Based on a Fordson tractor, the Muir Hill had three speeds in forward but only one in reverse. Trials were conducted in early May. It performed about as well as could have been reasonably expected, being barely able to pull 'an ordinary guards van' from Beddgelert to South Snowdon (Rhyd Ddu). Later in May it was tried to power the machinery at Boston Lodge. In a further trial it ran very well from Blaenau Ffestiniog to South Snowdon with a small van but could only return to Beddgelert at 2¼ mph because of its inadequate reverse gearing. These poor results were reported to the Board in June and the unit returned to Dolgarrog in August 1924.