Fixing bottlenecks

 
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
There are at least two major bottlenecks on the Melbourne suburban, these being double track sections each served by two or more routes:

*Jolimont to Clifton Hill, shared between Epping trains and those in the Northeastern group (Macleod, Greensborough, Eltham and Hurstbridge)
*Footscray to Newport, shared by the Williamstown and Weribee lines.

Other bottlenecks include:

*Caulfield to Dandenong, shared between the Carnboure and Pakingham lines, though the latter is single track on the outer section.
*North Melbourne to Newmarket, trains to Showgrounds shared this with Craigiburn ones on special occasions.

Is there are feasible way to fix these bottlenecks? Without them, there would be room to run more express trains, specifically, more trains to/from the outer suburbs would run express in the inner city, so giving our suburban rail network a higher capacity ceiling.

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  kuldalai Chief Commissioner

There is not a capacity issue between Clifton Hill and Jolimont or in the Clifton Hill Loop which has spare capacity to absorb increased service frequency with the committed extension from Mill Park (currently wrongly named as South Morang) to Mernda.

The entire section North Melbourne to Broadmeadows presents a capacity problem. In the medium term the plan is route VLP trains via Upfield.releasing train paths to Metro via Essendon. Longer term high capacity signalling can be installed. High capacity signalling is to be trialled soon on the Sandringham line.

With the Dandenong line the intention is to instal high capacity signalling as also to be installed in the new Metro tunnel.
  kuldalai Chief Commissioner

There is not a capacity issue between Clifton Hill and Jolimont or in the Clifton Hill Loop which has spare capacity to absorb increased service frequency with the committed extension from Mill Park (currently wrongly named as South Morang) to Mernda.

The entire section North Melbourne to Broadmeadows presents a capacity problem. In the medium term the plan is route VLP trains via Upfield.releasing train paths to Metro via Essendon. Longer term high capacity signalling can be installed. High capacity signalling is to be trialled soon on the Sandringham line.

With the Dandenong line the intention is to instal high capacity signalling as also to be installed in the new Metro tunnel.
  LancedDendrite Chief Commissioner

Location: Gheringhap Loop Autonomous Zone
Single track sections pose a far bigger 'bottleneck' to the network than duplicated track sections. As Kuldalai points out, some sections of duplicated track do pose medium term problems, mostly due to the presence of mixed traffic (stopping all stations + express + Vline) but these are dwarfed by the single-track sections on the network.

Duplicated track has a theoretical capacity of 24 trains per hour using uniform stopping patterns and conventional lineside signalling. Accounting for possible delays by including some extra headway into the timetable gets you down to 20 trains per hour. Only the City Loop tunnels are hitting that 20tph ceiling - and that's with anywhere from 2-4 separate lines converging on each tunnel.

On the other hand, single-line sections of the network can have capacities of 3-6 tph currently, with little prospect of improvement short of full duplication of those sections.
  Nightfire Minister for Railways

Location: Gippsland
There are at least two major bottlenecks on the Melbourne suburban, these being double track sections each served by two or more routes:

*Jolimont to Clifton Hill, shared between Epping trains and those in the Northeastern group (Macleod, Greensborough, Eltham and Hurstbridge)
*Footscray to Newport, shared by the Williamstown and Weribee lines.

Other bottlenecks include:

*Caulfield to Dandenong, shared between the Carnboure and Pakingham lines, though the latter is single track on the outer section.
*North Melbourne to Haymarket, trains to Showgrounds shared this with Craigiburn ones on special occasions.
Myrtone
How about you check the spelling of names of stations before posting !

The Is no such station In Melbourne called Haymarket ! Newmarket fits the bill for the location (there Is a Haymarket roundabout)


A way way Into the future plan Is to build an underground tunnel from around Clifton Hill/Merri (for the Epping line) through the CBD and Fishermen's Bend and out to Newport (for Werribee trains)
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
There is not a capacity issue between Clifton Hill and Jolimont or in the Clifton Hill Loop which has spare capacity to absorb increased service frequency with the committed extension from Mill Park (currently wrongly named as South Morang) to Mernda.
kuldalai
But there are only two tracks between Clifton Hill and Jolimont, how could there not be a capacity issue if it is shared by two routes and trains in the Northeastern group skip most stations.

The entire section North Melbourne to Broadmeadows presents a capacity problem. In the medium term the plan is route VLP trains via Upfield.releasing train paths to Metro via Essendon. Longer term high capacity signalling can be installed. High capacity signalling is to be trialled soon on the Sandringham line.
kuldalai
Routing VLP trains via Upfield would be questionable, even with the duplication of the track north of Gowrie, because of the frequent level crossings, some of which are over roads as busy and Brunswick road and Bell street. And the most effective way to remove level crossings, while also making the line more direct between Brunswick and the CBD, among other benefits is discussed here.

With the Dandenong line the intention is to instal high capacity signalling as also to be installed in the new Metro tunnel.
kuldalai
But we surely need at least one extra track if we are going to run any express services. I hope that high capacity signalling will be bidirectional.

Single track sections pose a far bigger 'bottleneck' to the network than duplicated track sections. As Kuldalai points out, some sections of duplicated track do pose medium term problems, mostly due to the presence of mixed traffic (stopping all stations + express + Vline) but these are dwarfed by the single-track sections on the network.
LancedDendrite
Are you sure, all single track sections are on outer sections of suburban lines, except for some on the Hurstbridge line, none are shared between two or more routes.
I should note that single track with passing loops at all stations can in fact support very frequent services.

Duplicated track has a theoretical capacity of 24 trains per hour using uniform stopping patterns and conventional lineside signalling. Accounting for possible delays by including some extra headway into the timetable gets you down to 20 trains per hour. Only the City Loop tunnels are hitting that 20tph ceiling - and that's with anywhere from 2-4 separate lines converging on each tunnel.
LancedDendrite
This is with uniform stopping patterns, which we tend not to have, nor should have, where two different routes share tracks. Trains on the longer route run (semi) express.

On the other hand, single-line sections of the network can have capacities of 3-6 tph currently, with little prospect of improvement short of full duplication of those sections.
LancedDendrite
It depends on the frequency of the passing loops, have them at every station, and let's say the stations are a mile apart, we may be able to run more trains an hour than that.
  Bogong Chief Commissioner

Location: Essendon Aerodrome circa 1980
I agree that the worst bottleneck is probably the single line bridge / tunnel arrangement north of Heidelberg. The reason it remains single line is that it would cost squillions to fix and, at the moment, the parliamentary seats it serves are mostly safe Labour. 20 years ago, Ivanhoe and Eltham were held by the Libs, but demographics have changed. While there are only safe seats in the area, neither party will pay much attention to the line and instead they will focus their pork-barrelling in marginal seats.

However it would be relatively affordable to fix the bottleneck between Jolimont and Clifton Hill. Simply return the South Morang line to it's original route via the Inner Circle. That route is inhabited by NIMBYs with disproportionate influence, but rebuilding the Inner Circle in a cheap and dirty "cut and cover tunnel" would silence most opposition and it would still be fairly economical.
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
Do you mean the the South Morang line should now share track with the (current) Upfield line between North Melbourne and Royal park and it should be a less direct route to the CBD than currently? I wonder how that would affect patronage on that line.

How about ways to fix the bottleneck between Footscray and Newport?
  LancedDendrite Chief Commissioner

Location: Gheringhap Loop Autonomous Zone
I'm getting a bad feeling about this thread...

Four things:
  • The correct terminology for the 'Northeastern Group' is the Clifton Hill Group.
  • Duplicating single-tracked outer-suburban track sections increases reliability by allowing for more headway. One delay on a single-track line can stuff up services in both directions simultaneously. This is an additional benefit to duplication, aside from the
  • Putting in passing loops at every station increases the theoretical frequency of a line but still has the same delay problem if it's still single track. You may as well go the whole hog and duplicate all the way.
  • Express services are inefficient on the Melbourne suburban network - unless you have triplicated or quadruplicated track, the operational cost of implementing them (dead running) is way too high. Running more services with a single uniform stopping pattern is the way to go - if you have to get rid of a few inner-suburban stations in the process, so be it.
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
I'm getting a bad feeling too...

Four responses:
*I know the term Clifton Hill group, but that includes the Epping line. I was referring to trains to Macleod, Greensborough, Eltham and Hurstbridge as the Northeastern group.
*Single track with passing loops can still be very reliable, I believe there are cases elsewhere in the world of well managed single track railways. Even double track is most reliable with provision for dual direction service on both tracks, so that single line working can be done if one track is out of service, it also allows trains to leapfrog.
*That's the reason for looking for ways to fix bottlenecks. Provision for trains to leapfrog and thus express services does give a higher capacity ceiling than a single uniform stopping pattern on only one or two tracks.
  Bogong Chief Commissioner

Location: Essendon Aerodrome circa 1980
Do you mean the the South Morang line should now share track with the (current) Upfield line between North Melbourne and Royal park and it should be a less direct route to the CBD than currently? I wonder how that would affect patronage on that line. ...
"Myrtone"

Well yes. Because the Upfield line is the least used and has the lightest traffic of any line in Melbourne (excluding short stubb lines to Willy and Alamein), so there would be less congestion than there is now on the two heavily used lines that go via Jolimont.

The disance might be 1 km or so longer, but the route would be faster as there's no need to build any stations on it other than relocating Rushall 200 metres to the west. The inner circle parallels Brunswick Rd - Holden St which is crossed by five tram lines, so there's no need for any new railway stations.

So, I'd expect most trains to run express from North Melbourne to Rushall, in stark contrast to the slow and awkward progression between the multiple wayside halts between Clifton Hill and Jolimont on the current route.
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
Well yes. Because the Upfield line is the least used and has the lightest traffic of any line in Melbourne (excluding short stubb lines to Willy and Alamein), so there would be less congestion than there is now on the two heavily used lines that go via Jolimont.
Bogong
I did mention that the indirectness of the line is probably a big reason for the low patronage.

The disance might be 1 km or so longer, but the route would be faster as there's no need to build any stations on it other than relocating Rushall 200 metres to the west. The inner circle parallels Brunswick Rd - Holden St which is crossed by five tram lines, so there's no need for any new railway stations.
Bogong
I can't imagine how it would be done without constructing new level crossings, not very warmly welcomed. You did mention cut and cover, but the current section of track around Rushall is at ground level.

So, I'd expect most trains to run express from North Melbourne to Rushall, in stark contrast to the slow and awkward progression between the multiple wayside halts between Clifton Hill and Jolimont on the current route.
Bogong
But the new line would still be very indirect, more so than the current Upfield line. And you know what indirectness is likely to do to patronage.
  Heihachi_73 Chief Commissioner

Location: Terminating at Ringwood
Who says Rushall station has to remain in its original position? Is there any merit in scrapping Rushall station and the following S-bend in favour of a brand new station and a massive realigned bridge over the Merri Creek? That 30km/h curve rivals my Life-Like train set.
  Bogong Chief Commissioner

Location: Essendon Aerodrome circa 1980
The reason the Merri Creek bridge near Rushall station is on such a weird angle is that it was located to allow easy running from the original track to the west, the Royal Park side. When it was decided to run trains from Clifton Hill to the east, that ultra tight 180 degree curve was installed.

If trains ran from the east again, the 30 kmh curve would be eliminated and trains would move a lot faster because they wouldn't have to slow down.
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
Who says Rushall station has to remain in its original position? Is there any merit in scrapping Rushall station and the following S-bend in favour of a brand new station and a massive realigned bridge over the Merri Creek? That 30km/h curve rivals my Life-Like train set.
Heihachi_73
A new station over Merri creek. I sure hope we also close Merri station in the meantime already being very close by and right next to the Clarke street level crossing. I've actually seen a photo taken just north of that station, dating from the early 1980s showing a Comeng in its original colour scheme, and the photo also shows a semaphore signal and interlocked gates, the latter accompanied by revolving red lamps.
  melbtrip Chief Commissioner

Location: Annoying Orange
I'm getting a bad feeling about this thread...

Four things:
  • The correct terminology for the 'Northeastern Group' is the Clifton Hill Group.
  • Duplicating single-tracked outer-suburban track sections increases reliability by allowing for more headway. One delay on a single-track line can stuff up services in both directions simultaneously. This is an additional benefit to duplication, aside from the
  • Putting in passing loops at every station increases the theoretical frequency of a line but still has the same delay problem if it's still single track. You may as well go the whole hog and duplicate all the way.
  • Express services are inefficient on the Melbourne suburban network - unless you have triplicated or quadruplicated track, the operational cost of implementing them (dead running) is way too high. Running more services with a single uniform stopping pattern is the way to go - if you have to get rid of a few inner-suburban stations in the process, so be it.
LancedDendrite

Running a 10mins services to  places like Pakenham is waste of resources, it be better to run a 20mins express service instead.

Running a train every 10 mins to Dandenong is better use of resources and at same time have express services to Pakenham and Cranbourne  (stops all stations to Dandenong  and then limited stops to  Flinders Street).
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
Concur with the post above, I did say that running trains to/from the outer suburbs express in the inner suburbs does heighten the capacity celing. Dwelling less on dwell times appears to be the key to capacity of commuter rail, and (non metro) heavy rail in general.
  Gman_86 Chief Commissioner

Location: Melton, where the sparks dare not roam!
Whacko, another thread by Myrtone.

First of all, Macleod, Greensborough, Eltham and Hurstbridge are not the "North Eastern Group" as you put it, they are the Hurstbridge line, which along with the South Morang line (hasn't been the Epping line for several years now) form the Clifton Hill Group. That is what they are called, you can call it whatever you like, but you're just going to confuse everybody else, and fail to get your point across in the process.

Secondly, the current section between Jolimont and Clifton Hill does not yet run at full capacity, not even at peak periods, so there is no real reason to look at spending big dollars fixing it as it isn't an issue. Maybe if Doncaster rail is ever built (not likely) then maybe we may need to do something, but otherwise, leave it alone for now. And no, the Inner Circle is not likely to return, at least not as a ground level railway anyway.

Thirdly, and probably not really the place for this but here goes: Is there any evidence that the low patronage on the Upfield line is due to the slight bend in the line from Royal Park to North Melbourne? I haven't once heard of any complaints about the route this line takes, apart from yours of course.

Finally: If you are serious about fixing bottlenecks on the Melbourne network, then you must duplicate as many single track sections as possible, regardless of what anybody says about other parts of the world running efficient railways with single track lines, these single track sections on the Melbourne network cause more trouble than any other issue. Between Gowrie and Upfield (all the way to Somerton if you want to do it properly), Dandenong to Cranbourne and Mooroolbark to Lilydale are all horrendous bottlenecks, and without fixing these, you are just wasting your time.
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
First of all, I call them the Northeastern group to make it clear that not all trains run to Hurstbridge, and the term Hurstbridge line suggests.

Secondly, I may have overestimated how busy it gets, but then again, there is a level crossing there and it does come down very frequently during peak periods.

Thirdly, Every other suburban railway runs more directly into the city, at least from the inner suburbs than the Upfield line. That bend from Park Street, Royal Park to Macauley station is quite significant. The Upfield line does not serve the University but does serve a popular living area for students and staff, so I'm sure diverting it would increase patronage.

Finally: I don't see how single track sections must be such a problem if there are efficent single track railways elsewhere in the world? But what I do see is that any increase in frequency is going to justify reducing the number of (busy) level crossings. I count level crossings, especially over busy roads as bottlenecks. Busy level crossings may well cause no less trouble than single track sections including stations without passing loops.
  Gman_86 Chief Commissioner

Location: Melton, where the sparks dare not roam!
1.As I said, regardless of what you want to call it, it IS called the Hurstbridge Line, and nobody else cares what you decide you want to call it.

2.Yes, well I would hardly call 1 level crossing, with many alternate options an issue, and of course the gates come down a lot during peak periods, that's why they are called peak periods.

3.Yes, but do you have any evidence to back that up, or is it just an opinion?

4.Level crossings are not bottlenecks (at least not for trains), yes there are limits to how many trains can run through any given crossing in a set amount of time, but that doesn't make it a bottleneck. Single track sections on the other hand are, just look at the issues on the Cranbourne line, 1 delay causes delay after delay when just one train misses its path which in turn causes a chain reaction that can go on for hours. This is practically the definiton of a bottleneck.
  Myrtone Chief Commissioner

Location: North Carlton, Melbourne, Victoria
1. I know, but to me Hurstbridge line means the route to Hurstbridge, not the short working ones.

2. What does "alternate options" mean? Would you call them an issue if they had full skirted barriers and came down no less than a minute before the fastest train arrives, as is the case with many crossing in the UK, Ireland and Germany?

3. What more evidence do you need than the directness of other suburban railways and a lot more northern suburb students and residents studying or working at Melbourne University than working in the Zoo or Flemington, or maybe anywere else other than, well, within the northern suburbs?

4. What does bottleneck mean in this case? A road vehicle stuck on a level crossing could conceivably cause a delay, also consider the traffic problems when a train gets delayed on a level crossing. Our double track sections, without bidirectional signalling, are still bottlenecks, but to a lesser extent. If we are going to reduce delays by dupulicating single track, just make sure that double track has bi-directional signalling.
  LancedDendrite Chief Commissioner

Location: Gheringhap Loop Autonomous Zone
Seeing as Myrtone seems to have a problem grappling with the terminology being used in this thread, here are some commonly accepted definitions:

Service:
A regular scheduled train that goes along a line and has a fixed stopping pattern. Example: the Greensborough to City Loop via Flinders St, Limited Express service

Line:
A set of railway tracks and related infrastructure that connects two places and/or other railway lines. Often labelled according to the ultimate destination of the line or the two places that it goes between. Example: Hurstbridge Line (Flinders St to Hurstbridge)

Group:
A set of railway lines that stem from a common originating point and run along a common alignment or set of railway tracks for part of the journey. The name of the group generally refers to the closest station to where the first line diverges from the others. Example: Clifton Hill Group (Hurstbridge line + South Morang line, diverging at Clifton Hill)

Bottleneck:
The point or points in a railway network that causes the most congestion, stemming from the metaphor of a bottleneck, which is (generally) the most fluidically restrictive feature of an opened bottle.

Myrtone:
A user who, by the behaviour he exhibits in threads of his own making (repeating arguments to posters after they tell him that they are wrong, lacking evidence to back up opinions when ask to provide it, copying the format of the post he is responding to), is clearly a troll.
  toastywarmhamster Station Master

Location: Space and Time
Seeing as Myrtone seems to have a problem grappling with the terminology being used in this thread, here are some commonly accepted definitions:

Service:
A regular scheduled train that goes along a line and has a fixed stopping pattern. Example: the Greensborough to City Loop via Flinders St, Limited Express service

Line:
A set of railway tracks and related infrastructure that connects two places and/or other railway lines. Often labelled according to the ultimate destination of the line or the two places that it goes between. Example: Hurstbridge Line (Flinders St to Hurstbridge)

Group:
A set of railway lines that stem from a common originating point and run along a common alignment or set of railway tracks for part of the journey. The name of the group generally refers to the closest station to where the first line diverges from the others. Example: Clifton Hill Group (Hurstbridge line + South Morang line, diverging at Clifton Hill)

Bottleneck:
The point or points in a railway network that causes the most congestion, stemming from the metaphor of a bottleneck, which is (generally) the most fluidically restrictive feature of an opened bottle.

Myrtone:
A user who, by the behaviour he exhibits in threads of his own making (repeating arguments to posters after they tell him that they are wrong, lacking evidence to back up opinions when ask to provide it, copying the format of the post he is responding to), is clearly a troll.
LancedDendrite
Finally!! Well said. According to Myrtone's flawed logic. I dont use the Burnley group , I use the Outer-Inner-Slightly Less Outer Eastern Group.
  dthead Site Admin

Location: Melbourne, Australia
[edit]Reminder, attack the issues, not the poster..... [/edit]
  bramt Deputy Commissioner

On to the issues then...

Actually, I think there are some capacity issues on the Clifton Hill section. Almost every morning around 8.40-9am trains are very congested between West Richmond and Flinders St, spending a lot of the time stationary. However, I think this might be due more to the capacity of platform 1 at Flinders St being less than the rest of the line (due to passenger crowding, possible driver changes, and the length of the platform requiring slower speeds to move through).

Not that that means more infrastructure is needed immediately, but...

The PTV network development plan identifies a tunnel from Victoria Park to Flagstaff as the preferred upgrade (to allow for hypothetical Doncaster trains too). Why can't Clifton Hill/Victoria Park -> Jolimont/Flinders St be quadded instead? Every morning as my train crawls through here I can see there is physically enough space along the whole alignment for 4 tracks without property acquisition. Has this been considered? Should be cheaper than a tunnel.

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