Mining and industrial equipment supplier Deebar is upgrading the Deebar Rail-Veyor remote-controlled, electrically powered light-rail haulage solution which it installed in 2005 at gold miner Harmony’s Phakisa gold mine, in Welkom.

The upgrade will increase the ore transport capability of the Rail-Veyor and, more importantly, stabilise and optimise the bulk handling system for years to come by modernising some of the key technical components of the system, Deebar marketing manager Richard Barley tells Mining Weekly.

“Technology has changed drastically over the past ten years and components – such as variable speed drives and the supervisory control and data acquisition (Scada) system, which includes a reporting facility – have seen significant improvements that allow for greater energy-savings and enhanced performance,” he explains.

Last year, Deebar, thus, partnered with South African industrial automation software developer Adroit Technologies to install the latest technology on the system. Adroit Africa will supply the latest software suite for the upgrade, which is expected to be completed in December.

Upgrading the System
Phakisa’s 5.1-km-long underground Rail-Veyor consists of two dump loops – one for reef and one for waste. The system negotiates six 30° bends along its route to transfer ore between Harmony’s Phakisa and Nyala shafts.

Barley explains that the upgrade involves replacing all the tensioners on the drive stations to ensure smooth entrances and exits at all drive stations. Programmable logic controllers will control the operation of the tensioners, which will apply only if a predetermined set of conditions are met, thereby ensuring reliable and safe operation of the Rail-Veyor system.

Brakes will also be installed at strategic points to improve the train control. “The original design of the system did not include brakes. The inclusion of brakes at strategic points will allow for more flexibility in the system’s operation, which will improve its overall effectiveness.”

In addition, the control system on the Rail-Veyor will be replaced with the latest control software and the Scada will be upgraded to the latest version. Barley highlights that this will enable the mine to receive reports on the Rail-Veyor system’s performance and any potential faults. Operations analyses and diagnostics could also be more detailed and easily obtained for maintenance personnel to view.

The upgrade is being performed only during scheduled maintenance times and Barley stresses that the only downtime the system will incur will be during final commissioning.

The Deebar Rail-Veyor
Barley describes the Rail-Veyor as “a cost-effective, environment-friendly bulk materials transport system”, which is based on the principle of a roller coaster, where a train consisting of a series of articulated trough-like cars runs up inclines, down hills and around bends on a rail that can turn back 180° within 20 m.

The Rail-Veyor consists of a light rail track with a number of two-wheeled cars that are interconnected, forming a long, open trough moving along the track. Each car is connected to the car in front through a swivel clevis that allows for articulated movement when negotiating curves and dumping.

Sealing of the gaps between cars is ensured by overlapping flexible rubber flaps, which prevent spillage of material and operate as discharge chutes to dump the load after it has been transported.

A number of equally spaced, energy efficient, dual-drive stations move the train, with foam filled tyres in contact with the side drive plates of the cars providing forward thrust. The Rail-Veyor has no locomotive or integral drive unit on the train and the rail weight is based on the car and content weight, rather than on driver weight as is the case with a conventional railroad system.

The Rail-Veyor was initially introduced in 2004 and, in 2005, Deebar secured its first order of the system for Harmony’s Phakisa shaft. “This was not only the company’s first order in South Africa but also the first installation of a system of this kind in the world,” says Barley.

He notes that a similar system was originally conceptualised in the 1960s by French State-owned rail company Seccam. It developed the light rail transport concept of a unitised train consisting of a series of closely connected open cars moved by side pressure of rotating tyres attached to stationary drive stations. “The basic concept was excellent, but because the mechanical and electrical applications required significant improvements, the system was flawed,” says Barley.

With the technology available today, he notes that Deebar was able to fine-tune the original concept and redesigned the system to ensure its maximum potential. The Rail-Veyor offers numerous advantages over alternative bulk materials handling systems, including lower operating and maintenance costs.

In addition, the system is highly flexible and can negotiate bends of up to 30° and operate at an incline or decline of 11°. A lightweight rail track is used and additional trains can be added to a system to increase capacity. The system requires no direct operator control, with loading and dumping performed automatically, while the design ensures no material spillage, allows for continuous loading and unloading, and facilitates the use of multiple loading and dump stations.

Market Interest
Barley notes that interest in the Rail-Veyor has not been hampered by the downturn in commodities prices, as the system offers significant benefits in terms of helping mines reduce their operating costs.

He highlights that mines, especially in South Africa, are required to focus on reducing their electricity cost. The Rail-Veyor assists with this, as the drive station is activated only when sensors detect a train arriving near the drive station, switching off once the train has passed through. “This means that, at any given time, only two sets of drives are running for each train.”

In addition, Barley notes that the system reduces the amount of labour required and does not involve any fuel costs, which will have significant benefits with the implementation of carbon credits in South Africa in 2017.

“Owing to its simple design and low operating costs, the Deebar Rail-Veyor is a substantially more cost-effective alternative to other bulk materials handling methods. “The system experiences minimal wear and tear on running components and requires lower capital investment than similar equipment such as conveyor belts.”

Deebar’s claims for its patented system are further bolstered by a study conducted in 2009 by supply chain analyst Crickmay & Associates, which involved a thorough investigation of 16 bulk materials handling systems. The study aimed to determine which technologies were best suited for certain transport requirements and, according to analysts, the Rail-Veyor was the only technology that proved competitive under every testing scenario.

Deebar is currently in negotiations for two new Rail-Veyor projects; one will include moving over 100-million tonnes of ore over a seven-year period and the other will be in the Steelpoort area, in Limpopo.