Electric Motors for semaphore signals

3514 Views 6 Replies 4 Participants Last post by jwealleans, Jun 5, 2006

John Webb

Discussion Starter · May 19, 2006

Many semaphore signals, particularly distants, are or were worked by electric motors. These appear to be a circular lower portion with a shaft coming out bearing the operating crank. On top of this round bit is a rectangular box, which I assume contains part of the operating system. But no book in my collection describes the inner workings of these motors. Can anyone point me towards a source of information, please?

Regards,
John Webb

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jwealleans

· #2 · Jun 2, 2006

Hi John,

I posted your query on the LNER forum and had the following from Mick Nicholson, who knows most of what there is to know about signalling:

Very simply the bottom part of the motor casing contains the actual motor, the top part contains the "Holding Off" coil. Basically the armature turns to operate the signal and then via internal contacts cuts itself off, the "Holding Off" coil being energised then holds the mechanism "Off". Like all railway equipment the entire outfit is "Fail Safe", either a power supply failure or the signal down wire breaking will instantly cause the signal arm to go to danger. Possibly a very crude and basic explanation but practically all the books in my collection deal with mechanical signalling. Given time and asking the right people I'm sure I could come up with more. Mick Nicholson.

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John Webb

Discussion Starter · #3 · Jun 2, 2006

Thanks for that. I thought it must be something along those lines. I was vaguely wondering if the mechanism could be reproduced in model form to give 'prototypical' operation of model signals.

Regards,
John Webb

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dwb

· #4 · Jun 3, 2006

>I was vaguely wondering if the mechanism could be reproduced in model form to give 'prototypical' operation of model signals.

I saw a demo of the new solenoid that Model Signal Engineering is selling for operating signals. It has a nice gentle motion and I was told that the action can be modified. If you don't already know the site, you can find it here:- Model Signal Engineering

David

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Doug

· #5 · Jun 3, 2006 (Edited by Moderator)

QUOTE (dwb @ 3 Jun 2006, 10:29) <{POST_SNAPBACK}>...If you don't already know the site, you can find it here:- Model Signal Engineering

That must be the worst websites I've seen in a while. Half of it doesn't work in Firefox as it has the slashes the wrong way around.

I hate having to open up Internet Explorer, but after the effort, the site is visible. I'll be ordering some of those items - just what I've been looking for.

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John Webb

Discussion Starter · #6 · Jun 3, 2006

Thanks for the bit about the new MSE solenoid - I'd seen it in the current 'Railway Modeller' when that came out two weeks ago, but thought it a bit expensive - hence the desire to do my own thing.
Regards,
John Webb

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jwealleans

· #7 · Jun 5, 2006

Andrew Hartshorne demonstrated the new mechanism for us at Derby when we were on the stand opposite him. It has a beautiful action and is as easy as you could want to install. We will certainly be using it for our next exhibition layout.

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