19-08-2013, 07:23 PM
(19-08-2013, 08:32 AM)dorothy.pipet Wrote: Is there a specific project that you are working on?
I suggest you start by reading up on "Tollerton" and "Raynes Park" controls. I think SSI8003-51D refers.
As Dorothy suggests, I suspect that the issue that you are referring to is commonly known as Tollerton Controls. Here is a basic description in this RGS document. There are other similar outlines on Simsig and deep in this thread on The Signalbox.

