Underground construction device

A method for operation of an underground construction device comprising a hydraulic assembly having an internal combustion engine and a first hydraulic pump driven by the internal combustion engine, a work device connected with the hydraulic assembly in a hydraulic circuit for introducing material to be pile-driven into the ground, a clamping apparatus comprising a hydraulic clamping cylinder and connected with the work device for holding the material to be pile-driven in clamped manner, a controller for opening and closing the hydraulic clamping apparatus, a second hydraulic pump for building up clamping pressure of the clamping cylinder of the clamping apparatus, and an electric motor operating the second hydraulic pump, the method comprising:

• (a) querying by the controller at least one operating state value during a break in operation when the work device is deactivated;
• (b) automatically stopping the internal combustion engine or sending a recommendation to an operator by the controller by way of a signal that the internal combustion engine be stopped if the at least one operating state value corresponds to a default value;
• and
• (c) maintaining the clamping pressure of the clamping cylinder of the clamping apparatus by the second hydraulic pump operated by the electric motor at least when the internal combustion engine is stopped.