An article on the Swansea Canal as promised. 800 words cannot do much justice to the canal, I have written 950 words, Steve Hughes of the RCAHMW has written three books on the canal and its infrastructures, over 1000 pages.


The Swansea Canal was constructed during the period referred to in Britain as the canal mania era, and was one of the six larger canals constructed in South Wales; there were several smaller waterways in addition. The Swansea Canal was built between 1794-98, and was only sixteen and a quarter miles in length. Although only short in mileage, it is of world importance in its canal structures, its water usage and in industrial developments. The Swansea Canal was important to the development and prosperity of Swansea during its first eighty or so years, and more important to the development of urban centres in the Swansea Valley. At the southern end of the canal at Swansea, alongside the Strand, were numerous wharfs and stockyards where goods were imported and exported. The Swansea Board of Health Plan 1852 shows coal yards, iron ore yards and timber wharfs along the lower section of canal adjacent to Swansea Harbour.

Among the larger users of the canal exporting finished goods and minerals downwards to Swansea were the Ynyscedwyn Iron Works, Ystalyfera Iron works, Primrose Coal Company, Ynisgeinon Coal Company, Gwaunclawdd Coal Company, with many smaller users relying on the canal for raw materials inwards. Among those were the Ynysmeudwy Pottery, Morriston Pottery, the Rose Copper Works and William Gilbertson’s ironworks. Initially, iron ore was mined close to the Swansea Valley ironworks, but from the 1840 period onwards, richer ores were imported through Swansea Harbour. Over sixty individual companies are recorded as using the canal for transport between 1794 and 1875 owning over 450 barges between them. In the heyday of the Swansea Canal c1870 approximately 18,000 barges travelled along the canal per annum.

Non-ferrous industries such as copper, zinc, nickel smelting was concentrated in the lower Swansea Valley, whilst the heavy industries of iron and steel, tinplate and coal mining were above Morriston. All of them using the Swansea Canal for the carriage of raw materials and finished goods. Another aspect of the Swansea Canal was in supplying clean canal water for industrial processes. As an example the Hafod Copperworks purchased several million gallons of water per year.

The direct influence of those industries was the creation of towns and villages such as Clydach, Pontardawe, Ynysmeudwy, Ystalyfera, Ystradgynlais, Cwmgiedd, Abercraf and the Twrch Valley settlements. Before the Swansea Canal was constructed, the Swansea Valley was agrarian, but afterwards it became a very industrialized valley.

The Swansea Canal had 36 locks along its length to raise the canal 372 feet above sea level at Swansea to reach the coal and iron bearing regions in the mid and upper valley. The canal had to span four major rivers in addition to smaller steams, including the Lower Clydach River at Clydach, the Upper Clydach River at Pontardawe, the River Twrch at Ystalyfera, and the Giedd River north of Ystradgynlais. The largest aqueduct was, and still is, the Twrch aqueduct that carries the Swansea Canal over the river of that name, and out of Glamorganshire into Breconshire. This aqueduct is of world importance in canal structural engineering. It is the first such structure in the world to be constructed using hydraulic mortar instead of several thousand tons of puddled clay to seal the water channel which was normal practice at that time. That is very important in structural engineering which relieved the aqueduct of a great deal of weight. Many aqueducts constructed prior to the Twrch collapsed because of the weight of the structure and inadequate foundations. The locks along the Swansea Canal were also constructed using the hydraulic mortar.

An important aspect of the Swansea Canal was in terms of its water usage. There were forty-two water-powered installations recorded as directly using canal water to power machinery such as the blast for blast furnaces, grinding stones in corn mills, flint mills in potteries, electricity turbines, power for tinplate works, farm water wheels, saw mills, woollen mills, and iron forges. The Swansea Canal had more water-powered installations per mile than any other canal in Britain.

The Swansea Canal was only sixteen miles in length, yet it was connected to industries several miles from canal wharfs by horse-drawn railways, over sixty such railways with a total length of 140 miles. It was that linked transport infrastructure which enabled industry to develop in remote locations. For example, the Brecon Forrest tramroad was nineteen miles in length, from the Gurnos wharf near Ystalyfera to Sennybridge, crossing into the Dulais Valley before passing through Penwyllt and Defynog. There were ten miles of railways on the Cribarth Mountain above Craig-Nos, which brought limestone and rottenstone down to the canal wharfs at Abercraf.

Among the more important industrialists who worked in canal-side industries was David Thomas. He was born in 1794 and became furnace manager at Ynyscedwyn Ironworks in the 1830’s. In 1837 he invented the hot-blast method of smelting iron ore using anthracite coal. That invention led to the expansion of the iron works in the upper Swansea Valley with Ystalyfera Ironworks claiming to be the largest ironworks in the world by 1858 and having the largest continual line of blast furnaces in Wales; eleven of them. David Thomas was poached by iron manufacturers in Pennsylvania in 1837, and went on to become the Chairman of the American Ironmasters Association; they nicknamed him David “Papa” Thomas, the father of the American anthracite iron industry.

Such was the Swansea Canal, an important waterway, innovative architectural developments, the catalyst for urban development, and world famous for its water usage.


Clive Reed BA (hons) Dip Loc Hist