M132, M133, and M134 (Tail Chemical Time, Anti-Withdrawal)

Bombs

Functioning

Armed condition

Fuzes used with

Arming time

Vane span, inches

Body diameter, inches

Over-all length, inches

Material

Cadmium or zinc plate, or cronak-treated zinc-plated steel

General: The only difference in these three fuzes is in the length of the arming stem. These fuzes are dependent upon chemical action for normal functioning, and atmospheric temperatures will have a direct bearing on the length of the delay. The fuzes are similar in principle to the M123 series, but are safer in that the solvent is contained in a flexible copper bellows rather than a glass ampoule. The fuze body does not project far beyond the adapter booster; hence, there is less chance of breakage upon severe multiple im-pacts. This fuze, as in the M123 series, has a ball locking device, and any attempt to re-move the fuze will result in detonation of the bomb.

Operation: When the bomb is dropped, the arming wire is withdrawn, and the vanes rotate. The vane assembly is the same as in the M123 series, and the vanes act through reduction gears like those in the fuzes of the AN-M100A2 threaded to the plunger carry-ing the knife edge. As the arming stem turns, the plunger carrying the knife edge threads down, compressing the sylphon bellows and piercing the gilded metal sealing cup. The T-slot channel in the knife edge allows the acetone to drain out of the bellows and act on the celluloid tubing delay element. The three felt washers and the glass wool wick absorb excess acetone and conentrate it on the delay element. As the delay element is dissol-ved after a minimum of five minutes, the compressed firing-pin spring thrusts the alumi-num ball retainer upwards, freeing the extension balls holding the firing pin in place. The firing pin spring then forces the firing pin down onto the Detonator M19A2.

If an attempt is made to withdrawn the fuze once it has been installed, the anti-with-drawal locking ball will ride into the shallow part of its groove and lock the lower part of the fuze body to the adapter booster. Further turning of the fuze will unthread the upper part of the fuze and permit the ball retainer to be forced up by the cocked firing-pin spring, allowing the balls to be forced out and the firing pin to striker the Primer Detona-tor M19A2.

Remarks: The concentration of acetone is not varied in these fuzes as in the M123 series, nor are additional celluloid plugs added to prolong the delay. Variable delays result only from temperature variations, as is indicazed in the following table:

Temperature (F)

122°

6

110°

7.5

85°

15

70°

21

55°

30

40°

40

32°

45

10°

80

Figure 345. Tail Time Fuze M132