Northwich in Cheshire is notable as being an old salt town, so much so that during its history there have been frequent occurrences of subsidence as the land has subsided into old salt workings below. This proved a big problem for bridges over the River Weaver, which provided Northwich’s water link with the River Dee. The bridge pillars gradually subsided.
This was solved in 1898 with the building of the Hayhurst Bridge, followed the Town Bridge in 1899, the first electrically powered swing bridges in Great Britain. Two bridges meant that one was always open to traffic.
To avoid the subsidence problem, these bridges were built on floating pontoons, said also to be also the first of their kind in the country.
I’ve included monochrome images, trying out the capabilities of my new phone’s camera. I thought the black-white bridges could look better this way, but the colour versions actually look better to me.