Running Resistance and Energy Consumption of Ore Trains in Sweden

Running resistance of ore trains consisting of Uad-type wagons is determined from full-scale measurements on Malmbanan. Tests are also run in curves with the Uad equipped with three piece bogies where the axles are non-steerable and an ore wagon equipped with bogies allowing the axles to better align themselves on straight track and more radially in curves, thus making them steerable. Influence of speed, axle load, curve radii, and train length is studied and quantified. The running resistance is parameterized and expressed in a general way so that it can be calculated for any Swedish ore train consisting of Uad-type wagons. The study shows that the increase in running resistance is linear due to the increasing axle load on tangent track and train length. The increase in resistance due to curves is significant and increases as the curve radius decreases. If the axles align themselves radially, the curve resistance reduces by 40 per cent, compared with the Uad. The results show which parameters in a running resistance formula should be paid extra attention when constructing a train model for simulation purposes. A comparison is made between ore trains and ordinary Swedish loco-hauled freight trains. The energy consumption of an ore train is not much affected if the operational speed increases from 50 to 60 km/h. Also, a reduced aerodynamic drag has a very little effect on the consumption due to the low operational speed. In this article, a review of the study is made with conclusions.