Tunnels 1: - P J Davidson (UK) Limited At Work 24/7 On The Channel Tunnel Rail Link Project
During one stretch of slipforming the track bed, the Commander III ran 10.5 days straight, 24 hours a day without stopping. During that time, Peter Davidson's crew laid down 4.7 miles (7.5 km) of track bed covering the entire length of one tunnel.
Concrete was delivered to the paver from P J Davidson's on site Compactor batch plant, sitting just outside the two tunnel entrances. It has a capacity to produce up to 157 yd3 (120 m3) of concrete per hour.
Concrete was delivered to the paver by Dux trucks that carry 8 yd3 (6.1 m3) and everything that went into the tunnel was in a preset sequence.
The tracks on the Commander III were built to tilt up to a 35 degree angle to accommodate the curvature of the tunnel.
We used a Leica 3-D stringless guidance system instead of a traditional stringline to control line and level. Tunnel conditions just weren't favorable for stringline use, plus the manpower needed to set up the line would have been considerable.
We completed our part of the CTRL contract two months ahead of schedule. In less than six months, Peter Davidson and his crew had slipformed almost 47 miles (75 km) of tunnel rail bed and walkways.