In 1802, Trevithick built one of his high-pressure steam engines to drive a hammer at the Pen-y-Darren Ironworks in Merthyr Tydfil, Mid Glamorgan . With the assistance of Rees Jones, an employee of the iron works and under the supervision of Samuel Homfray, the proprietor, he mounted the engine on wheels and turned it into a locomotive. In 1803, Trevithick sold the patents for his locomotives to Samuel Homfray.
The configuration of the Pen-y-Darren engine differed from the Coalbrookdale engine. The cylinder was moved to the other end of the boiler so that the fire door was out of the way of the moving parts. This obviously also involved putting the crankshaft at the chimney end. The locomotive comprised a boiler with a single return flue mounted on a four-wheel frame. At one end, a single cylinder with very long stroke was mounted partly in the boiler, and a piston rod crosshead ran out along a slidebar, an arrangement that looked like a giant trombone. As there was only one cylinder, this was coupled to a large flywheel mounted on one side. The rotational inertia of the flywheel would even out the movement that was transmitted to a central cog-wheel that was, in turn connected to the driving wheels. It used a high-pressure cylinder without a condenser; the exhaust steam was sent up the chimney assisting the draught through the fire, increasing efficiency even more.
Technical Specifications
- Power Type - Steam
- Build Date - 1803
- Total Produced - 1
- Average Speed - 2.4MPH
- A working replica can be seen at the Swansea Waterfront Museum