That looks like they have removed a perfectly good swing or lift bridge to put it in place.
Or perhaps a not so perfectly good one. I'm not sure about the history of that area, but that canal has been a route to nowhere since the demise of the Lapal Tunnel in *googles* 1917, and whatever may have once justified a bridge probably fell into disrepair and is now buried under a twisty maze of industrial estates, all different.
As it's now just footpaths on the far side of the bridge, I suppose it makes sense that they've retrofitted a simple footbridge to join things up.