North of Mbalabala the line drops steeply to a bridge over the Mzingwane River before climbing to a summit south of Esigodini. The section of the climb up the Mulangwane Gorge was steep, scenic and, most importantly, accessible, making it an obvious place to intercept the morning procession of northbound freights.
611 was working hard as it climbed to Mulangwane siding with the 06:30 Colleen Bawn - Mpopoma freight, train 318, on 27 June 1987.