London Underground Train That Switches Lines Halfway Through The Journey
From May 21st London underground trains have been operating on a new timetable.
As a result of this timetable, there’s one very unusual service which has been introduced - train number 171. Every weekday, this train starts as a Hammersmith & City line train before ‘transforming’ into a District line train.
click here to read the interesting 'MyLondon' posting