Because wooden rails wore away quickly, they were covered with [[iron]] plates, then replaced by all-iron rails. Cast iron rails were first used, but they were too brittle to handle heavy loads.
===Steam power===
The first steam railway [[locomotive]] was designed by [[Richard Trevithick]] (1771-1833), a mining [[engineer]] from [[Cornwall]], who in 1804 built a locomotive for the Penydarren iron works in south [[Wales]]; it proved impracticalbecause the weight of the engine kept breaking the relatively brittle cast-iron rails.
William Hedley (1779-1843) built three steam locomotives between 1813 and 1815. These worked successfully until 1828-29, when they were replaced by two more innovative locomotives, including the famous ''[[Puffing Billy]]''. Wylam was a true nursery of railway talent.