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, to 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.
I deliberately kept my previous article about Bristol’s FloatingHarbour short and sweet for two reasons: The first one being that I didn’t want people to immediately lose interest in a topic that is important to the city’s heritage, and the second one is because my name isn’t Isambard Kingdom Brunel.
All the same, I’ve decided to include some information about the Cumberland Basin for anybody who would like to know a bit more about how this important part of the system operates.
The Floating Harbour project was awarded to William Jessop, an engineer from Devonport, who started work on the scheme in 1804. It took 5 years to build and was officially opened on the 1st May 1809.
For the Cumberland Basin, his plans included two entrance locks from the river into the holding basin, and a junction lock between the basin and the Floating Harbour. Why it was called Cumberland Basin I’ve no idea, but it was used as a lock when there were a lot of ships sailing in and out of the harbour.
Bristol’s Floating Harbour doesn’t float, so why is it called that? It takes a bit of explaining, but to understand what the Floating Harbour is will help to explain why Bristol’s maritime history was so important to the city for so long.
The port developed approximately 8 miles from the mouth of the River Avon during the 11th century, which at the time would have had the distinct advantage of being in a very sheltered location. Not only that, the River Severn has one of the highest tidal ranges in the world, which meant that the fast-flowing tide could bring ships swiftly up the Severn and the Avon to the protection of Bristol’s inland harbour.
For centuries it worked well, but as the ships got bigger things became a bit more complicated. Anyone who has witnessed the ebb and flow of these rivers will know only too well how quickly the tide can go out as well as come in, and the bigger the ships became, the more often they got stuck in the mud – and there’s plenty of that here.