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Regarding the O-Bahn is dead because no one else uses it argument over in the Trams forum:

https://en.wikipedia.org/wiki/Cambridge ... ded_Busway
25kms, opened in 2011 - further extensions planned

https://en.wikipedia.org/wiki/Leigh-Sal ... id_Transit
22kms, opened in April 2016

Interestingly they both run double decker buses.

(Adelaide O-Bahn: 12kms, opened 1986)

There's one in Japan as well..
https://en.wikipedia.org/wiki/Yutorito_Line


Regardless, if nobody else in the world used a similar guided busway like we do, who cares.
Is the O Bahn here used with good patronage? Yes? Then that's all that matters.

SRW wrote:I'm happy that within the year we should have both the O-Bahn and new tram up and running - hooray public transport investment!

But I think in deciding to keep Rundle Road open, everything else in this project has become suboptimal. Now it seems like even more prime open space has been sacrificed to keep it two lanes while the length of the tunnel opening from Grenfell Street is far longer than was originally proposed. And it would've been great to see those power lines undergrounded too.

Perhaps when EastLink is eventually extended to the Parade they'll have to bite the bullet on Rundle Road.

I agree re: O-bahn exit/entry on Grenfell it is way deeper into the park lands than I thought.

I'm also suprised they haven't tried to ugrade he road surface on Grenfell St before the tunnel starts working.

Waewick wrote:I'm also suprised they haven't tried to ugrade he road surface on Grenfell St before the tunnel starts working.

I'm wondering if this is something to do with the apparent plans to turn Grenfell into a PT/Bikes/Pedestrian only route. Could be costly resurfacing Grenfell Street now if it's going to be significantly changed in the near future...

A question for those who know - on ABC 891 this morning, Stephen Mullighan was talking about the tunnel and about how they are doing tests on the effect of two buses passing in the tunnel. It was mentioned that the tunnel was quite narrow.

Does that mean that if in the future we scrap the o-bahn, the tunnel will be useless as it would be too narrow for unguided buses or would that have been considered?

Llessur2002 wrote:

Waewick wrote:I'm also suprised they haven't tried to ugrade he road surface on Grenfell St before the tunnel starts working.

I'm wondering if this is something to do with the apparent plans to turn Grenfell into a PT/Bikes/Pedestrian only route. Could be costly resurfacing Grenfell Street now if it's going to be significantly changed in the near future...

that is a fair point, didn't take into account the proposed changes.

in relation to Jimblys post, I hope you've mis heard that, surely the tunnel is capable of taking traffic in both directions at one time? that would be a farce if not.

All buses in the Adelaide Metro fleet are the same width.

jimbly wrote:A question for those who know - on ABC 891 this morning, Stephen Mullighan was talking about the tunnel and about how they are doing tests on the effect of two buses passing in the tunnel. It was mentioned that the tunnel was quite narrow.

Does that mean that if in the future we scrap the o-bahn, the tunnel will be useless as it would be too narrow for unguided buses or would that have been considered?

The whole point of the O-Bahn guided busway system is so we can have two lanes of busses going at high speed in a corridor far narrower than an unguided roadway or two rail tracks.

If the guided busway were scrapped, then the whole corridor would be unsuitable for rail or roadway as all the bridges would need to be replaced (both over the Torrens and under the roadways. So you'd have a far larger problem than just the parklands tunnel.

Not sure what you heard. Maybe they are looking at air displacement issues. Which as stated above, would be something you'd expect engineers would have looked at early on in the project.

jimbly wrote:A question for those who know - on ABC 891 this morning, Stephen Mullighan was talking about the tunnel and about how they are doing tests on the effect of two buses passing in the tunnel. It was mentioned that the tunnel was quite narrow.

Does that mean that if in the future we scrap the o-bahn, the tunnel will be useless as it would be too narrow for unguided buses or would that have been considered?

I believe the original O-Bahn in Germany was a short shared tram tunnel. Buses were fitted with the guiding wheels to enable them to share this tunnel with the trams. So even if the O-Bahn were eventually changed to rail, the tunnel would still be useful to North-Eastern suburbs buses for gaining access tot the city. I have asked previously if it would be capable of being used by trams, but no one seemed to know. I hope it would be for future flexibility.

monotonehell wrote:

jimbly wrote:...

...Not sure what you heard. Maybe they are looking at air displacement issues. Which as stated above, would be something you'd expect engineers would have looked at early on in the project.

Might just be to establish how fast the buses can pass one-another without shaking around to much and scarring the c**p out of the passengers.

fishinajar wrote:

monotonehell wrote:

jimbly wrote:...

...Not sure what you heard. Maybe they are looking at air displacement issues. Which as stated above, would be something you'd expect engineers would have looked at early on in the project.

Might just be to establish how fast the buses can pass one-another without shaking around to much and scarring the c**p out of the passengers.

fair point, hopefully that is it.

monotonehell wrote:The whole point of the O-Bahn guided busway system is so we can have two lanes of busses going at high speed in a corridor far narrower than an unguided roadway or two rail tracks.

That may be how it was sold, however the Southern Brisbane busway travels up to 90km/h, and has no guide track. From my observation, the width of the corridor is no wider. Could it be the Obahn was purchased for political purposes as commuters were promised something on rails, so this was a cheap compromise? -Just an observation,- I was far too young at the time, and all reports I have read from that time seem highly politicised, from both sides.

monotonehell wrote:If the guided busway were scrapped, then the whole corridor would be unsuitable for rail or roadway as all the bridges would need to be replaced (both over the Torrens and under the roadways. So you'd have a far larger problem than just the parklands tunnel.

Is this correct? Is it a weight issue with the bridges, and pantogragh clearance in tunnels? I kind of understand this with heavy rail conversion, but a light rail/ roadway would surely have no such issue.

claybro wrote:

monotonehell wrote:The whole point of the O-Bahn guided busway system is so we can have two lanes of busses going at high speed in a corridor far narrower than an unguided roadway or two rail tracks.

That may be how it was sold, however the Southern Brisbane busway travels up to 90km/h, and has no guide track. From my observation, the width of the corridor is no wider. Could it be the Obahn was purchased for political purposes as commuters were promised something on rails, so this was a cheap compromise? -Just an observation,- I was far too young at the time, and all reports I have read from that time seem highly politicised, from both sides.

monotonehell wrote:If the guided busway were scrapped, then the whole corridor would be unsuitable for rail or roadway as all the bridges would need to be replaced (both over the Torrens and under the roadways. So you'd have a far larger problem than just the parklands tunnel.

Is this correct? Is it a weight issue with the bridges, and pantogragh clearance in tunnels? I kind of understand this with heavy rail conversion, but a light rail/ roadway would surely have no such issue.

The width of both tracks on the O-Bahn is 6.2 metres (not counting the external barriers). The standard width of the South East Busway was spec'ed at 10.2 metres - wider on corners (not counting the external barriers). (I'm not sure about heavy rail widths, something like 12 metres?)

Originally the guide rails were only going to be installed on the "curvy" bit between Klemzig and Hackney in order to allow faster speeds. The rest of the busway out to TTP was intended to be a normal road. The public made a lot of noise and demanded the guides be installed along the entire project, due to safety and speed concerns.

The decision to install an O-Bahn instead of light rail was due to a number of reasons, mostly down to cost and the intrusion/destruction of the Torrens River valley. But it was political, as an election was won on it. In hindsight, it was the better choice. Cost-wise it was much cheaper to build with a cheaper maintenance cost than light rail. Performance-wise it performs better than the light rail alternative in terms of door to door services, with a similar capacity to light rail. All of the perceived benefits of light rail are also seen in fixed route infrastructure like busways (guided or unguided).

There would be no point replacing the O-Bahn with light rail other than system integration or end of life. In terms of capacity, when the upper limit is reached, heavy rail would be the next step.

There's been a lot of with hindsight reviews and studies of the busways, and despite peoples' "feelings" on the matter, the facts show the O-Bahn was a huge success on all measures. That success has only been recognised in the past couple of decades, with other guided busways being adopted in the UK and beyond (Cambridge, Manchester, Nagoya, Japan).

monotonehell wrote:Originally the guide rails were only going to be installed on the "curvy" bit between Klemzig and Hackney in order to allow faster speeds. The rest of the busway out to TTP was intended to be a normal road. The public made a lot of noise and demanded the guides be installed along the entire project, due to safety and speed concerns.

Thanks for the info, I was not aware of the option to only partially track the corridor but it does make sense to have done it properly, albeit for political browny points. Although not a fan of the busway, I do get that the "to door" service in the outer suburbs is better with the busway than fixed rail, but I'm not sure that pointing to the ongoing success of the busway proves it is better than heavy rail is correct. Would heavy rail with feeder bus services be more appealing for example if the CBD had an underground loop so that commuters were delivered more centrally, or SA could actually run a train system properly and at design speed?- It would certainly prove higher capacity and speed if run properly. I suspect this would be light years away, so maybe the idea of a PT/ pedestrian only zone for Grenfell/ Currie streets, with decent substantial shelters is the way to go for the next 30odd years, if the Obahn track can be maintained for that long.

One of the reasons for the success of the O-Bahn is that it is allowed to operate at much higher speeds than competing modes.

Thus, trams dodder down to Glenelg in their own right of way, but buses on the O-Bahn are allowed much higher speeds.

Makes rigorous comparison impossible.