Work was required to deepen, strengthen and widen the structure and to remove 135 years of coal and soot from the bricks from the steam trains that originally used the tracks. Last summer, 13 million litres of water were drained from the dock that runs above the tunnel to allow Crossrail workers to access the structure from above.
The rail tunnel originally served the Royal Docks when they formed the largest enclosed docks in the world, serving large ships from all over the globe. It survived a hit from a bomb during WW2 and is the only existing tunnel that will be re-used for Crossrail.
