Mixed Gauge Feasibility

 
  awsgc24 Minister for Railways

Location: Sydney
Although people such as Prime Minister Billy Hughes (c1920) welcomed the idea of mixed (dual) gauge tracks as a low cost way of solving the break of gauge problem, it came to be TOTALLY opposed by other people like Harry Clapp especially on main lines where high speeds are needed.

These days there extensive mixed gauge tracks in Brisbane, Melbourne, Adelaide, Perth-Northam, etc.

The particular question being asked here is what speeds do these mixed gauge tracks operate at, and what would be the permitted speeds if there were no mixed gauge (but same radius of curves, etc).

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  RTT_Rules Dr Beeching

Location: Dubai UAE
Although people such as Prime Minister Billy Hughes (c1920) welcomed the idea of mixed (dual) gauge tracks as a low cost way of solving the break of gauge problem, it came to be TOTALLY opposed by other people like Harry Clapp especially on main lines where high speeds are needed.

These days there extensive mixed gauge tracks in Brisbane, Melbourne, Adelaide, Perth-Northam, etc.

The particular question being asked here is what speeds do these mixed gauge tracks operate at, and what would be the permitted speeds if there were no mixed gauge (but same radius of curves, etc).
awsgc24

Hi,
to the best of my knowledge for Brisbane, the DG is limited to basically suburban sections from Aciaca Ridge to the City and port. So speed is not part of the equation too much. They might have 100km/hr speed boards. However they have not long ago DG's the track inland as part of a longterm plan for a large freight handling centre and while the points are not done yet, the main sections of track are DG (with NG out of use), and I believe the freighters maybe doing +115km/hr and XPT more.

Liekwise with WA I don't think NG and SG as DG is a big issue apart from the common rail wearing at uneven rates compared to the other two. As long as the points are built to a high standard I would have thought no issues with speed and if anything NG trains get a better ride. (Open to correction)

Mel, BG-SG by my understanding has always been problematic as the rails are very close and this limits the rail thickness or weight and hence the top end speed. I think they continued to use timber sleepers for DG for because of issue of making DG steel and concrete sleepers. Maybe they have that sorted now? But I believe the rails are still smaller than would be prefered and reading posts in Railpage in past there seemed to be a general comment that SD-BG as DG limites trains to about 80km/hr. Also something to do with close spacing between the rails makes it easier for rocks etc to get stuck in their and risk the train. so maybe why DG BG- SG trackage is limited to local where possible?

Note: Have you see the photos of the tripple guage track, where the BG and SG don't use common rails with each other? Rather they use a NG rail. SG say uses left NG rail and BG uses the right NG rail.
  Grantham Minister for Railways

Location: I'm with stupid!
If you want to know what speeds can be run on dual gauge lines, then it might be worth your while looking at dual gauge lines in Europe, where high speed rail is practical and reasonably common. Of course, you would need to apply their much higher standards of maintenance than we apply to any Australian railway, so you can be guaranteed that it won't be able to be applied here.

M
  62440 Chief Commissioner

With BG-SG the distance between running edges is 1600-1435 or 165mm. The rail foot of a 60 kg rail is 146, leaving a 19mm gap, 50 kg has a rail foot of 127 with a 38mm gap. The rail weight for high performance track is preferred 60 kg but SG-BG only allows max 50 kg hence the restriction which I understand is 80 km/h in Victoria and SA (Dry Creek to Osborn).
With NG-SG DG the rails are further apart and there is no foot width restriction.
The triple gauge had 4 rails so the outer pairs were further apart (though there were stretches with 3 rails on one side)
  bingley hall Minister for Railways

Location: Last train to Skaville
If you want to know what speeds can be run on dual gauge lines, then it might be worth your while looking at dual gauge lines in Europe, where high speed rail is practical and reasonably common. Of course, you would need to apply their much higher standards of maintenance than we apply to any Australian railway, so you can be guaranteed that it won't be able to be applied here.

M
Grantham
This notion of Europe having highly efficient dual gauge operations everywhere has been raised in another thread.

I'm not entirely up to speed with what's happening in Spain these days, but I think it would fair to say that dual gauge running would
account for less than 0.1% of all rail operations in Europe.
  Grantham Minister for Railways

Location: I'm with stupid!
This notion of Europe having highly efficient dual gauge operations everywhere has been raised in another thread.

I'm not entirely up to speed with what's happening in Spain these days, but I think it would fair to say that dual gauge running would
account for less than 0.1% of all rail operations in Europe.
bingley hall
Actually it is the high speed rail that happens more in Europe, the original post concerned track speed as much as dual gauge.

High speed depends on track geometry, condition and maintenance, the best of which is found outside Australia.

M
  awsgc24 Minister for Railways

Location: Sydney
If you want to know what speeds can be run on dual gauge lines, then it might be worth your while looking at dual gauge lines in Europe, where high speed rail is practical and reasonably common. Of course, you would need to apply their much higher standards of maintenance than we apply to any Australian railway, so you can be guaranteed that it won't be able to be applied here.

M
Grantham

In Spain, where the BG is 5' 6" and not 5' 3", the gauge difference is 9.5" and not 6.5", so the gap is wider and hence safer.

The higher speed SG track is unaffected by the gap as it is on the inside, while the not so high speed BG is affected by the Gap.

Why on earth did the idiot/vandal Sheilds choose 5' 3" rather than 5' 6" and cause all this trouble?
  Grantham Minister for Railways

Location: I'm with stupid!
Who cares?

If a narrow gap is dangerous, then just keep the fat track separate to the standard.

M
  Grantham Minister for Railways

Location: I'm with stupid!
It's a big country, there is room for two tracks!
  RTT_Rules Dr Beeching

Location: Dubai UAE
It's a big country, there is room for two tracks!
Grantham
In inner Melbourne I believe this is not the case, especially if there are tunnels and bridges involved
  Nightfire Minister for Railways

Location: Gippsland
In Spain, where the BG is 5' 6" and not 5' 3", the gauge difference is 9.5" and not 6.5", so the gap is wider and hence safer.

The higher speed SG track is unaffected by the gap as it is on the inside, while the not so high speed BG is affected by the Gap.

Why on earth did the idiot/vandal Sheilds choose 5' 3" rather than 5' 6" and cause all this trouble?
"awsgc24"


Iberian gauge Is 1668mm 5'5 2/3" not 1676mm 5'6"(Indian gauge)
  awsgc24 Minister for Railways

Location: Sydney
Iberian gauge Is 1668mm 5'5 2/3" not 1676mm 5'6"(Indian gauge)
Nightfire

IIRC, Spain and Portugal are slightly different by a few mm.

In any case, Iberian and Indian broad gauge are practically the same.
  awsgc24 Minister for Railways

Location: Sydney
It's a big country, there is room for two tracks!
Grantham

Quite.

One could of course have two tracks where the country is easy, but dual gauge where there are expensive and narrow bridges and tunnels.

Thus Gelong-Gherringhap now has one dual and one SG only track.
  Grantham Minister for Railways

Location: I'm with stupid!
Quite.

One could of course have two tracks where the country is easy, but dual gauge where there are expensive and narrow bridges and tunnels.

Thus Gelong-Gherringhap now has one dual and one SG only track.
awsgc24
You can place restrictions on restricted areas, though of course high speed will be out of the question. Building restrictive tunnels and bridges is a regressive step, a country as rich as Australia should be able to build magnificent structures.

M
  kuldalai Chief Commissioner

1. North Geelong  (Thompsons Rd) to  Moorabool is duplicated with one track being dg and the other sg .  (The dg is on the South side from Thompsons Rd to Anakie Rd and then on the North side from Anakie Rd to Moorabool.)

2. Whilst the Moorabool viaduct has been prepared for restoration of a second track (minor strengthening works) and earthworks were recently also completed between Moorabool and the Up end of Gheringhap for installation of a sg only South track, this work is to be completed at a future date .

3.  In the dying days of ANR a series of tests were conducted in South Australia with freight vehicles of both bg and sg within the same freight  train consist  at speed on dual gauge track .  The trials were quite successful , but the practice was not adopted generally .

4.  Dual gauge is where a common rail is installed over 3 total rails .    Where the two gauges are separated with 4 rails it is called gauntlet track .  The only example of gauntlet track in Victoria (and soon to dissapear) is the bg/sg gauntlet track on the Up East Suburban Line over Dudley St , West Melbourne.

5. The speed restriction for bg trains on dg tracks in Victoria (of usually 80kmh) is related to the risk of derailment potentially caused by any brake rigging, brake blocks falling in the narrow gap between the rails .  Above 80kmh in a derailment any damage is much greater .
  Lad_Porter Chief Commissioner

Location: Yarra Glen
On a single gauge track (be it NG, SG or BG), the rails would normally be placed equidistant from each end of the sleepers.  In a dual gauge setup, one of the gauges has to have its rails consistently not equidistant from each end of the sleepers, which could (possibly?) lead to some kind of long term imbalance or disruption to the track bed.  Is this a consideration?  In a dual gauge track, are the rails swapped around every so often to minimise the effect?
  Grantham Minister for Railways

Location: I'm with stupid!
On a single gauge track (be it NG, SG or BG), the rails would normally be placed equidistant from each end of the sleepers.  In a dual gauge setup, one of the gauges has to have its rails consistently not equidistant from each end of the sleepers, which could (possibly?) lead to some kind of long term imbalance or disruption to the track bed.  Is this a consideration?  In a dual gauge track, are the rails swapped around every so often to minimise the effect?
Lad_Porter
No and no. Makes SFA difference.

M
  RTT_Rules Dr Beeching

Location: Dubai UAE
No and no. Makes SFA difference.

M
Grantham

I would have thought the sleeper lengths past the outer rails was the same so that the pressure per length of sleeper on the ballast was the same
  Grantham Minister for Railways

Location: I'm with stupid!
I would have thought the sleeper lengths past the outer rails was the same so that the pressure per length of sleeper on the ballast was the same
RTT_Rules
No, there is a practical minimum, but it can be over length at one end if you don't mind paying for extra sleeper and extra ballast.
  awsgc24 Minister for Railways

Location: Sydney


[img]http://static.railpage.com.au/image_resize.php?base64_args=YTozOntzOjM6InVybCI7czo1NzoiaHR0cDovL3UxLmlwZXJuaXR5LmNvbS80NS8wOC84My8zNTA5MDg4My4zZjhjMWJiYS41MDAuanBnIjtzOjU6IndpZHRoIjtpOjY0MDtzOjc6ImNoZWNrZWQiO2I6MDt9[/img]
CarnivalTrain 029 par GrahamH, on ipernity

- GrahamH


 Note the check rail for sharp ARAII 5 chain (100m) curves.

What is the distance between the running rail and check rail? This distance is not large.

During debates about 3rd rail operation in in NSW and VIC on dual gauge between 1435mm and 1600mm, it was adjudged that the gap of "only" 165mm was too small to allow safe operation.

What is the similar gap of the check rail in QLD, and why is it allowed when dual gauge in NSW/VIC was not allowed, except perhaps in low speed sidings?

See: http://www.railpage.com.au/f-p1941636.htm#1941636
  awsgc24 Minister for Railways

Location: Sydney
On a single gauge track (be it NG, SG or BG), the rails would normally be placed equidistant from each end of the sleepers. In a dual gauge setup, one of the gauges has to have its rails consistently not equidistant from each end of the sleepers, which could (possibly?) lead to some kind of long term imbalance or disruption to the track bed. Is this a consideration? In a dual gauge track, are the rails swapped around every so often to minimise the effect?
Lad_Porter


On the Eastern Suburbs Railway in Sydney, sleepers are imbedded in concrete. On one side, the ends of the sleepers are perfectly aligned by a jig, and the other end is higgeldy-piggeldly depending on the various lengths of the actual sleeper.
  RTT_Rules Dr Beeching

Location: Dubai UAE
Note the check rail for sharp ARAII 5 chain (100m) curves.

What is the distance between the running rail and check rail? This distance is not large.

During debates about 3rd rail operation in in NSW and VIC on dual gauge between 1435mm and 1600mm, it was adjudged that the gap of "only" 165mm was too small to allow safe operation.

What is the similar gap of the check rail in QLD, and why is it allowed when dual gauge in NSW/VIC was not allowed, except perhaps in low speed sidings?

See: http://www.railpage.com.au/f-p1941636.htm#1941636
awsgc24




I don't think its unsafe to run BG/SG, as we all know they do, but its speed restricted due to rail proximity and the close spacing limiting the weight of rail that can be used for what is rail traffic with axle loadings far exceeding Qld western line. To the best of my knowledge SG inter modal and XPT trains on BG/SG track is limited to 80km/hr.

That photo from Qld is a tight curve, read very slow speed and I'm guessing much lighter rail than would normally be used for +115km/hr at +19t/axle loading. Basically the Western corridor track looks branch line standards compared to Qld's own CQ coal lines.
  Sulla1 Chief Commissioner

I don't think its unsafe to run BG/SG, as we all know they do, but its speed restricted due to rail proximity and the close spacing limiting the weight of rail that can be used for what is rail traffic with axle loadings far exceeding Qld western line. To the best of my knowledge SG inter modal and XPT trains on BG/SG track is limited to 80km/hr.

That photo from Qld is a tight curve, read very slow speed and I'm guessing much lighter rail than would normally be used for +115km/hr at +19t/axle loading. Basically the Western corridor track looks branch line standards compared to Qld's own CQ coal lines.
"RTT_Rules"


Probably 41kg rail on that curve and a speed limit of 30km/h. In a lot places on the QR network, including the Toowoomba Range, curves this sharp receiving heavier rails (50, 53 & 60kg rail) and concrete sleepers are not having the check rail reinstalled.
  nswtrains Chief Commissioner

Probably 41kg rail on that curve and a speed limit of 30km/h. In a lot places on the QR network, including the Toowoomba Range, curves this sharp receiving heavier rails (50, 54 & 60kg rail) and concrete sleepers are not having the check rail reinstalled.
Sulla1

Isn't the easiest solution (in regard to broad gauge) is to decide what routes would benefit most from standardization (exluding suburban) and then lay the chosen routes with gauge convertible sleepers and when that process is completed, move one rail inwards. Then abandon the rest.

I guess Qld can stay the same as it is too big to change over to standard gauge or even dual gauge (must be bigger than Sth Africa). WA is a different matter. What is not worth converting should be abandoned.

We may end up with a minimalist network, but an efficient one.
  Sulla1 Chief Commissioner

Isn't the easiest solution (in regard to broad gauge) is to decide what routes would benefit most from standardization (exluding suburban) and then lay the chosen routes with gauge convertible sleepers and when that process is completed, move one rail inwards. Then abandon the rest.

I guess Qld can stay the same as it is too big to change over to standard gauge or even dual gauge (must be bigger than Sth Africa). WA is a different matter. What is not worth converting should be abandoned.

We may end up with a minimalist network, but an efficient one.
"nswtrains"


That or, at least in the case of Queensland, undertake gauge 'equalisation' rather than standardisation...moving the narrow gauge interchanges southwards towards more logical interchange points where freight 'wants' to move to or from. A lot of freight originating north of Brisbane never takes a rail option because of relatively short distances to the break of gauge transhipment point and stays on trucks instead. Grain and cotton moving from northern NSW to Brisbane doesn't use rail because there's no cheap way of getting a standard gauge connection across the Toowoomba Range...why not extend narrow gauge southwards to Moree as a low cost alternative while we wait for the Inland Rail standard gauge link (this actually very nearly happened in the last months of the Goss Government in 1995)...it's not a perfect solution but it might be better than waiting for standard gauge links that are still decades away.

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