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BUTTERFLY BOMB - SD2 and M83 ' COLLECTION '

butterfly said:
Thanks Dave, no those particular pots dont have any holes in the bottom of them, but I know the ones you mean. I have one example in my collection and still havent been able to work out the significance of them. The three small holes are evenly spaced out and not just random, so they look as though they serve some purpose. However, these bakerlite pots were also used on the SD1 (anyone know if they were used on anything else??), and so may or may not have anything to do with the SD2's ??



Would appreciate any information regarding these holes if anyone can identify what they were for?

Pictures show a bakerlite gaine pot with holes next to one without.

regards Kev

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A few more with holes.
Dave.
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waffenamt said:
Next year for mine boys,not much time at the mo but im sure you will likey. ;) Thanks for the shows,very impressive and great to see.

cheers

waffy
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Waffy you've gone all quiet on us :tinysmile_grin_t:
Any sign of the photos of the SD2's?
Dave.
 
I'm wondering if these holes help channel the initiator flash charge towards the main charge to make sure that all the explosive detonates properly?
 
LEI-13-HG said:
I'm wondering if these holes help channel the initiator flash charge towards the main charge to make sure that all the explosive detonates properly?
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Hi Austin, interesting theory. Though I think if that was the case then it would be found on the majority of pots rather than a small minority.

I did wonder if they could be for some form of flash ignition during the testing process, where it wasnt necessary to detonate the main charge, but instead to show the SD2 had functioned on the range. I am not sure of the process to obtain such a flash, but is it possible that the bakerlite pots could be filled with some kind of flash emitting substance rather than the usual kl.Zdlg 34 gaine?? (this being inginted by the functioning of the fuze??) These may have been for use in the bodies with the hole in the bottom, which may also explain why the hole is there??

kind regards Kev
 
The thin-walled and very brittle bakelite gaine pot is filled with Nitropenta and blasts into molecules when ignited. In my opinion the holes do not help anything in this respect.
 
I was really pleased to finally track one of these down. Its a clip to hold the M83 wings together.
I know I know its really sad but to us butterfly collectors even the small things keep us smiling:tinysmile_twink_t2:

Dave.

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I spent an hour or so rooting around in the spares box this afternoon and found enough to make another SD2, its a bit of a relic but OK.

Dave.

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A theory.... a gaine pot with no holes contains an explosive such as picric acid, this is initiated via a Low Explosive charge to "detonate" the high explosive in the bomb body.
What if some SD2 bodies contained low explosive such as black powder ?(as per American grenade) If this is the case then only a flash would be required to explode the main charge. Maybe, (and I say maybe) the holes are there to pass a flash to the body filling direct from the fuze ? IE no filling in the gaine atall. is there any evidence indicating what the body filling consisted of ?
 
Nismosonic said:
A theory.... a gaine pot with no holes contains an explosive such as picric acid, this is initiated via a Low Explosive charge to "detonate" the high explosive in the bomb body.
What if some SD2 bodies contained low explosive such as black powder ?(as per American grenade) If this is the case then only a flash would be required to explode the main charge. Maybe, (and I say maybe) the holes are there to pass a flash to the body filling direct from the fuze ? IE no filling in the gaine atall. is there any evidence indicating what the body filling consisted of ?
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Hi Scott,

Thanks for your input on the gaine pots with holes.
The filling for the SD2's was cast TNT
regards Kev
 
butterfly said:
Always nice to see another completed SD2. Well done with that one...........and has millsbomber has already noted - a 67 fuze - NICE!!!

regards Kev
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Thanks Kev, as I've just sold one I thought it was time to build up the numbers again.

Dave.
 
SG500 said:
Waffy you've gone all quiet on us :tinysmile_grin_t:
Any sign of the photos of the SD2's?
Dave.
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Hi fellas,

Sorry but old waffy is having a bad time in life at moment. Will bounce back soon hopefully. Ive been having renovations on the house that are far from finished. Indeed,when im feeling like old happy-waff again then i will sort some pics.

best

W
 
Just a few fuzes.
A 70b and a couple of 70B2.
If anyone has a spare 70B1 or even a 70A please let me know.
Thanks.
Dave.

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Very nice Dave ...
Good luck on finding the others...I'm still hunting for the elusive type 70A - they are out there somewhere!!!!

regards Kev
 
Dave, you inspired me to post pics of the three versions of type 70 within my own collection.

Beneath each type is a photograph with the cover removed showing the interior mechanism. As can be seen from the photographs all three types vary quite a bit inside - though all are of the anti-disturbance type.

Kev

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all items are inert and FFE
 
Mmmmmmmmm A 70B1, very nice! Thanks for posting.

Kev what's the small triangular piece of metal on the B1 do? Its not on the other 2. The bit I mean is in the bottom left part of the photo of the dismantled B1.

Dave.
 
SG500 said:
Mmmmmmmmm A 70B1, very nice! Thanks for posting.

Kev what's the small triangular piece of metal on the B1 do? Its not on the other 2. The bit I mean is in the bottom left part of the photo of the dismantled B1.

Dave.
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The 'triangular piece' on the main gear is there instead of the 'pin' projection. The pin that you see on the other two is the bit that comes to rest on the sensitive spring mounted wieght - the movement of which initiates the fuze. Believe me that this is very sensitive and having seen one vibrate the way it does, hats off to all the former BD guys that had to go into the loft spaces with one of these fuzes in an SD2 - brave is not the word.
I have no idea why they changed from pin to the triangular piece, but they appear to have gone back to the pin also.

Here is a brief description of the operation of all three types of 70B fuze for anyone who may be interested.....and not 'bored' ......sorry, couldnt help it!!

70B .... a wire prevents the spring driven mechanism running until the arming rod is unscrewed during descent. Once the arming rod is unscrewed the wire moves across and the drive wheel moves until the release pin (beneath the drive wheel) comes to rest on the inertia spring.

Impact then causes the inertia spring to depress and the drive wheel moves under spring tension until the Stop pin (pin projection seen in picture) comes to rest on the nib of the inertia block. THE FUZE IS NOW ARMED.

Any subsequent movement causes the inertia block to move on the sensitive spring releasing the Stop pin and in so doing allows the drive wheel to move once again. A toothless section on the drive wheel allows free movement, so runs faster. A pin on the underside of the drive wheel strikes a release arm which moves to release the striker and function the fuze.

70B1 .... a wire prevents the spring driven mechanism running until the arming rod is unscrewed during descent. Once the arming rod is unscrewed the wire moves across and the drive wheel moves until the metal bar (mounted on the drive wheel) comes to rest on the locking lever. (The locking lever is held under spring tension, however prevented from moveing by a detent)

Impact causes the detent to move downwards and in doing so releases the locking lever, which moves across - the drive wheel is now free to move once more. Under spring tension the drive wheel moves until the steel lug on the drive wheel (triangular bit) comes to rest on the inertia block. THE FUZE IS NOW ARMED

Any subsequent movement causes the inertia block to move on the sensitive spring releasing the Stop pin and in so doing allows the drive wheel to move once again. A toothless section on the drive wheel allows free movement, so runs faster. A pin on the underside of the drive wheel strikes a release arm which moves to release the striker and function the fuze.

70B2 .... A wire prevents the spring driven clockwork from running untill the arming spindle unscrews during decent. Once free the spring moves across and the clockwork runs. Unlike the other two fuzes the clockwork of the B2 runs for 90 seconds - during which time the SD2 has come to rest on the ground. The clockwork continues to run until the Stop pin on the upper side of the drive wheel (seen in photo) comes to rest on the inertia block. THE FUZE IS NOW ARMED.

Any subsequent movement causes the inertia block to move on the sensitive spring releasing the Stop pin and in so doing allows the drive wheel to move once again. A toothless section on the drive wheel allows free movement, so runs faster. A pin on the underside of the drive wheel strikes a release arm which moves to release the striker and function the fuze.



You will see from the above descriptions that the 70B2 differs from the other two fuzes in that it only has two stages of operation - the other two having a three stage operation.

I have attatched a key to help recognise some of the parts mentioned - hopefully it will be of some help!!

regards Kev

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