Tunnelling work on line U4 of Germany’s Hamburg metro is getting underway with a 6.57m diameter Herrenknecht Mixshield TBM adapted to the soft ground conditions to drive parts of the twin bore tubes.
The Herrenknecht machine (S-440) will excavate 2,810m long stretches of the 4km tunnels being built for the U4 line between HafenCity and the downtown area.
Geology along the route comprises a mixture of gravel, clay, sand and silt. The TBM will drive at depths of up to 42m below the city and parts of the port area and place a segmental lining during advance.
The machine has a cutterhead torque of 3,950kNm, and is equipped with an isolated invert to minimise the risk of clogging. In addition, the stone crusher has the capability to break up rocks that range anything up to 500mm in size.
Factory acceptance of the TBM was in early March.
Herrenknecht Mixshield TBM Herrenknecht Mixshield TBM
