| Abstrakt: |
Although aluminothermic welding (ATW) is a well-established process for joining rail throughout the railway industry and the world, there is always room for development to better suit them for specific cases. In Queensland Rail, some improvements to (ATW) have been tested in the field based upon academic literature. The intention of these field tests was to adapt the (ATW) process to suit the stringent track access requirements imposed on the suburban commuting environment. In this paper, the results of trials carried out to shorten the specified time required for final grinding will be presented. One of the cases was translated into a table, which is now in use to compensate for further contraction when final grinding is done on short maintenance windows. Other trials to shorten the minimum cooling times to final grinding were attempted, which included a forced cooling experiment. However, these other trials were not implemented for reasons described in this paper. During the forced cooling trial, some long-lasting questions and misconceptions were also examined, such as: (a) Welds keep deforming vertically under traffic over the first six months after installation. (b) The final grinding introduces a heat input capable of interfering with the final alignment (apparent peak). (c) What is the best pre-set alignment of a welds and how to perform finish grinding. When investigated under the perspective of a light axle load railway, the answers to the issues mentioned above may be surprising. The above subjects will be discussed within this paper, with supporting evidence from field trials and based on experience accumulated on Queensland Rail's Brisbane Suburban network. [ABSTRACT FROM AUTHOR] |
