The original Blackwall Tunnel was one of the first major projects of the London County Council, formed in 1889. It was designed by the LCC's architect Sir Alexander Binnie, later responsible for the Greenwich Foot Tunnel and Vauxhall Bridge.
James Greathead, inventor of the improved tunnelling shield, served as a consultant. His shield and compressed air techniques were used on the project.
Work began in 1891 and the tunnel was opened on 22 May 1897. At the time, it was the longest underwater tunnel in the world (1344 metres). The work had been difficult and six people had been killed during construction.
The Blackwall Tunnel was a huge achievement at the time. It was designed for horse-drawn traffic and pedestrians, as motor traffic was still a novelty in 1897. Motor vehicles started to appear in large numbers only from the 1920s.
The most rapid growth of road traffic has come since the 1950s. As the old tunnel became a major bottleneck, a second, wider tunnel was opened alongside in August 1967. Despite this, the continued growth of traffic means that twin tunnels still suffer frequent problems. A third tunnel was considered briefly, but the plan was dropped.