Topic: | Re:Piccadilly trains held at Acton Town | |
Posted by: | Michael Robinson | |
Date/Time: | 29/04/15 12:20:00 |
"If a train is being held you are not delaying the passengers any further by holding at Turnham Green and opening the doors." I don't know the exact details of the Piccadilly line signalling but I think it is something called "fixed block" so the track is divided into blocks and a train simply isn't permitted into a block until the train in front leaves it. I think it is likely there is a block boundary between Acton Town and Turnham Green. In other words, just because a train is waiting outside Acton Town doesn't mean it can move forward and wait at Turnham Green instead as the train would be entering another block and the signalling doesn't permit it. The whole point of re-signalling the District and Piccadilly lines is to introduce a system called "moving block" which is more flexible and can allow higher frequencies of trains. |