DATA:

BOMBS USED IN

FUNCTIONING

ARMING TIME

FUZES USED WITH

OVERALL LENGTH

MAX. BODY DIAMETER

MATERIAL

ships, plastic vanes.

GENERAL:

This is a VT fuze of the bar type. It is designed to detonate the bomb at a point above the earth which will give effective fragmentation. This fuze is more sensitive to head on approach to a target than the ring type and less sensitive to "passing" ob-jects. It can be used interchangeably in any bomb which will take the AN-M103A1 when air burst is desired except in the depth bombs noted above where the air stream does not give sufficient velocity to the vanes because of the flat nose.

At the present stage of development, approximately 85% of the fuzes will function properly on approach to the target, a small percentage will be inoperative, and the re-mainder will function spontaneously after arming but before approaching the target.

OPERATION:

When the bomb is dropped, the arming wire is pulled, releasing the spring-loaded arm which jumps off freeing the vanes for rotation. The vanes rotate and drive the electric generator and worm and spur reduction train. After a minimum number of vane revolu-tions, the detonator lines up with the booster lead-in and at the same tine becomes electrically connected to the firing circuit. The rotor detent in the detonator rotor snaps into the rotor housing, locking the detonator in the armed position and at the same time whitdrawing from the keyway in the arming stem. The vanes continue to ro-tate driving the generator which in the meantime has activited the VT element and charged the firing condenser. The fuze is now armed.

Upon approach to the target under the proper conditions, the VT element activates the firing circuit which discharges the firing condenser, through the electric detonator, initiating the explosive train.

REMARKS:

Arming may be further delayed by use of M1 (T2E1) Air Travel Arming Delay. The de-vice clamps onto a bracket, preventing the vane locking arm from releasing the vanes until the preset air travel on the M1 device has been completed.

This fuze has a safety pin running alongside the booster to secure the detonator ro-tor in the unarmed position. Before installation in a bomb the safety pin should be remo-ved and reinserted. If it cannot be reinserted, the fuze is armed or partially armed and should be destroyed.

The bar of this fuze should not be used to tighten the fuze into the bomb and should be carefully protected from strain or shock. This fuze is not generally recommended for use in bombs less than 10 in. in diameter because of the possibility of damaging the bars in bombing up the plane and in releasing the bombs. Damage to the bars will cause a malfuncitioning of the fuze. A few fuzes of this type were issued as the T51 with a 4500 ft. Min. SAT but with other characteristics identical to the M166 (T51E1).