DATA:

BOMBS USED IN

FUNCTIONING

ARMED CONDITION

FUZES USED WITH

ARMING TIME

VANE SPAN

MAX. BODY DIAMETER

OVERALL LENGTH

MATERIAL

GENERAL:

These fuze are a combination of the M111A2 mechanical time fuze and the AN-M103 nose fuze, in which the former fuze has been assembled to a modified body and booster portion of the AN-M103 fuze. The setting pin of the AN-M103 has been removed and in its place the spring loaded lower arming pin has been inserted. The lower arming pin holds the detonator carrier out of line with the firing train until the arming wire is pulled.

The M135 incorporates a time setting which can be adjusted to the nearest .1 se-cond, and the fuze will fire accurately within plus or minus one (1) second; time cali-brations are made for every 1/2 second, with a 10 division vernier scale located on the non-rotating patr of the fuze for setting to the nearest .1 of a second.

The M136 incorporates a time setting which can be adjusted to a .2 of a second, and the fuze will fire accurately within plus or minus .3 seconds. The greater accuracy of the M136 is achieved by an improved clockwork mechanism. This fuze was developed to provide greater accuracy, presupposing that a method can be devied for accurately measuring the altitude of release.

OPERATION:

Prior to loading the fuzed bomb into the plane, the time setting is made and the time set screw tigthened. The arming wire is withdrawn as the bomb is dropped and the vanes start to rotate. The arming pin is ejected and the time mechanism starts to ope-rate, the lower arming pin being simultaneously ejected, allowing the spring loaded de-tonator carrier to move over into the armed position. After approximately 750 feet of air travel, the safety block is released from the fuze (see Operation of M111A2, page 181 for details on functioning). After the set time has expired, the firing pin will be freed and its spring will force it into the primer and detoante the bomb.

The bomb may be detonate if it strikes a target prior to complete functioning of the time mechanism, provided the arming wire has been withdrawn, in which case the firing pin would shear the rather delicate levers obstructing it.

REMARKS:

Effective use of these fuzes in G.P. bombs presupposes that a method can be devi-sed for accurately measuring the altitude of release.

The round knurled locking screw has been replaced in current production with a wing nut type, and replacement wing nuts are being sent to the field. This change was made so that ordnance personnel can get a good grip on the nut and eliminate the possibility that the setting might slip, and cause either premature or late functioning.

The M135A1 and the M136A1 fuze are the same as the M135 and M136 except that they incorporate a lower time limit of 10 seconds instead of 5 seconds. The minimum setting time was increased to prevent any possibility of damage to the plane by the bomb fragments. The M135A1 and the M136A1 will replace the M135 and the M136 respectively when available. It is recommended that a minimum setting of 10 seconds be used for all M135 and M136 fuzes now in the field.

These fuzes are not procured for Naval use.