Veteran TBM holes through on Tideway connection tunnel

3 July 2020

TBM Charlotte has completed her drive on an important connection tunnel that forms part of Thames Tideway, London’s 25km-long ‘super sewer’. Holing through on 2 July 2020 at Carnwarth Road, Fulham, southeast London, the 3m-diameter machine has been mining at average depths of around 30m on the Frogmore Connection Tunnel which has been excavated in two parts.

Previously, the TBM mined a 500m length from Dormay Street to King George’s Park. She was then hoisted from the shaft and taken back to Dormay Street to tunnel the 600m section to Carnwarth Road.

The 1.1km connection tunnel will take sewage overflows from King George’s Park into the main 25km tunnel at Carnwath Road, where it will be transferred to east London for treatment, instead of polluting the River Thames.

Now 26 years’ old, the remanufactured TBM has completed a total of six tunnel projects, having previously tunnelled parts of the Thames Water Ring Main Extension in 2008. Her next venture has yet to be decided.

Tunnelling on Thames Tideway is expected to be completed by 2022. The west section of the project is being constructed by a joint venture between Balfour Beatty, BAM Nuttall and Morgan Sindall.