On a modern street map the route of the tramway followed Gooyong Street, Rose Street, Throsby Drive (Tramway Bridge) and then between Campbell Street and Smith Street (including the Illawarra Master Builders Club carpark) to Osborne Park and Belmore Basin. The route can still be traced on a modern aerial or satellite photograph. In 1937 Australian Iron and Steel (later a subsidiary of BHP and then BHP Billiton) acquired the colliery for its Port Kembla steelworks. In 1942 a diesel locomotive was introduced at the mine, the first underground diesel locomotive in Australia.