No 100 existential issue

[MINENAZ16]

Hello,

I know it's not the first time there is a post about it but I'm trying to understand how this fuze works.
Indeed some diagrams show a fixed striker on the top + the side percussion pellet and other only the side percussion pellet at the base.

I've just cut a 100MkIIB and this fuze is made with two striker (top and base) and two primers.

I'm going to cut other models I found, 100Mk1, 100Mk2 and 100Mk2A and I could see....

Does anyone have any official documentation explaining the difference between the Marks.

Thanks

Best Regards.

 

[MINENAZ16]

Hello,

Today I killed a poor Mk1 from 1916 ; conclusion : two strikers like the MkIIB. I suppose the MkIIA is the same. My MkII and MkIIA are too clean to cut it, so I expect to find other in a bad condition to continue my experience.
I also hope to find a early version.
Waiting for a new cut !

Cheers.

 

[Bonnex]

Hello,

I know it's not the first time there is a post about it but I'm trying to understand how this fuze works.
Indeed some diagrams show a fixed striker on the top + the side percussion pellet and other only the side percussion pellet at the base.

I've just cut a 100MkIIB and this fuze is made with two striker (top and base) and two primers.

I'm going to cut other models I found, 100Mk1, 100Mk2 and 100Mk2A and I could see....

Does anyone have any official documentation explaining the difference between the Marks.

Thanks

Fuze, Graze, No 100
Design RL 21070A. Graze percussion. 'Designed, tried and approved in ten days' - OC Min 6478 of 2/8/1916. First trials fired 16/12/1914 by Coventry Ordnance Works. The wartime record of this fuze was poor, due to poor manufacture by contractors and the failure of the gaine attachment threads on setback. The cap is painted red where the gaine incorporates a delay. A Red patch on the body showed the location of the detonator. A Green tip indicated a tested needle.

Mark LoC Para
1 17208 of 21/1/1915 Introduction, with Gaine No 1
1A 18279 of 28/7/1915 Shortened adapter, reinforced with a steel ring
IB 18279 of 28/7/1915 Strengthened short adapter; disc retaining detent plug omitted.
1AW 18279 of 28/7/1915 As 1A but without reinforcing ring.
2 18279 of 28/7/1915 As 1 but with graze pellet stalk parallel instead of tapered.
2A 18279 of 28/7/1915 As Mk 1A but with graze pellet as Mk 2
2B 18279 of 28/7/1915 As Mk 1B but with graze pellet as Mk 2
2AW 18279 of 28/7/1915 As Mk 1AW but with graze pellet as Mk 2
All marks Obsolete: 24544 of 3/1/1921

 

[MINENAZ16]

Thank you very much Bonnex, it's the first time I read this info.

But I'm steel confused about this famous "graze pellet".

On the first diagram I posted (Mk ?) : "the impact throws the graze pellet forward, forces the percussion material against the needle and shoots the ignition flame down through the center of the graze pellet....to make explosion doubly sure the second percussion device is used, being released by the forward movement of the graze pellet." (...)

On the second diagram (Mark I) : If I understand well, only the second percussion occurs (no stricker-needle in the cap). Sorry I'm French so maybe I misunderstood the text (?).

And what about the Mk1 I autopsied today with the cap needle and the second percussion pellet ?

Best Regards.

 

[MINENAZ16]

Hello Bonnex,

A new question for you ;

Marking on this fuze is 100 II D.

I don't see the MkII D on your commentary.

Regards.

 

[Bonnex]

I'm afraid I don't know, my notes do not show a No 100 Mk IID. I suppose it is possible that the D indicates extra delay. TimG might know.

 

[MINENAZ16]

Thank you Bonnex,

So I'm waiting for TimG.

Cheers

 

[TimG]

Minenaz16,

As Bonnex states there is no listing for a Mk. IID (for Land Service).

However, a “D” after Mk. of fuze indicates a fuze with a brass disc inserted above the detonator in the detonator plug.

Whilst the stamping appears to be a "D" could it be a poorly struck or damaged "B"? I also note that the two "II" of the Mk. II appear to be "11"

If it were a “B” after Mk. of fuze, this indicates a fuze fitted with a one piece striker instead of a striker with a separate head.

TimG

 

[MINENAZ16]

Hello TimG,
Thank you.
I agree with you the II looks like a 11.
For the " D " I wondered if it was a B damaged or poorly made but I see no other trace to help.
Regards.