Hochtief Aktiengesellschaft Vorm. Gebr.helfmann

Gert Wittneben

Siegmund Hflm Babendererde

Otto Braach

Hans-Jurgen Flunker

The earth pressure shield for a tunnel and/or gallery excavator has a front working compartment formed by a separating wall having a digging tool and an annular reinforcing space substantially triangular in cross section positioned directly in front of the separating wall. So that an extensive restructuring of the machine is not necessary when moving from soft earth to hard ground, the annular reinforcing space is provided with a lower fluid feeder, a controlled upper pressurized air feeder, a plurality of fluid conductor pipes which are guided from below to an upper fluid outlet opening into the working compartment, and a fluid level controller. The invention is based on the consideration that a reliable and satisfactory support of the local front wall is only possible when the local front wall in the vicinity of the roof can be supplied with a fluid.

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Essen, Germany

Gert Wittneben