The double track Durban - Johannesburg main line crosses the Drakensberg mountains from kwaZulu-Natal into Mpumalanga province by way of the Majuba pass, over a distance of 37 km (23 miles). The ruling gradient is 1 in 66 (1.5%) with 800 metre (875 yard) minimum radius curves, three twin-bore tunnels and six bridges. At the bottom of the climb up the pass, this loaded 35-wagon motor car train from Durban is crossing an unnamed tributary of the Harte River with three clean 18E's up front. The wagons are type CML, rebuilt from container flats with steel mesh sides and flat rooves.