A branch off of a branch! 20118 & 20169 pass the junction for the short lived private siding to the BP oil terminal at Rhosgoch on the Isle of Anglesey on 11 September 1993. They are working the Pathfinder Tours 1Z18 'Anglesey Odyssey' railtour, at this point running as the 14:32 Amlwch to Cardiff Central. This long winding branch line from Gaerwen Junction to Amlwch was closing due to Associated Octel's decision to transfer the sole remaining freight traffic to road haulage. The line has remaining intact but increasingly overgrown ever since.