Japanese WW2 Type 89 time fuze




An interesting particular on the above pictured fuze is the orifice at the nose, which is actually a vent for the burning powder train contained in the body of the fuze. When fired, G forces set things in motion, initiating the burn. When the pressure builds, the orifice cover/plug is EJECTED and the resulting hole acts as the vent for the escaping gases. Neat, huh?



Nice fuze! Would you be so kind as to tell us about what size shell that baby would ride on, etc?




Thanks for asking.

Per the previously mentioned pamphlet, there’s a “spreadsheet” of fuze types indicating their use and a number of other details. On the “used in” category, the Type 89 fuze was employed in the following projectiles:

70MM Type 92 Batallion Gun
75MM Type 88 Field gun(mostly anti-aircraft type guns)
80MM(they note it as 8CM???) Type 10 Taisho Naval gun
105MM Taisho 14 (AA gun)


And just noted, they differentiate two Type 89s. One is designated as small. More to read about, I guess. This is going waaaaay past the accumulator stage.

By the way, I think mine’s the BIG one, not the small one. Just sayin’.



I’m not envious. No, I’m not. It says so right here!

You know that I’m not one to nit-pick and correct anyone but . . . what you call the gaine was, in US terminology, called the “head”, later the “adapter” and only in modern times called a gaine (or gain). The guts, which includes an AuxDet, are all attached to the fuze itself and the head/adapter/gaine is there to allow the fuze to be attached to the projectile body (shell).

But I’m not going to nit-pick. No, I’m not. It says so right here!




Again, I defer to your aged wisdom. In defense of my terminology, I was quoting text from 1945. (Is that “modern”?) And, I’m really not sure what point you’re disputing(correcting). You did note I mentioned the absence of a gain(e)? The book used gainE. Thought I’d follow suit. It WAS a British pub. We all know how they are about adding vowels.


Dear Gottalotta

Ah, it was a British publication. That explains a lot. Perhaps gaine was their word for head. Although I think they call their head a loo, don’t they??

I’ve not seen any US publication where the head or adapter was referred to as a gaine. I first encountered that word a couple of years ago when an artilleryman of much younger persuasion called it a gain and I had to ask him what he meant. He told me that was the modern term and so I naturally assumed he knew what he was talking about.

Perhaps the gaine does indeed contain the AuxDet but, in my day, it (AuxDet) was part of the fuze assembly.

Either way it’s still a nice piece of artillery.

The old M1917 US fuzes also had that smoke feature that you mentioned. The nose piece wasn’t detachable. The smoke came out 3 or 4 holes in the top part of the fuze body and the centrifical force disbursed it, making it a sorta tracer.

This is all much to do about nothing really. I’m still snowed in and down to my last bottle of Baileys. Now, THAT is important.



Aha! Good old Google. It says that the gaine is the AuxDet or Booster itself. So now I understand what that young artilleryman was talking about. And your description now makes sense too. (not that it didn’t before)

So, the head is still the head. The adapter is still the adapter. But the AuxDet is the gaine.



On the gain(e)/head thing, I’m fairly new to the artillery ordnance field, so I’m going with what I learnt. All “modern”, as it were. And having spent the bulk of that time over at BOCN, a decidedly British concern, gaine is common and well understood. Of course, your sense of history is far longer than mine which results in these confusions. At least now I’ll know what’s referenced when the head/AuxDet terminolgy is used.