Recognation SectionTail Pistol No. 17
U.S.N.B.D. - BRITISH BOMBS AND FUZES; PYROTECHNICS; DETONATORS
BRITISH FUZES & PISTOLS

 

 

 

 

 

BRITISH NOSE PISTOL

BOMBS USED IN

H.E. 20 lb. Mk I

NO. 16

FUNCTIONING

Instantaneous; impact

ARMED ACTION

When striker can be seen

 

through central hole in

 

base of fuze.  

FUZES USED WITH

None

Mk I

ARMING TIME

From 5 to 25 vane revo-

 

 

lutions, depending on

(For other Marks see REMARKS below)

 

setting

 

VANE SPAN

3.1" (5 vanes)

(Obsolescent)

MAX. BODY DIAMETER

3.3"  

OVERALL LENGTH

3.3" (less booster)  

 

   

DESCRIPTION:

The body is a hollow dome-shaped casting, recessed at the bottom to take the base, which is secured to the body by three screws. The top pf the body has a boss bored to take an arming spindle bush which houses an arming spindle and pinion. Loca-ted between a shoulder in the bore of the boss and a shoulder on the bush is a spring, which tends to keep the bush from moving inwards should the shear wire be broken. The bush has a slot cut in its side, to accommodate a guide screw. The arming vane is locked by a securing wire, which is threaded through a hole in the arming vane and a hole in a lug cast on the body. The base is threaded at the lower end to screw into the bomb body, and is bored centrally to allow the striker access to the detonator in the bomb. The safety gear train is formed by the arming spindle and pinion, which engages with an intermediate gear and pinion. The pinion of the intermediate gear engages with teeth cut on the striker holder, which is in the form of an interrupted-tooth gear wheel, having on its upper surface a triangular shaped stop which contacts the arming spindle and pinion after a predetermined number of revolutions of the arming vane. The striker is press-fitted into a hole in the striker holder adjacent to the triangular stop, and the striker is aligment with the arming spindle. The striker holder has marked on its under-side the numbers 5, 10, 15, 20 and 25 on the same pitch circle as the hole which houses the striker. When any one of these numbers is opposite the central hole in the base, approximately that number of revolutions of the arming vane will be required to bring the striker opposite the central hole in the base. The normal setting is 25. The striker holder rotates on a striker holder pin which is riveted to the base of the pistol, the striker holder being retained on the pin by a split pin.

OPERATION:

On release of the bomb, the vanes rotate and act through the arming spindle and pi-nion to rotate the intermediate gear and its pinion in a counter-clockwise direction. The pinion on the intermediate gear rotates the striker holder in a clockwise direction. After a predetermined number of revolutions the triangular stop on the upper surface of the striker holder comes in contact with the arming spindle pinion, aligning the striker with the arming spindle and hole in the base, and preventing further rotation of the striker holder. On impact, the arming vanes, arming spindle and pinion, and spindle bush are forced inwards against the spring, breaking the shear wire. The inner end of the arming spindle and pinion forces the striker into contact with the cap of the detonator in the bomb.

REMARKS:

If the pistol is not in the bomb, visual ispection through the hole in the base will in-dicate the number of vane revolutions required to align the striker with the pinion and the hole in the base, since the numbers 5, 10, 15, 20 and 25 are marked on the bottom of the striker holder and are visible when opposite the hole in the base.

No. 16 is obsolete; No. 16 Mk I, formely the No. 7 Mk I, obsolenscent.

Recognation SectionTail Pistol No. 17