The line originally began as a coal railway, built by the Berrima Coal Mining and Railway Company in 1881. That company opened a coal mine in the gorge of the Wingecarribee River, about 6 miles (9.65 km) west of Moss Vale and built a standard gauge line to a point above the gorge. It joined the Main Southern Railway at a point 1.5 miles north of Moss Vale, then known as Austermere and later as Bong Bong. The railway crossed the Great Southern Road, later Hume Highway, on the level. At the colliery end, coal was brought up an incline from the mine which laid across the Wingecarribee River.