It isn't always the case. The money spent on higher speeds, might be better spent on improved loading times at the mine or on some other aspect of the supply chain.
Why does people think that expensive, fast shiny new trains are the answer to everything?
I'm sorry, please point out where I said they needed "expensive, fast shiny new trains"?
I was asking if it was not more efficient to have faster trains - it's a single track line, surely a train spending as little time as possible on the line would increase the net amount of coal exported per week.
Of course, you'd be ignorant not to consider other factors, like crew conditions (I understand that the PL's and 48's are not too popular, understandably so), which leads to pressure from unions. The other issue is reliabiliy (again, the PL's rate low on this score from what I read). Of course, you also have fuel consumption, surely the more modern EL Class are more fuel efficiant than the older locomotives.
I do apologise for my question, I come from Sydney and have very little knowledge of the economics of coal haulage. I was inquiring that I thought it was better to speed up the existing trains, rather than contuing to run slow trains on the line, especially using leased locomotives (unless it's cheaper to lease 'em than to own 'em)...