Class 345 Testing and Introduction

Could be a combination of finding a more permanent solution to the teething problems previously experienced and preparation for testing systems in the tunnels later this year/early next year. It hasn't been said whether a single train will be used in the Dynamic Testing Zone or if units will be swapped out periodically.

The platform extension work must be completed before trains on the Shenfield Metro start running underground to Liverpool Street because the Platform Screen Doors (PSD's) are set up for the 9-car configuration. That means the deadline is to have all existing 7-car units converted to 9-cars by Dec 2019 although it will be a tight squeeze as 9-car formations are too long to fit into the the Nation Rail platforms at Liverpool Street.

Yes, they will run as such from the get go as some stations don't require extension work such as Paddington and Heathrow T's 1,3,4&5. It's not clear where the trains that first run through the tunnels from Paddington to Abbey Wood will come from although one would think they would be West end (Heathrow) units at it's over a year before East end units are due for their extension.