When was the double crimp added to the ogive of M48 and M51 Fuzes?

[jeff w]

I want to make sure I am putting a proper WW2 era M48 fuze on my WW2 dated ordnance.
In the WW2 era photographs that I have seen , the alloy ogive on M48 and M51 fuzes is always smooth.
But at some point in the fuzes evolution, a double crimp was added to the ogive. The crimp I assume, was to keep the ogive from spinning on the fuze body which would put the delay screw-head out of alignment with the screw hole in the ogive.
Was this double crimp introduced during the war or after?

 

[HAZORD]

I have a 42 dated fuze without the crimps, and the oldest dated fuze I've found so far with crimps is dated 52.

If you are looking for a non crimp fuze or 5, the fuzes for the 175 Gun used in Nam don't have crimps. The whole inside of the fuze is potted because of the G forces it had to withstand.

 

[jeff w]

I'm 90% sure this picture is WW2, probably Nov 44' or spring 45' (judging by the mud and lack of Korean hills). It shows the double crimp on one of the fuzes...

 

[jeff w]

OK I think this photo cinches it. I believe this is an M3 105 - not used by US forces in Korea. And I see leggings. You can see the double crimp on the round he is about to load. Wish I had saved captions with these pics...
So I'm thinking the double crimps started showing up in service around 44/45.

 

[M8owner]

I have a 4-43 dated M48A1, and it has the double crimp.

 

[MINENAZ16]

Hello,

Jeff W, where did you found your picture of soldiers and shells ?
This picture is very interesting as shells are French !!!
On the right, 100% sure French 155mm FATO GP
Other shells with US fuzes or lifting plugs really look like French 155mm B GP.
These kind of shells were copied by US in the 20's. but colors and markings on right shells are French ("GP" in white).
I know we used US fuzes on French shells in the 50's. (and US uniforms)
First time I see this combination. I'm very curious to know more (these old shells need a modification to be fitted with an US fuze)

Regards

 

[blu97]

Actuly the MK III shell had two driving bands

 

[MINENAZ16]

Thank you.
First time I see this model with M51 fuze (MkIIIA1 shell)
I assume small fuzes M46 and M47 need an adapter (MkIII shell)
Clearly a shell with French shape. I assume this shell is a adaptation of 155mm 15B.
I found this picture of US-Subs collection, post ww1 US 155mm HE, copy of French 155mm 15B with fuze MkIIIA. I assume this shell could be the MkIII.
Now the question is, why French shells 155mm Fato are mixed with US 155mm MKIIIA1 ?


US155MM




FRENCH 155MM 15B GP

 

[917601]

Interesting observation. Crimps- 2-52 dated M51 in my Bulldog round and crimp on an M57 fuze dated 1973. No crimps- 1943 dated 90mm M71 HE and no crimp on my Skysweeper M51A5 fuze dated 12-53 fuze, marked " empty".

 

[HAZORD]

One thing to keep in mind as you review your components, is that all the parts interchange. When projectiles are brought into a collection they are often missing fuzes. So the first fuze along goes in the hole. Fuzes have interchangeable parts. Unscrew the brass nose and the ogive can be changed, if it was damaged. The date that matters is the one stamped on the fuze.

 

[jeff w]

Jeff W, where did you found your picture of soldiers and shells ?

Unfortunately I don't know where I got the pictures.
They have the look of Signal Corps photos. And signal corps photos almost always have good captions.

 

[jeff w]

I found some info on this photo - Taken by a Life magazine photographer during WW2 - captioned as 1945 WWII US Army 1st Army Bomb Disposal EOD