From the wharves at Porthmadog harbor the line curved through the town and ran alongside the Y Cyt canal to Tremadog.

At Henefail the line turned north past Ynys-y-Pandy and on to Gorseddau where a short incline lead into the quarry.

[3] The line was horse operated using wagons and a passenger carriage supplied by the Boston Lodge works of the Ffestiniog Railway.

This 2 ft (610 mm) narrow gauge tramway crossed the Gorseddau on the level on the edge of Porthmadog and served the same wharves.

This would allow common rolling stock to be used between the Croesor and Gorseddau tramways and the Ffestiniog railway, all of which delivered slate to Porthmadog harbour.