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Building skyrail while the trains keep running

It’s January, and while lots of people have heard about the City Loop closure, less well-publicised are the shutdowns on the Hurstbridge, Alamein, Cranbourne/Pakenham and Frankston lines… plus more lines in the evenings.

Anyway, here’s something related – an expansion of a comment answer I left on a recent post.

The question was about how skyrail can be built while trains continue to run underneath. I thought I’d share a few photos from during the Dandenong line construction around Carnegie-Murrumbeena.

They had a bit of space to play with – not enough to do four tracks without land acquisition, but enough to build the two elevated tracks with gaps for water and sunlight to reach the grass and plantings in the public space below the new line.

It also meant they could keep trains running during much of the construction.

Early on they replaced the overhead stanchions with a special design:

New gantries at Carnegie station to allow trains to keep running while skyrail is built above.
Carnegie station 22/8/2016

The lower height at the sides allowed the new track structure to be put in place. The old station platforms had to be narrowed, but were mostly able to keep operating.

Murrumbeena station - skyrail under construction
Murrumbeena station 16/9/2017

The new elevated island platform was built above the old tracks, at a higher level than the new tracks.

Murrumbeena Station under construction
Murrumbeena 13/3/2018 (SE end of station)
Murrumbeena Station under construction
Murrumbeena 13/3/2018 (NW end of station, looking SE)

For much of the distance between stations, the new tracks and their support structures were built on either side of the old ones.

Murrumbeena skyrail under construction
Near Murrumbeena station, 16/9/2017, looking NW

Once the new structure was completely in place, trains could run on it, while the old track and overhead structures were removed, and landscaping took place.

View towards Caulfield, from Carnegie 16/6/2018
Carnegie 16/6/2018, looking NW
View from Murrumbeena towards Hughesdale during skyrail construction
Murrumbeena 3/6/2018, looking SE

It was a bit different in the Noble Park section. The rail corridor there was wider, allowing them to build the new tracks next to the old ones rather than above them.

Noble Park skyrail under construction: Heatherton Road
Noble Park 23/1/2018, Heatherton Road looking NW
Noble Park skyrail under construction: view from Heatherton Road looking towards station
Noble Park 23/1/2018 looking SE towards the station

At Clayton as well, the new structure was built alongside the old rail line and station.

Clayton station under construction
Clayton station 13/3/2018, looking SE

Overall the main part of skyrail construction probably took longer to build than the rail under (trenches) elsewhere on the network. But rail under requires a lot more preparatory work to move underground services first, so the big 6+ week rail shutdown is often accompanied by lots of smaller shutdowns.

In contrast, during most of the skyrail construction, trains were able to keep running. The main periods of no trains running was during construction of the ramps to carry trains to and from the elevated sections, which necessitated removal of the old track.

As I said in the earlier post, each method has pros and cons, and what works in one location might not work in another.

It’s not perfect – and much of the Cranbourne/Pakenham line is about to close again for several weeks for other upgrades, principally the rationalisation at Caulfield junction, and signalling work.

But there’s clearly a benefit from keeping trains running as much as possible during construction, and skyrail can help with that.

9 replies on “Building skyrail while the trains keep running”

I estimated that is would have taken at least 600 buses per day to replace the number of passenger trips on the Pakenham/Cranbourne line building a trench. Would not have had as much utility as the Skyrail does now. I moved to Hughesdale about July 2018 and got to use the new station when it opened. Would walk all the way to Carnegie underneath the Skyrail, much better than the road. Not long after it opened gates started appearing in fences next to the track and then fences got replaced with see through ones.

That’s not entirely true.
Many weekends saw buses replace trains in that Oakleigh to Caulfield section. Often multiple weekends in a row.

That year(2016 or 2017?) During the football season when most of the work was happening it was a bus instead of a train. From memory it was at least half that season had buses.

@Brad, good point. Quite a few weekend and evening closures in 2017-18, so it didn’t eliminate closures by any means. I do think though that for the removal of 9 crossings, it was less time than it would have been using other methods.

The Parkdale skyrail (Warrigal Rd and Parkers Rd) will probably break the pattern. The new elevated rail will be centrally located in the rail corridor, with both tracks to be supported on single piers – right in the same alignment as the current tracks. Unless they temporarily slew the current tracks to one side (which they did when build the Seaford Rd bridge), there will probably be an extended shutdown to build Parkdale skyrail.

@Andrew, there is a real concern that this will remove options at Caulfield for operations during disruptions. Currently they can switch some trains to other pair of tracks to/from the City if there’s a problem – this will remove that option.

As I understand it, it’s primarily related to the high capacity signalling upgrades for the Cranbourne/Pakenham tracks, and separation from the Frankston tracks makes this possible/easier.

It should also slightly increase train speeds, and reduce ongoing maintenance costs, but time will tell if the loss of flexibility makes that worth it.

The new Deer Park elevated section is being built next to the existing, so hopefully Geelong shutdowns are kept to a minimum.

During the current state government’s LCR works, the skyrail has definitely given the best possible results in almost all cases, unlike for example, Collingwood or Canterbury which are utterly awful eyesores and provided no benefit from having an elevated railway.
I’m curious however, what the plan is for future rail duplication, for freight lines, etc.?

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