Boltless Trapezoidal Tunnel Lining

The use of a boltless trapezoidal lining on the £416m (US$567m) west section of London’s Thames Tideway Tunnel is the world’s first-ever application of the technology. Its innovative nature was recognised at the Ground Engineering Awards 2020 where it won the award for Technical Excellence.

The Boltless Trapezoidal Ring design – essentially the brainchild of Colin Eddie of CECL Global and Ivor Thomas of the BAM Nuttall.