Alien B.,
My conclusion that you thought Alan was anti-rail was based on your statement that "For each decade these and similar essential projects are delayed the cost effectively doubles and mostly because of activists like you Alan!?"

Your argument was primarily about whether we should build what we need, and scarcely addressed Alan's point that this isn't, and would divert funding away from, the infrastructure that's really needed.

I apologise for the autocorrect error - I meant to say "well constructed track AND expansion joints". Together they're sufficient to easily cope with hot weather. And for the benefit of readers not familiar with modern railway practice, I'll clarify that I mean proper expansion joints. Unwelded rail sections held together with fishplates don't count, even if they were originally intended to serve that purpose.

Anyway, my point is that tunnelling is expensive. There are many good reasons to build rail tunnels, but preventing track buckling isn't one of them. That can be done far more cheaply by other means.

If a lack of parking is really what's limiting train use in the outer suburbs, that's a relatively easy problem to fix. But getting lots of passengers onto an orbital railway, when most of them have destinations nowhere near a railway station, is a much more formidable task!

One technique used in some places to overcome expansion due to heat
is that when the rails are installed, they are stretched, so expansion
just reduces the tension.
Does the proposed line have a connection to the CBD or Southern Cross ?
Unless it does there is no point in it going to the airport.
The majority of the airport rail traffic in Sydney goes to the CBD and
to Central station for connection to all other lines.

Bazz,
You are correct about tensioning rails, but there's a limit to how much that can be done, as we also need to avoid track breakages in cold weather.

They are proposing to build a line from the airport to the CBD first, part of which would also be utilised for the section of this line west of the airport.

Sorry but a loop is the only way to go, even if it takes passengers the long way round, and will probably be a complete circle before the turn of the century, to avoid endless criss-cross patchwork that ultimately costs several times more overall.

Can't think of anything superior save a monorail system that utilises the central divide on our highways to carry a monorail system that replaces the ubiquitous diesel burning bus traffic. Motorized walkways and escalators filling the gaps?

We complain about lack of forward vision and again when it's displayed!

Don't resile from my comment on the naysayer (expert) knowing all the reasons things shouldn't be done!

The best solution is, do it right the first time and consequently only do it once. which ultimately, invariably is the least expensive and most pragmatic option!
Alan B.

Build this thing, then run it as a government operation, & we will be paying through the nose for carting a few Melbournians around for ever.

There was a time, somewhere well back in the last century when Sydney suburban rail ran at a profit, but that time is long since past. No railway in Oz, with our wage structure is viable, other than the coal & iron ore railways

Build this thing with it's vast opportunity for corruption, the unions, constructions companies, & many politicians will become rich, in office or after, & the rest of Oz people will be subsidising it for ever.

Alan B.,
If there's one thing it will never be this century, it's a complete circle, as there's Port Phillip Bay in the way! And the small number of people travelling from Cheltenham to Werribee can easily do so via the CBD.

You seem to have got it into your head that this loop's exactly what's needed. But in reality it's very far from what's most urgently needed, as it would only cater for a small proportion of journeys in the area it serves, and the roads it would relieve are not the most congested.

What you dismiss as "endless criss-cross patchwork that ultimately costs several times more overall" would also give several times more benefits overall.

As for monorails, they're a specialist mode and tend to be a lot slower.and tend to have much lower capacity. I can't think of anywhere in Melbourne a monorail's the best solution, but I'm not a Melburnian so there may be something I've missed.

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Hasbeen,
Rail is viable for a lot more freight than just coal and iron ore. Your failure to realise this makes me wonder whether you're assuming t to still have the staffing levels of the 1970s!

Passenger rail tends to be lossmaking because governments recognise the benefits of keeping fares low outweigh the cost of the subsidies.