Although the bridge was some 8 meters wide, only half of it was available for traffic.
This roadway was shared by ox-carts, wagons, coaches and pedestrians coming from both directions.
At peak hours, a crossing could take up to an hour.
Attempts to tunnel under the Thames had been made in the past.
In 1799, engineer Ralph Dodd tried to build a tunnel between Gravesend and Tilbury and failed.
The project was abandoned and the engineers declared that a tunnel underneath the river was not feasible.
But Marc Brunel thought otherwise.
But the Emperor turned down his proposal and built a bridge instead.
Diagram of the tunneling shield used to construct the Thames Tunnel, London.
Each chamber was open to the rear, but closed in the front with moveable boards.
The whole process was repeated until the earth behind all the boards were excavated.
And although the shield worked well in preventing cave-ins, seep-ins were another problem.
A scale model of Marc Brunel’s tunneling shield in the Brunel Museum at Rotherhithe.
Photo: Duncan Kimball
It took another seven years for Brunel to raise enough money to restart tunneling.
He also built a better tunneling shield capable of resisting the pressure of the Thames.
The Thames Tunnel was a triumph of civil engineering, but it was not a financial success.
The tunnel cost more than half a million pounds to build, far exceeding its initial cost estimates.
In 1865, the tunnel was purchased by the East London Railway Company and converted for rail use.
It later became a part of the London Underground, and was in use until 1962.
