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German fuze sensitivity

E-tech

Well-Known Member
I have been reading about various German electronic bomb fuzes, and, while I understand the arming sequences and times, I am curious as to the sensitivity of the fuze's anti-disturbance feature. In one design, mercury switches are arranged on 3 different axes of possible movement- the slightest tilt from it's resting position will set it off. But how about the trembler switches? I've heard that tapping the bomb with a pencil could set it off. What possible arrangement of a weighted spring contact could give that type of sensitivity? Anyone have any info or detailed pictures of the switches?
 
Have a good gander through some of the older posts on german bomb fuzes mate.
There are some super write ups from some of our lads.:tinysmile_grin_t:

best

waff
 
In my 25b fuze the plastic top that held the trembler devices had melted due to being heated in a fire, I am not sure what happened but the pitch inside had all melted together. I dissolved the plastic to remove the components and found all of the trembler switches intact. looking at them I don't think a tap of a pencil would have set them of but heavy handling would have done it.
 
That's what I was thinking when I saw a trembler switch in the cut away section- the only way I know of to make tapping it with a pencil set it off, would be a an electronic switching circuit that changes potential in resistance when it is touched by something conductive- not very practical for a dropped bomb.
What is the trembler switch spring like? Similar to a spring found in a ball point pen? or is it more rigid? Is there a weight at the end?
 
Its true that just tapping a (50) anti disturbance fuze was enough to set it off , if a bomb with two fuzes was found the chances were that one fuze Usually the front one was a long delay type (17) whch was a clockwork fuze was ticking the other fuze would have been an anti disturbance type (50) it was this fuze that had to be immunised first before applying a clockstopper on the other one .there is a film produced for Bomb disposal made in about 1941 showing a bomb being tapped with a pencil and the meter connected to the fuze actually moving.
The type (50) did not contain mercury switches , this was found only in the (50) B y fuze designed to kill the officer attempting to defuze the bomb ,
 
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The trembler inthe type (50) consisted of a coil and a ball on the end
 
some basic drawings on German Elaz switches
 

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Hi its not electronic switching its really mechanical as the vibratory switch is moved it short circuits the stored electrical charge in the condensors (Capicitors to the youngsters) which in turn ignites the match composition.
hope this resolves the mystery
 
Thanks for the picture, Ammodillo, and thanks for the tip, Fuzeman!
I always figured that a design that sensitive wouldn't have much of a chance to kill a bomb tech- wouldn't vibrations from, say, a truck passing by set the thing off?
What about the mercury- tilt fuzed system. I've seen a picture that shows 3 different mercury switches, each on a different axis of movement.
The circuit looked like it would go off as soon as it was armed, unless the bomb had landed exactly right. Is that so, or did I miss something in the circuit diagram?
 
The fuze only became armed minutes after the bomb came to rest rather than seconds for the ordinary ECR fuze any movement thereafter would set it off.
 
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E-Tech,

The triple mercury tilt switches had me puzzled for decades until I saw a diagram of one. You will notice from the diagram you have, that these tilt switches have the electrodes mounted axially as opposed to the normally radially mounted pattern. As a consequence of this, the operating angle is greatly reduced, making the probability of bomb becoming armed in an 'firing position' minimal.

Regards

Tim.G.
 
Steve the 1941 film about bomb disposal sounds interesting, do you have any more details about it. I was wondering if the IWM has it in their archive.
 
And here is the actual fuze with the top removed exposing the 3 trembler switches in picture 2 its in the horizontal plane and the others its vericle But covered in brown filler
 

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Here is the (26) fuze used on the oil bombs the trembler can be clearly seen to the right in picture 2
 

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Hi Chris sorry for not comming back sooner the details of the video is produced by DD videos their number is DD4381
DD Videos are at 5 Churchill court 58 station Road North Harrow Middlesex HA2 7SA their web site is www,ddvideo.co.uk

And for those of you who knew north Harrow this place was the site of yours trulys watering hole , happy but many hazy nights staggering out of this pub .
 

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Hi Steve,

Is this the same story (film) thats with the DVD series from UXB?
The trainings film?
 
Hi Jack
Having a god holiday ? yes thats the same one which is with the special addition boxed set .
 
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