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Glamorganshire Canal

1942

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The Glamorganshire Canal was promoted to improve transport from ironworks and coalmines in the Merthyr Tydfil area to the coast at Cardiff. It was promoted by Merthyr ironmasters led by Richard Crawshay who raised the money for the canal. Thomas Dadford, both father and son, and Thomas Sheasby were appointed as engineers and contractors and work began following an Act obtained in1790. The canal was 24½ miles long and had 49 deep locks and a short tunnel in Cardiff and was completed in 1794. Boats using the canal were similar to day boats; they were 60 feet long and 9 feet wide and could carry up to 25 tons. Shortly after its completion it was extended a mile to a new basin and sea lock for larger ships, this was known as the Sea Lock Pound and meant the canal was 25½ miles long with 51 locks. From 1798 disputes constantly took place between the Crawshays and the other ironmasters as well as between the engineers and the canal company. One of the outcomes of the dispute was the Penydarren tramroad built by the Dowlais ironmasters from Merthyr to Abercynon parallel with the canal. The canal was very successful early on and by the 1850s was carrying 600,000 tons a year which caused two problems. The canal's Act had a clause limiting dividends to 8% so the canal company had more money than it knew what to do with, tolls were reduced and more money was returned to traders. Also the high levels of trade meant high levels of congestion especially at the Treble Locks at Nantgarw at Melingriffith where the canal had a narrow stretch next to a tinworks and at Cardiff. Water supply was a problem especially as congestion rose and reservoirs were built at Glyn-Dyrus near Merthyr in 1806 and at Nantgarw in 1821. Pumping engines were also erected in about 1806 at Pontyrun near Merthyr to pump from the River Taff and at Melingriffith to return water used by works. In 1814 the Sea Lock was lengthened and a dock was proposed. This was opposed by the Marquess of Bute who planned his own docks and in 1839 opened West Bute Dock, which was connected to the Glamorganshire Canal by a new lock. In 1836 the Taff Vale Railway Company was formed by a group of ironmasters who had fallen out with Crawshay. They got their Act, bought the Penydarren tramroad and opened their line from Merthyr to Cardiff in 1841. Initially the railways did not affect the canal, but by the 1860s traded had begun to fall off. In the mid 1860s the Bute trustees offered to buy the canal but this was refused, a second offer was made in 1883 and this was accepted as trade had fallen sharply and the canal had fallen into a poor condition. The sale included the Aberdare Canal and the Doctors Canal in Pontypridd. The section from Cyfarthfa to Merthyr had been abandoned in 1868 and by 1898 the length from Merthyr to Abercynon was abandoned. The length to Pontypridd closed following a burst in 1915 and a burst at Nantgarw effectively ended navigation in 1942. In 1943 the canal was bought by Cardiff Corporation who secured abandonment and by the 1950s the Sea Lock pound was disused. For further information on the Glamorganshire Canal see Edward Paget-Tomlinson's The Illustrated History of Canals & River Navigations.