Dual Gauge Turnouts - operation and detection

  WimbledonW Assistant Commissioner

Location: Sydney
Interlocked turnouts, whether mechanical or powered have two main components.

Firstly, there is a mechanism to drive the points between Normal and Reverse and vice versa.

Secondly, there is some apparatus to check that the switches are set and locked correctly and safely.

If the turnout is not set and locked correctly, then signal(s) won't clear.

Now a normal turnout has two blades, which are driven and locked separately.

A catchpoint may have but one blade, and half of the gear on the point motor is unused.

However a dual gauge turnout has three [or even five] blades, [which may exceed the capability of a single double sided point motor. So how is the drive and detection done? See next post by @KRviator for some answers.

There are a lot of dual gauge turnouts between Perth and Northam in WA. Can someone check? Does anyone know for sure?

Edited 6 times. [Some original text marked as superscripts.]

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  KRviator Moderator

Location: Up the front
A dual gauge turnout is certainly not beyond the capability of a single point motor. I've seen single point motors driving no less than 5 individual switchblades as part of a single DG turnout. This is accomplished by various point rodding and bellcranks abeam the turnout.

As for "some apparatus" to detect the lay of the points, this is incorporated into the point motor itself, typically a series of levers and switches except in the case of old-school lever-frame pointwork.

IF I can offer a bit of advice, @WimbledonW - if you are unsure of something, or haven't researched it and can provide a reference when asked, stop trying to pass off your comments as fact.

You have done it several times on RP previously and been called out on it, and while there's a great deal of leeway on RP for peoples opinions etc, the threads you create appear to have the intent of being used as a reference, however, the information you put forward is often wrong. The claim above of "a single point motor can't drive 3 switchblades" being a good example. This video shows 5 switchblades being driven from a single motor.

Inside a point motor, showing the detection rods, levers and electrical switches.

Inside the other end, showing the actual motor and the connections to drive it, though several wires have been removed, as this particular example is a training aid. Not shown is the drive rod - the thick one that actually moves the blades.
  duttonbay Minister for Railways

KRviator, your "this video" link is broken. It points to nothing more than "this%20video".  Can you supply the full link?
  KRviator Moderator

Location: Up the front
KRviator, your "this video" link is broken. It points to nothing more than "this%20video".  Can you supply the full link?
I know - I've got NFI what's going on with the BBCoding of the URL's lately, but I tried 3 times to make it work and gave up and went to bed. Evil or Very Mad

Here's the video, starting several minutes in, but right at that set of points I mentioned above. In this specific set, there's also two detection switches for the near-end switchblades that you can see paired together about 5m before the point motor. Make sure you click on the link to take you to the right time, not just the video start button. Wink

Video courtesy of Victorian Drivers View's YT channel.

  duttonbay Minister for Railways

Thank you. That's one mean turnout!

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