For the first time in the country's history a railroad tunnel was bored by machine in Rotterdam. The site for the 3,670-meter-long Botlekspoor Tunnel (two single track tunnels) in Rotterdam was right in the middle of the petrochemical industry. Hundreds of cables and lines run under the ground here and it is vital for this flourishing port that they are in no way damaged. The Botlekspoor Tunnel is an important section of the "Betuwe Route". This route - over 160 kilometers in length - provides rail goods traffic with a rapid, modern east-west axis into the hinterland.
To realize this, an Earth Pressure Balance Shield, 9,755mm in diameter was in use. The launch shaft had to be set up between a parallel-running railway track and a highway. The fact that rail traffic was not to be affected meant that the 110-tonne cutting wheel had to delivered in one piece and mounted onto the shield.
The EPB Shield - delivered and specially modified by Herrenknecht - is an ideal solution bearing in mind that the geology found there is one of sand and peat and layers of clay with groundwater pressure of up to 3.8 bar. For the first time, an EPB Shield was used in this kind of geology instead of a Mixshield. The machine desgin with solid matter pump and slurryfier box convinced with good tunnelling rates.
