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DCD Rolling Stock has revolutionised international railway logistics by increasing the lifespan of the average locomotive wheel by three times while reducing track wear by 60% and energy consumption by 3% through the development of its patented Jika passive hydraulic steering (PHS) system for locomotives. The company’s latest technological breakthrough in hydraulics is a more efficient, reliable and cost-effective alternative to the current mechanical linkage system for locomotives. The reduction of locomotive force also reduces the lateral movement of the rails on their sleepers that results in the rail spreading apart. Jika inventor, Pat Smit, says that the PHS also reduces the angle of attack between wheel and rail.

“It is also beneficial for traction and braking, but most importantly the system reduces the rolling resistance of locomotives when negotiating curves, reducing energy consumption by 3%,” he says, pointing out that by using a hydraulic system, the traditional links and levers can be dispensed with. “This reduces the number of components in a bogie, making the steering sub-system easier to maintain. Another issue that the Jika PHS overcomes is the lack of space within, and distance between the wheel sets of a bogie. This is particularly relevant in the case of three-axle bogies, where there is a central wheel set with its traction motor and braking system.”

The Jika has been specifically designed for commercial freight lines, where frequent and small radius curves are common. The replacement of train wheels is a regular and expensive process as it involves infrastructural costs, locomotive downtime and manhours. The Jika will also permit the use of more powerful three-axle bogie locomotives, as opposed to the less powerful two-axle bogie models. This system is equally important to heavy haul lines with axle loads of up to 30 tons. Another major benefit is that it can reduce flange wear eight fold. “This design benefit will ultimately extend the lifespan of the average locomotive wheel by three times,” he adds.

Proven performance in testing

DCD Rolling Stock is currently in discussions with various rail operators worldwide to undertake in-service testing in other environments to validate its initial data. Using instrumented wheel sets that measure and record the force that locomotives impart on the railway line, DCD Rolling Stock engineers discovered that the Jika reduced lateral forces by a factor of five in curves on these long wheelbase bogies. “During one test, official data revealed that a four ton existing lateral force on the rail was reduced to just 800 kg,” claims Smit. Following these successful tests, the Jika bogie was retrofitted onto bogies on three locomotives in August 2013, and will operate in full service. It will be compared against six similar locomotives fitted with conventional bogies for a six month trial period, starting in September 2013.

DCD Rolling Stock technical manager, Daryl Leggitt says that this is the first time that hydraulics have been applied to locomotive bogies in South Africa. “Three locomotives have been fitted with Jika. The first two have already done over 11 round trips of approximately 11 000 km, in addition to three round trips of 3000 km respectively. The trips were all fault-free.”

Smit believes that by adopting the Jika PHS system, customers will be able to save on the cost of replacement parts, in addition to minimising locomotive downtime. Legitt also reveals that the company has been working in conjunction with a leading university to design a hydraulic cylinder unit that is capable of six years of maintenance free operation. “The hydraulic cylinder will also feature a rugged design, as it will be exposed to numerous hazards such as high acceleration, possible pressure spicks, heat, vibration and flying stones from the track.”

DCD Rolling Stock officially filed international patents in May 2013 and Smit is confident that the Jika PHS will be a game changer in the local and international railway sector. “Adaptability is the key to DCD Rolling Stock’s innovation, and the development of the Jika PHS bogie is a technological breakthrough that will make railway logistics more efficient and competitive on a global scale. I am optimistic that DCD Rolling Stock has unlimited potential for growth through this new system,” he concludes.

For more information contact Phillip van der Westhuizen, DCD Rolling Stock, +27 (0)11 306 8311,

Posted in: DCD Rail
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