Following my recent post on painting track, I received an email from a reader to alert me that I’d installed one of the two catch points on my layout incorrectly.
Except I hadn’t.
Since others may assume I have made an error – and not bother to reach out – I thought it worth explaining here.
Bydemill may be freelanced, but I followed the track arrangement for GWR Highworth exactly. I simply bent back each end to keep the main track confined to my 24″ deep shelf. In reality, Highworth was laid out on a single large arc:
At Highworth, the cattle dock is located right on the switch that returns the loop track back to the main.
I’m not sure why the railway put the dock right on the switch – but it did. It’s not a big deal, because this is the end of the line anyway: As the track diagram shows, the main track ends just a few wagon-lengths after this switch.
In any case, the reason for the dock’s location doesn’t matter – except that cattle trucks spotted at the dock would be on the main track, with the switch aligned for the platform. And that means if they started to roll, they could run into the platform track and collide with any passenger coaches standing there.
That’s an official no-no when it comes to British railway track design – one that required protection in the form of a catch point.
In this case, the railway added the catch point just beyond the switch, so a runaway wagon would derail into the platform edge. This is reflected on the official signalling diagram (available from the Signalling Record Society).
Not ideal, but better than hitting a passenger train.
The other catch point at Highworth is more conventionally configured:
This catch point derails any stock that attempts to roll off the loop track and through the station throat.
One of the great things about following a prototype track diagram is you can simply copy what the real railway did, and then figure out the rationale later. Another great thing is that the prototype often does things that, as modellers, we’d never do because it would be “wrong”. That makes modelling based on a specific place that much more interesting.
The Model Railway Show 