Five months ahead of its official opening, the new cross-river link looked extremely impressive from the Old Kilpatrick side of the Clyde.
The bridge, designed by William Brown and opened on July 2, 1971, replaced the old Erskine Ferry crossing. That chain ferry had, in turn, replaced rowing boats before them a medieval ford where men and animals could cross the then shallow river by foot at low tide.
Built between 1967 and 1971 by Freeman Fox, the box girder bridge with cable stays is 524m long, not including the two approach spans of 68m each.
The masts of the main span are 38m tall, while the steelwork weighs around 11,000 tonnes.