Well I personally think that you, Myrtone, have a bias AGAINST viaducts!

Well I personally think that you, Myrtone, have a bias AGAINST viaducts!

I think he even has a bias against road over rail bridges too.

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.

There have been plenty of grade separations in Melbourne using embankments, however.

West Richmond - Clifton Hill. Hawthorn - Auburn. Canterbury. Malvern - Caulfield. Balaclava. St Kilda - Windsor. Patterson. Bay Road (Southland). Woodville Ave (Ormond).

It's been long noted that these don't share the negative features of skyrail simply because they have been there so long now that people don't notice them.

Historically, the railways have always chosen the most cost effective grade separation approach given the local topography, the available land, and the surrounding land use.

I suspect the move from embankments to viaducts is because the greater vehicle clearance required now means that embankments would be too expensive.

Hello All,

I would add that the comparative cost of reinforced viaducts that can be assembled by crane, and the use of large screw bore machines to dig the requisite holes is also now comparatively cheaper to any other method.

Look at buildings , any multi storey building now utilises a crane, as with proper logistics planning, a good proportion of the build can now be done in a day utilizing a mobile crane, which is quicker and safer than previous methods.

For the Metro area a viaduct allows almost all of the underfoot to be easily accessible, does not require expensive bridges to be built over a trench , reduces ( but not eliminates ) trespass and drainage is not a major problem.

Finally, there is a mining company in WA who intends to build a 300km + line all on viaducts as that is cheaper than a ground level railway, minimises ground works, and eliminates grade crossings and floods , so it is not surprising that viaducts are now preferred.

Regards, Radioman.

Well I personally think that you, Myrtone, have a bias AGAINST viaducts!

I think he even has a bias against road over rail bridges too.

@stooge spark I am not against viaducts in all locations, I favour them in low lying areas, especially near the sea. The problem is the reliance on them, and the idea of them as a a default. There are some locations where lowering the rail would flatten nearby gradients and is therefore the way to go. It may also keep other future options open.
And I noted at the start that I lean towards road based grade separations, mainly in flat areas where that can be done without building demolition.

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

And being elevated there is less chance of someone tresspassing on the line.

I'll add my 2c...

Yes there has been some commentary on social media and other places complaining that grade separations should all be rail under. But we all know this isn't practical for all locations - I'd like to think the community can get over this notion. Despite all the evidence that is usually presented as to why an elevated solution has been selected there are still naysayers that think that trenches are superior and are less of a blight on the community (because you can't see into them and notice the graffiti) (yeah right).

Since when has any kind of concrete construction looked pretty...?

I might add that for some of the more recent crossing removals that were done as rail under solutions - Ormond-Bentleigh - even this wasn't really a full trench as the line comes back to ground level between stations. This was a necessary way of doing things given the large drains that cross under the railway at Murray St and around Bentleigh. We all know that a bulk of the cost of a crossing removal is relocation of services. Some services can be modified but on the whole can't be relocated, at least the larger services. Regarding the CD9 project there were some things that couldn't be moved - the Gas pipeline, the Murrumbeena Main Drain and Mile Creek. It surprises me that trench advocates thought that these things could be pushed out of the way or, that railway grades would be adequate to get over the top of them and back down again. In the case of the Murrumbeena Main Drain which lies roughly midpoint between Murrumbeena & Hughesdale, it is just underneath the (old) embankment where the road on the south side is at its lowest point and where flooding has been an issue in the past. Despite pointing this out to trench advocates that this is where floods occur they still thought they could remove the embankment and put the railway down - nature doesn't work that way. Perhaps this was a reason the embankment was there in the first place...?

For me personally I can see the advantages of using rail over methods as a way of activating space underneath. I can also see the advantage of using rail under which has been useful for the many projects along the Ringwood corridor. And there is also the hybrids that are being built like at Seaford which is a rail up/road down solution.

Each project is different in some way and provided the reasoning behind the solution is logical (and not based on community sentiment like Edithvale & Bonbeach) then that's the way they should be built.

It surprises me that trench advocates thought

I think you’re giving the No Skyrail crowd a bit too much credit here.

The “trench advocates” as you call them were not ultimately motivated by the railway. The “controversy” about Skyrail has been the product of good old-fashioned NIMBYism, combined with an Opposition soundbite that caught on and fitted nicely on the front page of the Herald Sun. If the CD9 had gone ahead as a trench you can absolutely guarantee the same people would have been all over the media whinging about the cost and the noise and the ugliness and asking why couldn’t they have a viaduct and Dan Andrews is a bad bad man.

None of this is to impugn any of the  genuine “trench advocates” here or elsewhere who have argued their case based on sound engineering/economics logic and evidence. My point is simply that it can’t be assumed the Skyrail discussion in media and community advocacy is or will ever be rational.

None of this is to impugn any of the  genuine “trench advocates” here

I dunno, I can think of at least one who needs to be impugned.......

BG

Take a look at the gradient diagram of the Upfield line. Lowering the entire section from Anstey to Batman would flatten the gradient just after Batman and flatten part of the gradient between Brunswick and Moreland.

Take a look at the gradient diagram of the Upfield line. Lowering the entire section from Anstey to Batman would flatten the gradient just after Batman and flatten part of the gradient between Brunswick and Moreland.

It would also cost a squillion dollars more than rail over, for no discernible extra benefit. The rail gradient is of little or no consequence these days. It may have been in the days of suburban steam, but not now.

And yet rail-under is being considered for this project.

And yet rail-under is being considered for this project.

Of course it is, and so it should be. Competent planners explore all avenues.
My opinion remains as stated previously.

The result of raising or lowering is different. That's the long term. It also differs in what future options are kept open. And in fact, lowering an electrified railway does allow development on top. I know it's not common here, but it may be more common overseas.
There is a shopping centre next to Coburg station and dropping the line would allow expansion of the shopping centre and integration of it with the new Coburg station.

Embankment - requires large foot print, takes long time to build, the entire land underneath is lost for other uses and makes it easy to access the ROW for vandals, subject to subsidence and destroying houses either side.

Viaduct - fast to build, less trucks, smaller foot print, land underneath not lost for other uses, difficult to access ROW

Note : China has built the vast bulk of its HSR on Viaduct, ie nearly 10,000km of viaduct even in middle of no where its still on a viaduct.

Trench - basically falls into the same category as Embankment, with added benefit of risk of flooding

The result of raising or lowering is different. That's the long term. It also differs in what future options are kept open. And in fact, lowering an electrified railway does allow development on top. I know it's not common here, but it may be more common overseas.
There is a shopping centre next to Coburg station and dropping the line would allow expansion of the shopping centre and integration of it with the new Coburg station.

If the shopping centre owner wants to contribute the difference in cost and IF the terrain is suited to it then this sounds like an idea with merit. For that station.

That is very different to lowering the whole section of line that you are suggesting if no one is prepared to pay for the huge difference in cost.

Having said that property prices in Brunswick and West Brunswick have been going up very rapidly over the last few years so integrating the line into surrounding developments could be feasible in that corridor.

Student accomodation around RMIT University could be a good start. But as mentioned by other posters this has been tried before in Victoria with limited success.

The councils and locals would bristle at the thought of the line being closed for extended periods while they tug the trench and filled it with concrete.

BG

Embankment - No comment.
Viaduct - In spite of this, it isn't best for even most locations.
Trench - But what about tunnels, even cut-and-cover ones do better than viaducts. It is possible to roof over trenches, which allows for other uses.

And regarding gradients, railways have ruling gradients, diversions and extensions are built with these gradients or less steep. Building steeper is comparable to building a new line with a smaller loading gauge than the existing network.

If the shopping centre owner wants to contribute the difference in cost and IF the terrain is suited to it then this sounds like an idea with merit. For that station.

The terrain is suited to it, or at least that's what the gradient diagram suggests.

That is very different to lowering the whole section of line that you are suggesting if no one is prepared to pay for the huge difference in cost.

What whole section? Could it be lowered in stages?

Having said that property prices in Brunswick and West Brunswick have been going up very rapidly over the last few years so integrating the line into surrounding developments could be feasible in that corridor.

Property prices have to do with supply and demand. Building over the tracks means more supply.

No comment on the rest.

There is a shopping centre next to Coburg station and dropping the line would allow expansion of the shopping centre and integration of it with the new Coburg station.

Raising the line on a viaduct can do that as well, you know.
From what I understand, I think you mean building another block for some more shops, not an expansion of a northland style shopping centre (which doesn't exist in Coburg, let alone near the station).

Of course it can, but I my point is that rail under also allows it, at least if it is dedicated to electric trains.

Next Railpage thread coming: "Bias in favour of cut and cover".

I've learned long ago that once Myrtone has made up their mind on a subject, no discussion will change it.

Don't waste your time and lock the thread down.

What you should understand is this; If I bring up a factor that you aren't taking into account, things like "doesn't matter" don't convince me. You can't (easily) convince me that it's unimportant.

I am not biased in favour of "cut and cover" because I'm not saying this, or any other method is even the best default. I still don't see the problem with roofing over the cutting of an electrified railway, I know some have tried to explain it, but I don't get it. I can see a problem with roofing over a railway used by steam and/or diesel trains, however.

What you should understand is this; If I bring up a factor that you aren't taking into account, things like "doesn't matter" don't convince me. You can't (easily) convince me that it's unimportant.

I am not biased in favour of "cut and cover" because I'm not saying this, or any other method is even the best default. I still don't see the problem with roofing over the cutting of an electrified railway, I know some have tried to explain it, but I don't get it. I can see a problem with roofing over a railway used by steam and/or diesel trains, however.

There are myriad problems, the first of which is PRICE. Governments need to strive for the best outcome for taxpayers not railfans.

Then there is geology, other services lying under the rail line such as gas, water, sewerage, electricity etc etc- on a line like Upfield build many years ago through older suburbs with LXs very close together this probably includes old brick sewer mains and a heap of asbestos covered ducting as well.

Then there is the fact that with a Skyrail type project you can do much of the work with the existing line still operating especially in the initial stages as we have seen recently with projects on the Caulfield group. Normally for a trench you would consider skewing the existing line or digging the trench next to the existing as was done with Ginifer and St Albans but there would not be the room for that in the Brunswick > Coburg corridor, the corridor is far too narrow so you would need to close the line for the entirity of the project, months and months, probably a year or longer.

The social cost of that alone would be enormous let alone the economic cost

BG

Then there is geology, other services lying under the rail line such as gas, water, sewerage, electricity etc etc- on a line like Upfield build many years ago through older suburbs with LXs very close together this probably includes old brick sewer mains and a heap of asbestos covered ducting as well.

Okay, sometimes services under the railway preclude lowering it, so definitely rail over in cases like that.

Then there is the fact that with a Skyrail type project you can do much of the work with the existing line still operating especially in the initial stages as we have seen recently with projects on the Caulfield group. Normally for a trench you would consider skewing the existing line or digging the trench next to the existing as was done with Ginifer and St Albans but there would not be the room for that in the Brunswick > Coburg corridor, the corridor is far too narrow so you would need to close the line for the entirity of the project, months and months, probably a year or longer.

But this is a short term consideration, not a long term one. Also, rail under may keep open future options that are precluded by raising the tracks.