Madocks had always had a regional plan in his mind, which involved improving communications and creating industry.
At Blaenau Ffestiniog the quarrying and mining of slates was hampered by the difficulties of getting them to market.
He had once tried to develop a port at Ynys Cyngar, some 2 miles (3.2 km) from his embankment, now known as The Cob, but the effects of diverting the Glaslyn through its exit sluice were such that it had scoured out a conveniently deep channel by Ynys Tywyn, the island at the western end of the Cob.
He had already built a canal from there to Tremadog, and the Ynys Tywyn location was now better suited for a harbour than Ynys Cyngar.
He realised that a railway from Blaenau Ffestiniog could transport slates directly from the quarries to ships in the harbour, and set about obtaining Acts of Parliament to sanction both, but there was some local opposition to the schemes.

A route for the railway was surveyed in 1821 by George Overton, and another by William Provis in 1824, but neither was approved by Parliament.
Nor did a second scheme by Provis in 1825.
However, the harbour was authorised, and could be used by vessels up to 60 tons by late 1824.
Williams was by this time the Director of Works for the newly named Port Madoc Harbour, and took on responsibility for the railway plans, as Madocks was suffering from jaundice.
A rival scheme, backed by the banker Meyer Rothschild, was proposed to run down the Croesor Valley on the other side of the Moelwyn mountains, but included inclines over the hills to reach Blaenau Ffestiniog.
The line proposed by Provis was rejected in Parliament, in favour of Rothschild's route, but then local landowners became suspicious of the rival scheme, and it too was defeated.
Madocks had always had a regional plan in his mind, which involved improving communications and creating industry. At Blaenau Ffestiniog the quarrying and mining of slates was hampered by the difficulties of getting them to market. He had once tried to develop a port at Ynys Cyngar, some 2 miles (3.2 km) from his embankment, now known as The Cob, but the effects of diverting the Glaslyn through its exit sluice were such that it had scoured out a conveniently deep channel by Ynys Tywyn, the island at the western end of the Cob. He had already built a canal from there to Tremadog, and the Ynys Tywyn location was now better suited for a harbour than Ynys Cyngar. He realised that a railway from Blaenau Ffestiniog could transport slates directly from the quarries to ships in the harbour, and set about obtaining Acts of Parliament to sanction both, but there was some local opposition to the schemes.
A route for the railway was surveyed in 1821 by George Overton, and another by William Provis in 1824, but neither was approved by Parliament. Nor did a second scheme by Provis in 1825. However, the harbour was authorised, and could be used by vessels up to 60 tons by late 1824. Williams was by this time the Director of Works for the newly named Port Madoc Harbour, and took on responsibility for the railway plans, as Madocks was suffering from jaundice. A rival scheme, backed by the banker Meyer Rothschild, was proposed to run down the Croesor Valley on the other side of the Moelwyn mountains, but included inclines over the hills to reach Blaenau Ffestiniog. The line proposed by Provis was rejected in Parliament, in favour of Rothschild's route, but then local landowners became suspicious of the rival scheme, and it too was defeated.
William Madocks