Thursday, August 28, 2008

History of Iron plate rail and Edge rail and Wrought iron and steel

Iron plate rail

In 1768, the Coalbrookdale Iron Works laid cast iron plates on top of the wooden rails, providing a more durable load-bearing surface. These were later used by Benjamin Outram at his foundry in Ripley, Derbyshire, the first time standardised components were produced. It was these that led to the name "platelayer" for workers on the permanent way. The advantage was that a considerable variation in wheel spacing (gauge) could be accommodated. However, wheels would bind against the upright part of the plate, and mud and stones would accumulate. On the Little Eaton Gangway in 1799, where Outram used passing loops on the single track, moveable plates were provided, called "pointers", which became shortened to "points".

Edge rail

From the late 18th century, iron "edge rails" began to appear. The British civil engineer William Jessop designed smooth iron edge rails, which were used in conjunction with flanged iron wheels, introducing them on a route between Loughborough and Nanpantan, Leicestershire, as an adjunct to the Charnwood Forest Canal, in 1793-4. In 1803, Jessop opened the Surrey Iron Railway in south London, arguably the world's first horse-drawn public railway. Being of cast iron these rails were short, around three feet long, of a "fish-bellied" design. They had a foot at each end by means of which they were fastened to stone blocks in the ground.

Wrought iron and steel

Cast iron is a brittle material and the short lengths meant that they soon became uneven. However, developments in the process of hot rolling iron meant that longer length rails could be produced. In 1805, the first wrought iron rails were produced at Bedlington Ironworks near Durham. The first steel rails were produced by Robert Forester Mushet and laid at Derby station in 1857[8]. Modern railways still use steel rails, but they are typically welded together to form lengths of continuous welded rail; these remove the additional wear and tear on rolling stock caused by the tiny differences in rail surface height at the joint between adjacent rail sections.

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