The modernization of the more than 9-kilometres-long section of the 1st railway corridor between the stations Brno-Maloměřice and Adamov was carried out under our leadership. The construction activities in the narrow Svitava valley with confined space resulted not only in the reconstruction of tracks, bridges, platforms and other railway structures and technologies, but also in the rehabilitation of four tunnels in Blansko, which we carried out as well. The works included cement and chemical grouting of the rock mass, drainage, foil waterproofing of two tubes, rehabilitation of the surface, and also repairs to the portals and their surroundings. The modernization was carried out during a full traffic closure and together with two other connected constructions.