The Historic Tennant Canal

Close to 200 years Neath and Swansea have been linked by the Tennant Canal from Aberdulais to Port Tennant.

The Canal was the brainchild of George Tennant 1765 - 1832.
George Tennant 1765 – 1832

The Historic Tennant Canal – Site of Importance for Nature Conservation (SINC 226). The Tennant Canal is 8 miles in length from Port Tennant, Swansea to its junction with the Neath Canal at Aberdulais.

For close to 200 years Neath and Swansea have been linked by the Tennant Canal from Aberdulais to Port Tennant. (originally called the Neath and Swansea Junction Canal, but by 1845 it had become known as the Tennant Canal.) The Canal was the brainchild of George Tennant. He emerged into the South Wales industrial scene and embarked on his project to build a canal that would carry the mineral wealth of goods of the Neath Valleys to the docks at Swansea.

The Tenant Canal at Neath Abbey 1860/2013.
The Tenant Canal at Neath Abbey 1860/2013

Construction of the canal began on 8th October 1817 under the direction of the engineer William Kirkhouse, and the canal was completed by autumn 1818 running from near the east pier on the River Tawe at Swansea to the River Neath at (Trowmans Hole) known as Red Jacket Pill – The site is called Red Jacket because it was the site of a copper works making casings for armaments. Part of an existing, but disused Glan-y-Wern canal was also included in the scheme. ‘Records show that on the first day of construction in 1817, the 67 workmen jointly consumed 61lb of bread, 30lb of cheese, and a barrel of ale.

The Neath River lock at Red Jacket Pill.
Left – The river lock at Red Jacket Pill (Trowmans Hole) had a chequered history. Once the line to Aberdulais basin had been opened, it was barely used, and Tennant thought about removing it in 1832. However, it was back in use sometime later and was unused again in the 1880s, only to be rebuilt in 1898 / Right – Tennant Canal Sea Lock at Port Tennant, Swansea Docks 1890.

Tennant believed that Swansea docks would provide a better shipping point than Neath or Giant’s Grave so in 1820 Tennant embarked on a more ambitious project. He planned to extend his canal from a junction near Red Jacket Pill, through Neath, and up to Aberdulais where the River Neath will need to be crossed so the new canal could be joined with the existing Neath canal. He sought support from local landowners, including Lord Jersey, Lord Dynevor, and the Duke of Beaufort, but none was forthcoming. So he decided to build it as a private canal, without an Act of Parliament, and work started in 1821 again under engineer William Kirkhouse. It would become the longest private canal in the UK.

Scheduled Monument - The South end of Skewen Cuttings and tramroad bridge in distance.
Engineering problems were experienced in Skewen – Scheduled Monument – The South end of Skewen Cuttings and tramroad bridge in distance. Source: Ancient Monuments. Skewen cuttings with low water pressure due to a damaged supply Weir at Aberdulais. The Canal structures supporting its banks are now collapsing.

William Kirkhouse: Engineering problems were experienced in Skewen/Neath Abbey, where a 500-yard (460 m) cutting was required through what appeared to be quicksand. Eventually, an inverted masonry arch had to be built to contain the canal and stop the sand from collapsing. George Tennant wrote in 1824 of a quicksand ‘of the finest grain and most subtle nature – and so deep that no tool which could be introduced was long enough to reach the bottom’.

It ran from the east pier on the River Tawe at Swansea to Aberdulais Basin where it met the Neath Canal. The water was 5 feet (1.5 m) deep between Red Jacket and Aberdulais, and 7 feet (2.1 m) deep from Red Jacket to Swansea harbour. At the Swansea end, Tennant built a sea-lock, so that boats could enter Fabian Bay, and named the area Port Tennant.

The Aberdulais Aqueduct remains seriously damaged. 2020
Pictured: 2021 – The Aberdulais Aqueduct still remains seriously damaged, completed in 1824 to join the Neath and Tennant Canals, is a Grade 11* listed building and Ancient Monument. British Listed Buildings.

Just before reaching Aberdulais Basin the canal had to cross the River Neath, which it did via the still spectacular Aberdulais Aqueduct. The aqueduct itself was 340ft long with ten arches together with an additional single-span cast-iron trough over the Aberdulais cut navigation. (ref: Neath Canal history) The total length of the lock-free canal between Swansea to Aberdulais opened on 13 May 1824, was 8.5 miles (13.7 km), it had cost around £20,000, which did not include the price of the land or of the harbour at Port Tennant.

The first barges laden with coal from Protheroe’s collieries in the vale of Neath crossed the Aqueduct and slowly made its way to Swansea accompanied by a brass band, pleasure boats, and thousands of spectators. Final completion meant that a route to Swansea was made available that did not utilise the river Neath in any part of its line. The Cambrian newspaper reported: ‘ We yesterday witnessed with great satisfaction, in which we were heartily joined by some thousands of spectators, the opening of Mr. Tennant’s Junction Canal’ and the paper later reported that in its first seven weeks of use, 376 barges carrying 5930 tons of coal and timber had used the canal plus “no inconsiderable number of passengers have also been bourne upon it, and the inhabitants of Neath and vicinity are allowed to navigate it with their families, servants, shop goods and parcels all free of charge”.

The canals faced competition from the Vale of Neath Railway after 1851, but the Tennant remained profitable until the 1890s. An unusual aspect of the Tennant’s success was that tolls were maintained, although tonnage dropped. Most canals at this time made significant cuts to tolls in an attempt to remain competitive with the railways. The Neath Canal had virtually ceased by 1921. Navigation on the Neath Canal came to an end in 1934, and on the Tennant Canal soon afterward.

It was then used as a water source for new local industries like the BP Oil Refinery at Llandarcy and BP Chemicals at Baglan. (both closed by 2004.) Since 2013, Port Tennant Company has had an agreement to supply significant quantities of water from the canal to industry at Baglan Bay. This was done using large pumps near Jersey Marine but on 24th March 2021, the company closed. Baglan group of companies liquidated.

Tennant Canal Pump house near Jersey Marine.
Large pumps were in operation on the Tennant Canal near Jersey Marine but on May 6 2021 they were switched off, ending the Canal’s last source of funding.

The canal remains in the ownership of the Tennant Family.

More on the History.

The Tennant Family – A Scratch in Glamorganshire by Keith Tucker 1998
Neath and Tennant Canal – Wikipedia
Neath Times – Facebook Page
Swansea Council – Tennant Canal

BBC News – YouTube.