Crossrail has completed a major part of refurbishment work on the Connaught Tunnel ahead of schedule.

Earlier in the year, dam walls were installed in a section of the Royal Docks that runs above the tunnel to allow Crossrail workers to access the tunnel from above. However, the dam had to be removed by the first week of September to allow ships to pass through the dock ahead of a trade exhibition at the ExCeL exhibition centre in Custom House.

Following three months of work around the clock, the work has now been completed, the dam walls have been removed and the dock has been re-opened.

A cofferdam the size of a football pitch was installed and 13 million litres of water drained from the Royal Docks. This allowed workers to deepen, widen and strengthen the central part of the tunnel to accommodate new Crossrail trains.

Sections of the tunnel were in a poor condition and parts of it were narrowed during the 1930s so that the dock could be deepened to accommodate larger ships with brickwork removed and steel segments installed. This material has now been removed and a larger, stronger structure has been put in place in preparation for the start of Crossrail services in 2018.

The tunnel was built in 1878 and has not been in passenger use since December 2006. It is the only existing tunnel that will be re-used for Crossrail.

Linda Miller, Connaught Tunnel Project Manager said: “It was a race against the clock to get the work completed and the dock re-flooded, so it’s great news that we’ve got it finished ahead of schedule. It’s been a fantastic effort by the whole team to get the job done safely, quickly and effectively.”