Bias in favour of viaducts

 
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
There is quite a lot of bias on this site in favour of viaducts, which many call SkyRail. There was a thread called 'Skyrail the entire network'. There the original poster had a bias to an extreme that someone else pointed out that it's a loony idea.
Then another later noted that not every grade separation can be an elevated solution, and it would likely be a trench if located on a hill. He also said that an elevated solution should be considered wherever possible.
While I agree that a viaduct shouldn't necessarily be dismissed by overshadowing and ugliness if not in a particularly visually sensitive area, I don't entirely agree with elevated rail being better for connection and open space to the community.
Putting a railway underground can be very good for that in fact.
A railway cutting with lots of bridges over it can also be very good for connection and it is possible to build things above it, even roads and footpaths can go above an electrified railway, at least if not used by diesels.
In fact, I, on the whole lean towards road based grade separation, and this ought to be considered in flat areas where it's possible without building demolition.

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  tazzer96 Deputy Commissioner

Viaducts are cheaper.  Thats why they have bias towards them.
  John.Z Chief Train Controller

The view from the CD9 skyrail is magnificent. Can't see into anyones backyard in particular, but it gives a good view of the suburbs and the city. Bring it on.
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
Viaducts are cheaper.  Thats why they have bias towards them.
tazzer96
But some others prefer rail under, think about the long term.
  Valvegear Dr Beeching

Location: Norda Fittazroy
There is no bias.
There is a good deal of considered opinion.
Myrtone please note - it is not bias to have a differing opinion.
  BrentonGolding Chief Commissioner

Location: Maldon Junction


https://www.youtube.com/watch?v=ck4ND9W6tkU

This thread deserves to go the way of the Dodo.

BG
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
Well, the belief that elevated rail should be considered wherever possible is already biased, suggesting that it is the best default. Are those suggesting it thinking about built-up areas?
As for road based solutions in flat areas where it can be done without building demolition, heavy rail traffic needs flatter ruling gradients than road traffic, so it's easier to change the level of the road than the railway.
I would think it is better the change the level of the road before an area is built up than to change the level of the tracks afterwards.
  justapassenger Minister for Railways

Elevated is the default option for grade separations in existing built up areas on merit, not bias.

Construction is far cheaper, mainly due to having less need to relocate underground services (this is only necessary where one runs across the corridor near the location where a pier is to be installed) and find something to do with the millions of tonnes of excavated material.

Activating the space underneath an elevated railway is far cheaper than building a deck over a lowered line. The elevated railway For a place like Melbourne where it's common to get all four seasons worth of weather in a single day, the elevated line can act as both a shade from the sun and shelter from the rain for the people using the linear park and community spaces underneath.

Aside from cost, the benefit to the community of an elevated line is that the railway no longer acts as a barrier dividing the community like a railway at ground level or in a trench does. A person can cross the corridor at any point, without needing to detour via the nearest crossing point. Adding an extra path across the corridor only takes a landscaper to pave it, not engineers and construction crews to build a footbridge.


As has been noted, things are very different when brand new infrastructure is being built in greenfield areas. A preferable solution there is to partially lower or partially raise the railway (largely dictated by hydrology) at points where the railway crosses roads, with the remainder of the height difference to be made by road over/under bridges.

If building a greenfield railway, consideration should be given to having elevated stations with a 3% ramp up to them from each side and a road crossing at ground level underneath. This enables train drivers to use gravity to their advantage, lessening the wear and tear on brakes when stopping and lessening the energy needed to accelerate back to line speed after stopping at the station.
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
Construction is far cheaper, mainly due to having less need to relocate underground services (this is only necessary where one runs across the corridor near the location where a pier is to be installed) and find something to do with the millions of tonnes of excavated material.
justapassenger
And what does "cheaper" mean in this case? And in the short term or long term? And that excavated material can be used to build embankments. That has been done many times in many places before.

Activating the space underneath an elevated railway is far cheaper than building a deck over a lowered line. The elevated railway For a place like Melbourne where it's common to get all four seasons worth of weather in a single day, the elevated line can act as both a shade from the sun and shelter from the rain for the people using the linear park and community spaces underneath.
justapassenger
And yet some others prefer rail under, think of those anti-skyrail lobbies.

Aside from cost, the benefit to the community of an elevated line is that the railway no longer acts as a barrier dividing the community like a railway at ground level or in a trench does. A person can cross the corridor at any point, without needing to detour via the nearest crossing point. Adding an extra path across the corridor only takes a landscaper to pave it, not engineers and construction crews to build a footbridge.
justapassenger
And an underground railway doesn't either.

No comment on hydrology.

If building a greenfield railway, consideration should be given to having elevated stations with a 3% ramp up to them from each side and a road crossing at ground level underneath. This enables train drivers to use gravity to their advantage, lessening the wear and tear on brakes when stopping and lessening the energy needed to accelerate back to line speed after stopping at the station.
justapassenger
Yet this is not that common, most of our railways don't have that. Ramps like that weren't considered when our railways were built.

I still don't believe that is any best default.

If a railway is uphill towards a level crossing or a series of them on both sides, that favours grade separation by lowering the tracks, not raising them.
  drunkill Junior Train Controller

Location: Melbourne, Australia
Cheaper and doesn't cut a community in two like a trench does.

Sure, you can built bridges over a trench, but it rarely happens and there are less pedestrian links than needed.
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
Still no one has answered my question about what cheaper means, it's not clear whether the short term or long term is meant. Plenty of bridges over rail cuttings exist, and in some places that is the whole point of a cutting.
Until the mass grade separation from Caulfield to Dandenong, the only rail viaducts anywhere in the metropolitan area were two between Flinders and Spencer street stations. There have been quite a few grade separations in the past in already built up areas, and while some have involved bridges over roads, none have involved viaducts.
  Heihachi_73 Chief Commissioner

Location: Terminating at Ringwood
The only problem with a trench is that they don't cover it after the tracks are laid, rendering the space above entirely useless (which could be used for retail, residences, parking, or even a park/playground). For example, Boronia uses the space between the down end of the station and Boronia Rd for a large carpark, whereas the current trend of trenched stations is to leave a huge suburb-dividing hole with the exception of the road/pedestrian bridges and the station concourse (e.g. Mitcham). Underground stations don't have to be like Box Hill or Melbourne Central with the station entrance hiding in the middle of a shopping centre, likewise elevated stations don't have to be like Canterbury with its huge suburb-dividing wall of concrete to stare at from ground level.
  justapassenger Minister for Railways

Still no one has answered my question about what cheaper means, it's not clear whether the short term or long term is meant.
Myrtone
Both.

A bridge, which simply needs appropriate foundations and the pieces carried in on trucks, is cheaper than doing massive earthworks and then building a bridge (or numerous bridges) over the top.

The only reasons you would do an underpass are if the topology is very favourable to an underpass, or if the area is flat but politicians choose to go with a poorly optimised solution. Both of these factors have come into play on certain parts of the LXRA project, which is very much a politically motivated road improvement project.

Proper tunnels underground are even more complex than underpasses, and therefore only used when the terrain is an insurmountable obstacle or if the real estate above is way too expensive.

The reason that rail-based solutions are preferred in existing built up areas is that a bridge of a corridor which does not have any nearby junctions (i.e. railways running straight through) is always simpler than a bridge of a corridor which does have nearby junctions (i.e. a matured road network). This is why the big section of elevated line through the Carnegie area has been done this way, rather than building nine separate bridges over the railway with each requiring major reconfigurations of the nearby road network to accomodate the approach ramps.

The increased benefits of bridges have already been explained quite adequately in this thread and do not need to be repeated. The Carnegie elevated section will unlock 23ha of parkland, and I'm very interested to see how it is activated.
  trainbrain Chief Commissioner

Still no one has answered my question about what cheaper means, it's not clear whether the short term or long term is meant. Plenty of bridges over rail cuttings exist, and in some places that is the whole point of a cutting.
Until the mass grade separation from Caulfield to Dandenong, the only rail viaducts anywhere in the metropolitan area were two between Flinders and Spencer street stations. There have been quite a few grade separations in the past in already built up areas, and while some have involved bridges over roads, none have involved viaducts.
Myrtone
Bias? =What a load of coddswallup, just to make you happy, they are going to build two new Rail Bridges betwwen Eltham and Montmorency just to keep you happy.
  True Believers Chief Commissioner

Myrtone why did you make a pointless thread? There is no bias for elevated rail.

It's cheaper and more effective way of separation in already developed areas. The usage of space is maximised. The connections are much greater. And on the Upfield line it is a viable option as depicted in the diagrams.

Trenches divide up the community, more disruptive to underground services. And usage of space is minimised in most cases leaving the space above empty. And the connection are much lower.

Cut and cover is even more costly since you have to keep a long section of rail underground, so much more disruptive to underground services. Impractical along freight, and diesel train corridors, unless you have venting structure, then there is the cost of decking the whole corridor and developing on top, which in Melbourne a pretty urban spread city wouldn't work as effectively.

There was a university study covering this, but the link to it is broken. Daniel Bowen summarised it pretty well on his blog post. https://www.danielbowen.com/2016/03/02/under-or-over-level-crossing/
  woodford Chief Commissioner

Still no one has answered my question about what cheaper means, it's not clear whether the short term or long term is meant. Plenty of bridges over rail cuttings exist, and in some places that is the whole point of a cutting.
Until the mass grade separation from Caulfield to Dandenong, the only rail viaducts anywhere in the metropolitan area were two between Flinders and Spencer street stations. There have been quite a few grade separations in the past in already built up areas, and while some have involved bridges over roads, none have involved viaducts.
Myrtone
Not really correct, the line between West Richmond and Clifton hill is almost entirely on an embankmant, while not a viaduct there are numerous bridges over streets AND the line was built AFTER the suburbs were formed, ie  a large number of properties had to be cleared to build the line.

As far as I am concerned the advantages of raising a line over lowering it has been made quite clear in this and other threads on the subject. Constantly re asking the  question will not get you a different answer.

woodford
  BrentonGolding Chief Commissioner

Location: Maldon Junction
Constantly re asking the  question will not get you a different answer.

woodford
woodford
Well said Sir, well said indeed.

BG
  BrentonGolding Chief Commissioner

Location: Maldon Junction
Add to that drainage problems and associated costs with trenched sections as opposed to elevated where water can just run off into gutters.

And I would think ongoing maintenance would be cheaper and easier on an exposed line as opposed to a trenched one as well. If you had an extended section of trenched line then every item such as replacement sleepers, rail if required, top up or replacement ballast, overhead repair items etc would need to be brought in from one end of the trench or another along the rail line, I can't see the crews dropping a pallet of sleepers down though the gap between the wires and the sides of the trench.

BG
  potatoinmymouth Chief Commissioner

the line between West Richmond and Clifton hill is almost entirely on an embankmant
woodford


Not to mention a significant portion of the Burnley-Box Hill section, including a number of stations like Canterbury which would probably be described as Skyrail if built today.
  LancedDendrite Chief Commissioner

Location: Gheringhap Loop Autonomous Zone
Construction is far cheaper, mainly due to having less need to relocate underground services (this is only necessary where one runs across the corridor near the location where a pier is to be installed) and find something to do with the millions of tonnes of excavated material.
And what does "cheaper" mean in this case? And in the short term or long term? And that excavated material can be used to build embankments. That has been done many times in many places before.
Myrtone
These days there is a preference for using uniform engineered fill to build embankments in order to reduce the risk of uneven consolidation - which is rather important when you've got a tight construction schedule. The days of local cut-and-fill construction and using flocks of sheep to compact embankments are long gone.

Excavated soil from a railway corridor is automatically assumed to be contaminated in one way or another. That could be EPA scheduled contamination such as herbicide residue, oils - you name it, the VR probably spilled it or belched it out onto railway land at some stage. But more relevant to this discussion is the soil composition. Not all soil is suitable for use as engineered fill and screening it doesn't always fix the problem. Soils ain't soils...
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
Not really correct, the line between West Richmond and Clifton hill is almost entirely on an embankmant, while not a viaduct there are numerous bridges over streets AND the line was built AFTER the suburbs were formed, ie  a large number of properties had to be cleared to build the line.
woodford
And the line between Flinders street and Jolimont is in a cutting, with a bridge over it. There are countless other examples of rail cuttings.
For example, the Sandringham line between South Yarra and Greville street Prahran is in a cutting. There are three road bridges over it, at Toorak Road, a less well known street called Argo, and at Chapel street. There is also a footbridge between Toorak road and Argo street.
And another cutting between Prahran station and Union Street, Windsor, with bridges at Chapel street and the quite residential Green street. And another trench between Windsor station and Alma Road, East St. Kilda. And finally, another cutting between Glen Eira road, Ripponlea and just after Elsternwick station. There is a bridge at Hotham street, a footbridge, and one at Glen Huntley road.

And there is another cutting from South Yarra to Chapel street, with bridges at Toorak road, Williams street and of course at Chapel. And from Cromwell road, South Yarra to Williams road, Toorak, with bridges at those two roads. Finally, a cutting from Toorak station to Malvern station with six road bridges and a footbridge.

As far as I am concerned the advantages of raising a line over lowering it has been made quite clear in this and other threads on the subject.
woodford
And there are other advantages of lowering the rail line over raising it. Why else was rail under selected for St. Albans, which is quite flat?
  trainbrain Chief Commissioner

Not really correct, the line between West Richmond and Clifton hill is almost entirely on an embankmant, while not a viaduct there are numerous bridges over streets AND the line was built AFTER the suburbs were formed, ie  a large number of properties had to be cleared to build the line.
And the line between Flinders street and Jolimont is in a cutting, with a bridge over it. There are countless other examples of rail cuttings.
For example, the Sandringham line between South Yarra and Greville street Prahran is in a cutting. There are three road bridges over it, at Toorak Road, a less well known street called Argo, and at Chapel street. There is also a footbridge between Toorak road and Argo street.
And another cutting between Prahran station and Union Street, Windsor, with bridges at Chapel street and the quite residential Green street. And another trench between Windsor station and Alma Road, East St. Kilda. And finally, another cutting between Glen Eira road, Ripponlea and just after Elsternwick station. There is a bridge at Hotham street, a footbridge, and one at Glen Huntley road.

And there is another cutting from South Yarra to Chapel street, with bridges at Toorak road, Williams street and of course at Chapel. And from Cromwell road, South Yarra to Williams road, Toorak, with bridges at those two roads. Finally, a cutting from Toorak station to Malvern station with six road bridges and a footbridge.

As far as I am concerned the advantages of raising a line over lowering it has been made quite clear in this and other threads on the subject.
And there are other advantages of lowering the rail line over raising it. Why else was rail under selected for St. Albans, which is quite flat?
Myrtone
YAWN...………………………….
  Lockie91 Chief Train Controller

And the line between Flinders street and Jolimont is in a cutting, with a bridge over it. There are countless other examples of rail cuttings.
For example, the Sandringham line between South Yarra and Greville street Prahran is in a cutting. There are three road bridges over it, at Toorak Road, a less well known street called Argo, and at Chapel street. There is also a footbridge between Toorak road and Argo street.
And another cutting between Prahran station and Union Street, Windsor, with bridges at Chapel street and the quite residential Green street. And another trench between Windsor station and Alma Road, East St. Kilda. And finally, another cutting between Glen Eira road, Ripponlea and just after Elsternwick station. There is a bridge at Hotham street, a footbridge, and one at Glen Huntley road.

And there is another cutting from South Yarra to Chapel street, with bridges at Toorak road, Williams street and of course at Chapel. And from Cromwell road, South Yarra to Williams road, Toorak, with bridges at those two roads. Finally, a cutting from Toorak station to Malvern station with six road bridges and a footbridge.



Myrtone
I think you have managed to answer your own question. You have listed all the examples of rail cuttings in Melbourne and all the missed opportunities of "decking over". Building a few bridges still leaves a massive scar through an area and highlights how expensive it is. if there was any financial gain in the extremely complex engineering solution of decking over, we wouldn't be wasting time here. Victrack own the air right above all of these cuttings and have tried before to encourage developers to build above a rail line. it is just to darn expensive. Fed Sqaure east is a prime example of this.

As for St Albans, Main Road East had already been selected by the previous government as rail under before the Labor Government was elected. The LXRA then smartly added Furlong road to it. St Albans was originally priced at $400 million, thats just one removal. Again that just highlights how expensive it is.

Move on...
  reubstar6 Chief Train Controller

From a rider's point of view, looking into the suburbs is much nicer than looking at graffiti-filled concrete.
  Crossover Train Controller

Location: St. Albans Victoria
And the line between Flinders street and Jolimont is in a cutting, with a bridge over it. There are countless other examples of rail cuttings.
For example, the Sandringham line between South Yarra and Greville street Prahran is in a cutting. There are three road bridges over it, at Toorak Road, a less well known street called Argo, and at Chapel street. There is also a footbridge between Toorak road and Argo street.
And another cutting between Prahran station and Union Street, Windsor, with bridges at Chapel street and the quite residential Green street. And another trench between Windsor station and Alma Road, East St. Kilda. And finally, another cutting between Glen Eira road, Ripponlea and just after Elsternwick station. There is a bridge at Hotham street, a footbridge, and one at Glen Huntley road.

And there is another cutting from South Yarra to Chapel street, with bridges at Toorak road, Williams street and of course at Chapel. And from Cromwell road, South Yarra to Williams road, Toorak, with bridges at those two roads. Finally, a cutting from Toorak station to Malvern station with six road bridges and a footbridge.


I think you have managed to answer your own question. You have listed all the examples of rail cuttings in Melbourne and all the missed opportunities of "decking over". Building a few bridges still leaves a massive scar through an area and highlights how expensive it is. if there was any financial gain in the extremely complex engineering solution of decking over, we wouldn't be wasting time here. Victrack own the air right above all of these cuttings and have tried before to encourage developers to build above a rail line. it is just to darn expensive. Fed Sqaure east is a prime example of this.

As for St Albans, Main Road East had already been selected by the previous government as rail under before the Labor Government was elected. The LXRA then smartly added Furlong road to it. St Albans was originally priced at $400 million, thats just one removal. Again that just highlights how expensive it is.

Move on...
Lockie91
        Also the line is on an upgrade from Furlong road to past St albans is on an upgrade anyway which minimises the digging required whereas to put the roads under ; ( Furlong and Main road ) would have been far more disruptive to the community ,
          Further along at Keilor - Melton Highway the where there is more space to do so the road has been elevated over the tracks and the tracks have remained at ground level .
          In between at Taylors Road and Kings Road the tracks remained at Ground level and the road went underneath at both locations as both space and topography allowed this to occur .
          So on this stretch of line 3 different solutions have been applied ; Rail under in a trench , Rail under at Ground level & Road elevated according to what suites each location which is at should be .

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