Work is now starting on the green roof for the 700 metre long Burton Green tunnel near Kenilworth. Work is now starting on the green roof for the 700 metre long Burton Green tunnel near Kenilworth. HS2 engineers have installed the final roof segment on the 700-metre-long Burton Green tunnel. The 16-metre-wide twin-box-shaped tunnel will carry high-speed trains beneath the village of Burton Green, near Kenilworth. This starts at the site of the Burton Green Village Hall and then follows the existing field boundaries linking with Berkswell Station.