Fuze workings

[Rob Heanley]

I have gone through numerous old threads and apologise for missing anything relating to this. My question is about the 80 and 85 Fuzes. I have an example of a No.80 VII fuze. The 0-22 seconds rings appears not to have been set. Ie the cross on the graduated ring is in line with the markings on the upper rings which seem to indicate that it has not been set to delay. The holes on the time rings are open. The fuze has clearly been fired and bares the scars. The rings is missing which would, I gather indicate it was used with a shrapnel shell.? Can anyone tell me what this means. My guess (which is probably wrong) is that my example was used as a percussion fuze so not fired for an intended aerial burst. I currently understand the percussion elelment of such fuzes was in place as a back up to the time element if the shell hits the ground first. It seems extravagent that the more complex T&P fuzes were purposefully used as percussion fuzes only.

Sorry this is fairly technical inquiry but any help/info very welcome.

Thanks,

Rob

[18th Battalion]

Rob, is your fuze in relic condition, or has it been cleaned up?

I'm wondering if it's ever been taken apart before you got it, does it still have the set screw in the top cap?

It's always useful to have a picture.

Paul

[Rob Heanley]

Thanks Paul,

I picked my example up in the area behind the Bois Francais near Mametz. I've cleaned it up and am able to decipher markings. I will attach a pic tomorrow if possible, I agree its far easier than describing it.

Top cap has no screw in place and hole is visible.

Thanks again,

Rob

[Rob Heanley]

Shamelessly I have stolen this image from a previous post. Mine is identical to this including the position of the timing ring to the ring above. I must apolgise for stealing this pic from the owner but I'm having IT problems.

So my question is regarding the setting of 80 fuzes. Does it mean that if the shell fuze is found on the field looking like this, after a little cleaning ,that it was used as a percussion fuze as the timing rings havent been set. Am I interpreting this correctly?. Does anyone know if the no.80 and perhaps no.85 fuzes were used as percussion only?

Thanks all,

Rob

[18th Battalion]

Rob, as far as I have been able to discover, the No.80 Time & Percussion fuze, is primarily a timed detonation with a "percussion" backup should the shell hit the ground or an object before the timer detonates it.

I can only guess that your fuze, if originally set to "0" is possibly firing shrapnel rounds over open sights at approaching infantry, essentially a big shotgun?

Perhaps one of the ordnance experts here can confirm this or provide another explanation.

Paul

[Rob Heanley]

Who are the big names on this forum in Artillery?

I've been through books at the IWM and lots of online searching but cant find info on shrapnel fuzes set to 0. Paul's theory seems a fairly plausible one. The date on my fuze is 10/17 which, given the location of the find, (Bois Francais infront of Mametz) puts its possible use in either Operation Michael and the German offensive on early 18 or possibly later in the allied march to victory. If the first; then I guess the British Artillery were firing in an enemy action and this may affect their ability to prepare time fuzes?

I am generally at a loss to why a "T&P" Fuze that has undoubtedly been fired would be set to 0 time delay making it a percussion only fuze. As I said it seems an extravagent use of one.

Any thoughts welcome.

Thanks all,

R

[auchonvillerssomme]

I have just looked at mine and 3 of them are set at zero, all relics, found in the Somme region. but in excellent condition which might indicate they have never been set. I have numerous others which I will check tomorrow afternoon.

[Rob Heanley]

Thanks for that. Its a strange one to figure out. I am certain my example has been fired. Its scarred and lined from cap to base and these are in keeping with how I imagine damage from hitting the ground would look.

It also appears that the threaded ring at the base is cracked almost all the way through so I imagine that was caused by an explosion. Strange that so many are set to 0. Presumably some of the other examples you have are set to some level of delay? (very envious by the way, so far I just have the one).

Rob

[Seadog]

This may be of interest:

Lots of battlefield relics here:

Flickr Photoset

Regards

Norman

[Rob Heanley]

Certainly is. Thank you. Doesn't answer my awkward question about the use of the Fuzes set to 0 time delay. That's what's beaten me. Good diagram though thank you.

[nigelfe]

Bethal, 1911, 'Modern Artillery in the Field'

Chap VI Ammunition, pg 88:

Reviewing shrapnel "the fuze can also be set to percussion, that is, to act on striking the ground or target. This is useful for ranging or for direct fire at guns or houses"

Chap X Fire Discipline, pg 160:

"The range may be found by percussion ranging, when the shells are burst on the ground, or by shrapnel ranging, when they are burst in the air, or by a combination of the two."

pg 163:

"When the 100 yard bracket has been obtained it is verified with percussion shrapnel.

When the bullet strikes are visible, the process of time shrapnel ranging is much facilitated, and verification with percussion may be omitted."

[18th Battalion]

Presumably, based on niglefe extracts from 'Modern Artillery in the Field', setting to zero must disable the timed element of the fuze by closing off the channels with the timer powder, as I believe the time delay adjuster ring is the only externally moveable part?

BTW. I've got 2 No.80 fuzes, one is set to 12.5 and the other 6.5 secs