New milestone achieved on Tideway
28 September 2020Tunnelling on Tideway has now reached another significant marker with the completion of the western section of the main tunnel, which at depths of between 30-35m below ground is also the shallowest along the entire alignment.
Having started tunnelling in May 2019, the 8.13m-diameter Herrenknecht EPB TBM (‘Rachael”) holed through 30m below ground into the shaft at Acton. During its seven kilometre journey on a gentle uphill gradient from Fulham, the TBM has excavated around 725,000 tonnes of spoil, which Tideway says is equivalent to around 60 times the weight of the Shard – the UK’s tallest building.
The machine had arrived at the unloading point on the River Thames in late 2017, having been transported from the Herrenknecht plant in Schwanau via Kehl, Rotterdam, Denham Wharf and Gravesend.
Tideway senior project manager Neil Binns said: “From designing and manufacturing the TBM, to providing logistics support for its delivery by river, to the above-ground operation, as well as the skill of the tunnelling team – this is a fantastic achievement and a wonderful example of the teamwork required to clean up the River Thames.”
The Western Section of the project has seen nearly 1,100 shifts worked by around 200 staff. Exploiting the river to transport concrete segments and remove spoil from the works has, according to Tideway, kept 25,000 trucks off the road, thereby significantly boosting the green credentials of the project.
Tideway is the 25km ‘super sewer’ that will run mostly under the River Thames at depths of 30–60m+, transferring sewage eastwards under gravity. The £1.1bn project is designed to intercept, store and ultimately prevent around 39 million tonnes of raw sewage entering the river annually through combined sewage overflows. Construction is scheduled for completion in 2024.
