MSD entry and exit shaft installations:
Precise guidance from start to finish.

MSD special structures for the entry and exit shafts of tunnel construction sites enable controlled and safe entry and exit of tunnel boring machines. In addition, they reliably protect against earth falls and water inrush.

MSD entry shaft installations ensure a successful start.

To place the tunnel boring machine (TBM) exactly in position, MSD builds so-called shield cradles in the entry shaft – steel jacks which enable the enormously heavy machine to be aligned with millimetre precision. A special rear stiffening construction with thrust ring in which the first complete lining segment ring is installed provides stable support for the actual start-up process. It provides the TBM with the necessary back-pressure for advancing, until the respective new installed segments take on this task.

MSD starter and travel-out gaskets withstand the pressure.

If tunnels run below groundwater level, we also the advance against earth and water pressure. To this end, we develop, build and install all the necessary components and systems in the entry shaft – including the concrete casing pipe, flange and starter gasket. Different, particularly reliable sealing systems are used, depending on the diameter and expected earth or water pressure. We naturally install equivalent systems for removing the TBM in the exit shaft.

MSD entry shaft installations product overview:

  • concrete casing pipe
  • starter gasket
  • Shield cradle/starter cradle
  • Compression ring and rear stiffening construction

MSD exit shaft installations product overview:

  • concrete casing pipe
  • Travel-out panel
  • Housing/gasket
  • Travel-out cover
  • Extension
  • shield cradle