In Adelaide, railcars are much heavier than trams. That means they are more expensive to build and to accelerate and brake.SBD wrote: ↑Tue May 19, 2020 2:02 pmSo for the less-informed amongst us (I may not be the only one), what is the defining difference between a train/heavy rail EMU and a tram/light rail running in a dedicated corridor? Both have steel wheels, steel tracks and electric motors fed by overhead power lines. None of Adelaide's metropolitan railways share track with other trains any more. Most of our tram tracks are in dedicated corridors.rubberman wrote: ↑Tue May 19, 2020 12:04 pmWell, yes, you can put in bigger motors in big vehicles. That doesn't change the fact that you can do the exact same job with a smaller and cheaper vehicle.1NEEDS2POST wrote: ↑Mon May 18, 2020 11:02 pmPedestrian access is still a problem for many stations in Adelaide. This discussion about North Adelaide is one example. The thing is, it's very inexpensive to solve compared to other infrastructure projects. There are plans to remove level crossings from Adelaide, but few talk about grade separation of pedestrians. The thing is, grade separation of little pedestrians is far far far cheaper than grade separation of railways and roads and it directly leads to higher public transport usage.
We need more subways in Adelaide. More pedestrian subways, that is.
That has little to do with the trams and has more to do with the fact that you want short stop spacing. A tram/train/bus that stops frequently is always going to be slow. All modes can be built to accelerate just as fast as one another. Many overseas metros accelerate much faster than Adelaide's trains. I see no reason why they can't fit more powerful motors to the new EMUs and make them accelerate and brake harder.
Property development and transport planning should be complementary, but they're not in Adelaide. For all of the metro railway stations, every 200 m from the station should be zoned to allow medium density residential.
Nobody disputes you can do it, the question is why should the taxpayer pay extra to achieve the same outcome?
Is the difference the signalling and control systems? Does one have better safety systems than the other?
Railcars can travel at higher speeds, and can be coupled together in long trains. However, those are only advantages if stations are far enough apart and there's a high passenger load.
So, for example, a tram and a train going between stops one km apart might each get up to 70kph before they have to brake for the stop. So, each can do the job equally, but the train costs more to build...for doing the same job. The train also sonsumes more energy because it has to accelerate a greater mass. Thus, unless the passenger load is greater than a tram can handle, a tram is cheaper and more energy efficient at smaller station spacings. Trams/light rail wins.
HOWEVER, if we make the stations 5km apart, everything changes. The heavy rail vehicle can achieve 100kph before starting to brake, while the tram tops out at 70kph. So, as the tram putters into the station, the heavy rail is loaded and away under this scenario. Heavy rail wins.
So, it's horses for courses.
In addition, heavy rail has more stringent safety distances needed than trams. Trams have much shorter emergency stopping distances because of the magnetic track brakes and slower design speeds. That means heavy rail requires extra signalling that is simply unnecessary for trams/light rail.