In 1849 the GWR manufactured the “Corsair” and “Brigand” saddle tank locomotives for passenger services on the steep and winding South Devon Railway in their own workshops in Swindon. Since the bogie could not be moved sideways, the first coupled axle was not given wheel flanges. The “Corsair” still had a sledge brake, the “Brigand” received a shoe brake on one wheel.
As the operation of the South Devon Railway was finally handed over from the GWR to a specially founded company, the two locomotives were used on other lines. A further 13 locomotives were ordered, but the production of these was handed over to Hawthorns'. In these, the diameter of the driving wheels had been reduced by three inches.