Rheneas' twin was built in 1866 by the Fletcher, Jennings and Company with a different deisgn and style to Talyllyn. The 0-4-0 tank engine had a back tank (behind his cab) and a well tank (between the frames). A long wheelbase allows his firebox to sit in front of the rear axle with the Fletcher's Patent inside valve gear driven off the front axle. This was an arrangement particularly inaccessible to move. In a bad condition of increasing decrepit, Dolgoch continues to operate the service single-handedly until 1952 when Edward Thomas, the twin of Peter Sam came to be available and Dologch was due for an overhaul between 1954 and 1963.
He doesn't speak in Very Old Engines with Talyllyn pulling his train on the final page of that book and is mentioned in Gallant Old Engine that he like Rheneas had saved the Talyllyn Railway (and Skarloey Railway) from closure by the British Ministry of Transport under its secretary of state, Ernest Maples and British Prime Minister, Harold MacMillan decided not to do it because Dolgoch saved the railway from closing down for goodness to dieselisation across the Other Railway in the early 1960s.