The O-bahn

[Aidan]

The purpose of ballast is to spread the load of the rails/sleepers as well as the rollingstock when it goes over it over poor soil. Dump enough ballast in and you should be fine.

The spreading of the load isn't the main problem - it's the seasonal expansion and contraction of the clay that causes the trouble. Many places have some soil movement as the top few feet of clay shrink and swell, but Adelaide summers are so hot and dry, that the clay to a depth of about 4 metres shrinks, which makes it rather difficult to keep the track straight. Geotechnical engineers can solve the problem, but not without spending a lot of money.

Besides, the Noarlunga line south of Hallet Cove goes through some pretty dodgy soil and yet we are (barely) able to reach 90km/h.

Yes, the trains are capable of 120 but the track condition limits them to 90. It just wasn't built to a very high standard. And most people who have driven along the northern end of Lonsdale Road know the problem is not confined to the railways.

As an aside about railway flooding, the Commonwealth Railways ran the old narrow gauge Ghan through water upto 2ft deep before dieselisation without any major issues (other then the train arriving 2 weeks late).

Are you sure it was only two weeks? I seem to recall reading about the old Ghan arriving 2 months late!

[Will409]

Yes, the trains are capable of 120 but the track condition limits them to 90. It just wasn't built to a very high standard. And most people who have driven along the northern end of Lonsdale Road know the problem is not confined to the railways.

Wrong and I will explain why.

In 1984, the former State Transport Authority introduced a system wide speed limit of 90km/h after taking into consideration line clearances and track access by the public via entry points like level crossing mazes, it has nothing to do with the build quality of the track. You have to remember that the 90km/h limit was put in place back when track maintenance standards were better then what they are now. The Noarlunga line was built in stages between 1915 and 1978. Until 1975, the line was single track all the way to the then terminus of Lonsdale. When the track was duplicated, the pre existing line was also upgraded with new sleepers and ballast through out. Heavy 107lb per yard/53kg per metre rail was also used beyond Hallet Cove with the rest of the line using 94lb per yard/47kg per metre rail. By Australian rail standards, this is fairly heavy rail.

The current Noarlunga line rebuild program will see the line upgraded with concrete sleepers throughout, CWR (Continuously Welded Rail), extra ballast as well as some rail replacement using 50kg/m rail which will see the speed limit on the line raised to 110km/h.

[SRW]

The current Noarlunga line rebuild program will see the line upgraded with concrete sleepers throughout, CWR (Continuously Welded Rail), extra ballast as well as some rail replacement using 50kg/m rail which will see the speed limit on the line raised to 110km/h.

(emphasis mine)

I had wondered if that would occur. Very good to hear.

[Will409]

The current Noarlunga line rebuild program will see the line upgraded with concrete sleepers throughout, CWR (Continuously Welded Rail), extra ballast as well as some rail replacement using 50kg/m rail which will see the speed limit on the line raised to 110km/h.

(emphasis mine)

I had wondered if that would occur. Very good to hear.

It's not like it is that hard to do and they can use the current rails to do it. Some minor preparation of the rail itself, remove the fish plates and bolts, shove the thermit pot over the join, dump some thermit in and apply some heat to the pot, pour the molten thermit around the join. Allow it to cool and then grind away the excess and you are done, welded rail.

[monotonehell]

It's not like it is that hard to do and they can use the current rails to do it. Some minor preparation of the rail itself, remove the fish plates and bolts, shove the thermit pot over the join, dump some thermit in and apply some heat to the pot, pour the molten thermit around the join. Allow it to cool and then grind away the excess and you are done, welded rail.

Which then buckles in extreme heat and cold?

[Norman]

It's not like it is that hard to do and they can use the current rails to do it. Some minor preparation of the rail itself, remove the fish plates and bolts, shove the thermit pot over the join, dump some thermit in and apply some heat to the pot, pour the molten thermit around the join. Allow it to cool and then grind away the excess and you are done, welded rail.

Which then buckles in extreme heat and cold?

Track on concrete sleepers doesn't buckle as much in the heat and cold as it is with wooden sleepers, especially when they're in bad condition like we have here.

[monotonehell]

It's not like it is that hard to do and they can use the current rails to do it. Some minor preparation of the rail itself, remove the fish plates and bolts, shove the thermit pot over the join, dump some thermit in and apply some heat to the pot, pour the molten thermit around the join. Allow it to cool and then grind away the excess and you are done, welded rail.

Which then buckles in extreme heat and cold?

Track on concrete sleepers doesn't buckle as much in the heat and cold as it is with wooden sleepers, especially when they're in bad condition like we have here.

As much or not at all? I don't understand the whole buckling issue, apart from my high school science knowledge. Shouldn't there be expansion gaps to stop the buckling?

[Will409]

Which then buckles in extreme heat and cold?

Track on concrete sleepers doesn't buckle as much in the heat and cold as it is with wooden sleepers, especially when they're in bad condition like we have here.

As much or not at all? I don't understand the whole buckling issue, apart from my high school science knowledge. Shouldn't there be expansion gaps to stop the buckling?

There are some expansion gaps used but every 50 or so kilometres. However, the use of heavy concrete sleepers with strong track clips and deep ballast (which SHOULD also be spread over the end of the sleepers) does hold the track down so it alomost has no room to move except for in extreme cases. Timber sleepers or badly tamped steel sleepers that have no real grip and light ballast (or in TransAdelaide's case, full of dirt and mudholes) are ideal conditions for buckling track. Steel sleepers can also fracture easily if they are not cracked.

[Shuz]

Is it possible to attach a poll to the thread, asking if people like the O-Bahn as it is, or should be converted to heavy rail, or a tram route?
It be interesting to see what people think. I would expect that the people who use the route would rather it as it is, but for those whove used it once in their life or just 'know' that its there would prefer a rail option.

[monotonehell]

Is it possible to attach a poll to the thread, asking if people like the O-Bahn as it is, or should be converted to heavy rail, or a tram route?
It be interesting to see what people think. I would expect that the people who use the route would rather it as it is, but for those whove used it once in their life or just 'know' that its there would prefer a rail option.

No point really, all the gunzels would vote "make it a rail line grunt grunt"
I think that you're right though. People whoi are unfamiliar with it think it's not as good as a rail line. I've lived in both Salisbury and the NE suburbs and used both the feeder bus connecting to rail and the OBahn and I know which one is quicker and less hassle. - Transfering from feeder bus to rail and back is a pain in the bum.

[Norman]

Is it possible to attach a poll to the thread, asking if people like the O-Bahn as it is, or should be converted to heavy rail, or a tram route?
It be interesting to see what people think. I would expect that the people who use the route would rather it as it is, but for those whove used it once in their life or just 'know' that its there would prefer a rail option.

No point really, all the gunzels would vote "make it a rail line grunt grunt"
I think that you're right though. People whoi are unfamiliar with it think it's not as good as a rail line. I've lived in both Salisbury and the NE suburbs and used both the feeder bus connecting to rail and the OBahn and I know which one is quicker and less hassle. - Transfering from feeder bus to rail and back is a pain in the bum.

This is not always the case though, not everyone catches the bus home... a lot go to the Park and Ride facility. And after peak, most services are just feeders anyway for the Jetbuses, M44 and 541.

[Pat28]

Is it possible to attach a poll to the thread, asking if people like the O-Bahn as it is, or should be converted to heavy rail, or a tram route?
It be interesting to see what people think. I would expect that the people who use the route would rather it as it is, but for those whove used it once in their life or just 'know' that its there would prefer a rail option.

No point really, all the gunzels would vote "make it a rail line grunt grunt"
I think that you're right though. People whoi are unfamiliar with it think it's not as good as a rail line. I've lived in both Salisbury and the NE suburbs and used both the feeder bus connecting to rail and the OBahn and I know which one is quicker and less hassle. - Transfering from feeder bus to rail and back is a pain in the bum.

This is not always the case though, not everyone catches the bus home... a lot go to the Park and Ride facility. And after peak, most services are just feeders anyway for the Jetbuses, M44 and 541.

Still a poll would be rather inetresting! but for the arguements sake - rail all the way

[monotonehell]

This is not always the case though, not everyone catches the bus home... a lot go to the Park and Ride facility. And after peak, most services are just feeders anyway for the Jetbuses, M44 and 541.

As opposed to a train where ALL services at all times require feeders and EVERYONE must either drive to the park and ride or transfer to a bus? The OBahn is flexible, it can provide door to door services when the demand is there, or switch to a feeder service mode when it is not.

Face it, the OBahn has the best of both kinds of PT. When ever people try to argue otherwise they 'conveniently' forget half of the facts.

Trains are good for moving a lot of people from ONE place to ONE other place (or points in between).
Buses are good for moving many people from many different points to many other different points.

An OBahn corridor allows those buses to bypass congestion and service multiple points a distance from either end of the track and where exchanges are provided.

In high density corridors, trains are best. TODs and so on. But in the suburban sprawl that we have, buses are best. So until Cleverick's master plan is put into practice the OBahn provides an important part of Adelaide's Public Transport system at a much lower cost than a train line, both to build and run.

[jk1237]

This is not always the case though, not everyone catches the bus home... a lot go to the Park and Ride facility. And after peak, most services are just feeders anyway for the Jetbuses, M44 and 541.

As opposed to a train where ALL services at all times require feeders and EVERYONE must either drive to the park and ride or transfer to a bus? The OBahn is flexible, it can provide door to door services when the demand is there, or switch to a feeder service mode when it is not.

Face it, the OBahn has the best of both kinds of PT. When ever people try to argue otherwise they 'conveniently' forget half of the facts.

Trains are good for moving a lot of people from ONE place to ONE other place (or points in between).
Buses are good for moving many people from many different points to many other different points.

An OBahn corridor allows those buses to bypass congestion and service multiple points a distance from either end of the track and where exchanges are provided.

In high density corridors, trains are best. TODs and so on. But in the suburban sprawl that we have, buses are best. So until Cleverick's master plan is put into practice the OBahn provides an important part of Adelaide's Public Transport system at a much lower cost than a train line, both to build and run.

Why then, has no other city in the world (except 1), even those with low density sprawl, not put o'bahns everywhere? Why are most people in other cities more than happy to take a bus to a interchange, to connect to a fast, uninhibited, a/c, quiet, spacious, voice announcements (etc) train to the heart of the city, with quite sophisticated railway stations.

Yes the o'bahn cost much less than a rail line to set up, but I guess very plain, diesel, cramped, non a/c buses would be cheaper to buy than spacious, a/c, voice announcements equipped - electric trains.

Anyway, from what Ive noticed over the years, 60%+ of all passengers in an average o'bahn bus will leave the bus at either Paradise or Modbury, rather than staying on past TTP to their bus stop in the suburbs, so yes the o'bahn is flexible, does it need to be that flexible - Not really.

[muzzamo]

Why then, has no other city in the world (except 1), even those with low density sprawl, not put o'bahns everywhere? Why are most people in other cities more than happy to take a bus to a interchange, to connect to a fast, uninhibited, a/c, quiet, spacious, voice announcements (etc) train to the heart of the city, with quite sophisticated railway stations.

Because the o-bahn itself as a concept is a bit of a gimmick. The concept of a busway however is immensely popular right around the world. Just take brisbane they are planning to roll out heaps of them. Already there is a North-South one with a tunnel linking it under the city.

Advantage of paved busways over o-bahn is that broken down busses can be passed, doesn't require bus modification, can be used by emergency vehicles and taxis, etc.

So yeah the O-Bahn itself is a fantastic busway implementation, its just that the guided concrete tracks are a bit of a gimmick (introduced in Adelaide because of the need for a narrow corridor apparently) and arent used anywhere else.