Jika PHS was invented by Mr Pat Smit, product engineer with DCD Rolling Stock, South Africa. The system is designed to replace the traditional links and levers in a bogie with a hydraulic system, for which patents have been applied for in several countries."Mechanical linkage systems in locomotives have proven to be inefficient, as a large amount of time and money is spent on maintenance," says Smit. "Bearing this in mind, DCD Rolling Stock began research on a more user-friendly and cost-effective solution for locomotive bogie steering and maintenance in 2009."

The system is particularly aimed at freight locomotives as it reduces rolling resistance through curves, which the company says should cut energy consumption by 3%. It should also make it possible to use more-powerful Co-Co locomotives on lines with frequent sharp curves.

Jika PHS is designed to reduce the angle of attack between wheel and rail and reduce wheel-rail forces which should help prevent rail spread. Smit says the system can reduce flange wear eight fold.

The performance of the Jika PHS bogies fitted on the three test locomotives will be compared with six locomotives equipped with conventional bogies. The trials, which started in September and will last six months, will focus on recording wheel tread and flange wear reductions as well as noise levels and lateral wheel-rail forces.

DCD Rolling Stock says additional testing will be required and that it is working with a university to design a hydraulic cylinder which is capable of operating for six years without maintenance.

Smit believes the return on the investment in Jika PHS will be rapid despite a higher first cost: "The initial cost increase will be minimal and, taking into account that Jika PHS extends wheel life by up to three times, it should pay for itself in a matter of months."


Close-up of Jika PHS on the bogie.