Calls for an engineered crossing of the Humber Estuary began as early as 1872, when merchants in Hull proposed a tunnel to speed up trade between the two sides of the river.
But it was not until 101 years later that a scheme was able to progress to the construction phase. It was then that work began on the suspension bridge that carries traffic over the river today.
The Humber Bridge has a main span of 1.41km, which was the longest in the world when completed in 1981. It also has a 530m side span at its southern end and a 280m side span at the northern end.
Consulting engineers at Freeman Fox & Partners based their design for the bridge on its predecessor, the Severn Bridge near Bristol.
A suspension bridge was chosen because the Humber has a shifting riverbed and its navigable channel is always changing, leaving little opportunity to site support piers.
The bridge was designed to cater for wind speeds of up to 105mph at deck level. It contains dual carriageways, footpaths and cycle tracks.
Construction work took eight years, and involved the use of 480,000 tonnes of concrete as well as 27,500 tonnes of steel. More than 1,000 workers were on site at peak times.
The southern cable tower was founded in shallow water 500m from the shore, and placed on foundations 36m deep.
A temporary jetty was erected from the shore to the site of the tower, where a cofferdam was driven in and filled with sand to form a temporary island from which the tower could be built.
The steel shortage of 1973 delayed these temporary works and, even when they started, they were more difficult than envisaged.
The northern cable tower was placed on reinforced concrete foundations 44m by 16m and 8m deep.
The two suspension cables comprised 14,948 wires of 5mm diameter, plus an additional 800 similar wires on the north side span.
The Queen opened the Humber Bridge on 17 July 1981. As well as transporting business vehicles and holidaymakers between Hull and Grimsby in record time, the bridge allowed the UK civils industry to reach new places.
The bridge showcased the quality of the UK civil engineering industry to a global audience and helped contractors and consultants win work on structures around the world.
Freeman Fox & Partners worked on projects including the Fatih Sultan Mehmet Bridge across the Bosphorus in Istanbul. UK expertise was also used on famous suspension bridges including Tsing Ma Bridge and Stonecutters Bridge in Hong Kong.