British No.5-1 Bomb Fuze

[ordnance]

Recently acquired this WWI British bomb fuze and would like to know more about it. Can one of the members supply more information about its history and the models of bombs it was used with? Were these used as a nose or tail device? This one is dated 4-18. Thanks.

Rick

 

[TimG]

Rick,

What you have is actually a 'pistol' not a 'fuze'

The No. 5 was a tail pistol (with one exception)

Used with;
Caseless Incendiary bomb MkI
GP 50, 120 250 & 500 lb bombs
RAF 500, 520 & 550 lb bombs
RFC 230 lb bombs
RL 112, 250 520 & 550 lb bombs

It was also used as a nose pistol on the Stokes mortar.

For further details see 'British Bomb and Rocket Pistols and Fuzes 1914 - 2007) by David Andrews and Alan Swan (Both BOCN members)

Regards

TimG

 

[ordnance]

TimG,

Thanks for that info.

I suspected I might have been using incorrect terminology regarding the fuze vs. pistol issue. It's never been clear what the difference was in terms of design and function, at least to me. Perhaps it's primarily a British designation but the Americans used it occasionally, such as with the Mk6 depth charge pistol.

Is the Mk5-1 bomb pistol a fairly common item in ordnance collections over there? Don't think I've seen another over here, but it has always been more common to see WWI German souvenirs than British.

One last question....with a 4 1/2" wide propellor, it would be too wide to fit in either a 3" or 4" Stokes. Did they trim the blades when this pistol was used with mortar shells?

 

[kahu1]

Hi ,
My understanding (open to expert advice here!) of the difference of fuze or pistol is ,

a fuze is supplied ready fitted with a charge,can be boosted ,

and a pistol is essentially a mechanism to fire a seperately supplied and fitted cartridge/charge ,though even this seems to have exceptions.

cheers ,Bob.

 

[TimG]

Bob's explanation covers it, unless you want to get pedantic. I think they're rather rare this side of the Atlantic as well. How it was used with the Stokes Mortar, I've no idea. Somewhere, I think I've got a handbook for the Stokes, I'll have a look and see if it sheds any light on the matter.

As a matter of interest, what are the maker's intitials stamped on the body?

Thanks

TimG.

 

[ordnance]

Thanks Bob. That explaination sounds logical.

The only markings on the body are on the opposing wrench flats. Below the "No 5-1" it is marked "M.M.L" with a little character in the L. Perhaps for Ltd.?

Rick

 

[kahu1]

Found some plates of fuzing configuration in
AP1243 JUNE 1939.

I only have chapter 2( aircraft bombs),but lots of pretty pics of 1914-1939 era bombs.

112lb bomb.

cheers Bob.

 

[Bonnex]

Stokes, Sangster and Mills

...

One last question....with a 4 1/2" wide propellor, it would be too wide to fit in either a 3" or 4" Stokes. Did they trim the blades when this pistol was used with mortar shells?

Rick, I would be interested to know why you think it was used with the Stokes. Certainly trials were done with a 'Sangster fuze' (No 25 Grenade) which also had wind vane arming, but I have not read anything that would suggest using this sort of pistol.

Mills Munitions Ltd used the MML monogram but I couldn't be sure that they made this pistol, they did however make fuzes for the Stokes.

 

[TimG]

Norman,

It was I who stated it was used in the Stokes mortar. In the above mentioned publication it states -

"The No. 5 Mk. I pistol was assembled with a Relay Mks I or II and a 0.05, 2.5 or 15 second delay detonator for use in the Stokes mortar, when it was known as the 'Stokes Assemblage' and was given the nomenclature of 'Fuse, No. 18 Mk. I"

I would interested to see how it was used. I can't see it being fitted to the base of the mortar, so one assumes that it was fitted to the nose. However, it is an inertia fuze and the unscrewing of the vane and the wind pressure thereon would more than likely force the striker into the detonator. Perhaps that's how they intended it to function. Except there's no way one could use the 0.05 second delay.

Regards

Tim

 

[Bonnex]

Norman,

It was I who stated it was used in the Stokes mortar. In the above mentioned publication it states -

"The No. 5 Mk. I pistol was assembled with a Relay Mks I or II and a 0.05, 2.5 or 15 second delay detonator for use in the Stokes mortar, when it was known as the 'Stokes Assemblage' and was given the nomenclature of 'Fuse, No. 18 Mk. I"

I would interested to see how it was used. I can't see it being fitted to the base of the mortar, so one assumes that it was fitted to the nose. However, it is an inertia fuze and the unscrewing of the vane and the wind pressure thereon would more than likely force the striker into the detonator. Perhaps that's how they intended it to function. Except there's no way one could use the 0.05 second delay.

Regards

Tim

Ah, thanks Tim, I have heard of the Stokes Assemblage but thought this was just the name of an aerial bomb fuzing assembly devised by a bloke called Stokes. I had no idea that it might refer to the Stokes Mortar. Let me know what you find please.

I guess if fitted to the nose of the Stokes' bomb, cylindrical variety, the bomb would flip in flight putting the fuze in right attitude (until the vane, which offered drag up to this point, falls away and then who knows what way the bomb will face). A tail would help and I have seen one fitted to the nose of a cylindrical Stokes bomb.

 

[TimG]

Norman,

Having looked at 'Details of Aerial Bombs, Air Ministry 1918' your thoughts were well founded. The Stokes' Assemblage was an aerial bomb fuzing assembly. It was used with the 112-pound and 230-pound bombs. I don't know how the referance to Stokes Mortar crept into the description given in the publication mentioned.

Regards

Tim

 

[ordnance]

Thanks to all for the additional information. Just what I was looking for.

Rick

 

[Bonnex]

Stokes Assemblage

Norman,

Having looked at 'Details of Aerial Bombs, Air Ministry 1918' your thoughts were well founded. The Stokes' Assemblage was an aerial bomb fuzing assembly. It was used with the 112-pound and 230-pound bombs. I don't know how the referance to Stokes Mortar crept into the description given in the publication mentioned.

Regards

Tim

That's a relief Tim, I spent a little time studying the Stokes and its bombs (mainly the cylindrical chemical sort) and never saw this fuzing arrangement used and it does seem rather an expensive option. Even so I wouldn't discount its use on say, a 4-inch (or 4.5-inch) cylindrical bomb used as an aerial bomb. Perhaps Dave and Al might pick up on this and confirm the Mortar connection.