ALLIED BOMBS AND FUZES

DESIGNATION:

TYPE OF MISSILE:

CLASSIFICATION:

PRINCIPAL MARKINGS:

MARKINGS:

NOSE BOMB FUZE M-104 or M-109. Typical subsidairy markings: LOT 521-2 Manufactu-res mark: P.A. Pioatinny Arsenal: 8 40 Month and year: all of these markings appear on top of striker head.

BOMBS USED IN:

M-104 used in the 23 lb. M-40 Fragmentation Bomb. M-109 used in the 20 lb. M-41 Fragmentation Bomb.

DATA

M-104 and M-109

1

COLOR

Unpainted aluminum.

2

OVERALL LENGTH

4.4 inches (including booster cup)

3

OVERALL WIDTH

2.2 inches

4

MATERIAL OF CONSTRUCTION

Aluminum alloy body, cadmium-plated striker and striker head, brass delay train cup.

5

PARTS

1

10

2

11

3

12

4

5

13

6

14

7

8

15

9

6

The M-104 and M-109 are slike in construction and operation except that the M-109 has a stronger spring beneath the striker head, and the striker head disc is not as large as the M-104. The base of the fuze is threaded externally to screw into the bomb and internally to receive the lower deto- nator cup. The arming pin is spring loaded and passes through the fuze hori- zontally, being held in position by a split pin. The spring loaded arming striker is held back by the arming pin. The arming striker is set in a vertical channel with a primer cap at one end which enters into the black powder ring. The black powder ring is housed in the brass disc located between the upper cap and the body proper. The detonating striker rests on a creep spring in a ver- tical channel in the center of the fuze body. The striker head is free to move in the upper cap of the body. A horizontal loaded slider containing primer cap rides in a horizontal shaft extending the width of the fuze body. In an unar-med position the slider is held from between by a delayed arming disc crim-ped in position at one end of shaft.

7

POSITION AND METHOD OF FIXING IN BOMB

Screw into nose of bomb.

8

FUZES LIKELY TO BE FOUND WITH

Alone.

9

COMPONENTS OF EXPLOSIVE TRAIN

In the arming assembly – the primer cap fires the delay powder train in cop- per housing. The timing train: The primer cap: The upper detonator in fuze body beneath the primer: Lower detonator in cup screwed into base of fuze.

10

ARMING TIME

2.5 seconds after arming pin is removed.

11

OPERATION

The M-104 is used in the 23 lb Bomb which has a parachute attachment. When the parachute opens it removes the split pin; and the arming pin (5) (spring loa-ded) springs out and falls away. The withdrawal of the arming pin releases the spring loaded arming striker (8) which goes forward in its channel striking a primer pellet (9). The flash of the primer pellet sets off the black powder train (4) which burns in an arc 326 degrees where it ignites a small pellet of black powder (12). The explosion blows out the delayed arming disc (11) which in turn releases the spring loaded striker (7) to move over under the detonation striker (2). Then upon impact the striker (1) head is forced down pressing the striker into the small pri-mer cap in the slider which initiates the detonation.

The M-109  is used in a bomb without the parachute and thus the split pin is re-moved from the arming pin when it is released from the plane. The striker head is smaller too, so that wind pressure will not detonates the bomb before inpact.

12

SAFETY FEATURES

If the delayed arming disc (brass colored) is not in place, the fuze is armed, so leave it alone. The M-104, with the mushroom striker head is a semi-always acting fuze and is very sensitive to touch at any angle.

Note

The M-104 is being replaced by the M-120 and the M-109 has been repleaced by the M-110, and now by the AN-M 110A1.