At this time the planned construction of the line was to extend to Sorbie, as the available share subscriptions would only reach that far. However Sorbie was a poor location for a terminal, and thoughts turned to reaching Garliestown, another two miles (3 km) further. Certain directors agreed to subscribe further funds, amounting to £7,000 and the work was quickly put in hand. The line was opened throughout from Newton Stewart to a Garliestown station on 2 August 1875. Wheatley procured a second engine, no. 2, an 0-4-2 pannier tank, formerly an 0-4-2 tender engine, no. 146 of the NBR.