Four amazing historic structures?
January 2025 Meeting Report
Our opening speaker for 2025 was local structural engineer Ian Hume. Whilst employed by English Heritage he was involved in the refurbishment and structural renovation of many iconic structures nationwide. He spoke about four in particular, namely the Iron Bridge in Shropshire, the Tunnel under the Thames, the Crystal Palace, and the Anderton Boat Lift in Cheshire.

The architect responsible for the first cast iron bridge was Thomas Pritchard. It was built between 1779 and 1781 by Abraham Darby III at the start of the Industrial Revolution using dovetail joints and pegs made of iron which copied those used in timber construction. The bridge was arched to allow for the passage of tall boats. In the 1960s it was almost sold for scrap, but a concrete arch across the river bed was added in 1972 to support the structure and in 1979 it was blast cleaned and repainted. It is now Grade I listed.
The Tunnel under the Thames was designed by Sir Marc Isambard Brunel, father of Isambard Kingdom Brunel. It was completed in 1843 as a foot tunnel before becoming a railway tunnel in 1869. Strengthening and conservation work was completed in 1997 and the tunnel is now Grade II listed.
The Crystal Palace was built for the Great Exhibition of 1851. Sir Joseph Paxton was the architect, engineer and gardener who oversaw its construction. The largest building in the world at that time, it required 293,000 panes of glass at an equivalent cost of £280 million today. In 1854 it was dismantled and moved to a new site at Sydenham but was destroyed by fire in 1936. However, because of its sheer size, some structures escaped the blaze and Ian was involved in the salvage and refurbishment of several of these features.

The Anderton Boat Lift was designed by Edwin Clark and built in 1875. It involves a complex mechanism by which narrow boats were lifted in tanks from the River Weaver to the Trent and Mersey Canal. The hydraulic system failed a few years later, however, and the structure was redesigned. In 1996 the boat lift was again closed down for repainting and repair. At this point it was decided to return it to the original hydraulic system.
Ian has obviously enjoyed his involvement with these four amazing structures of their time, and from the audience’s response it was clear that his enthusiasm was contagious!
Report by Kathryn McLachlan