In 1860, with the threat of possible invasion hanging over Portsmouth, the old bridge from the mainland – which had not been strengthened since the time of the civil war – was demolished.
It was replaced by a new bridge and fortifications – the Hilsea Lines – were built. The fortifications were part of the group of defences against the French known later as Palmerston’s Follies. There were the Solent forts and those on Portsdown Hill.
At that time Portsbridge was the only road on to Portsea Island and was of great strategic importance.
In the 1920s much of the fortifications were demolished to make way for new roads development, work that was going on in this picture. The new Portsbridge was opened in 1927 allowing the ever-increasing flow of traffic easier access to the island.