An unusual feature of freight operation on the line was the carriage of  gauge slate wagons (provided by the GWR) on standard gauge transporter wagons between  and Blaenau Ffestiniog where the wagons were off-loaded in the large station yard and their loads of dressed slate transferred to standard gauge GWR wagons for carriage back the way they had come then on via Manod and Bala.
Freight operations on the line featured a unique characteristic: gauge slate wagons (owned by GWR) were transported on standard gauge transporter wagons between and Blaenau Ffestiniog. The slate was unloaded at the large station yard, and then transferred to standard gauge GWR wagons for return travel.