Saturday, 23 October 2010

A Bridge Too Far?
Span Information
In October 1964 Harold Wilson and the Labour Party won the General Election with an overall majority of four seats. This proved to be even more unworkable when over the next two years this majority was reduced to two seats. In an effort to save his government in 1966 he persuaded Barbara Castle the then Minister of Transport to 'bribe' the electorate of Hull North by promising to finance the building of the Humber Bridge. The by-election was duly won as was the hastily organised General Election which followed.
The Humber Bridge opened to traffic in 1981 but the idea of a bridge over the estuary goes back much earlier than that.

MV Lincoln Castle operating the ferry service between Hull and the north Lincolnshire coast which had started in 1820.

After many years of neglect Lincoln Castle was being broken up in Grimsby when we visited a few weeks ago.

Construction of the bridge commenced in 1973 and proved challenging from the start. The geology of the area, particularly on the south bank, caused lengthy and costly delays, as did strikes and bad weather. The foundations for the south tower, which is set into the river bed, had to be 36 metres deep whilst those of the land-based north tower are only 9 metres deep.
The suspension design was developed from the Severn Bridge and has a design lifespan of 120 years. Consulting engineers for the project were Freeman, Fox & Partners.

Some interesting statistics:-

The main cable is 2ft3ins in diameter.

Over 44,000miles of wire are used in the cables.

27,000 tons of steel and 480,000 tons of concrete

A little further up the Humber is South Ferriby Sluice where the New River Ancholme drains into the Humber. This drainage scheme was first constructed in the 18th century but 50 years later Sir John Rennie proposed to straighten and widen the drainage canals replacing the multi spanned bridges by single span ones.
At Horkstow he built one of the earliest examples of a suspension bridge. At 140ft long and 14ft wide this cast iron and timber construction is somewhat smaller than Barara Castle's bridge just up the river but no less elegant.
I believe this is the only suspension bridge built by Rennie and is rather grand for an accommodation bridge.
The iron was cast at Gospel Oak Ironworks in Tipton, Staffs. and the bridge was completed in 1836, 150 years before the Freeman, Fox and Partners design. I wonder what lifespan he predicted for it!

Rennie is probably better known for his work on the Kennet & Avon Canal such as the Dundas Aqueduct

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