Wayss & Freytag Ingenieurbau and ZÜBLIN receive contract to construct the new mine water drainage tunnel in Ibbenbüren
- More than 7 km of tunnelling
- Contract value in the three-digit million range
Frankfurt, Stuttgart, Oct. 11, 2021. On 4 October 2021, RAG Aktiengesellschaft awarded a bidding consortium consisting of Wayss & Freytag Ingenieurbau AG (50%, technical lead) and Ed. Züblin AG (50%, commercial lead) the contract for the construction of a new mine water drainage tunnel for dewatering the Ibbenbüren mine - one of the last German coal mines - which was closed down in 2018. The contract has a construction volume in the three-digit million range; the multi-year construction work is scheduled to start in November of this year. From the end of 2024, the approximately 7.4 km long tunnel will drain off the mine water from the former mine, which has been rising in a controlled manner since the deep dewatering system was shut down. The tunnel, with an internal diameter of 3.6 m, will be excavated in two parallel sections by two tunnel boring machines from two access points. For this purpose, a 250 m long section will be excavated as a launching pit and a 70 m deep central shaft with an internal diameter of 32 m will be excavated. The tunnel will be constructed with a precast segmental lining and an invert channel to drain off the mine water. In addition, the existing mining shaft Von-Oeynhausen-1, which is partially filled below the connection of the new tunnel, is to be reinforced: The new drainage tunnel will be connected to it at a depth of 100 m, via which the mine water will ultimately be led to the treatment plant in Gravenhorst.