The world’s first single span cast-iron bridge was constructed in 1777 and was officially opened in 1781. Made entirely out of cast iron, the bridge was one of a kind until bridges were developed with cast iron such as the Tay Bridge. Due to a shortage of timber in the area (used for making charcoal to fuel blast furnaces), coke was used instead of charcoal to fuel the smelting furnaces. The method, developed by Abraham Darby ensured that high-quality iron could be produced in the large quantities needed to be used to construct the bridge.
Why was it Constructed?
The bridge was constructed to carry pedestrian traffic over the River Severn from Broseley to Madeley Wood in Shropshire, however, the bridge closed in 1934 and was deemed as a World Heritage Site in 1986. The iron bridge is a symbol of where the Industrial Revolution started, increasing tourism within the small area. The renowned bridge is believed by locals and tourists to be a part of their heritage and is an important landmark within the UK.
Many bridges were built using the cast iron used on The Iron Bridge in Shropshire, however many suffered problems and in some cases ended in major problems and disasters. Because of this, cast iron was replaced with wrought iron beams.
Weathering and Aging
In 1784, imperfections and cracks were found on the bridge, showing signs of movement causing distress to the local community. Repairs went underway in 1800 to restore the bridge, placing two small timberland arches to relieve pressure on the river span.
Further improvements have been made over the years, due to the ongoing movement of the gorge slides where the bridge is placed. English Heritage spent years surveying the foundations of the bridge and subsequently found that a 19th Century earthquake affected the ground and pushed the sides of the gorge closer together. A concrete inverted arch was created over the riverbed to aid with the foundations. Aesthetically, the bridge has been painted and blast cleaned over the years to remain appealing and presentable to its visitors.
Although the bridge over time has undergone extensive repairs, it currently is enduring a major conservation project to repair cracks within the cast iron. In January 2017, English Heritage announced that the project would cost around £3.6 million. However, English Heritage proclaimed that The Hermann Reemtsma, a German foundation had donated one million euros (£889,680) in aid to carry out the necessary repairs on the structure. The foundation believed that the bridge showcased great engineering skills pioneered in the UK and adopted throughout Europe. English Heritage has also invested large sums to contribute to the repairs and has set up a crowdfunding campaign to complete the full restoration after describing the bridge as one of the wonders of the modern world.
The bridge is an important part of the town and surrounding area of Coalbrookdale and has been listed as a grade one bridge, where it is of exceptional interest to the general public.