Steam spring



Steam springs

Killingworth Colliery locomotives

George Stephenson's first locomotive was the Blücher of 1814. This was a four-wheeled locomotive with the wheels coupled by spur gears. It suffered from poor traction on the relatively new technology of edge rails with flanged wheels, put down to the problem of maintaining a good contact with them. It was the first of a batch of early Stephenson locomotives known as the 'Killingworth Colliery locomotives'. Stephenson's next design was a development of this, still with four wheels, but now using a chain drive to couple them together. This was his first locomotive to use steam springs.

''The Duke''

Stephenson had gained a reputation as a builder of locomotives and was approached to build the first locomotive for use in Scotland, on the Kilmarnock and Troon Railway. The Duke was larger, with six wheels, and used the same chain drive and steam springs as the Killingworth locomotives. As this locomotive was to be built for an outside customer, Stephenson could no longer use the workshop facilities at Killingworth and so it was built at his friend William Losh's Walker Iron Works in Newcastle. Improvements of this locomotive were detailed in a patent, jointly filed with Losh, on 30 September 1816.
The Duke was probably completed in 1817 and ran at Kilmarnock, but seems to have continued the problems of rail breakage. It was sold to the Earl of Elgin in October 1824 for his railway in Fife, but being too heavy for the rails was used as a stationary pumping engine in a quarry at Charlestown, and from 1830 at a colliery near Dunfermline; its subsequent fate is unrecorded.
Most Scottish depictions of The Duke are inaccurate, being based on the Killingworth locomotives or even Stephenson's Rocket, but in 1914 a commemorative silver model was made for the centenary and this alone seems accurate, showing the six wheels and the cylinders of the steam springs.

Hetton Colliery locomotives

Five locomotives were built for Hetton Colliery between 1820 and 1822, four of which were named: Hettton, Dart, Tallyho and Star. These were of similar design to The Duke, but four-wheeled with 3' 9" wheels. They were built with steam springs, later removed owing to problems with steam leakage.
In 1852, Lyon was built as a replica of these early Hetton locomotives.