What was the issue?

The open top of typical heavy haul rotary dump cars generates a large proportion of the aerodynamic drag for empty ore trains at speeds of approximately 70km/h and above. Innovative methods for reducing this drag were needed compatible with loading and dumping systems whilst also seeking to ascertain the potential for energy savings that may exist from improvements in aerodynamics in empty hopper and ore wagons.

What was done?

A survey of known equations and recent literature.

Equations relating to the drag on flat plates and ‘brick shaped’ objects were explored

Using train simulation savings were calculated for flat track and two typical iron ore and coal haulage routes.

What was found?

Fuel reductions were indicated, noting uncertainties from a range of assumptions and possible slower running speeds. The adequacy or margin in locomotive power verses the track topography will also affect what savings can be realized.