By Rose Bell
The construction works for the connections between the open cut approaches and the tunneling section of the Silvertown Tunnel has been completed by Riverlinx CJV, which is the construction joint venture of Ferrovial Construction, BAM Nuttall and SK ecoplant working on behalf of Transport for London.
While completing the work to link both Northbound and Southbound tunnel structures from the Silvertown portal to the Greenwich portal, on 11 April 2024 the final transition section of the tunnel was cast in Silvertown. In order to connecting the circular TBM-constructed tunnel to the in situ concrete arch shaped Cut & Cover tunnels, a complete transformation of the tunnel shape was required.
To construct the four transitions, a self-propelled, self-erecting formwork was used, nicknamed The Crab, whereas this 70 t tracked structure was moved into position and folded out to create the unique shape using hydraulic rams. The Crab then acts as a temporary structure for the installation of steel reinforcement before concrete is placed and allowed to cure. Once the concrete has cured enough to be self-supporting, the machine folds the shutters inward for transport through the bored tunnel to the next transition location.
While the scheduled date for inauguration of this project is 2025, currently it is moving towards the completion of the final stages, and remains on track for the new tunnel.
