The preliminary package deal for the arched construction spanning 4 tracks – two HS2 traces in addition to two East West Rail traces – was initially budgeted at £40m when procurement began three years in the past.
However HS2 chairman Sir John Thompson confirmed the constructing he known as a “shed” will now value £100m.
Sir John advised a rail trade convention this week: “This shed, you’re not going to consider this, value greater than £100m to guard the bats on this wooden.”
The tunnel is designed to guard a colony of endangered Bechstein bats positioned within the historic Sheephouse Wooden, designated as a web site of Particular Scientific Curiosity, which lies subsequent to the route.
The Sheephouse Wooden Bat Mitigation Construction will cowl a 900m stretch of the railway that lies within the flight path of the uncommon bat species.
Building on the web site is being overseen by essential HS2 contractor EKFB.
