Higher temperatures are affecting many constructions, and nowhere is this more evident than in London’s Hammersmith Bridge. The Victorian-era suspension bridge that towers over the River Thames has been struggling particularly as of late, with cracks appearing throughout its foundation, according to a press release published by the Hammersmith and Fulham Council.
Wrapping the bridge in foil to deflect the sun’s heat
To deal with this issue, engineers have started wrapping the bridge in foil to keep the cracks from spreading and ultimately destroying the development. In August of 2020, the bridge even had to be shut down due to these cracks, and it only reopened for river traffic, cyclists and pedestrians last July.
This reopening was due to the work of Hammersmith & Fulham Council’s world-leading engineers, who installed a pioneering £420,000 (around $50,000) temperature control system to keep the bridge at a safe temperature and deal with any stresses on its pedestals.
“The safety of the public is our first priority,” said Sebastian Springer, Arcadis Project Manager on the bridge works. “The temperature control system allows us to track weather spikes and maintain a constant temperature. As we deal with the current extreme heat, we are also coming up with innovative solutions to keep the temperature within the threshold.”
How does the system work?
The bridge’s chains are anchored to the river bed and are kept below 13 degrees Celsius (about 55 degrees Fahrenheit) at all times. If they happen to reach 18 Celsius, the bridge will have to be shut down again since the brittle cast iron is especially sensitive to temperature fluctuations.
Monday and Tuesday of this week were expected to be particularly hot, so the engineers ran the cooling systems throughout the night and wrapped the parts of the bridge above the water in foil to reflect away the sun’s heat.
One of the world’s oldest suspension bridges
Hammersmith Bridge was built-in 1887 and is currently one of the world’s oldest suspension bridges. This makes it very expensive to repair. Just the first phase of works to stabilize the micro-fractures in the pedestals would cost the council £8.9m ($10.6m).
The council has further been told by the government to pay 33 percent of the original estimated £141m ($168m) to £163m ($195m) required for repair. “We have made it clear we can only raise that amount of money via a road user charge or toll,” responded the council.
The bridge is listed as a Grade II structure made out of wood and wrought iron and a suspension held in place by cast iron pedestals. It is today a national landmark and an important part of Britain’s engineering heritage.