Y fuze details?

[clareowens]

I have read a few articles regarding the Y fuze. They all note that a dry battery was used and that there were three mercury switches in an X-Y-Z 90 degree arrangement so that any movement would detonate the bomb. They also mention the use of extreme cold to disable the battery so that the fuze would be rendered safe - at least until it warmed up again.

I have imagined the following:
1. There was an impact activated permanent switch that would activate the battery circuit.

2. There would still have to be some sort of R-C delay built into the firing circuit, since the bomb could move for at least a few seconds after the initial impact. This also would be necessary because in every situation at least one of the mercury switches would be closed and the resistance of the R-C delay would prevent the closed switch(es) from quickly draining the battery or immediately detonating the bomb.

3. With those conditions, how would freezing the battery do any good? I must be missing something. Of course, a wiring diagram would explain everything.

Also, what was the battery voltage?

Thanks,

Clare

 

[TimG]

Clare,

http://www.bocn.co.uk/vbforum/threads/4201-The-German-Y-fuze-sectioned

Note the design of the Mercury tilt switches, their operating range is significantly less than normal tilt switches.

TimG

 

[TimG]

Found this -



TimG

 

[clareowens]

OK, thanks! I see from the diagram of the sectioned fuze that the design of the mercury switches only allows for a momentary contact, unlike the usual mercury switch that has a uniform cross section. Clever design, all right. It was amazing luck finding one with a faulty circuit.

I wonder whether the effect of using liquid Oxygen would have been to freeze the batteries and the mercury as well? The freezing point of mercury is -38F or -39C and although the freezing point of a Zinc-Carbon battery's electrolyte is most certainly well above that, I have to believe the folks who came up with the freezing scheme must have been very conservative in the setup of the process. In the story of the Y fuze they talk about measuring the battery response of a real fuze installed in a bomb but I wonder if they ever measured the actual battery temperature?

OK, that's enough Wondering and Believing for one day.

Clare