Richard Trevithick’s locomotive made the world’s first steam-powered railway journey at the Penydarren Ironworks in Wales.
The ironworks stood near Merthyr Tydfil and employed Trevithick’s high-pressure steam technology. Under the supervision of works proprietor Samuel Homfray, Trevithick mounted an engine on wheels and adapted it for the Merthyr Tramroad, an industrial plateway used to move materials.
On 21 February 1804, the locomotive hauled roughly 10 tons of iron, five wagons, and about 70 people from Penydarren to Abercynon. The journey covered approximately 9.75 miles and took 4 hours 5 minutes. It demonstrated that steam traction could move a substantial load on rails, decades before railways became a dominant form of public transport.
The experiment was not an immediate commercial success. The locomotive was very heavy for the brittle cast-iron plates, which broke under its weight, so the tramroad returned to horse power. The engine was also unnamed; “Penydarren” or “Pen-y-Darren” is the name commonly attached to it because of the ironworks where it operated, not necessarily an official locomotive name.