Nearly four years after the beginning of the works, Vinci Construction Grands Projets (subsidiary of the french group Vinci), appointed by the public water-management network Scottish Water and in a joint venture with its British partner Costain, just handed over the Shieldhall tunnel DB works near Glasgow. Jobsites consisted in digging two wells, 20m deep and 15m wide, a 250m open trench as well as a 5km long tunnel. To complete this operation, Vinci teams used a 1000t mixshield slurry tunnel boring machine, with a 5,5m diameter in the front. They faced some complications as crossing several coal mines and the shallow depth of the tunnel. Once in use, the Shieldhall project will enable to boost wastewater treatment flow of the Glasgow city in order to stop the spill in the river Clyde.