Here you can see the new low level platform at St Albans peeking out from beneath the cantilevered structure above.

Over at the Blackburn Road works they got lucky – there are only two tracks between Blackburn and Nunawading, but some free space either side of the rail corridor. This allows the piling rigs to start work while trains are still running.

I believe similar works were possible for part of the Middleborough Road and Mitcham projects – despite their need to close the railway for an extended period to dig out the tracks.

If they were using some form of automated track layer, doing it all in one go would make sense. But at St Albans they just used a single ‘octopus’ spreader to lay the track, placing eight sleepers at a time.

The bus replacements for the RFR project were a PITA:

http://www.theage.com.au/news/national/commuters-angry-at-rail-delays/2005/06/22/1119321789208.html

Back in 12005 I was commutering from Geelong and had to put up with them for a number of weeks.

Somehow I forget about the Regional Rail Link works on the Bendigo line – the entire route from Sunbury – Bendigo was closed on 17 January 2005, reopening to Kyneton on 2 November 2005, and the rest of the line on 20 February 2006. That’s over a year!

If you had a look at St Albans Platform 2, it was actually demolished and replaced with a temporary platform, which was cantilevered over the cutting. Which means yes, it would be unsafe to dismantle. If it failed, it would have gone straight into the new platform below.

While it looks like that wasn’t the case with Ginifer, it is still precariously close.

If you actually see how quickly they have installed it, for the entire length, it’s been just a few days!

The North-McKinnon-Centre project on the Frankston line was actually a half’n’half. Due to the generally wide corridor and 3-track configuration, piling works were able to be completed “online”. The easternmost (down) track was closed while piling was undertaken on the east side. Then it was reopened, and the westernmost (up) track was closed for piling to be undertaken on the west side. At most times, 2 tracks remained operational, so the 6+ months piling works were mostly undertaken “online”.

There were 33 days of 2- to 9-day duration shutdowns during this stage – ie: “offline” – for preparatory works, service relocations, signal and power changes, bridge construction and station demolition.

Then came the “big dig”: 37 continuous days of closure while major works were undertaken “offline”. The end result was a half’n’half project.

If trenching or short bridging was used on the the Caulfield to Dandenong project, it would have been a mostly “offline” project. (Assuming short bridging was even possible between the closely located Carnegie, Murrumbeena and Hughesdale stations.) This would have been very disruptive for 25+ thousand daily train users, with the tracks closed potentially for many months. The major advantage of the long elevated viaducts solution for Caulfield to Dandenong is the ability to construct the viaducts “online”, due to just enough space being available alongside the existing tracks. This project will end up being a half’n’half, due to the preparatory and finishing works that will be needed. But the amount of “offline” time should be much lower than if trenching or short-bridging methods were used.

On the southern end of the Frankston line, no matter which removal method is used, the works will be mostly “offline”, due to the very narrow rail corridor, and availability of only 2 tracks. It’s going to be very disruptive for 10+ thousand daily train users, with the tracks closed potentially for many months. Most people probably don’t yet realise what they’re in for.