Fuse markings

[depaor01]

Hi all,

Bought this fuse in the Musee d'Abris in Amiens some years ago. I'm intrigued by the markings - particularly the crossed out ones. Why would these have been obliterated?

I'd like to know the significance of all of them if possible.

Any info welcome.

Thanks,

Dave

[calibre792x57.y]

One of the British No. 100 series fuzes for HE shell. These went from design to production within ten days in 1914 and would exhibit a notorious range of faults from prematures to failing to operate at all. There then followed a string of modifications to overcome these faults and eventually ran with its variants such as the No.101 to scores of different marks. Some were to overcome faults, others to adapt it for different shells. These changes were often incorporated on fuzes in stock and the old Fuze number or Mark number would be obliterated by overstamping as shown and the new number or mark restamped. So your fuze was a modified No.101E as far as I can make out. This nose graze fuze was used on HE shell generally and ran to about 18 Marks! The RL is for the factory, Royal Laboratories, and the date 1/18 for January 1918 is the date it passed inspection. About all I can tell you. - SW

[depaor01]

Outstanding Sommewalker. Thanks very much. So I'm guessing a nose graze fuse detonated on impact as opposed to being timed. I always assumed mine to be from a shrapnel shell.

Cheers,

Dave

[calibre792x57.y]

Umm - no. These fuzes were all inertia designs where the detonator was fired when the forward motion of the shell was checked and either the detonator cap or the striker( depending on the design) ran forward against an anti-creep spring to fire the ignition chain which led to the detonation of the main charge. This system inevitably led to a delay of a few micro-seconds. This was good when you are attempting to penetrate overhead cover before exploding the shell, but not so good when you want to produce maximum fragmentation to produce a highly lethal burst. For the latter you need a direct action fuze where the striker is driven directly into the detonator. Hence the cratering of the battlelfield, which actually produced obstacles for the infantry's advance- an effect of the the inertia fuzes, and one of the weaknesses of the No.100 series. This was overcome by adopting a French design as the No. 106 fuze in 1917 which was a D.A. fuze. Generally there were no delay fuzes (other than chemical delays such as in the No.80 and 85, which are properly time fuzes) in the British arsenal. The Germans did use a clockwork delay to produce air-bursts and there was an attempt by the British to copy this, but it did not reach service during the War. You have to appreciate that this is all a simplification of a very complicated subject. My course was three years. I don't have room to repeat it! - SW

[depaor01]

Simplification! Thanks for the explanations SW. My education in these matters is sadly lacking.