Nowadays a number of tunnels are constructed in urban areas in weak rocks with high or low overburden. In both cases geodetic methods are used to monitor displacements and control stability. In special cases additional other measurement systems are used to supplement the information gained by geodetic methods. This paper deals with the information gained by using a continuously recording horizontal chain inclinometer installed from the tunnel face. The increased information on the rock mass – support interaction can be used to better control the construction process and allows detecting unexpected changes in the rock mass earlier than with traditional measuring methods.