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Japanese Bomb Fuse Type99 Mk3 D-2(a) diagram

Dronic69

Well-Known Member
Premium Member
Hi All,

Just wondering if anyone has a better (clearer) copy of the following drawing of the Japanese Bomb Fuse Type 99 Mk 3 [D-2(a)]:


The diagram is out of the U.S.N.B.D "Japanese Bombs & Fuzes" July 1944 publication - as you can see I do not have a good copy!

A couple of references state that this fuse could be "externally" wound and referred to as point 10 on the digram (Winding hole plug) - does anyone have any more detail on this? Perhaps a photo of the actual winding key etc?

It's an interesting fuse as the mechanical clock mechansim is almost identical to the ones used in artillery time fuses except for the top winding section.

Thanking you all in advance.

Cheers
Drew
 

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I hope that this is of help. This is taken from TM-E9-1984 ENEMY BOMBS & FUZES SECTION VII JAPANESE FUZES.

Cheers,
Robert
 

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Stefan / Robert,

Yes much clearer - thank you both very much - now I can almost work out how it should function!!! LOL :tinysmile_twink_t2:

It is still not clear how the external winding hole was used and what key(?) was used to wind it up????

Cheers
Drew
 
Hi All,

So after a couple glasses of red wine I found the hole :tinysmile_twink_t: - winding hole that is! (LOL)

(The exploded view diagrams were a little misleading as the external winding hole is shown to aligned to the "setting stud"......................)

But the remaining question is, since both the internal clock mechanisms are almost identical, why does the Type 99 bomb fuse have ability to externally wind the mechanism in the field and not the artillery version (ie Type 91 Time fuse)?

Would it be a fair assumption that the clock mechanisms are pre-wound before leaving the factory for both types of fuses?
(For the Type 99, the "shipping Safety Pin" as shown in Alpini's diagram would ensure the safety block in held in place if the clock mechanism was factory pre-wound)

Are they pre-wound in the factory? or expected to be set in the field? Both require a similar effort to disassemble with a common retaining ring system..............

Any thoughts on this would be of course greatly appreciated!

Thanks

Cheers
Drew
 

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