A peculiar structure with the combined purpose of conveying two large-diameter water pipes across the River Clyde and providing a tidal weir which maintains the water level further upstream, the Pipe Bridge and Weir was built in 1949. It replaced an earlier weir built in 1901, which collapsed in 1941 after scour undermined its foundations. Designed by the City Engineer, the structure was built by Suffolk-based contractors Ransome & Rapier. The weir prevents erosion of the river banks upstream, which would otherwise remove silt that was then deposited downstream necessitating the regular dredging of quays and docks. The three electrically-operated sluice gates (24.3m / 80 feet in length and 3.6m / 12 feet high) could be raised at high-tide to allow the passage of vessels upstream, although this now rarely happens.
The weir represents the tidal limit of the river and represents a sudden distinction between brackish and fresh water, resulting two eco-systems which interact artificially and provide a unique habitat for various species.
There is no public access to this bridge.