Your guy's guesses are as good as anyones! Here is some interesting info on this locomotive, courtesy of wikipedia... In 1802, (Richard) 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. Homfray was so impressed with Trevithick's locomotive that he made a bet with another ironmaster, Richard Crawshay, for 500 guineas that Trevithick's steam locomotive could haul ten tons of iron along the Merthyr Tydfil Tramroad from Penydarren (51°45′03″N 3°22′33″W) to Abercynon (51°38′44″N 3°19′27″W), a distance of 9.75 miles (16 km). Amid great interest from the public, on 21 February 1804 it successfully carried 10 tons of iron, 5 wagons and 70 men the full distance in 4 hours and 5 minutes, an average speed of approximately 2.4 mph (3.9 km/h).[16] As well as Homfray, Crawshay and the passengers, other witnesses included Mr. Giddy, a respected patron of Trevithick and an 'engineer from the Government'.[17] The engineer from the government was probably a safety inspector and particularly interested in the boiler's ability to withstand high steam pressures.