According to South African rail, port and pipeline company Transnet, increasing rail capacity in South Africa is critical for unlocking coal export opportunities for neighbouring African countries and the domestic market.

The rail utility discussed its approach to increasing rail capacity earlier this year at the twelfth annual South African coal export conference, which was organised by London-based information and analysis company IHS Markit. The Cape Town-based conference provided the necessary platform for Transnet executive Brian Monakali and Transnet Freight Rail (TFR) civil engineer Lindiwe Mathebula to explain the company’s approach to facilitating coal transportation on heavy-haul lines.

The pair reported that TFR transports 14% of South Africa’s yearly freight tonnage and owns and maintains a network of about 22 000 km, which is connected to South African ports and rail networks in neighbouring countries. TFR operates 4 500 trains a week on the integrated train plan and, in total, transports about five-million tons a week, having moved a total of 214.5-million tons in the 2015/16 financial year.

TFR’s coal export line spans 978 km. This route includes the Waterberg coal line from Lephalale, in Limpopo, to the Mpumalanga mining town of Ogies, which accounts for 438 km; the coal ‘backbone’ from Ogies to Ermelo, in Mpumalanga, which comprises 210 km; and the rest of the export line from Ermelo to the KwaZulu-Natal town of Richards Bay, which adds a further 420 km to the total length.

Monakali and Mathebula explain that, to increase volumes and create additional capacity, TFR needs more trains that are heavier. It also needs to reduce throughput times, create a dedicated rail corridor and run longer trains closer to the source of coal. Implementing supporting technologies that incorporate standardisation, an integrated system approach and operational planning are also necessary to increase rail capacity, in addition to introducing strategic loading locations.

Meanwhile, to relieve pressure on the Ermelo–Richards Bay line, TFR is considering the proposed SwaziLink Project, which will divert general freight away from the key coal export line. The project will comprise a rail line between Lothair, in Mpumalanga, and Sidvokodvo, in Swaziland.

In terms of implementing new technologies, Monakali and Mathebula explained that TFR was looking to deploy 22 electric dual-voltage locomotives that can run on both alternating current and direct current sections.

The rail utility is also looking into using electronically controlled pneumatic braking, which allows for better train control and shorter stopping distances, owing to air-powered brakes on the wagons. This means brakes are applied uniformly as they receive a brake command simultaneously.

The pair also explained that the use of wire-distributed power allows for train drivers to effectively manage high coupler forces for heavy trains on steep grades. On-the-fly changeover facilities will eliminate the need for lengthy yard dwell times, while condition assessment systems will detect faults on the rail line.

Beyond South Africa
Owing to ageing and depleted coal mines in Mpumalanga, Limpopo’s Waterberg region has been earmarked as an important coal destination for South Africa.

TFR completed Stage 1 of its coal line expansion – between Waterberg and Richards Bay in 2016. This involved the construction of a 1.8-km-long passing loop at Matlabas, enabling 100-wagon trains to cross without disrupting the operation of other trains on the line.

Stage 2 of the coal line expansion is currently under way and involves running three 100-wagon trains a day. Once completed, Stage 2 will increase the Waterberg’s railing capacity from two-million tons a year to six-million tons a year. This phase will be completed by mid-2018.

According to Monakali and Mathebula, the company will look to create capacity beyond South Africa and into Botswana, unlocking the Southern African nation’s abundant coal reserves. This will create the potential for the export of up to 100-million additional tons a year and would require the construction of a 4 km bridge for the rail to cross the Limpopo river.

The pair noted that this project is expected to stimulate economic growth in both Botswana and South Africa, provide a route to unblock Botswana’s coal reserves, and will link Botswana’s mines to the TFR rail network.