Re: "lost" trains

[Stuart Ellis <mpp@zipworld.com.au>]

In regards to the disappearance of the light engine NR at Sydneham.   The track
circuit involved has two devices, conventional frequency track circuits and DPU
devices fitted, which is a small box fitted inside the running rail. It's purpose
is to pick up the wheel as it passes, due to the fact the DPU is basically a coil
of wire, and when the wheel passes (metal) it is supposed to create a magnetic
field and trigger the electronic device attached. The unit involved NR 14 is
supposed to suffer from "hollow wheels", and I have no idea what they mean by this
yet, and cannot explain why. I do know that there were plenty of RSA signal branch
engineers and other staff on site for a few days afterwards to solve this one. As
a result, all light engine movements are now required to work under block working
conditions, especially from Meeks Road to Enfield south until further notice.

 I hope this is of some help

Stuart Ellis