Story card, Thames Tunnel (watercolor)

A Family Portrait
The French gentleman Marc Isambard Brunel was a creative engineer, an inventor whose boldest and most difficult venture was the tunnel under the Thames. His watercolour shows a cross-section of the tunnel, designed by him, with him walking through it (on the left) and his son, Isambard Kingdom Brunel, being rowed up the river overhead.
In 1825 Brunel embarked on a project to dig a tunnel for carriages and pedestrians between Rotherhithe and Wapping. The riverbed is a treacherous mixture of sand and gravel, and he did not know that the dredging of gravel for roads had lowered the riverbed. Realising that the enterprise was dangerous, Brunel followed the example of the woodworm Teredo navalis, which burrows its way through the oak timbers of ships, and invented a ‘tunnelling shield’ to keep his workmen as safe as possible.
Even so the work was no picnic. The tunnel was dark, apart from the dim glow from a few candles. The air was foul, not only because there was no ventilation, but also because through the gravel overhead seeped a continuous trickle of raw sewage. Marc soon became ill and had to allow his son, only 21 years old, to take over as chief engineer. On several occasions the tunnel flooded, and on 12 January 1828 there was a catastrophic flood.Six men were killed, and Isambard was pulled unconscious from the foul water.
After running into both technical and funding difficulties, the tunnel was finally completed in 1842. It was a financial disaster, but a technological triumph. Queen Victoria knighted Marc Brunel, and developed versions of his tunnelling shield are still in use today, while the tunnel carries the East London Railway between Rotherhithe and Wapping.
This watercolour is important because the engineer himself painted it, and in those wild Victorian days, few engineers had the time for watercolours.I love it because the painting shows the embodiment of the grandest dream of a brilliant engineer.Adam Hart-Davis