The site of the new High Speed 2 (HS2) approach tunnels into Euston station has been revealed after work to demolish a former carriage shed was completed.
The work to clear the site now paves the way for the arrival of specialist tunnelling teams to start on site next year.
The new 21km long twin tunnels will run to the new Old Oak Common Station which will be linked to Crossrail.
In a change to the original plans, which brought trains into the station at ground level, the tracks have now been lowered by 500mm at the north end and the tunnel has been extended with the Euston portal now situated just south of Mornington Street Bridge.
This change means that the tracks will be low enough to pass under the existing Granby Terrace and Hampstead bridges without the need to demolish and rebuild them, minimising local disruption.
Project promoter HS2 Ltd will deliver 11 new platforms in two phases, doubling capacity at the station, providing a new concourse and expanded Underground station, linked for the first time, to the nearby Euston Square Tube station.
However, concerns have been raised in recent weeks about the two stage process which will involve the Network Rail side of the station developed separately, making the station a disjointed transport hub.
Demolition of disused carriage sheds took nine months and was managed by HS2 Ltd’s London enabling works contractor, CSJV, comprising Costain and Skanska, working with demolition contractor Keltbray.
HS2 Ltd said up to 70 people were employed on site during the “painstaking” demolition of the shed next to to the West Coast Main Line.
It said specialist teams had used drones to survey the inside of the Victorian structure, before taking the fragile roof structure apart. In total, more than 7,000 glazing panels had to be removed from the 250m-long building. The team then used cranes to remove the 27 huge 50m-long steel trusses which supported the roof.
The sheds were built to house carriages and were later used for Royal Mail trains, but taken out of use in 2004. Surplus track, switches and points removed from the sheds have been donated to the Bluebell railway, a heritage line in Sussex.
HS2 Ltd London programme director Rob Carr said: “The demolition of the old carriage sheds marks an important step forward for the project, clearing the way for the start of construction works next year, and the delivery of one of the most exciting new stations on the HS2 route.
“I’d like to congratulate the team on a job well done and look forward to moving ahead to the next stage of the project.”
CSjv programme director Peter Jones added: “The CSjv team, consisting of people employed from the local area and other experienced professionals, alongside Keltbray have worked carefully and efficiently to ensure that this structure has been demolished safely.
“It marks a great milestone in the construction of HS2 and shows the fantastic progress that we are making in Euston and across Area South.”
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