Dr Day, a well-regarded train planner with decades of experience, has not commented publicly on rail planning since retiring from RailCorp in 2008. And while he ultimately supports the north west proposal, which the government last week revealed would be a privately run shuttle between Rouse Hill and Chatswood, he argues it will not be without political pain when the line is finished about 2019.

And the way the government is building it will also provoke the urgent construction of another harbour crossing, he says.

Under the plan unveiled by the Premier, Barry O'Farrell, and the Transport Minister, Gladys Berejiklian, last week, commuters using the north west trains will have to transfer at Chatswood for the lower north shore and the city.

''The adverse impact on the very large number of passengers forced to interchange makes the minister's decision to support the metro alternative without detailed public discussion truly heroic,'' Dr Day has written.

He said a less risky and more conservative approach would have been to build the north west line as originally planned, as a simple extension to the heavy rail network from Epping.

This would have allowed direct services to the city, and ''avoided the need for massive interchange on a railway ill equipped to cope with it''.

Read more: http://www.smh.com.au/nsw/expert-warns-of-rail-change-risks-20120629-2180w.html#ixzz1zJM5XFqP

There's a reason the very fast train is a predictable pre-election teaser: it's an absolutely irresistible idea. So why don't we just build it already? Dominic Knight writes.

For years, I've dreamed of sauntering down to Melbourne's Southern Cross station and sliding into a comfortable seat on board a shiny new Very Fast or even Extremely Fast Train. I'd sit and work on my laptop, or read a book, or recline my seat to take a nap while the landscape whizzed by, faster than a Saudi diplomat being pursued by the AFP.

Occasionally, kind people would come past with coffee and snacks, and perhaps an in-seat massage. And then, less than three hours later, I'd alight at Sydney Central, and get on with my day.

http://www.abc.net.au/news/2016-04-11/knight-our-ridiculously-slow-road-to-a-very-fast-train/7316778

Yes, dear Dominic... But FAST TRAINS ARE VERY EXPENSIVE. First they need the injection of MASSIVE cash by governments. Second they need to be "corridored", that is they need a specially dedicated highway, expressway sized corridor — a) for the railway and b) for the servicing roads. These corridors aver very disruptive. Third the trains don't run on thin air.

They need a lot of electricity to move at more than 350 kms an hour. In order to be efficient and environmentally friendly, this energy IN THE FUTURE would have to come from solar and wind turbines along the rail line with MASSIVE electricity STORAGE. Otherwise the cost of moving the trains would be too expensive and more CO2 unfriendly than planes. Sydney to Melbourne in three hours? Possible... But you will need some dedicated localised by-passes for other "fast trains" using the same line, say from Bendigo to Melbourne and from Goulburn to Sydney. 

Within the first year of operation more people would want access from country towns on the line with dedicated fast trains. Should you stop at all the towns with the same train to Melboune, the Sydney/Melbourne trip would take more than 5 hours, possibly 6. Nothing wrong with this. Many of the fast trains in Europe are using existing lines which have been upgraded. None of the existing Australian train lines can be upgraded to fast train standards. 

By the time you run the fourth fast train between Sydney and Melbourne, you would have had to spend about AUD10 billions, by the time you run the 100th train you would be AUD12.7 billion in debt. By the time you run the 1000th train, you could be more than AUD15 billions down the drain. Do the sum: ALL of France fast trains are subsidised by the government and run on nuclear supplied electricity. The nuclear supply of electricity is also subsidised to the hilt...

Unless we are prepared to accept wind farms and solar farms down the way, such a project would bleed cash to death just on energy cost.

See images at top.