Colin Cole

The effect of lubrications on a curved track to heavy-haul wheel-rail contact wear is studied. To analyse wheel-rail contact wear damage due to existing high-adhesive AC locomotive, a methodology for investigation is proposed, and the locomotive models are required to run at 20 km/h under maximum traction efforts, and the simulations include a DC locomotive for comparison. An extended creep force model, which was developed by Polach and has been widely used for the wheel-rail contacts under dry and wet conditions with variable friction coefficients, is further extended to apply for the typical low-coefficient-friction modifier, oil, and grease lubricant conditions. The wear models from two pairs of wheel-rail materials are used to predict the wear rates, and the wear numbers Tγ are presented for discussions. The simulations show that the lubricants significantly reduce the wheel-rail contact wear.

As efforts are being made to quickly adopt zero carbon technologies and replace fossil fuel powered trains, the design requirements are explored using train dynamics simulations to establish energy needs. The test case was a freight train of 3030 gross tonnes consisting of two locomotives and thirty wagons operating on a relatively flat coastal rail route. Then, assuming rapid deployment of existing and near market technologies, speculative locomotive designs are proposed for both battery only and hydrogen-battery systems. Batteries were assumed as rack mounted systems and hydrogen assumed at 250 bar gaseous. The results showed that full recovery of dynamic braking required only a very small amount of storage to capture and allow re-use, requiring a battery of only 6% of the trip total of recovered energy. The haulage task was found to require traction energy of 10.7 MWh per locomotive but reduced to a net requirement of 7.6 MWh per locomotive with recovery of dynamic braking energy. The large mass of batteries needed for the operating trip, however, limits the practical operating range. The results showed that, although hydrogen storage and equipment occupy considerable space and the containment systems have large mass, the space and mass requirements for a hydrogen system in this case study could be as low as half that required for batteries, while higher pressure or cryogenic approaches to hydrogen storage will allow the scaling for longer range.