The extension was built without an act of Parliament and there was a long delay while Tennant attempted to resolve a dispute with a landowner over the routing of the canal.

Among those attending was Lord Vernon, who had already built a short canal near Giant's Grave to connect the River Neath to furnaces at Penrhiwtyn.

Dadford costed the project at £25,716, but in early 1791 Lord Vernon's agent, Lewis Thomas, proposed two new cuts, and the idea of using the river was dropped soon afterwards.

3. c. 85), passed on 6 June 1791, which created The Company and Proprietors of the Neath Canal Navigation, who had powers to raise £25,000 by the issue of shares, and an additional £10,000 if necessary.

[2] The canal was to run from Glynneath (called Abernant at the time), which was not as far up the valley as Pontneddfechan, to Melincryddan Pill at Neath, where it would join the river.

3. c. xxx) was passed on 26 May 1798,[2] to authorise an extension of about 2.5 miles (4.0 km) to Giant's Grave, where better facilities for transferring goods to seagoing vessels were available.

The Fox family, who were based at Neath Abbey, but who were scouring ironstone further up the valley, agreed to construct a new feeder in 1807 to mitigate the problem.

Based on the receipts, it has been estimated that some 200,000 tons of coal were carried when trade was at its peak, supplemented by iron, ironstone and fire clay.

[10] Facilities at Giant's Grave improved, and included jetties to enable ships' ballast to be landed and dumped, rather than being thrown overboard.

From 1824, when the connection to the Tennant Canal opened, much of the trade crossed the river and passed down the western bank to the port of Swansea.

[15] Crymlyn Bog is now one of NRW's Lifequake Projects, and the Glan-y-wern Canal is scheduled to be cleared of overgrowth to improve drainage.

https://naturalresourceswales.gov.uk/about-us/news-blog-and-statements/news/lifequake-project-launch/?lang=en George Tennant, born in 1765 and the son of a solicitor in Lancashire, moved to the area in 1816, after he had bought the Rhydings estate.

He planned to make it suitable for barges of 30 to 35 long tons (30 to 36 t), which would gain access to the river Neath through a lock at Red Jacket.

Where the canal turned northwards across Crymlyn Bog, he would extend it to the west, to terminate at a lock into the River Tawe, near Swansea harbour.

He believed that Swansea docks would provide a better shipping point than Neath or Giant's Grave, and hoped that the canal would encourage the development of the corridor through which it ran.

The lack of an act of Parliament to authorise the canal proved to be a problem in April 1821, when L. W. Dillwyn refused permission for Tennant to cut through his land to pass under the Swansea road.

Dillwyn, who was a Neath Canal shareholder, was sent a conciliatory letter and eventually agreed to negotiate with Tennant, whom he described as "that terrible plague Mr.

The total length of the canal, when it was opened on 13 May 1824, was 8.5 miles (13.7 km), and it had cost around £20,000, which did not include the price of the land or of the harbour at Port Tennant.

A new branch of the canal was built in 1909, which included a lock into the newly constructed Kings Dock, where a lay-by berth was provided on its north side.

Establishment of industries at Port Tennant, which included Charles Lambert's copperworks in the 1850s and a patent fuel works in the 1860s, resulted in increased traffic of coal, from both Glan-y-wern and Tir-isaf collieries.

[26] The part which covered the final section of the canal is no longer a road, although the dual carriageway runs over the site of the Glynneath basin.

[32] This extended the navigable section north-east past Aberdulais basin to Lock Machin, a stretch of 3 miles (5 km).

[32][37] A new car park and slipway were provided from the B4242, and the Clun locks were renovated, to give 6 miles (9.7 km) of navigable canal from central Neath to Abergarwen.

Extension to the south is blocked by a bridge at water level in Neath, but in 2009 Neath Port Talbot Council commissioned the Prince's Foundation and British Petroleum to investigate options for the regeneration of the Canal Green area, between the river and the railway line, and the proposals suggested that it should be replaced by a lifting or bascule bridge.

The management company then negotiated with Natural Resources Wales for permission to pump water from the Riven Nedd into the canal to maintain the contracted supply to the Baglan Energy Plant.

A number of concerned local residents are trying to get the management company and Natural Resources Wales to take action to remedy the problem before the whole of the canal is seriously damaged.

[34] A feasibility study in 2008 for Neath Port Talbot Council, Swansea Council and the Welsh Assembly Government looked at various options for the top end, including terminating the canal near the Lamb and Flag public house, south of the final two locks, where there is room for a modest terminus at Chapel Fields.

[43] At Swansea, the Tennant Canal could be relinked to the Prince of Wales Dock, and hence to the River Tawe, which has become a large marina since the construction of a tidal barrage.

[46] A report for Natural Resources Wales by Trilein Ltd. recommended a range of initiatives to better connect the urban areas of the city to the more rural east of the county, including Crymlyn Bog.

[47] The opening of the Tennant Canal in 1824 inspired Elizabeth Davies, who owned a lollipop-shop in Neath, to write a 19-verse poem, which was published by Filmer Fagg of Swansea.