Tension and Release Firing Device M315-Second Delay Detonator M1
U.S. EXPLOSIVE ORDNANCE
PART 5 - MINES
Chapter 16 - FUZES AND FIRING DEVICES

Delay Firing Device M1

General: This device is designed for firing explosive charges by chemical delayed ac-tion. The are issued in boxes on ten, with different delays. The delay depends on the concentration of the corrosive liquid in the glass ampoule, the color of the safety tab on each device indicating the delay of that device. In addition, the delay varies with the temperature. A chart with the temperature correction for each device will be found in the box.

Description: The principal parts of the device are the glass ampoule containing the corrosive liquid, the spring-loaded striker, the restraining wire preventing the striker from impinging on the percussion cap, the standard nipple base, and the identification and safety strip. The restraining wire runs along the side of the ampoule and is securely atta-ched to the end of the devcie by the screw and lead washer. The safety strip rund through the device between the striker and base, and would prevent the device from firing should the glass ampoule be broken in handling or shipping.

Operation: After a blasting cap has been crimped to the base and the device inser-ted in the explosive charge, the device is actuated by squeering on the copper tube which houses the glass ampoule. This will break the ampoule and permit the corrosive li-quid to react upon the restarining wire. After looking through the inspection hole to make certain that the striker has not already been released, the identification and safety strip is removed. The corrosive liquid will eat through the restraining wire after the delay and free the striker to be forced down on the percussion cap by the striker spring.

Remarks: If it is absolutely necessary to disarm, insert the safety pin through the in-spection holes.

Troops must not approach an installed charge employing this delay fuze. Areas where they have been installed should be marked. Time delay starts when the tube is squee-zed, not when the safety tab is withdrawn.

Figure 253. Delay Firing Device M1 (right) and
15-Second Delay Detonator M1 (left)

Tension and Release Firing Device M315-Second Delay Detonator M1