Work is due to commence in July on the US$8.9M track lowering and relining of a 330m long rail tunnel south of Ipswich in the UK. The work is part of a US$71M project to enhance the use of rail transport to the port of Felixstowe. Once the trackbed is lowered, larger freight containers will be able to be transported through the tunnel, increasing the viability of the port.
Client Network Rail is financing the project with European Union funds and awarded the design and construction contract to Scott Wilson with Alfred McAlpine. During an eight week possession period, the 7m high by 7.5m wide arch tunnel will have its track lowered and the current brick invert replaced by a concrete slab. Work may also be required on the existing brick lining which varies between five and eight courses of bricks thick.
The geology is mainly clay with gravel beds and with the tunnel passing through a hill below groundwater levels. A spokesperson for Alfred McAlpine told T&TI that water was likely to be a problem whilst trying to pour the concrete slab. In an effort to protect the concrete pours, gullies will be fitted to the walls to collect inflows and divert them away from critical works.
