News & Discussion: Regional Transport

[Heardy_101]

Do you have any credibility to what you say, Heardy?

Excuse me? Just a bit uncalled for. In answer to your question, the answer is yes, I do.

And Aiden is right - Cable Cars operate on the steeper gradients, while the Electric Trams, Trolley Buses and Diesel Buses (some of the Trams are actually Melbourne W2 Class Trams!) operate on the gentle gradients.

The reason why I made the observations with some of the grades on the O-Bahn is because some of them are quite long, not very steep but like the Freeway they can be long.

[rubberman]

Monotone, I can quite believe that that is the speed they do operate at.

What they are capable of is something else. Like I said, US interurbans (on which Sir William Goodman based the Glenelg line) regularly scheduled services one hundred years ago which were doing much much more. With modern electric motors and control systems, there is no reason why speeds should be less!

I don't have my copy of Roger Wheaton's "Rails to the Bay", but iirc the travel time from Glenelg to the Railway station (Not sure how he calculated it - must have been Glenelg-Vic Sq, then normal car to Rly Stn) was about seven or eight minutes less than today. That is with many more tram routes crowding King Wm. St., and no level crossing signals or grade separation at Sth Road.

Heardy, in Prague, there is a very long stretch of 8% grade from the River up the hill to Troja. That feels scary, but the trams tackle it without a problem. I should imagine that if it can be done in a European capital with winter ice on the rails etc. it can be done here. Should our transport operators wish it. There are youtube videos of it and you can see how steep it is by the slope of the track compared to the houses on the side. Long and low slopes are eaten for breakfast by trams. The line to Glen Osmond for example, was not only regularly used by two motor D and E cars in MTT times, but the line had only one feeder from the East Terrace converter station.

Bondi trams are legendary for speed and there was a reason for it- they were fast. Yet there were some serious slopes down to the beach. Present day operators would soil themselves at the speeds these trams operated at...all with open sides and the conductor walking along the step on the side of the tram.

[claybro]

Are you sure? What I've read shows that the OBahn operates at around 80Kmh, heavy rail at about 60kph, light rail where it has right of way at about 50kph, while on street light rail (trams) at around 40kph.

Existing diesel railcars 80km/h. New Electric trains 100km/h plus. Trams 60km/h, but elsewhere in the world trams operate at higher speeds 80-100km/h. That we hurl a flimsy articulated bus at 90km/h along a concrete track, but restrict a rigid body tram on the Glenelg line to 60km/h is a bit of a mystery to me.

[monotonehell]

Monotone, I can quite believe that that is the speed they do operate at.

Those speeds are the average on rail speeds for each mode. For example to work out the Glenelg tram's average speed you'd need to factor in the parts of the trip on street, the parts in its own corridor, any stops and any delays at level crossings. For the OBahn you'd have a similar list of items, except no level crossings and we'd need the on street speed for buses. I found a reference that quotes the average on track speed for OBahn of 60kmh (but only includes stops) {1}. Some of these figures are very hard to find. But I guess you could say that the on street parts of both the tram and the OBahn would be almost equivalent. So this supports the light rail is slower than OBahn claim.

Heardy, in Prague, there is a very long stretch of 8% grade from the River up the hill to Troja. That feels scary, but the trams tackle it without a problem. I should imagine that if it can be done in a European capital with winter ice on the rails etc. it can be done here. Should our transport operators wish it. There are youtube videos of it and you can see how steep it is by the slope of the track compared to the houses on the side. Long and low slopes are eaten for breakfast by trams. The line to Glen Osmond for example, was not only regularly used by two motor D and E cars in MTT times, but the line had only one feeder from the East Terrace converter station.

I think this is a property of what ever rolling stock is put into service. We see European trams performing in ice and snow, and yet our trams couldn't get around the KWS/North Tce corner because some leaves were on the track. I understand they've since added sand pots for friction. Perhaps they should have rubber tyres?

Bondi trams are legendary for speed and there was a reason for it- they were fast. Yet there were some serious slopes down to the beach. Present day operators would soil themselves at the speeds these trams operated at...all with open sides and the conductor walking along the step on the side of the tram.

Hence the saying, "went through him like a Bondi tram."

{1} https://docs.google.com/viewer?a=v&q=ca ... Z49lBJYLXg

This is a good balanced summary of the OBahn experience. It's pretty much all the conclusions I came to back in 2007 after a lot of synthesis of what information was available at the time (not that much). Ignore the high operational cost of trams quoted in the table though, I'm pretty sure that was the cost of our pre-modernised ancient system.

I especially love the summary at the end...

Rail Enthusiasts – most cities have a significant number or rail enthusiasts, who love
the complex engineering, sounds, and interesting operating practices and workings
of rail systems, most of which aren’t present in bus systems. Why is it that the
introduction of new trams several years ago in Adelaide saw 170 tram enthusiasts
travel on a new tram under test at 2 am so they could be the first to ride on it? I have
never seen the same interest with buses!

There seem to be many people – especially males – who will catch a rail vehicle but
would not catch a bus. There are probably many people using trains and trams, mad
some politicians, who are “closet” rail enthusiasts.

[rubberman]

Monotone, I think we are arguing about semantics here. I agree that light rail in Adelaide is slower than the O-Bahn. However, that is not because light rail per se is slower than O-Bahns, merely that management in Adelaide have decided to make it so. For example if I drive a Porsche down the street slower than a farm tractor, it is not because farm tractors are faster than Porsches, it is because I choose to drive the Porsche slower. Same with light rail vs O-Bahn in Adelaide - managers choose to drive the light rail slow.

Light rail could be faster than the O-Bahn if they wanted it to be. The present Glenelg trams do not perform anywhere near their existing potential, let alone what could be done with more powerful trams/motors.

[[Shuz]]

I find that the tram drivers here are a lot gentler and cautious in their approach to driving the trams than the ones in Melbourne.

[monotonehell]

Monotone, I think we are arguing about semantics here. I agree that light rail in Adelaide is slower than the O-Bahn. However, that is not because light rail per se is slower than O-Bahns, merely that management in Adelaide have decided to make it so. For example if I drive a Porsche down the street slower than a farm tractor, it is not because farm tractors are faster than Porsches, it is because I choose to drive the Porsche slower. Same with light rail vs O-Bahn in Adelaide - managers choose to drive the light rail slow.

Light rail could be faster than the O-Bahn if they wanted it to be. The present Glenelg trams do not perform anywhere near their existing potential, let alone what could be done with more powerful trams/motors.

It's not semantics. We're using pretty much the same definitions of words.

So what you're saying is, "things could be faster if..."

Well the OBahn can (and was) driven up to 110KMh, they don't do that any more due to safety concerns. The figures I quoted above were based on international standard practice. Trams could be given complete right of way, all intersections be split grade and the vehicles given super speed motors. But that's not what your average contemporary urban tram network vehicle contains.

In terms of speed the OBahn is at the top of ALL modes of urban transport. This is a fact from established experience.

I wish I could find the literature I had in the past, but this will have to do. This is an analysis of capacity against speed of various forms of PT. Sorry the professor who put it together is not a graphic designer so it's a dog's breakfast of a graph. You may need to open the image in a new tab as this forum might cut off the right hand side on smaller screens.

You can see in terms of speed the OBahn is well above all other forms of standard PT and is in the same league as commuter rail. Heavy rail is slower but has a far greater range of capacity. Light rail with its own right of way is close to that in both speed and capacity. However light rail on street suffers on both counts.

PT capacity v speed

CapacitySpeed.png (387.7 KiB) Viewed 3562 times

[rubberman]

Monotone, I agree that you can say that the O-Bahn is faster than the Glenelg line. The reason being that the stops are limited on the O-Bahn compared to the line to Glenelg. However, if you converted the OB to light rail and allowed the same speed as the buses, the laws of physics tell you that you get the same, er, speed.

If you have a dedicated track with vehicles able to travel at the same speed, and with the same stop spacing and dwell times, you get the same overall performance. That is just basic physics.

In fact, a modern tram, such as the Skoda 15T, with six double leaf doors would probably be faster overall, based on a shorter dwell time at each stop, than a single door entry of OB buses.

What those graphs show is that if you have a typical light rail with typical (usually 500-600m) stops, it will be slower than an O-Bahn with much much longer stretches between stops. What those graphs do not show is what the situation would be if you had light rail with OB stop spacings.

By the way, are you sure that that graph is correct? Let's say that an OB bus had 150 people in it (a bit of a squeeze), then a unidirectional capacity of 45000 per hour means that there must be 300 buses per hour. That is, one every twelve seconds. I'd like to see that. So, do the OB figures take into account the same safety margins that are incorporated in the other modes on that graph?

[monotonehell]

You've misread the graph (don't blame you it's horrid). The OBahn is listed on there as having something like 4000 to 8000 "peak directional capacity". The capacity of the OBahn has been estimated at 18,000 passengers per hour in each direction, using articulated buses operating at 20-second headways. They're no where near that as yet.

Note that this graph is not about the Glenelg tramway it's an average of experience. The Adelaide OBahn's data, however, has been layered onto the original graph (along with Brisbane, St Kilda and Bogota).

So for the operating speed _range_, that's the vertical axis:
* For trams you'd take the top of the exclusive right of way, right down to the bottom of the arterial.
* For the OBahn you'd need to take the OBahn's little red line, down to the local bus's block.


The conclusion that all these reports come to is that a guided busway is cheaper to build and cheaper to run than light rail at about the same speed. It's only when your expected capacity is going to exceed somewhere around 12,000 peak directional capacity that light rail could be considered. But at that point you'd probably be better looking at heavy rail. Another factor that's coming to light is that light rail is a bit of a fail on street.

[rubberman]

Monotone, I shall take your word about the graphs.

The conclusion that all these reports come to is that a guided busway is cheaper to build and cheaper to run than light rail at about the same speed. It's only when your expected capacity is going to exceed somewhere around 12,000 peak directional capacity that light rail could be considered. But at that point you'd probably be better looking at heavy rail. Another factor that's coming to light is that light rail is a bit of a fail on street.

First of all, I have to say that since most of the western world lost its expertise in tramways after the second world war, but did invest heavily in bus technology and operation, it is not surprising that the finance is skewed that way.

However, to base planning on that skewed basis is a little faulty in my view. Technology for light rail did progress in Germany and in the Eastern Bloc, so that much more competitive costing and operational procedures are actually realisable - should management choose to use them. For example, the list price today of low floor six door trams from Europe is about half what Adelaide paid for its 'Bib and Bub' 'Two Birney's and a bath' Citadis. That's right, one can purchase better trams for half the price we paid for the Citadis. Add to that, much faster travel times on comparative lines. (For example, look up the travel times on the Barandov line in Prague which not only runs part through the city and then in its own right of way like the Glenelg-Entercentre line, but also has an extremely long climb to the terminus).

The figures are further skewed by the fact that many light rail/tramways such as the Sydney light rail are so unnecessarily slow and overcapitalised (by signals for example), so of course the operating and financial figures will show that they are less economical than buses. As an example, the south parklands has a plethora of signals allowing for the shuttle to shunt. When the tramways used to run in its heyday, there were sidings and crossovers at Morphettville which used to run more frequent trams in between the normal operation, and no signals - effectively doing exactly the same thing. So why do we need them now? (Hint; that is a trick question. The German BOSTRAB standards say you don't need them for our sort of light rail).

My question to you would be that if we compared like for like - ie a modern, well run busway, with a modern well run tramway/light rail - would the analyses you cite show the same results. When we are talking about trams being bought for double what they could be, and unnecessary signalling and other appurtenances being added to the cost of light rail, there is a lot of fat to burn off before a valid comparison can be made.

[Aidan]

Mono, when (apart from in testing) did buses ever do 110km/h on the O-bahn? They were designed for 100km/h and AFAIK that was always what the top speed limit was. And although they considered reducing it because of stability problems on low floor articulated buses above 80, I don't think they ever actually did.

The O-bahn is one thing we got right. Most of the world's O-bahns are far too slow. They're treated as a cheap substitute for light rail, and are not as attractive to passengers.


Rubberman, I can't think of anywhere where low floor light rail reaches 100km/h. Can you?

[rubberman]

Rubberman, I can't think of anywhere where low floor light rail reaches 100km/h. Can you?

Can't think of one technical reason why not, should management wish it. Can you?

My point was that it is management who are making the restrictions, and not on any sound technical reasons for so doing. My point also was that even with the more conventional tramway like the Glenelg line, one can purchase trams cheaper than we have (management decision) and have much less expensive infrastructure (such as signalling - another management decision) and run faster (a further management decision) while still adhering to conservative safety and operational standards of long standing and good technical backing (The German BOSTRAB for example).

What I find a little tedious are comparisons between a well run busway (like the O-Bahn) and a light rail system that has purchased expensive vehicles and plant and runs far slower than equivalent best practice systems overseas. If one is to be honest in comparisons, then compare like with like, and then draw conclusions. At the moment it is like asserting that tractors are faster than Porsches having observed the situation where the road rules are set up so that Porsches may only travel half the speed of the tractors and with someone with a flag walking in front - it's safer, you know.

There is a point to this, not just a snark at management. That point is, that if one actually makes valid comparisons, then one can pick out areas for improvement and work on them. If one sticks one's head in the sand and thinks that every thing is rosy in the garden, then one will never ever improve.

[Aidan]

Rubberman, I can't think of anywhere where low floor light rail reaches 100km/h. Can you?

Can't think of one technical reason why not should management wish it. Can you?

I know there are lots of technical reasons why doing so would be far more difficult than with high floor. But I expect they could be overcome if someone was willing to throw enough money at it.

Disclaimer: I'm civil, not mechanical.

[rubberman]

LOL! And the price we paid for the Citadis (Two Birneys and a bath) is not throwing money at it? Or signals?

Throwing money at stuff has not been a problem as far as the evidence to date has shown.

[Aidan]

LOL! And the price we paid for the Citadis (Two Birneys and a bath) is not throwing money at it? Or signals?

Throwing money at stuff has not been a problem as far as the evidence to date has shown.

No, we have not thrown money at that problem. Our existing trams are off the shelf designs - if we want something capable of 100km/h, it's likely to cost much more. At the time we acquired the trams, there was a shortage of tram manufacturing capacity. Now there's a surplus.