Waterworks/Curtain Bridge   

Waterworks Bridge also used to be known as the Curtain Bridge. Some years ago there was an additional structure on top of the bridge containing two steel 'curtains' which could be lowered down if necessary to block the river and divert the flow via the adjacent weir. I don't know if the system was ever used. When I moved out of Hackney in 1981 the complete structure was still in place. During the 1990s I noticed that the steel curtains had been removed, and now only the bridge itself remains. (Source: John Pridige).
Lea Marshes Bridges