world's first large iron structure was the Iron Bridge, near Telford in Shropshire. Built
Iron Bridge's builders used the technology that they knew. They joined the sections of the
bridge with woodworking joints. Here is a dovetail...
and here, a through housing. Notice how a piece of the iron has cracked away -
showing how cast iron is brittle.
of the Iron Bridge's joints. This one is complete but shows a crack.
are very stong and cannot be deformed. Here the strength of triangles is used to in
scaffolding to support the wall of a derelict building.
is a very commonly used material in our time. These concrete flyovers are at the ferry
terminal at Calais.
lifeboat hanging from its davits. The davits are a series of levers to hold the boat over
the side of the ship and ropes and pulleys to loower it into the water
levers and pulleys at work in this dockside crane (Calais Ferry Terminal)
iron and concrete piers reach out from the shore at Dover Ferry Terminal.