Hassan Joudi's account of the 1864 Great Sheffiled Flood was commended by the judges.
The 1864 Great Sheffield Flood
During the mid-1800s Queen Victoria saw thousands of her subjects migrate to emerging industrial centres like the town of Sheffield. The Sheffield Waterworks Company's civil engineers set themselves the ambitious task of upgrading the region's infrastructure to supply the mills with water power and the growing population with clean water. To achieve this several colossal dams would be built west of Sheffield to create four artificial reservoirs as part of the 'Bradfield Scheme'.
In March 1864 with the industrial revolution in full flow, the Dale Dyke dam, the biggest Britain had ever seen, was nearing completion. The embankment type dam consisted of two sloping stone walls placed back-to-back with a central core-wall made of watertight puddled clay. This barrier would have had to withstand enormous pressures and prevent water seeping through.
Disaster struck on the stormy night of the 11th, a small huddle of engineers had gathered amidst heavy winds and lashing rain, worrying over a finger-size crack that was spotted. Whilst chief engineer John Gunson was still curiously inspecting the surface crack a colleague exclaimed "get out of the way".
Like a scene in a Hollywood blockbuster movie the dam collapsed beneath him and he hurled himself to safety just in time. From the side Gunson watched as large chunks of his dam - five years in the making - crumbled and as one newspaper described it later, "the water demon leaped with a voice of thunder from his oozy bed, and rushed with headlong fury down the gorge below".
Gunson knew he was safe but for the villages and heavy industry that lay downstream the sweeping barrage of water was hell incarnate. In a matter of minutes the full contents of a space one mile long, a quarter of a mile wide and on average 40 feet deep was emptied.
The subsequent flooding reached as far as Lady's Bridge in central Sheffield, leaving in its wake 270 dead innocents, and a host of razed and mangled property. The degree of damage was illustrated by the unprecedented massive total of £274,000 paid to 7,000 insurance claims.
The true cause of the collapse was only settled in 1978 when then ICE Vice-President G. M. Binnie issued a study which settled the matter once and for all. Due to the unknown high plasticity and compressibility of puddled clay as a material, water seepage occurred which caused erosion and formed a cavity deep inside the core-wall that was well outside detectable range at the time. With further erosion the cavity grew and reached the surface, and under heavy wave action from stormy weather, it widened to a full-scale breach.
This tragedy was one of the earliest major engineering failures of the industrial revolution and introduced the concept of failure in design that we know today. As a pile of rubble now lay where a pioneering structure should stand, the British public also had to deal with the reality that advanced technology brought many benefits but also the increased risk of failure.