A review on recent developments in rail temperature prediction for use in buckling studies

Railways all over the world suffer from track buckles caused by variations in thermal stresses arising from temperature fluctuations due to climate. Notable studies during the 1960s to 1980s include Kerr, Samavedam and Kish from the Volpe Centre in the United States, Esveld from the European Railway Research Institute and Hagaman and Kathage for the Railways of Australia (ROA). Buckling and trackparameters which contribute to track instabilities have been studied and characterised comprehensively during those years. From the 1990s, track lateral stability studies have focused on risk analysis andmanagement procedures probabilistically using software such as CWR-SAFE. Recently buckling research has been on forecasting rail temperatures. Two notable rail temperature prediction models have beendeveloped by Chapman et al. with the UK Rail Safety and Standards Board, Zhang and Lee from Ensco Inc, and Federal Railroad Administration in the United States. An advanced predictive model like that developed by Chapman for rail temperature signifies for industry the difference between blanket speed restriction procedures and focused operational management based on localised risk conditions determined using a scientific approach. This paper gives a comparative review on the models developed by Chapman et al and Zhang and Lee, and what knowledge is currently available in Australia including studies by Whittingham and, more recently, Munro. It also outlines the steps that the Australian rail industry needs to take to further develop a comprehensive track stability management system. Collating existing knowledge is the first step for the Australian railway industry to have a more compreehnsive hot weather rail management policy.