White diamonds

The track circuit was patented in America by William Robinson in 1872.

The L&Y is believed to have made a trial in 1897. An experiment with a single auto signal was installed between Middleton Junction and Castleton in

The LNWR made their first trial installation at Rugby in 1911 and by 1914 had installed over 200 track circuits.

Sources: L&YR Signalling by Tom Wray, pub by L&YR Soc A Pictorial Record of LNWR Signalling by Richard D Foster, pub by OPC.

Did they use the white diamond on the signals to tell the driver he didn't have to tell the signalman, though?

Incidentally track circuits came comparatively late in the UK because of the use of Mansell wheels with wooden disks.

Yes, that was the purpose of the diamond.

No, the wooden wheel centre was easily bypassed by using a copper strap between axle & rim. The reason was for slow take up of track circuits was cost.

Kevin Martin

"John Shelley" wrote in news:F9Rci.119$% snipped-for-privacy@newsfe3-gui.ntli.net:

John,

Thanks very much, very helpful indeed.

It could have been the use of the absolute block though. With the US almost universally using permissive block (at least for goods trains), their introduction was more fundamental to operations than in the UK.

Richard

I don't think so as large parts of their systems were dark into the

Chris

In "rural" areas, certainly, but in "built up" areas, e.g. round New York and towards Philidelphia signals were in use from very early on.

Richard

The North East (known as the rust belt) being very much like Europe in population density and industry compared to the rest of US so requiring similar signalling as used in Europe at the same time.

Chris