Devonshire Granite and London Bridge

Written by Connor Clinton, Science Communication Student at the University of Sheffield

Few stones in Watson's Collection can claim a journey as remarkable as this granite from Haytor Quarry in Devonshire. This light grey granite was formed 260-290 million years ago as part of a large igneous intrusion. It was quarried for use in some of London's most ambitious 19th-century building projects, most notably London Bridge.

The ‘Old London Bridge’ had stood for six hundred years by the 19th century, but its cramped design was beginning to falter as it blocked the increasingly busy river traffic of the Thames. A bill for a new bridge was passed in 1823, to be paid for by the City of London. The chosen design came from Scottish engineer John Rennie, who had passed away in 1821. After seven and a half years of construction using the granite from Haytor Quarry, the new bridge was opened by King William IV in 1831.
 

The story of the new bridge took an unexpected turn in the 20th century. By 1967, Rennie’s bridge was struggling to cope with the weight of modern vehicles and was beginning to sink. Rather than demolish it, the city put the bridge up for sale. It was purchased by American entrepreneur Robert McCulloch for $2.4 million. Earlier, in 1964, McCulloch had purchased land in the Arizona desert to test his companies boat motors and house his workers. McCulloch wanted to grow the company town into a tourist destination and a thriving city, but he needed something to draw people in, and he believed Rennie's London bridge was the perfect fit. 

The 10,276 exterior granite blocks from Rennie's bridge were dismantled and shipped to McCulloch's land in Arizona, which had been named ‘Lake Havasu City’. The shipping, assembly, and dredging of a man-made channel underneath the bridge cost an additional $7 million. To overcome the issue of automobile traffic at Lake Havasu, a steel interior framework was built to support the original granite. It is the granite from Haytor Quarry that lines the reconstructed bridge, which now resides in an American desert five thousand miles from its origin in Devonshire. To replace the bridge that had been removed, a new one was constructed using concrete and steel. It was opened by Queen Elizabeth II in 1972.