Question to the Department for Transport:

To ask His Majesty's Government what is (1) the route of the tunnels between Old Oak Common and Euston, and (2) the location of their Euston end portals; and how these features interact with any designs for the HS2 station at Euston.

From Old Oak Common station, the twin bore Euston tunnels will head north-east under Kensal Green Cemetery before broadly following the line of the Network Rail West Coast Main Line into Euston. The alignment curves in a southerly direction under Primrose Hill and the bored tunnels will end beneath the junction of Parkway and Gloucester Avenue.

From this point the twin bore tunnels will transition into a group of structures termed the Euston approaches, rather than interfacing directly with the station at Euston. The Euston approaches include a set of sprayed concrete lined (SCL) tunnels that connect to the twin bored tunnels. The Euston approaches will broadly cover the area between London Zoo car park and Hampstead Road.

The immediate structure that is to interface with Euston station is a retained cutting, which extends for circa 600m from a northerly direction to the entrance of Euston station. This will enable the HS2 lines to fan out into the necessary configuration for the station and its platforms.