matthewg wrote:
The Oscars are probably already running at the performance limit of the infrastructure. Trains with a higher top speed will make no difference with out infrastructure enhancements - something the current government seems really really keen to avoid doing.
Not entirely. Some parts of the infrastructure are zoned for up to 140 km/h. The line is pretty straight or only slightly curved between Sydney and Waterfall and between Thirroul and Nowra - about 75% of the line. Yes it's true that a 160 km/h train is not going to make any difference over a 130 km/h (Oscar) or 145 km/h (Endeavour) train in terms of raising
average speed, which is the critical issue. Presently the trains are being run at the performance limits of the brains of the NSW transport administration. That's the real problem.
By comparing lines with similar track profile, I've estimated that Transperth could cut 20 minutes off the Thirroul-Nowra journey time using Transperth's existing performance standards, including their trains which have a maximum speed of 130 km/h, same as the Oscars.
If the line between Coledale and Waterfall was bypassed and straightened, an operation to Transperth's present standards could do a Sydney-Nowra journey in 1hr 55min, compared with the present 2hr 40min. (I've subtracted the unnecessary 10 to 15 minute wait at Kiama from these calculations.)
Except for Waterfall-Coledale, very little curve-easing is needed on the south coast line. The only major work I would consider desirable is duplication from Unanderra to as close to Kiama as possible without having to tackle the tunnel - that is, to Minnamurra or Bombo. Duplication isn't necessary (except for overtaking sidings for the Manildra trains) between Kiama and Nowra because a Transperth performance would see a single trainset doing a return trip quickly enough for an hourly connection at Kiama.
Such improvements between Sydney and Waterfall and Thirroul and Nowra are possible right now, without having to wait around for the Waterfall-Coledale issue to be addressed.
Here's the present problem - how a typical train runs in a stretch of track zoned for 100 km/h (the 60 sign applies to the passing siding):
https://www.youtube.com/watch?v=9ZptAyPtbYE
Go make a cup of tea while you're watching this. The train will still be there when you come back.