating cord

4-11