No 23 Mk I Base plug glitch

[Millsman]

I was given this yesterday. A nice battlefield find.

The problem with the No 23 Mk I and rods penetrating the grenade is known and Tom published a good note about Gibbons No 23 Mk I plugs being subject of a complaint a while ago.

This is the first example I've seen of it actually happening.

Maker is H & B plug dated 7 / 16, so one of the early ones.



John

 

[gothica7]

Mornin bud, I assume it still would have worked? Maybe with less distance travelled?I hope this example didnt kill any British Tommies,



Andy

 

[siegfreid]

John . Very good find . They actually tried making them from steel & they sometimes turn up but it was difficult to manufacture them in quantity as the threads had to be individually turned as you can't cast steel . They soon introduced the cast iron MkII plug with the reinforced ridge . Mike

 

[Millsman]

Hi Andy

I've measured the rod and despite some rusting degradation it is still the full 5.5 inches long.

By holding it up against a cutaway it looks as though the rod would have penetrated about 75% into the cavity under the anvil where the fuze sat. So it is possible that this may not have stopped the grenade from working properly as it didn't reach the igniter cartridge.

Let's hope it did what was intended.

 

[Millsman]

John . Very good find . They actually tried making them from steel & they sometimes turn up but it was difficult to manufacture them in quantity as the threads had to be individually turned as you can't cast steel . They soon introduced the cast iron MkII plug with the reinforced ridge . Mike

Thanks Mike

I've got some steel 23 Mk I plugs (in fact I got two yesterday) and they are quite rare beasts. They must have been difficult to stamp as well.

 

[BMG50]

its more likely the blast forcing the plug onto the rod when the grenade detonates, these base plugs fly for miles from the original point of detonation so plenty of force to push upon a rod. I have seen how the threaded stud from a mills base plate poked a hole in the base plug.

 

[Millsman]

its more likely the blast forcing the plug onto the rod when the grenade detonates, these base plugs fly for miles from the original point of detonation so plenty of force to push upon a rod. I have seen how the threaded stud from a mills base plate poked a hole in the base plug.

Looking at another H & B No 23 Mk I it's clear that the central hole was drilled almost through the whole plug leaving just a couple of mm metal in front of the rod. I can't agree with you on the plug being forced onto the rod because if that was the case there would be literally thousands of these rod and plug combinations in the fields.

Here's the complaint that Tom uncovered.

 

[khanmak]

This example was recovered during an archaeological dig in North Wales. Bit of an oddity. Could the rod have penetrated so far and stopped where its is?

 

[Millsman]

"Could the rod have penetrated so far and stopped where its is?"

That is the obvious question. If it went that far it would have had to have hit the striker, which because of the bottom rim and possibly the spring could not have exited the grenade body. I would have thought the maximum depth of penetration was about 2 inches (50mm).

All I can say is it looks genuine, needs to be restored to remove the accumulated rust and encrustation. Then we might have a clue.

 

[TimG]

Mark,

Yes, more than feasible. The compressed spring, striker combination has smashed its way through the top of the casting to exit the body, very closely followed by the anvil and rod (almost).

TimG

 

[Millsman]

I think that's a big assumption Tim.