Do you mean to say that rather than winning the work from their road based competitors, the rail industry is winning it from their sea-faring competition?
I honestly didn't know we moved that much domestic freight by sea. I would have thought all of it went by road, rail or air.
BH is correct.
For many years the domestic transit of shipping containers have been based on marginal cost pricing. This has effectively undercut land transport, especially rail on the E-W line.
Big freight forwarding firms such as Toll can pick and chose any mode based on price and delivery schedules. So, for example, if sending containers from Perth to Melbourne they will look at availability of shipping slots and time, the latter impacted by a stop in Port Adelaide vs back loading prices on rail or road.
The number of international container ships moving along the southern coast during the current Covid period is way down. Thus availability and frequency of possible slots is also down.
When I was a strategic transport planner back in the 90s, it was difficult to interest the (Libera/National) Federal Govt in the notion of "robustness", namely making sure there was more than one string in the bow so a system could withstand shocks. Indeed, their overall understanding of systems analysis was negligible and they did not understand that optimising each element of a system does not necessarily lead to an optimal long term overall result.
This was the time when coastal shipping was opened up to international shipping lines, with little regard to the long term sustainability of rail freight. In fact rail was seen as the poor cousin, as it is largely to this day.
This is not confined to Governments just on the right - see Vic - but all Govts under the influence of the powerful road freight lobby. Unlike in the USA where there is a broad agreement between road and rail industries that rail dominates the long haul and road the distribution role.