Abstract: In a cutting wheel (103) for a tunnel boring machine, a tool condition monitoring device is provided to monitor the condition of at least one mining tool (112, 115, 118) during removal of a geological structure present, during tunneling, at the cutting wheel (103) in a tunneling direction. At least one support part (121, 124, 127) is installed separately and at a distance from the or a relevant mining tool (112, 115, 118). In the relevant support part (121, 124, 127), a current conductor element is embedded, which is interrupted in terms of its ability to carry current after a wear limit which is characteristic of the condition of the relevant mining tool (112, 115, 118) has been reached. In this way, the condition of mining tools (112, 115, 118) can be reliably determined during a relatively simple maintenance operation or retrofitting with a support part (121, 124, 127).

Abstract: An apparatus for excavating a tunnel includes a cutting wheel equipped with measuring modules of sensor means on its cutting wheel face in order to directly sample the consistency of the material present between the cutting wheel face and a tunnel face by recording different types of measured values characteristic of this.

Abstract: A sealing unit (115) for sealing an annular gap (109) formed between a seal wear ring (106) and a seal carrier (112) has a sealing ring holder (118) which is U-shaped in a receptacle region and which, together with the receptacle region, encloses a fixing region (209) of the sealing ring (121).

Abstract: In a tunnel boring machine with a shield skin (106) extending in a longitudinal direction, a sensor unit (118) for detecting convergences has a number of hydraulic distance sensors (121) equipped with an extendable probe (124) with extension path measurement. By virtue of the distance sensors (121), the distance between the shield skin (106) in the area of the relevant distance sensor (121) and the surrounding rock mass (103) can be detected as a distance value, so that the thickness of an annular gap (115) can be determined. The distance sensors (121) are arranged in the longitudinal direction of the shield skin (106) at a measuring distance which corresponds to a typical ring width of a tubbing (112). A central unit evaluates the distance values of the distance sensors (121) to determine convergences.