Just to clarify, West Anglia Inner & Romford - Upminster services will transfer to London Overground and the Shenfield Metro will transfer to Crossrail.
Overground will replace the 317s it will be getting but it isn't clear which units these will be - they are already getting 17 315s (according to an article in Modern Railways).
The /8s were converted to work with the /7s on Stansted Express and have slightly more luggage space and different coloured moquette, the /5s are basically standard 317/1s (as per the Great Northern 317s) in all ways but number.
Just to clarify, West Anglia Inner & Romford - Upminster services will transfer to London Overground and the Shenfield Metro will transfer to Crossrail.
Overground will replace the 317s it will be getting but it isn't clear which units these will be - they are already getting 17 315s (according to an article in Modern Railways).
The /8s were converted to work with the /7s on Stansted Express and have slightly more luggage space and different coloured moquette, the /5s are basically standard 317/1s (as per the Great Northern 317s) in all ways but number.