 These fundamental improvements in steam engine designs by Trevithick did not change for the whole of the steam era.Amid great interest from the public, on 21 February 1804 it successfully carried 10 tons of iron, 5 wagons and 70 men a distance of from Penydarren to Abercynon in 4 hours and 5 minutes, an average speed of nearly .This locomotive proved that steam traction was a viable proposition, although the use of the locomotive was quickly abandoned as it was too heavy for the primitive plateway track.