By: Jill Stanford
17th October 2003
A beneficiary of funding from Mark Shuttle- worth’s venture capital company HBD, STS is developing and marketing advanced track systems for use in the global railway industry.
Its main product is the STS panel track system, a precast concrete beam-track system. Different versions of the system are suitable for mine track, urban light rail or main-line surface track.
The main advantage of the STS panel track system is enhanced geometric stability, which reduces dynamic effects which result in loss of alignment and damage to track structure and rolling stock.
The product is also cheaper to manufacture, stronger, more durable and can be laid faster than traditional track.
“The manufacturing and installation of STS pro-ducts is outsourced to licensed contractors and, in this way, instead of competing with local contractors, we offer them new market and revenue opportunities,” says STS MD Errol Braithwaite, who developed the technology. “This business model is important because the client is afforded the opportunity of receiving competitive bids on a proprietary product, and it contributes to the local economy,” he says.
For example, a new railway line in northern Mozambique will be built using local manufacturing and contracting capabilities rather than foreign. Local communities will benefit directly from technology transfer as STS trains them up in the manufacturing and installation of its products. “This model is already being used successfully at De Beers Wesselton diamond-mine in the Northern Cape, where beams are being cast underground using local concrete, reinforcements and labour,” says Braithwaite.
Casting the panels underground frees up valuable hoist time, while reduced maintenance requirements result in less downtime.
The concrete centre drain doubles as a convenient hopper spillage collector where product can be re-covered simply by cleaning the drain. Trackside drains can also be replaced by the centre drain to allow double walkways in haulages for safer passageways.
A second contract is in progress at AngloGold’s Mponeng mine near Carletonville. STS is also about to begin a surface rail project and is attracting more interest from all parts of the world.
“The design and construction of conventional railway track is based on technology which has hardly changed in more than a century,” says Braithwaite. “In this time, traditional railway tracks using ballast (crushed stone) and cross-ties (sleepers) have served the industry tolerably well, but they do suffer from a number of intractable problems which prejudice their suitability for modern railway requirements,” he says. These include spreading, fouling, and degradation of the ballast. This results in loss of track geometry as well as track resilience, which results in reduced safety, accelerated fatigue damage to rolling stock as well as track components (reduced service life), frequent maintenance requirements (with associated costs), resulting in service interruptions with consequent efficiency losses and reduced revenues. There is, therefore, a worldwide interest to move away from traditional ballasted track systems towards more stable structures, which not only reduce the dynamic interaction between the wheel and the rail, but also provide enduring track geometry. Improved geometry enables increased train speeds and increased operational efficiency. “The focus of this shift has been on the development of the so-called ‘beam track’ as well as ‘slab track’ solutions,” says Braithwaite.
The technical advantages of beam-track and slab-track systems have been recognised internationally for many years, but because historically they have tended to have a higher initial capital cost than conventional systems, their use has largely been limited to special applications.
Edited by: Jill Stanford