SA’s fourth-largest chrome exporter Tharisa has had to rely heavily on road transport to move bulk commodity because of constraints caused by the state-owned railway operator Transnet Freight Rail.

Tharisa normally sends 70% of its 1.5-million tonnes of annual chrome exports by rail with the balance moved on road. In the March quarter, however, this split was evenly divided because of weather-induced constraints on the railway line from Tharisa’s opencast mine near Brits to the bulk harbour at Richards Bay...