In August 1788 a lease was granted to Edward Elton to construct a canal some 3.5 miles long from his colliery at Glan-y-wern of to Trowman’s Hole (Red Jacket Pill) on the River Neath, virtually opposite to Giant’s Grave. The canal was completed in May 1790. There was no physical connection with the river, cargoes having to be transhipped to river barges lying in the tidal pill. Elton eventually became bankrupt and died c.1810, following which the Glan-y-wern Canal became disused.
In 1817 George Tennant (1765 – 1832), a son of a Lancashire solicitor purchased the Rhyddings Estate and colliery. Having constructed a canal (Rhyddings Canal) and an incline plane from the colliery to a wharf on the River Neath, he took an interest in the Glan-y-wern and Red Jacket Canals. He proposed to lease the former, clean, widen and deepen it to take river barges of 30-35 tons, and to build a river lock at Red Jacket. His intention also was to extend the Glan-y-wern Canal to enter the River Tawe in Swansea harbour by way of a river lock and thus to join the two rivers to provide improved facilities for industries in the Neath valley and the estuary.
Tennant approached the big local landowners but got no financial support and decided to go ahead on his own. Work began in 1817 with William Kirkhouse as his engineer and by the autumn of 1818 the new canal was completed. It was now 4 miles long between the two rivers, with a branch 1.4 miles long to Glan-y-wern. Barges of 50 to 60 tons coming down the River Neath could now enter the canal via the river lock at Red Jacket and continue to Swansea.
Traffic transferring to the canal, however, was small and to increase trade Tennant approached the Neath Canal Company to complete its obligation to build a lock from its canal at Giants Grave into the River Neath, as provided for in the Neath Canal Act of 1798. The building of the lock would then allow the transfer of barges from the Neath Canal across the tidal river to George Tennant’s canal. During his efforts to get the lock sanctioned, Tennant realised that to extend his new canal from Red Jacket Pill up to Aberdulais and to make a direct connection with the Neath Canal was a better option.
In 1821 work began on the canal extension under the direction of William Kirkhouse. George Tennant had sought to raise the finance to build his canal from local sources, landowners and businessmen, but decided he would have better control of his interests by providing the finance himself and to proceed without an Act of Parliament.
Considerable difficulties were experienced when quick-sand was encountered during building the canal through the 500 yard cutting at Neath Abbey. To prevent the canal banks slipping into the cut, Kirkhouse constructed an inverted arch along the length of the cutting.
By April 1821 canal construction was approaching Cadoxton when progress was halted by a protracted dispute regarding the purchase of land from the Dillwyn Family. It took almost two years, after prolonged bitter argument and negotiation, before consent was given to proceed and agreement made, much to the advantage of the Neath Canal Company and disadvantage to George Tenant.
The canal was finally completed in May 1824 with the opening of the Aberdulais Aqueduct, which by way of the Aberdulais Basin formed a junction with the Neath Canal. Lock free for 8½ miles from Swansea to Aberdulais, it was necessary to construct a lock ahead of the aqueduct to raise the water level to that of the Neath Canal. 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)
Initially called the Neath and Swansea Junction Canal, it later came to be referred to as the Tennant Canal. It had 6 short branches : –
- Dulais branch to the forge and rolling mill on the River Dulais – now the National Trust,
- Aberdulais Falls complex,
- Vale of Neath Brewery branch (Cadoxton),
- Neath branch (opposite town quay) with a river lock,
- Neath Abbey Iron Works branch,
- Neath River branch (Crown Works) with a river lock
- Tir-isaf Colliery branch (Port Tennant) – ran parallel to the Glan-y-wern Canal
Whilst the Tennant Canal originally terminated on communal wharfs inside the eastern breakwater of the river Tawe, an opportunity arose to purchase disused adjoining land which was developed into a tidal harbour. Designed and constructed by Kirkhouse for George Tennant it was opened c.1824 and became known as Port Tennant.
With the demand for additional docking facilities at Swansea, work began in 1879 to create the Prince of Wales Dock – incorporating much of the site of ‘Tennant’s port’. Completed in 1881, the dock provided access from the canal together with its own dedicated wharfs. A subsequent extension of the Prince of Wales Dock resulted in the canal terminus being further relocated to the recently opened King’ Dock (c.1909) with a provision of a lock into the port.
Given that most of the traffic on the Neath Canal was diverted into the Tennant Canal at Aberdulais , the commercial history and decline of the latter reflects that of the former, the navigation having been disused from mid 1930s. The canal has since been retained as a source of water to industries at Baglan Bay.
The canal remains in the ownership of the Coombe-Tennant Family.
- The Canals of South Wales and The Border, Charles Hadfield, University of Wales Press
- Canals of the Welsh Valleys and their Tramroads, DD & JM Gladwin, The Oakwood Press