Mike Stone wrote:Another odd facility is a limit of shunt facility on the new up Acton Relief (dive-under) to allow movements between Acton Wells and Paddington.
There always was a Limit-of-Shunt on the Up Relief (down direction), west of Acton Main Line platform 4. It (SN6139) was decommissioned at Easter 2015, and a new one SN6137 commissioned at Christmas 2016. As stated, it's for trains to come from Acton Wells, then reverse behind the junction signal to go towards Old Oak or Paddington. Routes to the new signal require the points reverse, so that the train could go onto the very eastern end of the dive-under. But most trains doing this move will be tampers/locos etc, so will not need to go as far as the points.
The down-dir shunt signal (T6293) on the Up Relief at Maidenhead was decommissioned at Christmas 2016. It was used for shunts from platform 4 to 5 and vice versa, some of which were timetabled. (e.g. last train on a Sunday off Bourne End, returning ECS to Reading depot.) Now that platform 5 has access to/from the Twyford direction, this isn't needed any more. But the fixed red on the Down Main can perform the same function.