The war on (low floor) tram bogies

[Myrtone]

This is a centralised place where the relative merits of pivoting and fixed tram bogies for low floor trams can be discussed.

Let me start:
The Citadis (both the Melbourne C class and Adelaide 200 series), the E and G class Melbourne trams are all about 95% low floor but the Citadis type mentioned have fixed bogies and their low floor areas are completely flat. The E class has pivoting bogies and upcoming G class has pivoting end bogies, but they have slight inclines next the the doors and slopes in the aisle, the former criticised by the Australian Quadriplegic Association.
The bogie-under-cab principle of some variants of Citadis in France (Strasbourg, Nantes and Paris) does allow a completely flat low floor area without constraining end bogie movement and this would be a good thing to consider for the G2 class, if built. However, those Citadis variants too, are more like 95% low floor.

Yes, the Skoda 15T is also bogie-under-cab, and while its articulations are 700mm wide, they are narrower than the articulation gangways of the other tram types mentioned and visually forbidding, and it has not gone well, with very few orders for it.

Reece Martin designed a better low floor tram that does away with twin-axle bogies altogether. If this becomes a reality, this is sure to flood the market.

[1whoknows]

And the most significant line in the video by this wanker is

"despite being completely unqualified to do so I am going to design....."

so don't waste your time folks.

[Myrtone]

Please stop trolling or insulting Reece Martin. I know he is not qualified to do so, but it is sure to become a reality if it does get built and does work.

[tonyp]

And the most significant line in the video by this wanker is

"despite being completely unqualified to do so I am going to design....."

so don't waste your time folks.

And don't waste time on the post that contains this link. Individual swivelling wheelsets were tried in the 1990s and were a maintenance and reliability nightmare. After more than 30 years of trial and error, the tram industry has developed what works best, is most reliable and has least maintenance. Reece Martin or any other amateur is not going to come up with anything better at this stage. The only significant compromise to accommodate engineering has been number and distribution of doors and sometimes aisle width, plus the previously discussed choice of fixed bogies to reduce purchase price.

Re the Škoda 15T, which has been, according to the OP, so "unsuccessful" that's it even been sold in China, beating out local products, here's an interior photo showing how terribly "cramped" it is.



Don't believe this guy's bs. This Škoda model and the Siemens Avenio have the best distribution and number of doors on the market because of thoughtfully designed bogie location. Here's the Avenio, which can be found in Munich and some other European cities.



Let me also cut through the troll's pedantry about low floor and state simply that low floor means a stepless gangway in the passenger area (aisle and doorways) and may be ramped to a degree (typically when passing over wheelsets), as long as it's stepless. Some trams, like the Škoda or the CAFs in Sydney, are even stepless under the seats. All of those Melbourne and Adelaide trams mentioned in the OP are, by definition, 100% low floor, not 95% low floor.

After some 40 years since the first "low floor" (low-entry) trams were introduced, it's a bit of a waste of time talking about refining low-floor tram design. There are better-designed trams and not-so-well-designed trams on the market, but the point is that there's a choice and it's up to operators (who, likewise, are better or poorer at knowing what they're doing) to choose what they think is best for their system. The only negative influence, unfortunately, is that price is scored much more highly than engineering and other functionality factors in tenders. The outcome is of course that you get what you pay for.

Finally, I think it's ridiculous to be having nit-picking discussions about ramping in stepless tram floors, when we have this gigantic problem with buses in Australia, a problem that, similarly to trams, was solved about 30 years ago but somehow survives almost unchallenged in Australia. Almost like the sailing ship with the news hasn't reached our shores yet - except through a pommie at Custom Denning.

ulf2.jpg

[Myrtone]

And don't waste time on the post that contains this link. Individual swivelling wheelsets were tried in the 1990s and were a maintenance and reliability nightmare. After more than 30 years of trial and error, the tram industry has developed what works best, is most reliable and has least maintenance. Reece Martin or any other amateur is not going to come up with anything better at this stage. The only significant compromise to accommodate engineering has been number and distribution of doors and sometimes aisle width, plus the previously discussed choice of fixed bogies to reduce purchase price.

How about individual computer steered wheel-sets? That is what the "RMTransit High Capacity Low Floor Metro Train" would surely have if it becomes a reality.

Re the Škoda 15T, which has been, according to the OP, so "unsuccessful" that's it even been sold in China, beating out local products, here's an interior photo showing how terribly "cramped" it is.

Only two orders for it outside China does not sound successful, at least not in capitalist countries. China still have a soviet style of government that withholds information as is very secretive, such as covering up COVID-19 until it spread beyond its borders.

This Škoda model and the Siemens Avenio have the best distribution and number of doors on the market because of thoughtfully designed bogie location. Here's the Avenio, which can be found in Munich and some other European cities.

But the Avenio still has wheelbox intrusion.

And what about the Citadis variants for Strasbourg and Nantes and the latest ones for Paris, all of which have bogies under the cabs, minimising wheelbox intrusion?

Let me also cut through the troll's pedantry about low floor and state simply that low floor means a stepless gangway in the passenger area (aisle and doorways) and may be ramped to a degree (typically when passing over wheelsets), as long as it's stepless. Some trams, like the Škoda or the CAFs in Sydney, are even stepless under the seats. All of those Melbourne and Adelaide trams mentioned in the OP are, by definition, 100% low floor, not 95% low floor.

You once said on Railpage that some tram types marketed as 100% low floor are not really 100% low floor because of steps up to some of the seats, and even referred to them as 95% low floor in a transit Australia article.

After some 40 years since the first "low floor" (low-entry) trams were introduced, it's a bit of a waste of time talking about refining low-floor tram design. There are better-designed trams and not-so-well-designed trams on the market, but the point is that there's a choice and it's up to operators (who, likewise, are better or poorer at knowing what they're doing) to choose what they think is best for their system. The only negative influence, unfortunately, is that price is scored much more highly than engineering and other functionality factors in tenders. The outcome is of course that you get what you pay for.

I am not sure what you mean by this.

Finally, I think it's ridiculous to be having nit-picking discussions about ramping in stepless tram floors, when we have this gigantic problem with buses in Australia, a problem that, similarly to trams, was solved about 30 years ago but somehow survives almost unchallenged in Australia. Almost like the sailing ship with the news hasn't reached our shores yet - except through a pommie at Custom Denning.

Buses are not the same as rail vehicles such as trams, they tend not to use platforms, like both trams and trains do. Most buses also have doors next to the driver's seat, this being wheelchair accessible, often with a foldout ramp.
Wheelchair accessible doors on trains (counting trams as small trains) are not right next to the drivers seat and in case of trams are often near the middle. Is the Australian Quadriplegic Association being ridiculous?

Trains don't have sloped floors, even the vestibule floors of double decker trains are also completely flat, so why should trams have them? Unlike with a bus, the need for such slopes can be avoided simply with the bogie-under-cab principle.