The original Blackwall Tunnel took 6 years to build, and when it opened in 1897, it was the longest underwater tunnel in the world. It was an expensive process, with 600 people rehoused in order to clear the site in Greenwich, and total costs reaching £1.4million.

The Blackwall Tunnel opened as a single tunnel, with two lanes. In 1967 a second tunnel was opened to ease overcrowding.