Locomotives, wagons and bogies supplier DCD Rolling Stock, a member of international manufacturing and engineering company DCD Group, has sold 33 discharge hopper wagons to platinum mining operations in South Africa over the last five years, says DCD Rolling Stock supply chain manager Phillip van der Westhuizen.

The company’s side-discharge hopper wagons are used to transport and offload ore from mine shafts to processing plants.

Van der Westhuizen explains that, over the last decade, DCD Rolling Stock has worked closely with platinum mine engineers to adjust the design of certain discharge hopper wagons, adapting their mechanical and safety requirements.

DCD’s latest discharge hopper wagons are designed to respond to the South African platinum belt needs, while being adaptable for other international operations . They feature a unique safety mechanism on the side discharge doors that prevents the doors from accidentally opening in transit and causing spillage, which improves mine safety, adds DCD Rolling Stock technical manager Daryl Leggitt.

The unique mechanism, which DCD calls a ‘central shaft over top dead centre locking device’, comprises three offset levers connected to the doors, with three links per door.

The levers have two end stops to ensure that they rotate over the centre position, preventing the doors from opening accidentally. 

The company tells Mining Weekly that the wagons, which are developed and manufactured at the DCD Rolling Stock site in Boksburg, Johannesburg, have the majority market share for this type of wagon in South Africa.

The wagons are designed according to State-owned freight logistics group Transnet and the Association of American Railroads' specifications, and to suit customer requirements.

Each wagon has a 60 t capacity and a volume of 31 m³, with dimensions of 9.532 m × 2.518 m × 3.165 m, which can be customised to customers' needs. 

DCD Rolling Stock GM Petrus Mulaudzi notes that the side-discharge hopper wagons have created many opportunities for the company, which plans to introduce the product to other markets and countries in the near future.

Van der Westhuizen says DCD’s primary customers are mining houses, which currently have to deal with challenges associated with an industry-wide downturn. However, the company remains optimistic that the industry will recover.

Meanwhile, DCD Rolling Stock has developed an ergonomic, cost-effective solution for bogie steering – the patented Jika passive hydraulic steering (PHS) system – which serves as an alternative to the current mechanical linkage system for locomotives.

The system reduces wheel and track wear by 80% and the energy consumption of a locomotive by 3%. It is also set to significantly reduce operating and maintenance costs for rail, as well as track maintenance operators.

DCD Rolling Stock product engineer and Jika PHS inventor Pat Smit says the Jika PHS is a technological breakthrough in hydraulics.

One significant benefit of the Jika PHS is that it can reduce flange wear eightfold, says Smit.

The system is undergoing full rail-service trials.

DCD expects that the trials, which are being conducted by the company, will be concluded by year end, with commercial sales of the Jika PHS planned for 2015.