RAILforum: Another question

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Posted by vdsteelman (Member # 4497) on :

In regards to this pic:
http://www.railpictures.net/viewphoto.php?id=154601

why are there so many signals for just 4 tracks?

Thanks,

Ben

Posted by George Harris (Member # 2077) on :

This is about the minimum for this situation. I will leave it to someone more into signalling to explain it. GeoffM, maybe.

Posted by Geoff M (Member # 153) on :

There are only four "signals" as such, but each signal has two or three lamps in order to show different aspects. An aspect is a certain light combination. Each combination has a specific meaning to the engineer. In this case, I believe they're all red meaning "stop". A top green allows maximum speed; a top yellow means the next signal is at red.

The outer two signals have an extra lamp in order to show the "go slow over the switch" indication, which the two centre tracks do not need.

The description above is not complete but this webpage shows common aspects and their meanings, along with some other useful information: http://broadway.pennsyrr.com/Rail/Signal/aspects_us_cl.html
Also see the parent page: http://broadway.pennsyrr.com/Rail/Signal/
Note that different railroads have variations on this theme - I'm not too familiar with specifically Canadian signalling.

Geoff M.

Posted by George Harris (Member # 2077) on :

Thank you, Geoff

Posted by Ken V (Member # 1466) on :

Since the photo taken is of a Canadian Pacific Railway signal, the Canadian Rail Operating Rules applies here.

Here is a link to the Transport Canada web page describing all the possible signal combinations and their meanings.

Posted by Geoff M (Member # 153) on :

Thanks, Ken. I was aware that it was Canadian, hence my reference, but couldn't find any relevant pages.

Geoff M.