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Help needed with these British containers

kradman

Well-Known Member
Picked up these 2 British Army containers , anyone know what they were for ? they are 20cm in lenght and 7cm across the base , thank you for any help
 

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These are what is known as Bulpitt cylinders, so called because they were produced in extruded aluminium and/or steel, by Bulpitt and Son (B & S), Cardiff Works, Birmingham in various designs for packaging of bulk fuzes.

This has been covered recently in a thread but I cannot remember the context.

The only thing missing from your cylinder is the flat white rubber ring, with a little ear which stuck out on the inner surface of the ring to help with pulling it out.
It is made of the same rubber as the bung in the convex lid shown. The cylinder was evacuated to form a partial vacuum and removal of the bung first helped with getting the inner lid off.

They are generally associated with the 'L' series of British fuzes. I think one of the outer packages used was the F624.

There were various designs according to fuze shape and you would have to obtain a suitable fuze or find a kindly friend who would let you try his fuzes. This is an ROF (W)44 cylinder of 1959 and 60.
 
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they were used with late no. 117 fuzes - the inner packing determining what shape fuze could be accommodated . Dave
 

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This one is by the same maker and dated 61, it is 355mm long without the lid and I don't at the moment have a lid for it, the cartridge case is a .50.

Web fuze tin N19 Mk1 003.jpgWeb fuze tin N19 Mk1 005.jpg
 
You may also find cylinders with stepped bodies (similar to Richard 709's photo), also fuze inner containers, that held V(ariable) T(ime) (proximity) fuzes.
 
Oh yes it does!

To quote the British "User Handbook of Anti-Aircraft Ammunition 1949"

"5.23 Proximity or Variable Time (V.T.) Fuzes"

TimG
 
I think that was just a smokescreen that became accepted as fact. There is no time element in a proximity fuze, let alone a variable one. It might have a time element for self destruct purposes I suppose.
 
The term VT was initially used as a cover for the development of the fuze*, but ultimately became an official designation. From an engineering perspective it quite appropriately describes the time to detonation being a variable - a function of the distance travelled to when the proximity circuit is triggered.


*Described in "The Deadly Fuze", Ralph Baldwin (Published 1980, ISBN 0 354 01243 6).
 
A Variable Time fuze is just that. It functions in the proximity of the target, regardless of the variable height of the target and has a preset self destruct time should it fail to find a target.
A designated Proximity fuze is set to operate at a given height above the ground, regardless of how far or how long it takes to reach its ground target.
Some of the first VT fuzes were used in the ground role but were no real improvement over existing time fuzes and were not cost effective, which eventually led to the development of proximity fuzes.
 
VT fuze functions can get quite complicated. TVT (Timed Variable Time) fuzes run with VT throughout the flight. This typically gives the target 20 seconds or so to do sums on the detected signal from the fuze and ECM the thing into an early functioning or no function at all until the self destruct operates.
A CVT (Controlled Variable Time) fuze switches on the VT function about 2 seconds from the target. This improves the survivability of the fuze but requires more effort at the gun.

To over simplfy it TVT is good for AA targets and CVT for say, ships and shore installations.

The N97 which I worked on for a short while could do TVT, CVT and DA. That was the best part of 50 years ago so I expect one or two improvements have have been made since then. I am not sure if TVT and CVT were NATO acronyms or just British ones.
 
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