Even as a preliminaryvreport these things are written in a convoluted language after comments from all parties involved. , so as to keep everyone happy. The report clearly says that the wheel profiles and treads of both Vlp and XPT stock were within tolerances for operation over sg and dual gauge trackage. generally and meets Australian Standards.
The report clearly says the dg turnouts were tested with sg rollingstock, but not XPT stock prior to commissioning .
Coming to the specific dual gauge turnout design used on the flyover :
A photograph within the report shows clearly that where a sg narrow profile XPT wheel transfers from a sg rail to bg rail that a sg xpt wheelset is out of gauge and the wheel will fall into the four foot.
So by inference the turnout design is the problem in that a wide profile sg wheel as on vlp and gsr carriages will negotiate the specific turnout design as intended. However the thinner profile XPT wheel and this type of turnout present an issue with transfer of the sg wheel through the turnout.
Thus the current focus to 1. to alert all rail operators to the potential of derailment with thin profile sg wheels through specific design types of dg turnouts. and 2. the modification of the track componentry within the offending dg turnout type to allow for the passage of sg wheelsets of all types.
One should be very careful of being critical here of any party as dual gauge trackage especially turnouts and crossovers, gauge splitters are very complex engineering designs. The report indicates clearly that all parties including VLP have been pro active in identifying the issue, correcting it and learning from it .
