Bias in favour of viaducts

 
  Nightfire Minister for Railways

Location: Gippsland
Much of what I have pointed out has been ignored, as usual. For example, I said that the idea is this if a level crossing is on top of a hill and the railway is uphill towards the crossing on both sides, then lowering the tracks is the obvious method of grade separation. Nobody responds, so no indication as to whether it is true or false.
Myrtone
That's probably the case for Union Road and Mont Albert Road level crossings on the Ringwood line.

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  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
While there may be other factors, if the level crossing is already higher than the track towards it (on both sides) than making the railway even higher is a rather loony way to grade separate the level crossing.
One other factor, in some cases, is underground services that cannot feasibly be diverted. In absence of such services, gradients are sure to be more important than, say, any short-term factors.
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
I know that gradients as steep as 2% are allowed, but does that mean that it is ever a good idea to increase existing gradients that are less than that when they could be flattened? If you know the answer to the question, just explain it, don't ignore the question.
  justapassenger Chief Commissioner

I know that gradients as steep as 2% are allowed, but does that mean that it is ever a good idea to increase existing gradients that are less than that when they could be flattened? If you know the answer to the question, just explain it, don't ignore the question.
Myrtone
Absolutely, there will be many occasions where the best overall result will involve greater gradients than were there before.

At most, the effect of the gradients on railway operations will be one of the factors which are considered as part of the Multiple Criteria Decision Analysis of the various options. It will usually be given a fairly low weighting, thanks to modern traction handling gradients so comfortably.

At the least, the only consideration given to the issue of gradients will be to simply check that each proposed option complies with the relevant standards for the gradients on both the railways and roads where they are to be changed.

This sort of decision requires the ability to see the forest for the trees, i.e. not focus too exclusively on any one part of the whole picture.
  Jack Le Lievre Chief Train Controller

Location: Moolap Station, Vic
It's not a short term consideration for those using the line, catching RR buses from Coburg to the City for 12 months? No thanks.
Construction costs, and disruption during the construction come under short term, the long term effects of the construction (which differ according to the method) come under long term considerations.
Myrtone
You may think that it is a Short Term Consideration, but it is actually a Long Term Consideration, as has been seen around the World, due to the fact that once you get people off of their regular PT (Train or Tram) and put them onto Rail Replacement Buses, you end up losing between 5-25% of them to their own private transport i.e. their car, and they generally don't come back either ever or for years after the project is completed. Which then creates more congestion on the road network.
  Crossover Train Controller

Location: St. Albans Victoria
It's not a short term consideration for those using the line, catching RR buses from Coburg to the City for 12 months? No thanks.
Construction costs, and disruption during the construction come under short term, the long term effects of the construction (which differ according to the method) come under long term considerations.
You may think that it is a Short Term Consideration, but it is actually a Long Term Consideration, as has been seen around the World, due to the fact that once you get people off of their regular PT (Train or Tram) and put them onto Rail Replacement Buses, you end up losing between 5-25% of them to their own private transport i.e. their car, and they generally don't come back either ever or for years after the project is completed. Which then creates more congestion on the road network.
Jack Le Lievre
Has this happened i Melbourne to any noticeable extent ? Or are people happy to see progress being made and are prepared to put up with some inconvenience as long as this is the case ?
  62440 Chief Commissioner

I know that gradients as steep as 2% are allowed, but does that mean that it is ever a good idea to increase existing gradients that are less than that when they could be flattened? If you know the answer to the question, just explain it, don't ignore the question.
Myrtone
Have a look at the track profile at Reservoir, at the end of a long steep incline. You can maintain the gade and push the station slightly north or go down. Then look at what is under the ground and the elevated option stands out. Also have fun planning road deviations during construction of the cut option. Much easier to put in a few pylons and lift spans in! There are plenty of locations where the elevated option comes with a greatly reduced land take with a side benefit of useful land
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
Absolutely, there will be many occasions where the best overall result will involve greater gradients than were there before.
justapassenger
And I don't understand why this wasn't explained before when I mentioned gradients, there is nothing obvious about this.

If a level crossing is due for removal, and someone who knows the gradients in the area assumes that the solution that flattens those gradients would be the preferred solution, is this assumption understandable, even if the existing gradients are less than 2%.

At most, the effect of the gradients on railway operations will be one of the factors which are considered as part of the Multiple Criteria Decision Analysis of the various options. It will usually be given a fairly low weighting, thanks to modern traction handling gradients so comfortably.
justapassenger
Even so, the idea that increasing gradients that could be flattened would be the way to go does seem hard to believe and that that the best overall result would mean steeper gradients than before surprises me. Remember, I think in pictures, and also in patterns.
And many others here, possibly even those makers of these decisions, are failing to get pictures that I can clearly see.

At the least, the only consideration given to the issue of gradients will be to simply check that each proposed option complies with the relevant standards for the gradients on both the railways and roads where they are to be changed.
justapassenger
That does seem like not really taking

This sort of decision requires the ability to see the forest for the trees, i.e. not focus too exclusively on any one part of the whole picture.
justapassenger
I'm not sure what this means.

You may think that it is a Short Term Consideration, but it is actually a Long Term Consideration, as has been seen around the World, due to the fact that once you get people off of their regular PT (Train or Tram) and put them onto Rail Replacement Buses, you end up losing between 5-25% of them to their own private transport i.e. their car, and they generally don't come back either ever or for years after the project is completed. Which then creates more congestion on the road network.
Jack Le Lievre

When compared to things like running costs and amenity, it is a short-term consideration.

There may be occasions where a level crossing removal will mean greater gradients then before, say if there is an aqueduct right under the level crossing, even though it is at the top of the hill, and it is to close to the surface for a trench to be dug.

But surely solutions that flatten gradients are more likely to be preferred than solutions that increase gradients. Even if not, is the assumption understandable.
  Nightfire Minister for Railways

Location: Gippsland



When compared to things like running costs and amenity, it is a short-term consideration.

There may be occasions where a level crossing removal will mean greater gradients then before, say if there is an aqueduct right under the level crossing, even though it is at the top of the hill, and it is to close to the surface for a trench to be dug.

But surely solutions that flatten gradients are more likely to be preferred than solutions that increase gradients. Even if not, is the assumption understandable.
Myrtone
Glenhuntly to Paterson Is an example where train unfriendly grades were Introduced as part of the level crossing removal process.
the 3 new station are all In dips, requiring extra braking for trains Intending to stop at the stations and extra acceleration to drag a stationery train out of a hollow and up to (or as close to) line speed)

Not the mention the extra forever ongoing costs associated with managing storm and ground water.
  justapassenger Chief Commissioner

Absolutely, there will be many occasions where the best overall result will involve greater gradients than were there before.
And I don't understand why this wasn't explained before when I mentioned gradients, there is nothing obvious about this.

If a level crossing is due for removal, and someone who knows the gradients in the area assumes that the solution that flattens those gradients would be the preferred solution, is this assumption understandable, even if the existing gradients are less than 2%.
Myrtone
The answer to your question here is that your assumption is valid, but less important than you think it is.

The very fact that the policy for level crossing removal projects in Victoria is to set a ruling gradient rather than to prohibit all increased gradients should be enough to show you that your assumption is not of high importance.

The preferred solution will always be the one which does the best job of balancing ALL of the various impacts associated with the project.

At most, the effect of the gradients on railway operations will be one of the factors which are considered as part of the Multiple Criteria Decision Analysis of the various options. It will usually be given a fairly low weighting, thanks to modern traction handling gradients so comfortably.
Even so, the idea that increasing gradients that could be flattened would be the way to go does seem hard to believe. Remember, I think in pictures, and also in patterns.
And many others here, possibly even those makers of these decisions, are failing to get pictures that I can clearly see.
Myrtone
The problem is that you are seeing just a small part of the picture, not the whole picture.

To get around the problem of people only having a partial view of the picture, planners use a tool called a Multiple Criteria Decision Analysis (or Multi-Criteria Analysis) to analyse the impacts of a project in an objective manner and put forward the best options for adoption. Eliminating bias completely is probably a lost cause in Australia given that final approval of infrastructure projects is often a political decision, so the best that planners can do is to present good recommendations which encourage good decisions.

In the case of the sort of planning study related to a level crossing grade separation project, one particular planning study in SA had the MCA considering the impacts of the construction and operation on 25 different criteria (grouped into four categories) for the four main options - road overpass, rail overpass, road underpass, rail underpass. One of the criteria was the impacts on rail transport, which is where all aspects of the proposed rail line design (including gradients) were discussed.

When reporting the findings of the MCDA, a good pictorial representation (which should help you) of the information is to have it shown it in a table with cells coloured according to the level of impact in each of the criteria - the pages shown below have used no impact or positive impact green, slight negative impact yellow, moderate negative impact orange, high negative impact red. A quick glance is all that's needed to see which option has the most green and which has the most orange/red.

You can also show the overall scores for each of the options on a graph.

Here are a few pages with the results of the MCDA conducted as part of a planning study related to a suburban level crossing grade separation project proposal in SA. I've redacted some information (name of the proposed project, title of the various options) to eliminate bias. Have a look at each of these pages:
1. all criteria - link
2. construction impacts only - link
3. operational (i.e. post-construction) impacts only - link
4. financial criteria only - link
5. financial criteria excluded - link

Having had a look at that, tell me which option you would prefer to go ahead with for that project and why. Once you've given your answer, I'll give you an update on what happened after this planning study was completed.

At the least, the only consideration given to the issue of gradients will be to simply check that each proposed option complies with the relevant standards for the gradients on both the railways and roads where they are to be changed.
That does seem like not really taking
Myrtone
Is this an incomplete sentence?

I'm guessing what you meant to write was something along the lines of “That does seem like not really taking the gradients seriously.” Correct?

If so, I do agree. But that was exactly the point I was making - simply checking for compliance rather than considering the impact would be an example of the lowest level of priority given to the rail gradients.

It goes something like this:
Absolute priority given to rail gradients- design the whole project around the proposed gradient of the railway line, regardless of what other detrimental outcomes may result from selecting that option
Reasonable priority given to rail gradients - consider the railway gradients as part of a logical process aimed at finding the most satisfactory outcome for all aspects
Minimum practical priority given to rail gradients - check for compliance but otherwise ignore the railway gradients


Would you not agree that the middle option is the most logical approach to take?

This sort of decision requires the ability to see the forest for the trees, i.e. not focus too exclusively on any one part of the whole picture.
I'm not sure what this means.
Myrtone
Sorry, I forgot about your difficulties with idioms so I'll explain it.

To see the forest for the trees means that you can see the whole issue, not just part of it.

To not see the forest for the trees means that you are focused on one part of an issue and running the risk of getting so overwhelmed by detail that you'll be rendered incapable of understanding other parts of the issue.

The origin of the idiom lies in the world of biology. It is impossible to understand a forest by doing a very detailed study of just one tree, because a forest is a heavily interlinked system. In turn, this means you won't be able to get a full understanding of that tree either, because the growth and health of that tree is influenced by the health of the whole forest.

Or consider this word-picture:
If you are an expert in designing public toilet facilities, you are not qualified to be the lead architect for designing a new school building. You may be engaged by the lead architect to consult on the design of the toilet facilities incorporated into the school, but that will only be one part of the bigger project and you will not be permitted to have any input on designing the classrooms or staff offices.  

Going back to a suburban rail project, this means that focusing on the gradients may lead to you being ignorant of other aspects associated with a project. Sound decisions might appear to be wrong (or 'biased') to you because you have only considered the gradients and not other issues like service relocation, Austroads standards, usage of public space, community severance etc.

A key part of exercising intelligence is knowing what you don't know. You certainly know way more about the gradient profiles of railways in the Melbourne metropolitan area than I do, so I would never question you on that. Have a look through all my posts, I have never questioned the accuracy of your knowledge in that area.

In turn, I am confident that I am one of many forum members who know significantly more about modern railway operations and public planning processes than you do, and I am sure I would not be alone in appreciating it if you started adopting a more respectful and open attitude to others when they answer questions you have about areas where you have less knowledge. Deal?
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
Glenhuntly to Paterson Is an example where train unfriendly grades were Introduced as part of the level crossing removal process.
the 3 new station are all In dips, requiring extra braking for trains Intending to stop at the stations and extra acceleration to drag a stationery train out of a hollow and up to (or as close to) line speed)
Nightfire
Actually, in that case, there was a compelling reason for that, apparently, some large underground pipe that is, for all intents and purposes, indivertible.

Not the mention the extra forever ongoing costs associated with managing storm and ground water.
Nightfire
I didn't realise that there was a need to manage this in that location, nor that there would be an ongoing cost. I gather that the only reason for rail under in that location is that the railway already ran under Brewer road near Patterson station.

What if the railway were only lowered under McKinnon and Centre roads and raised over North Road? It already ran over Woodville Avenue between Ormond and Glenhuntly.

While I couldn't think of anything to stay about most of your long post:

The answer to your question here is that your assumption is valid, but less important than you think it is.
justapassenger
Ah okay, and to anyone reading this, if a valid assumption is less important that it might seem, then someone needs to say so.

Having had a look at that, tell me which option you would prefer to go ahead with for that project and why. Once you've given your answer, I'll give you an update on what happened after this planning study was completed.
justapassenger
The pages to which you linked are hard to grasp, especially as it is in quite small print.

At the least, the only consideration given to the issue of gradients will be to simply check that each proposed option complies with the relevant standards for the gradients on both the railways and roads where they are to be changed.
That does seem like not really taking
Is this an incomplete sentence? I'm guessing what you meant to write was something along the lines of “That does seem like not really taking the gradients seriously.” Correct?
justapassenger
Well, sorry for the incomplete sentence, I couldn't think of how to say what I wanted to say on it, but it did feel as if consideration given to gradients is too low.

If so, I do agree. But that was exactly the point I was making - simply checking for compliance rather than considering the impact would be an example of the lowest level of priority given to the rail gradients.
justapassenger
And too low because heavy rail needs very flat gradients, much flatter that roads, tramways or even light rail lines.

It goes something like this:
Absolute priority given to rail gradients- design the whole project around the proposed gradient of the railway line, regardless of what other detrimental outcomes may result from selecting that option
Reasonable priority given to rail gradients - consider the railway gradients as part of a logical process aimed at finding the most satisfactory outcome for all aspects
Minimum practical priority given to rail gradients - check for compliance but otherwise ignore the railway gradients
justapassenger
Given the sort of ruling gradients that trains need, either top or middle. On the whole, railway gradients ought to be given a higher priority than road gradients.

Maybe if it is possible to change the level of the road crossing the railway, then almost absolute priority to rail gradients, especially more than 1%, would be the way to go. But if not, then reasonable priority, even though gradients as steep as 2% are allowed, it seems a good idea to avoid gradients steeper than 1% wherever possible.
Even the recent grade separation in St. Albans only involves gradients as steep as 1.96%.

To see the forest for the trees means that you can see the whole issue, not just part of it.
I had some idea of what it would mean, just wasn't quite sure.

It is impossible to understand a forest by doing a very detailed study of just one tree, because a forest is a heavily interlinked system.
justapassenger
It not just impossible, but it is really absurd of someone to think so.

If you are an expert in designing public toilet facilities, you are not qualified to be the lead architect for designing a new school building. You may be engaged by the lead architect to consult on the design of the toilet facilities incorporated into the school, but that will only be one part of the bigger project and you will not be permitted to have any input on designing the classrooms or staff offices.
justapassenger
And what impact would the design of classrooms and offices have on the design of restroom facilities?

Going back to a suburban rail project, this means that focusing on the gradients may lead to you being ignorant of other aspects associated with a project. Sound decisions might appear to be wrong (or 'biased') to you because you have only considered the gradients and not other issues like service relocation, Austroads standards, usage of public space, community severance etc.
justapassenger
As for service relocation, I am happy to consider that if I know at least some of the underground services in that area. Some underground services can simply be deemed to not be relocatable if that would be too costly and too disruptive.

A key part of exercising intelligence is knowing what you don't know. You certainly know way more about the gradient profiles of railways in the Melbourne metropolitan area than I do, so I would never question you on that. Have a look through all my posts, I have never questioned the accuracy of your knowledge in that area.
justapassenger
I didn't realise you didn't know things like this. I'll give you an example in our eastern suburbs:
Heatherdale road, Heatherdale. Before, there was a station and a level crossing together on top of a hill. Uphill towards the station on one side and towards the level crossing on the other. Now the railway runs through the hill and under Mitcham road and that would probably have made more sense in the first place. It makes more sense to have a railway through a hill and under a road than to have a level crossing with opposite gradients on each side.

In turn, I am confident that I am one of many forum members who know significantly more about modern railway operations and public planning processes than you do, and I am sure I would not be alone in appreciating it if you started adopting a more respectful and open attitude to others when they answer questions you have about areas where you have less knowledge.
justapassenger
Look, when I said lowering the railway is the way to go wherever it flattens gradients, I was thinking of locations where there are no such underground services in the way. I do accept that this might not be the way if there are underground services that, say, cannot be moved.
  jdekorte Deputy Commissioner

Location: Near Caulfield Station
Just quick clarification re the Ormond - Bentleigh grade separation projects.

Yes, all stations were put into dips and then rise back to ground level between stations.  This is due to the Murray St Drain and drains near Bentleigh all of which form part of the Elster Ck catchment.  

I've read reports on the building of this project and the innovative means of doing so.  There was a significant groundwater problem to deal with, especially with McKinnon and Bentleigh.  Just to give a quick rundown on what I have learned so far:

- All stations are equipped with very expensive pumps imported from Singapore which work 24/7 to manage the ground water. I believe these can be sort of viewed at the down end of each island platform.

- McKinnon & Bentleigh are essentially giant concrete boxes designed to weigh them down to stop them floating.  Each have a very thick floor of concrete which was laid over layers of crushed rock, stone and waterproof matting.

- Ormond has giant steel tubes which are visible over the platforms which hold the walls apart.

- When installing the extensive steel sheet piles, the water table had to be lowered temporarily in order to achieve this. Likewise the trenches also had to be temporarily dewatered.

- It is quite probable that when Edithvale and Bonbeach are grade separated that they will require similarly expensive treatment to make them watertight as they are close to the bay.  These treatments could also be used for Mentone and Cheltenham which are also in the sand belt areas.

Link: Conference paper (8th Australian Small Bridges Conference):
Title: Sheet Pile Retaining Walls - Design and Construction in a brown fields environment.
Summary: This paper deals with the construction methods used in the Ormond - Bentleigh project and is extremely interesting reading.
https://www.eiseverywhere.com/file_uploads/a006ae0b8378b98eedb487305731a78a_Sheet_Pile_Retaining_Walls_Design_and_Construction_in_a_Brown_Fields_Environment_Amir_Holakoo_KBR.pdf
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
Yes, all stations were put into dips and then rise back to ground level between stations.  This is due to the Murray St Drain and drains near Bentleigh all of which form part of the Elster Ck catchment.
jdekorte
Maybe putting the railway over North Road would have been a better choice.

I've read reports on the building of this project and the innovative means of doing so.  There was a significant groundwater problem to deal with, especially with McKinnon and Bentleigh.
jdekorte
So why rail under at Ormond as well?


- All stations are equipped with very expensive pumps imported from Singapore which work 24/7 to manage the ground water. I believe these can be sort of viewed at the down end of each island platform.

- McKinnon & Bentleigh are essentially giant concrete boxes designed to weigh them down to stop them floating.  Each have a very thick floor of concrete which was laid over layers of crushed rock, stone and waterproof matting.

- Ormond has giant steel tubes which are visible over the platforms which hold the walls apart.

- When installing the extensive steel sheet piles, the water table had to be lowered temporarily in order to achieve this. Likewise the trenches also had to be temporarily dewatered.

- It is quite probable that when Edithvale and Bonbeach are grade separated that they will require similarly expensive treatment to make them watertight as they are close to the bay.  These treatments could also be used for Mentone and Cheltenham which are also in the sand belt areas.
jdekorte

-Nevertheless, rail under was the way to go at McKinnon and Bentleigh because the railway already ran under Brewer road near Patterson station.

-Those tubes would have been avoided with rail over.

- As for Edithvale and Bonbeach, the more sensible option is rail over and I wonder if the anti-Skyrail people living there have a basic knowledge of the local geography, rail gradients, etc. Furthermore, there are currently no rail trenches in any low lying area close to the sea, there seem to be none in Australia, and I have not heard of any elsewhere in the world.
  jdekorte Deputy Commissioner

Location: Near Caulfield Station
Yes, all stations were put into dips and then rise back to ground level between stations.  This is due to the Murray St Drain and drains near Bentleigh all of which form part of the Elster Ck catchment.
Maybe putting the railway over North Road would have been a better choice.

I've read reports on the building of this project and the innovative means of doing so.  There was a significant groundwater problem to deal with, especially with McKinnon and Bentleigh.
So why rail under at Ormond as well?
-Nevertheless, rail under was the way to go at McKinnon and Bentleigh because the railway already ran under Brewer road near Patterson station.

-Those tubes would have been avoided with rail over.

- As for Edithvale and Bonbeach, the more sensible option is rail over and I wonder if the anti-Skyrail people living there have a basic knowledge of the local geography, rail gradients, etc. Furthermore, there are currently no rail trenches in any low lying area close to the sea, there seem to be none in Australia, and I have not heard of any elsewhere in the world.
Myrtone
Actually, yes and no. The Brewer Road bridge was one of the reasons the trenches were built but it isn't the main reason. The main reason Ormond - Bentleigh is rail under is due to previous planning and the change of government in 2014.

I'm summarising a blog post on the topic by Daniel Bowen who lives in the area: https://www.danielbowen.com/2016/03/09/bentleigh-skyrail/

The North Road (Ormond) project was funded by the Coalition government in 2014 who were voted out in Nov. 2014.  Following the election the project was combined as a single works package with the Burke Road (Gardiner) project which was also funded, and McKinnon & Bentleigh were added into the works package in order to maximise the project benefits while also lowering some costs.

Basically, planning had already commenced on the Ormond project for a rail under solution with early plans having the rail over bridge between Glenhuntly & Ormond removed - this didn't happen under revision of the project.  It made sense to have McKinnon & Bentleigh to go under as well despite the complex engineering required.  There was no indication that this project was ever destined to be elevated.  Remember that previously the line sloped upwards from Bentleigh to Ormond and due to this topography I'm guessing this was also a factor.  Yes the grades up from Ormond are steep however freight trains seem to manage this. The Brewer Rd bridge was one of the concern but not the major concern in project design. And in terms of the project itself, the Brewer Rd bridge has been left untouched.
  62440 Chief Commissioner


- As for Edithvale and Bonbeach, the more sensible option is rail over and I wonder if the anti-Skyrail people living there have a basic knowledge of the local geography, rail gradients, etc. Furthermore, there are currently no rail trenches in any low lying area close to the sea, there seem to be none in Australia, and I have not heard of any elsewhere in the world.
Myrtone
Have a look at Esplanade in Perth (whatever it is called now). It is massive to stop it floating.

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