One day in Great Yarmouth the circus came to town. Excited crowds gathered on the banks of the River Bure and on the Yarmouth Suspension Bridge. They were there to watch Arthur the clown sail up the river in a washtub pulled by four geese. (The trick being a tow line underwater attached to a rowing boat).
A crowd of four to five people deep, many young children, stood on the bridge. At 5.40pm on 2nd May 1845 one of the eyebars failed. A second eyebar, unable to take the load, failed five minutes later and the deck fell into the water taking most of the crowd with it. Seventy-nine people died of whom fifty-nine were young children.
Yarmouth suspension bridge was completed in 1829. It was designed by Joseph John Scoles who was more of a church builder. When the span was increased from 19 metres to 26 metres, the length of chain was similarly increased in length, but Scoles wasn’t consulted; the towers should also have been increased in height. The chain sagged despite the length of the bridge increasing.
The eyebars (a metal bar with holes at either end used to bolt rods together) were made by a local blacksmith. Scoles used the correct specification for the iron but failed to do any tests. (Unlike Thomas Telford who was very keen on testing). There were also problems with the welding.
In 1832 the bridge had been widened for the width of two carriages and the railings moved to the very edge of a deck. The additional weight was borne by one chain and could not cope with the crowd loading on the day of the circus visit. Previous to the widening the number of people on the bridge could easily be handled. The defective eyebars were ultimately given as a cause of the collapse by the inquest. It was recommended that public bridges be regularly inspected.
There is now a memorial nearby commemorating the loss of life.
I expect we’ve all complained at the time taken to repair structures, when roads are closed for bridge building, the time taken to detour round a river or chasm as the construction drags on. But engineering requires precision for a good reason and materials are tested to destruction to ensure they are fit for purpose. These days bridges are built by a consortium of architects, engineers and builders, and there are surveyors and safety inspections. Let’s hope there are no repeats of the Yarmouth disaster.