Heavy haul coal train dynamics simulation comparisons of the COALlink and Central Queensland systems

This paper compares the heavy haul train experiences of two large coal haulage operators: COALlink, Spoornet, South Africa and QR, Australia. Both rail systems have developed different train designs to meet their specific haulage needs. The reasons for these differences are examined using a combination of simulated and measured data. The first part of the investigation is focused on existing train systems. The trains compared are the head end powered COALlink train of 21,500 gross tonnes and the distributed power Coal and Mainline Freigt train of 7900 gross tonnes. The advantaes of distributed power are explored for the 21,500 tonne COALlink train using the configuration of two equal wagon rates. The paper also explores by simulation the scope for each system to operate even larger trains, COALlink extending to 32,300 gross tonnes and Coal and Mainline Freight to 18,500 tonnes. To enable some method of normalised comparison using simulation the experimental technique of applying the same set of driving rules to each simulation was used. This allowed simulations to be completed over the full length of the haulage system. This technique imediately highlights the differences and similarities of the two systems. The simulation results confirmed the need for higher power-mass rations in QR trains and illustrate the in-train force reduction benefits of distributed power.