'William Hedley' (1773 –
January 9 1843[1]) was one of the leading industrial engineers of the early 19th century, and was very instrumental in several major innovations in early
railway development. While working as a 'viewer' or manager at
Wylam's Colliery near Newcastle upon Tyne, he built the first practical
steam locomotive which relied simply on the
adhesion of iron wheels on iron rails.
He was born in
Newburn, near
Newcastle upon Tyne in 1773. Before Hedley's time, such locomotives were far too heavy for the track that was then available. While most lines used cable haulage with stationary engines, various other schemes had been tried. William Chapman at the
Butterley Company in
1812, attempted to use a steam engine which hauled itself along a cable, while, at the same company, Brunton had produced the even less successful "mechanical traveller", or
Steam Horse.
However, in 1812,
Matthew Murray and
John Blenkinsop had produced the first twin cylinder steam locomotive, ''
The Salamanca'', for
Middleton Colliery railway near
Leeds, using a
pinion engaging with teeth along the iron
edge rails track (first
rack railway). This had been the first steam locomotive railway to work successfully, but the system was complex and expensive.
Hedley felt that if the pairs of wheels were connected, as with
Richard Trevithick's engines, if one pair began to slip, it would be counteracted by the other. The mine owner,
Christopher Blackett had just replaced the wooden
waggonway with iron flanged 'L' section plate rails. Hedley first constructed a test carriage operated by manpower, to test the
adhesion under various loads. He then used it as the chassis for a locomotive constructed to Trevithick's pattern with a single cylinder and a simple straight through fire tube to the boiler.
This engine was not satisfactory. Its motion was erratic, because of the single cylinder, and it produced insufficient steam.
He built a second engine, with the assistance of the, later to be famous,
Timothy Hackworth, his foreman smith, and his principal engine wright, Jonathan Foster, using the 1812 twin cylinder plan of
John Blenkinsop and
Matthew Murray and a return tube boiler. This was the famous
steam locomotive, ''
Puffing Billy'' which first ran in 1813 and is now preserved at the
Science Museum in
London. Its success encouraged them to build a second engine ''
Wylam Dilly'', which is now in the
Royal Museum in
Edinburgh. In the same year, his system for using a coupling between the wheels was patented.
However there was still considerable wear to the track, and the engines were rebuilt using twin four-wheeled bogies, introduced in Blackwell's design mentioned above. Initially the wheels were without flanges for use on the flanged plate rails. In about 1830 the line was relaid with the stronger edge rails, and both locomotives reverted to their original pattern, but with flanged wheels, which is how they are today. Both locos remained in active service until 1862.
Hedley died in 1843. His descendants remained heavily involved in the coal-mining industry until nationalisation in the 1940s. In 1971, a charitable foundation was set up in the Hedley name, with assets based on the compensation from nationalisation.
References
★
The Victorian Railway and How It Evolved, Ransom, P.J.G., , , Heinemann, ,
1. Today in Science History: January 9 - Deaths
External links
★
Hedley Foundation