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+---- Thread: Points Backdrive - what is it? (/showthread.php?tid=2433)
Points Backdrive - what is it? - ledwardz - 19-02-2021
Hello,
not an exam question, just after some general info.
Can someone tell me what a point backdrive D switch is?
What is the point backdrive used for and how this relates to the D switch?
Thanks in advance for any info.
Lee.
RE: Points Backdrive - what is it? - Jerry1237 - 19-02-2021
Back-drives assist the point machine to physical drive/shove the metalwork and keep the relevant gaps between the stock and switch rails. Point machines drive the tips of the switch rails, back-drives are further down the switch rails. Some organisations and switches may have more than one back-drive.
A, B, C etc., is a PWay term to describe switch types where A is the shortest and each type gets longer (in UK parlance). So the term is literally a back drive for a D type switch (points in signalling speak).
Hope that makes sense.
RE: Points Backdrive - what is it? - ledwardz - 22-02-2021
(19-02-2021, 03:28 PM)Jerry1237 Wrote: Back-drives assist the point machine to physical drive/shove the metalwork and keep the relevant gaps between the stock and switch rails. Point machines drive the tips of the switch rails, back-drives are further down the switch rails. Some organisations and switches may have more than one back-drive.
A, B, C etc., is a PWay term to describe switch types where A is the shortest and each type gets longer (in UK parlance). So the term is literally a back drive for a D type switch (points in signalling speak).
Hope that makes sense.
Perfect! thank you very much for the response.
Lee.