Double action

Contractor Matthias Strobel has used a Liebherr LRB 255 piling and drilling rig in a double rotary drilling application during construction of the Emmerauentunnel Luegde, Germany.

Due a narrow valley the tunnel, which forms part of a relief road for the town and is 700 m long, was built in a flood plain between the River Emmer and the historical city walls.

The € 2,64 million contract was divided into five parts, which in turn were separated by a transversal partition of drilled piles. The piles - up to 13 m long and 1,06 m in diameter - were installed by the LRB 255 using a DBA 250 double rotary head.

The 670 kW LRB 255, which can be fitted with a 30 m leader and is equipped with a rope crowd system that provides up to 45 tonnes of pull and push force, requires no separate power pack. This gives a fuel saving of up to 40%.