On the 19th July 1843 crowds thronged the slipway at Bristol’s Great Western Dock to watch Prince Albert launch the ‘world’s first great ocean liner’, and on the 19th July 1970, exactly 127 years later, crowds once again lined the banks of the Avon to see the grand old lady brought back home to her birthplace.
Those 127 years had taken their toll, and she had been left to see out her final days 8,000 miles away down in the South Atlantic: That was, until a rescue operation was organized to make sure that the old girl had the dignified end to her life that she deserved – and what a life it was.
When the SS Great Britain was launched, she was the most advanced ship in the world using revolutionary new techniques to transport passengers in luxury to the other side of the Atlantic – and that was just the beginning. In total, she travelled over a million miles around the world before being scuttled at Sparrow Cove in the Falkland Islands in 1937, but why was she built in Bristol?
Prior to the creation of William Jessop’s Floating Harbour in 1809, the River Avon flowed through where Underfall Yard now stands.
The construction of Cumberland Basin and the New Cut meant that an island was formed between where the river was diverted and Bathurst Basin at Redcliffe. This island became known as Spike Island.
Jessop’s plan included an ‘Overfall’ Dam to allow excess water in the Floating Harbour to flow over into the New Cut, but by the 1830s the harbour was becoming badly silted up.
Although Jessop had included sluices with his Overfall Dam, the main method of clearing the silt out was to drain the harbour and remove it by hand, which was less than ideal to say the least.
Isambard Kingdom Brunel was brought in to make improvements to both Cumberland Basin and the Overfall Dam, and for the Overfall Dam he recommended developing Jessop’s sluices further and using dredger boats to remove the silt.
He devised an Underfall system where three shallow sluices could be used in a way that would control the harbour water level according to the tide and weather conditions, and a fourth ‘deep scouring’ sluice which could be opened at low tide when a powerful undertow (undercurrent) would suck the silt into the New Cut to be carried away by the next tide.
This Underfall system is still in use today, although a more modern system of dredging is used.