Transnet Freight Rail (TFR), in conjunction with various stakeholders, intends to increase the throughput of manganese exports to 16-million tons a year on the Hotazel–Port Elizabeth railway line.
This expansion coincides with the develop- ment of a new manganese terminal at the Port of Ngqura, near Port Elizabeth. The railway line is classified as a general freight corridor and is known for its fairly challenging en-route topography.
To achieve a throughput of 16-million tons a year on a predominantly single line necessitated a review of the existing train operating method and, with the advances in train- handling technology, the logical step was to increase train lengths to the maximum safe ‘envelope’.
TFR’s Technology Management Train Design department conducted the first in-service test to investigate the possibility of increasing the current 104-wagon, head-end train to a 208-wagon (two sets of 104 wagons) radio distributed power (RDP) train, with eight locomotives placed throughout the train.
Optimal locomotive distribution was based on initial simulations, with four locomotives in the front, three in the middle and one at the rear. The distribution of power throughout the train not only improves train handling through severe terrain but also facilitates lower in-train forces and reduced brake, charging and stopping distances.
The ability to run the same number of trains daily and consistently, with a longer train, increases the volume per train from 6 552 t to 13 104 t, resulting in a more operationally cost-effective solution.
The objective of the test train was to evaluate the RDP technology for long trains in this general freight corridor, to determine the appropriate train-handling techniques for various terrain profiles and to develop a train-handling guideline. The test team benefited from the lesson learnt with the development and commissioning of the 342-wagon RDP train on the iron-ore line between Sishen and Saldanha.
In-service testing was divided into static and dynamic tests. During the static tests, brake propagation and recharging times were measured at the Mamathwane yard, at the Tshipi Borwa private siding. During the dynamic tests, in-train forces and brake- system characteristics were monitored and measured to compare with simulated results. In addition, radio receptivity, specifically in tunnels, was monitored and measured during the course of the test train’s journey to determine the appropriate positions of the radio signal repeaters.
The static test was conducted on September 11 and 12 and the dynamic test was con- ducted from September 13, from Hotazel to Port Elizabeth.
The train arrived safely at Swartkops, in Port Elizabeth, at about 03:00 on September 15. The initial results of the RDP system were positive and the in-train dynamics were within acceptable limits.
The test train that introduced the RDP technology into TFR’s general freight heralds a new era for rail modernisation in South Africa.
To subscribe to Mining Weekly’s print magazine email firstname.lastname@example.org or buy now.