Merthyr Tramroad

The Merthyr Tramroad (sometimes referred to as the Penydarren Tramroad due to its use by Trevithick's locomotive built at that ironworks) was a 9.5 mile long line that opened in 1802, connecting the private lines belonging to the Dowlais and Penydarren Ironworks with the Glamorganshire Canal at Abercynon, also serving the Plymouth Ironworks along the way. Famous as the line on which Richard Trevithick's experimental locomotive hauled the first train to carry a load (of 10 tons of iron). It was largely superseded when the Taff Vale Railway opened in 1841 and sections gradually went out of use over the two decades from about 1851.

The four principal ironworks at Merthyr Tydfil were Dowlais (built 1759), Plymouth (built 1763), Cyfarthfa (built 1765) and Penydarren (built 1784). Initially the output of these ironworks was carried by packhorse or on carts 25 miles to Cardiff. In 1794 Cyfarthfa works was linked to Cardiff by the Glamorganshire Canal, the other three ironworks were linked to it by tramways. Richard Crawshay of Cyfarthfa Ironworks held the controlling interest in the canal company and claimed preferential treatment. The upper heavily locked section of the canal suffered from congestion.

A Bill for a tramroad from Merthyr to Cardiff was defeated in Parliament in 1799 by opposition from the Glamorganshire Canal proprietors but the upper section of the proposed line was built anyway, compulsory powers were provided for by provisions in the Glamorganshire Canal Act but were not invoked.

The engineer was George Overton and construction began in 1800 under the supervision of Richard Hill of the Plymouth Ironworks. It was completed in 1802.

The Dowlais company already had edge rail lines of narrower gauge from their works to near the head of the canal at Merthyr and these were converted to 4 ft 4 in gauge plateways to connect with this new line allowing through running.

In 1804 Trevithick's pioneering steam locomotive made a few experimental runs along this line.

In 1815 a wooden bridge over the Taff near Quakers Yard collapsed beneath a train carrying iron from Penydarren. The whole train including the horses, the haulier and four other people riding on it fell into the river killing one horse, badly cutting another and injuring two of the people.

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