Following the 1900 sale of Cwmorthin, it was taken over by Oakeley Quarry, working the same slate veins but from the other side of the Allt-fawr ridge. They began working the quarry through the mountain, and so there were no Cwmorthin men available to operate the inclines. In order to reduce the number of trips across the mountain to operate the tramway, they tried to insist that Conglog must run trains of 10 wagons or more, but this was not easy to achieve, and eventually a compromise was reached, whereby Cadwaladr Roberts, one of the consortium of men working the Conglog Quarry, could operate the inclines himself, at his own risk.