n addition to the weakened commodity market adversely affecting the sales of underground locomotives, three further challenges that suppliers and manufacturers of underground transport equipment face are inadequate equipment maintenance by mining companies, the incorrect use of equipment and poor maintenance of infrastructure.

Goodman locomotives manufacturer Trident South Africa (SA) international marketing manager Simon Lewis suggests that prob- lems regarding equipment, rail and tunnel maintenance might be attributed to a lack of funds, an unwillingness to slow operations or a lack of information.

Mining companies might not be aware of how frequently locomotives should be serviced; they might be reluctant to decommission them or close down a tunnel, as that will affect production, or they simply do not have the necessary funds for consistent pre-emptive maintenance, he adds.

Lewis says, when operators use locomotives and other equipment incorrectly, which could result in premature failure, it is either due to a lack of information or irresponsible behaviour, which mining companies can easily rectify if they enforce more stringent monitoring practices and ensure that drivers are adequately trained.

On Trend
Lewis points out that, in underground operations, electric systems are preferred to diesel systems, as they do not produce any emissions and require less maintenance.

Trident’s 3 t and 4 t Wolf locomotives are both available in two electric models – a 48 V battery-operated model, with an output of 5.5 kW, and an overhead trolley line model that draws current from overhead power lines that run through the mine.

The Wolf locomotives, designed to move through small tunnels in deep-level, hard-rock mining operations, specifically in South America, were introduced onto the market in February last year. In August, Trident SA delivered the first of two batches comprising ten locomotives to State-owned diversified Bolivian mining corporation Comibol.

Lewis says the locomotives’ main features are their direct-drive gearboxes, which ensure minimal power loss and reduced maintenance, small dimensions for ease of movement in confined spaces, and camtactor or solid-state controllers, which can vary the amount of power fed to the motor.

The locomotives are about 2.4 m long, 1.4 m high and 1 m wide, with an operating mass of about 3.5 t.

Trident SA, which was founded in Wadeville, Gauteng, in 1969, acquired the global manufacturing and distribution rights for all new Goodman equipment in 2003. Thereafter, the company began to develop new locomotives and customise previous versions, such as the 6 t locomotive.

This 6 t locomotive is generally used to move ore and has a small wheelbase and relatively small dimensions to cope with windy and small tunnels. The standard version is fitted with an 84 V battery with an output of 15 kW. It is about 3 m long, 1.5 m high and 1.25 m wide.

“This product has been around for decades, though our locomotives are engineered to order, based on customer requirements, so there are many versions. Nevertheless, you will find a ‘six tonner’ in most of the South African gold and platinum mines,” Lewis states.

The main safety concerns when producing a locomotive are braking, controllers and wiring, he states, asserting that Trident SA ensures its locomotive brakes comply with the requirements of Chapter 8 of the Mine Health and Safety Act.

Trident SA also uses high-quality fail-to-safe controllers and ensures that all wiring is done to the highest standards, Lewis concludes.