Beyer Garratt number 143 departs Porthmadog Harbour Station after crossing the Britannia Bridge. The route north from here takes the train through Porthmadog's industrial zone before crossing the National Rail diamond. The Welsh Highland Heritage Railway (There are two Welsh Highland Railways, but that's another story too long to go into here.) trackage parallels the Garratt's route for a short distance after the diamond before ending at Gelert's Farm where their museum is located. The Garratt will continue across the flat plain of the Aberglaslyn River heading for a passing loop at Pont Croesor.