Dee bridge disaster

A new bridge across the river Dee in Chester was needed for the Chester-Holyhead railway, a project planned in the 1840's for the expanding British railway system. It was built using cast iron girders, each of which was made of three very large castings dovetailed together. Each girder was strengthened by wrought iron trusses along the length. It was finished in September 1846, and opened for local traffic after approval by the first Railway Inspector, General Pasley. However, six months later, a local train fell through the bridge and five died. The bridge had been designed by Robert Stephenson, and he was accused of negligence by a local inquest. Cast iron was known to be brittle, yet that same day, May 24th,1847, the track was covered with ballast to prevent the oak beams supporting the track catch fire. Ironically, Stephenson took this precaution because of a recent fire on the Great Western Railway at Uxbridge, London. Isambard Kingdom Brunel's bridge caught fire and collapsed. Statue of Robert Stephenson at Euston Station, London Robert Stephenson FRS (October 16, 1803–October 12, 1859) was an English civil engineer. ... The original Bristol Temple Meads station, first terminus of the GWR, is the building to the left of this picture The Great Western Railway (GWR) was a British railway company, linking South West England, the West Country and South Wales with London. ... Brunel before the launching of the Great Eastern Isambard Kingdom Brunel (April 9, 1806 – September 15, 1859), FRS was an British engineer. ...

The accident occurred a few hours later when the locomotive reached the final girder. It cracked in the middle, allowing all the carriages to fall into the river Dee fifty feet below. The extra load undoubtedly helped cause the accident. The design of the bridge was seriously flawed, and many other bridges of similar structure had to be demolished. William Fairbairn had warned Stephenson of the problem of cast iron girders only a few months before construction of the bridge at a meeting at the Institution of Civil Engineers in London, but his advice was ignored. A subsequent Royal Commission condemned the design and the use of cast iron in railway bridges. But cast iron was used very successfully in the The Crystal Palace of 1851 and the Crumlin viaduct in south Wales (built in 1857). However, the first Tay Rail Bridge of 1878 failed catastrophically due to its poor use of the material, putting the cast iron lugs on the columns into tension. The Tay disaster stimulated engineers to use steel, as exhibited by the magnificent Forth Railway Bridge of 1890. Sir William Fairbairn Sir William Fairbairn (February 19, 1789 - August 18, 1874) was a Scottish engineer. ... The Institutions headquarters Founded on 2 January 1818, the Institution of Civil Engineers (the ICE) is an independent professional association, based in central London, representing civil engineers. ... Cast iron usually refers to grey cast iron, but can mean any of a group of iron-based alloys containing more than 2% carbon (alloys with less carbon are carbon steel by definition). ... The facade of the original Crystal Palace side view of the Crystal Palace A huge iron and glass building, The Crystal Palace was one of the wonders of 19th Century Britain, if not the world. ... There are a number of settlements named Crumlin: Crumlin, Caerphilly, is a town in Wales. ... Original Tay Bridge (from the South) The Tay Bridge, properly named, is a railway bridge (approx. ... The old steel cable of a colliery winding tower Steel is a metal alloy whose major component is iron, with carbon being the primary alloying material. ... ...

References

• LTC Rolt, Red for Danger, Sutton Publishing (1998).
• PR Lewis and C Gagg, Interdisciplinary Science Reviews, 45, 29, (2004).

External links

• Reprint of paper on Dee bridge disaster at http://materials.open.ac.uk/about_us/29-2-177.pdf