Re: Ringwood

[Notagunzel <notagunzel@bigfoot.com>]

Tony Gatt wrote:

> Yep, got that bit.. fine with that.. but...
> 
> I need to know about the triangle things inside the left hand rail. They sit
> next to the signal and look like they may be some form of detector loop for
> the passing of wheels. I believe there are some on the Epping line...
> 
> They look like a plastic "wedge" and sit flat to the sleepers..

These are called 'Pin Point Detectors', and are used within a Jointless
track circuit.

Jointless tracks have a transmitter at one end, and a receiver at the
other (rocket science so far), but for varios reasons, a pin point
detector can be installed within the track, and a seperate track relay
hanging off it.  This will pick when the track is clear between the
transmitter and the receiver, even when a train may be between the Pin
Point Detector and the Receiver.  They are used especially for overlaps,
level crossings, pedestrian gates etc...

Hope this helps. :o)

-- 
Mr Notagunzel.
Trying to avoid the Gunzels.
notagunzel@bigfoot.com
(Thinking about doing something more at
http://www.bigfoot.com/~notagunzel)