For centuries, ships visiting Bristol had used the strong tidal current to carry them the six miles between the city and the mouth of the river Avon. Careful navigation was needed to ensure that they reached their destination before the tide ebbed, forcing the ships to go aground at whatever point they had reached. The quaysides couldn’t accommodate many ships and by the late 1700s the demand far out-weighed the space. In the last part of his career, the famous canal engineer William Jessop became much involved in harbour improvement projects, including the Bristol docks, where his imaginative scheme for redirecting the tidal waters of the River Avon enabled the old river course through the city centre to be enclosed as the ‘Floating Harbour’.  The scheme impounded 83 acres of the tidal river Avon, meaning that for the first time ships in the port of Bristol could stay afloat at all times. The Floating Harbour allowed the city’s merchants to continue trading from their long-established warehouses on Narrow and Broad Quays, the Grove and the Backs. The Bristol Docks Company was formed to construct the Floating Harbour following the passage of an Act of Parliament in 1803, sponsored by the City Corporation and the Merchant Venturers. The engineer William Jessop had originally proposed a smaller scheme, which would have involved a shorter cut from Prince Street, near the city centre, to Rownham. However this would have meant that ship owners could have avoided using the new Floating Harbour and the scheme was amended to include a greater area of the river Avon, to force ships to enter and pay the levies. At the same time, it inadvertently allowed masses of room for port expansion over the next 150 years. Jessop didn’t intend this, but by placing the entrance locks at Hotwells, as far up the river as anyone believed a ship could safely travel on one tide, he impounded far more of the river than was needed for trade at the time.