The Iron Bridge
The Iron Bridge is the first cast iron arch bridge in the world. It spans 1779 the Severn at the said place after the bridge Ironbridge south of Coalbrookdale in Shropshire, England. It was therefore originally (and still occasionally ) called Coalbrookdale Bridge. When advertising for the bridge and the originally designated as Severn Gorge valley was renamed in Ironbridge Gorge. The Ironbridge Gorge Museum is on the UNESCO list of World Heritage Sites since 1986.
Construction
The bridge still complies with all the former notions of an arched bridge. It consists of five parallel to each other standing cast-iron arches, which are connected by Zimmermannsart, are clamped between large abutments on both banks, and carry a narrow deck for a road. It has a wingspan of 30 m and is 60 m long, including the abutments and sloping driveways. The bridge consists essentially of 482 castings, count the panels and railing added, there are a total of 1736 castings.
History
Until the construction of the bridge ferries were the only way to cross the Severn Gorge, but the iron industry in the 18th century, grew rapidly and made a more reliable and faster way necessary. 1773 Thomas Pritchard hit the local iron producers John Wilkinson to build an iron bridge before. In the next two years Pritchard unveiled plans ready and the producer of iron Abraham Darby III was commissioned to build the bridge.
To finance the construction cost of 3200 pounds ( the equivalent today of £ 312,239 ) shares were issued and Darby wanted to pay for any additional costs. As instead of the predicted 300 tons of iron actually 378 tonnes were used ( at a cost of 7 pounds per ton ), Darby cost the company almost £ 3,000.
As previously existed had no experience in bridge with iron, methods have been applied from the carpentry. The exact mechanism of the Year 1779 are not known. The first of two arched bridge spanning the River Severn on July 2, 1779. Then still had to be built access roads. The bridge was opened on New Year's Day, 1781. For documentation, the BBC had built in 2001 a model of half-size in order to explore the possible construction methods.
Only a few years after its completion were due to movements in the foundation for cracks in the iron and in 1802 had to be replaced by a temporary wooden structure of the southern stone pillars, in their place then finally an iron arc was used.
The last major work on the foundations were held in 1972, after in 1934 the road traffic was stopped on the bridge and had to pay pedestrian until 1950 toll. Since 1950, the bridge is owned by the Shropshire County Council.
Museums
Today in the Valley are a number of museums to find who the era of early industrialization on the topic. These include a furnace for molten iron from the 18th century, the Blists Hill Open Air Museum with exhibits from the Victorian era, the Coalport China Museum (porcelain), the over Rosehill House ( museum about the daily life of the 18th century ) and a workshop brick making. The Iron Bridge over the Severn or the Museum Association is the anchor point of the European Route of Industrial Heritage (ERIH ).