Description
These fuzes are fundamentally the same, the principal difference between the No. 30 and No. 37 being in length, and the fact that, because of its additional length, the No. 37 arming spindle is fitted with two universal joints. The No. 30 Mk II fuze body is of tubular section and is externally threaded at one end to receive a coupling nut, which secures a tubular tail piece to the fuze body. Screwed into a flange on the fuze body is a locating pin for insertion into the slot in the exploder container of the bomb. The lower end of the fuze body is closed by a C.E. filled magazine, which has a thin bottom wall. The upper end of the magazine is closed by a diaphragm having a firing channel communicating with the magazine, the channel being stemmed with C.E.
An arming vane is secured to the end of the arming-vane spigot, and a flanged arming-vane spindle supports a rotatable pinion and counterweight. The pinion meshes with two gear wheels, one fixed to the tail piece and having 59 teeth, the other engaging the arming spindle and having 60 teeth. Secured to the arming spindle is a locking rod projecting into and retaining a pivoted shutter in the unarmed position. The shutter contains a detonator, and has a spring which forces it about its pivot to line up with the firing channel when the locking rod is withdrawn.
The fuze has two identical delay mechanisms, each consisting of a striker, a creep spring, an igniferous detonator, a delay pellet, and an adjoining powder pellet, so positioned that the powder pellet extends over a flash channel, and that one end of the delay pellet adjoins a firing hole, which opens into the bottom of the striker chamber. The strikers are retained in the unarmed position by the arming spindle, which is screwed into the sides of the strikers. Stop pins prevent the arming spindle and the strikers from jamming.
The Fuze No. 30 Mk I includes a special and a normal delay. The arming mechanism is the same, but the delay mechanism differs in that the striker for the special delay is supported by a shear wire when released by the screwed arming spindle. There is no creep spring beneath this pellet. The normal delay activates the fuze as described above, but the special delay functions when the fuzed bomb strikes one-inch mild steel plate with a velocity of 500 ft. per sec. When this occurs, the wire supporting the striker is sheared, and the striker moves against, and fires, the igniferous detonator below it. The flash from the detonator passes through the firing hole to the delay pellet, which ignites the powder pellet. The flash from the powder pellet passes through the flash channel and the flash plug and ignites the detonator, which fires the C.E. in the magazine by detonating the C.E. in the stemmed channel.
The No. 30 Mk I* is the same as the Fuze Mk II, above. The No. 30 Mk III is similar to the Mk II, except that it is fitted with a stirrup and a packing washer, and has a fork secured to the safety clip to press the arming vane spigot firmly against the packing washer to form a watertight joint while the fuzed bomb is being taxied over water.
Functioning
No information about functioning.
See Also
Nothing else to see.
Source(s)
OP 1665, British Explosive Ordnance (1946)
