unknown british (export?) fuze

[Alpini]

Hello,

I am looking for details about this damaged fuze. It has the following stamps:

S/20.35 VAD 1937

S/20 sounds like 20 seconds? 35 = Model of 1935? Made by Vickers Armstrong in Dartford 1937?

It has no broad arrow on the surviving parts.

The only tracks I found is a similar looking japanese fuze for 40 mm (2-Pounder) shells and a very bad drawing of a dutch fuze which is also looking the same. The japanese version has different inner parts. So could it be a export version for the Netherlands? Was the fuze used in the Royal Navy? Is there a british fuze No.?

Finally, doest anybody know the thread size of 2-pdr shells? According to the japanese drawing it seems to have been a 1" thread but what's the thread pitch?

Regards, Alpini

 

[collector]

It does look a bit like the British fuze no.121 or the no.125?
just thinking.

 

[MINENAZ16]

Hello,

I'm sure Alpini knows it's a British made fuze of the 121, 124, 125 series design.
I can't help for marking only that I saw many british fuzes of this family without designation markings on top. S/20 sounds nomenclature for export.
Herewith picture of japanese fuze.



Regards

 

[AE501]

The fuzehole of the 125 is what is described as 1.2" (1.196" actual) and 14 TPI. It is graduated 1 - 10 with a full run time of 16.9 seconds. Is yours graduated, I see the Japanese fuze is also graduated 1 - 10.
Alpini's fuze has the 'P' denoting gunpowder.
As you know the British 125 was mainly used with naval 2pr and 6pr and any mark would have been followed by the letter 'N'.

 

[Bonnex]

I am not sure that this will be helpful but the Vickers fuze S22 would be readily identified as a No 80. I mention this because conceivably the S20 predates the S22 by a short period which would make the S20 design in the 1902/3 period. I appreciate that this is a huge assumption.

Vickers supplied some not-quite-121 fuzes with their 1.57 Toffee Apple Mortar Bomb and this thread makes me wonder if the S20 was used for this purpose (I think 'The Doctor' has studied this more than most and may be able to comment).

 

[MINENAZ16]

I am not sure that this will be helpful but the Vickers fuze S22 would be readily identified as a No 80. I mention this because conceivably the S20 predates the S22 by a short period which would make the S20 design in the 1902/3 period. I appreciate that this is a huge assumption.

Vickers supplied some not-quite-121 fuzes with their 1.57 Toffee Apple Mortar Bomb and this thread makes me wonder if the S20 was used for this purpose (I think 'The Doctor' has studied this more than most and may be able to comment).

Hello,

As far as I know fuze no 121 changed of designation with 1.57in trench how. and became no 123 with a booster attached.

As you talked about S/22, here is the diagram :

 

[Bonnex]

Thank you. Interestingly my drawing shows the S22 as a classic No 80. The drawing, which is in a bound volume of ordnance, carriages and ammunition diagrams, seems to be dated 1905 and is from Vickers. I will scan the drawing when I can.

 

[Alpini]

The fuzehole of the 125 is what is described as 1.2" (1.196" actual) and 14 TPI. It is graduated 1 - 10 with a full run time of 16.9 seconds. Is yours graduated, I see the Japanese fuze is also graduated 1 - 10.

Can you please check again if it is 14 TPI / dia. 1.196?

I measured the drawings of a No.121 and No.124 (took the average pitch between the single turns in relation to the fuzes total length) and both are near 16 tpi. But I also know that the threads were often drawn inaccurate in these old drawings. And I also wonder about the diameter because the American drawing about the Japanese fuze which I posted initially quotes 1.02" as thread diameter. Measured from the drawing I get 1.04" and 1.02".

Sadly the graduation of my fuze has not survived. I only can say that it had a detonator like the Japanese type because several where found and destroyed.

Thank you,

Alpini

 

[Alpini]

Thank you. Interestingly my drawing shows the S22 as a classic No 80. The drawing, which is in a bound volume of ordnance, carriages and ammunition diagrams, seems to be dated 1905 and is from Vickers. I will scan the drawing when I can.

I am not sure about Vickers, but Krupp also named the fuzes "S/xx" where XX was the maximum delay time. And these designations were not unique. It could happen that for example a mechanical time fuze with 43 sec running time was named S/43 like the well known pyrotechnical "Dopp.Z. S/43" too. It seems the military designations for fuzes were choosen better than the private companies did.

 

[Bonnex]

Thank you, that would explain the two different S22 fuzes. The volume also contains an S35 which I will scan also.

 

[Bonnex]

Many thanks Alpini, it makes sense now. Herewith three extracts from the volume, two look the same but have slightly different drawing numbers.

 

[MINENAZ16]

I'm sure Krupp made fuzes with different construction but same designation.
Example of Belgian S/35

 

[Alpini]

Hello Bonnex,

whow, very interesting drawings. All three are 100% Krupp fuzes. The last one is for shells 100 mm and larger. Nearly the same was exported to Turkey and the Netherlands (and may be many more countries). Do you know if Vickers produced (and exported) them?

 

[greif]

Hello Alpini,

Not quite the same fuze but strongly related. Unfortunately I do'nt have the Original document. I only have this scan.

Regards,
greif

 

[Alpini]

Hello Greif,

awesome - exactly what I need. And I can tell you - it is the same fuze for sure. The internal construction ist the same, and also the designation S/20.35 fits perfect. And it has most needed diameters and thread pitch!

Thank you very much!

 

[MINENAZ16]

Hello Greif,
Thank you.
Now you answered a question, one day I found a diagram with google image of a vickers armstrong fuze without other details : http://www.ioffer.com/i/vickers-armstrong-fuzes-color-plates-inert-121035333

I assume the diagram of s/22 I posted is from the same book.


Regards

 

[Bonnex]

Hello Bonnex,

whow, very interesting drawings. All three are 100% Krupp fuzes. The last one is for shells 100 mm and larger. Nearly the same was exported to Turkey and the Netherlands (and may be many more countries). Do you know if Vickers produced (and exported) them?

Thanks Alpini,
I am not sure about Vickers commercial sales abroad. Obviously they had a strong customer base in the British forces and clearly were happy to sell Krupp's designs to the military (eg the No 80 fuze). They did pay Krupp royalties although needed a bit of legal encouragement after World War One to pay for the Krupp's fuzes that they had made during that conflict.

 

[Alpini]

Does anyone have an idea about the graduation of the S/20.35? The name lets guess it was 1-20 and the drawing also looks like 1-20. But I think the small diameter of this fuze has not enough space for such a long scale. For a 1-20 s scale the fuze would have more than double strokes around.

The drawing of the 121 Mk.II also looks like 1-20 but I think that couldn't be true. The comparsion of the right sides of the scales below looks the same on all fuzes so I think all had 1-10 s scales?

 

[MINENAZ16]

Hello,

Same question about max graduation, but as the No125 could burn to 16.9s with 10 for graduation max, nothing really obvious.
You have to find another complete one...
I assume you noticed that the shape of your S20.35 is not exactly the same as the diagram : no notches on the setting ring on the diagram.

Regards

 

[Alpini]

Yes I noticed this small difference. My S/20.35 is for a fuze setting machine and the S/20.35 on the drawing is not.

And I think you are right, the scale is 1-10 independent of the fuzes maximum burning time. It is a time scale (not distance) but the numbers are not seconds (on all fuzes of this series).