Readers Ben and Jess were right! The previous photograph was the Detroit Bridge in Salford Quays. Strangely enough, I never knew it was called the Detroit Bridge, but I am glad somebody did. I have now been researching it in more depth and found it was originally a railway bridge and it wasn't always in its current location. Sadly I couldn't find out where it used to be, but Salford Quays isn't too big to be able to work out a couple of possible previous locations.
My 24 hour experiment is over and three people commented, which is one more than I had hoped for! Meaning that 1% of my visitors in the last 24 hours commented. I hope to do this again when my visitor numbers are ten times what they are now, maybe 30 people will comment then! I'm still blown away by the fact somebody actually knew the name of the bridge, let alone where it was and that it was even a bridge. Thanks to everyone who commented, and thanks for reading everyone who didn't. Normal service will resume tomorrow.