Nowadays, haulage systems designed for underground gold operations offers virtually unlimited capacity transport capacity in tunnels with sections as small as 4 m2. Regardless the scope of the round, loading and haulage can always be carried out in a single continuous operation without troublesome car switching. This by no means the least reason why the design of many manufacturers of haulage systems has been recognized for their quality and some of them has been identified as the natural partner to modern full face boring machines. Essentially, haulage employed in many gold operations consists of a number of special cars drawn by a locomotive. The bottom of each car body comprises a chain conveyor, which facilitates the transfer of rock from one car to the next. The discharge end of each car is adapted to fit the loading end of the car behind. In this way, the chain conveyors form a single, train-long unit. With a capacity of approximately 11 m3 in each car, a set of, say, six cars provide a total haulage capacity of no less than 70 m3.
Haulage systems used in underground gold operations are equipped with chain conveyors eliminate the need for external car discharging equipment. At the transfer point, the entire load can be self-discharged to a chute or a dump. Various methods may be employed for discharging to a dump, for example, the entire load may be discharged from one end of the train or skew dumping may be practiced. In the second case, the front and rear bogies of each car are run on parallel tracks, bringing the car body in a diagonal position, and car are discharged individually, but simultaneously.
Haulage of Loaded Train
When haulage systems are employed in gold mines, there is no need for double tracks, switches or switch control stations. Nor is it necessary to blast extra area for passing points and switches, a factor implying considerable saving, especially id such spaces must be later reclosed with concrete. Using haulage systems the tunnels will not be made larger than required for the ultimate purpose. One man can handle loader, shuttle car and locomotive. If trains comprise several cars, requirements will not exceed two or three men at most. Output per man7hour is thus consistently high where the haulage system is employed.
The economic advantages of the haulage systems are particularly noticeable when driving narrow tunnels and drifts. However, even in large section tunnels and over long haulage distances, a good design of the haulage system offers very attractive costing by virtue of its large capacity, high haulage speed and simple operation.
Shuttle trains employed in gold operations are operated in combination with a loader located closest to the face. The loader discharger rock at the forward end of the leading shuttle car. When this car is fully loaded, the loader makes a brief pause while the load is transferred to the next car. The conveyors in both cars are employed for these operations. When the leading car has been emptied, the loader recommences its work. The fully loaded car is hauled away for dumping while the leading car is left in place so that the loader may continue working during the haulage phase.
Straightforward Discharging