Less blue, but a very interesting bridge over the lower Ouse. Used to be a swing bridge, but now static and part of the South Downs Way
Swinging section. It was operated by a crank from on the bridge section, which turned a wheel against the large toothed cog you can see at the top of the pillars. It ran on the small wheels round the top of the large cog.
Underneath, and another view of the cog mechanism. Not a view I am very familiar with.
If you look carefully, you can see the drive cog.