4. Tower Bridge, London

The 1800’s proved to be an increasingly important commercial period for the East End of London, which meant that a new bridge was needed across the Thames near the Tower of London. However, the difficulty of designing such a bridge rested in the need to maintain the flow of road traffic while also enabling the passage of tall-masted ships.

Although Sir Horace Jones’s design ultimately triumphed, F. J. Palmer’s futuristic bridge would have been fascinating to see in action. His creative idea involved movable platforms at either end of the structure, allowing for traffic to cross the bridge unhindered, even when boats are passing below.