[smallspy]

OK, then define this:

Helsinki's New Tram - Transtech

Note:

https://www.hel.fi/static/hkl/artic.pdf

Emphasis on "very flexible rubber elements in wheels". That's for radius compliance as much as vertical undulation absorption, curving performance and dynamic stability.

There's lots of detail here:
https://www.researchgate.net/figure...bogies-with-independent-wheels_fig1_267830130

And to those wondering what an "articulated bogie" is:

https://en.wikipedia.org/wiki/Bogie#Articulated_bogie


http://www.transtech.fi/download/103/low-floor_tram/pdf

There's nothing to define there. They don't use the term steerable to describe the trucks or wheels.

Once again - "steerable" means something very specific. What they are describing are rotating trucks, which, once again, was a very unusual thing for a fully low-floor streetcar to have until very recently.

Since you're fond of Wikipedia entries, please allow me to point you to this one: https://en.wikipedia.org/wiki/Radial_steering_truck

Dan

 

[DSC]

There's nothing to define there. They don't use the term steerable to describe the trucks or wheels.

Once again - "steerable" means something very specific. What they are describing are rotating trucks, which, once again, was a very unusual thing for a fully low-floor streetcar to have until very recently.

Since you're fond of Wikipedia entries, please allow me to point you to this one: https://en.wikipedia.org/wiki/Radial_steering_truck

Dan

Dan: I am afraid you are wasting your time; some people are too set in their ways to change or adapt their ideas to reality or facts. :->

 

[steveintoronto]

A steerable axle is one which it is able to rotate and continue to be perpendicular to the rails.

That's *EXACTLY* what an articulated bogie does. Call it Fred for all I care. It's steerable. *Even if it has no continuous axles*!

And a reminder as to where your nose got out of joint:

steveintoronto said:

Addendum: Took some time to find more detailed info on the bogies and the "steerable axles" (which is what I thought they meant, but it might be terminology used mostly in the West), and there's a number of really sensible engineering features to these vehicles.

I posted a link to this, obviously you didn't access it, or if you did, you couldn't read it. The authors of this and many articles on the subject are not American, and thus use a different terminology to achieve *exactly as you yourself describe it*:

The articulated bogie
Source publication






https://www.researchgate.net/figure...tc9xTJl3Km5dDpoJ740fzuxoCA5YzwFvbx2n6sYlJpkfw

TRAMWAY/TRACK INTERACTION: DYNAMIC ANALYSIS AND PERFORMANCE EVALUATION OF AN ARTICULATED BOGIE WITH INDEPENDENT WHEELS
Article
Full-text available

• https://www.researchgate.net/profile/Paul_Fisette?_sg[_sg]=kPjYXprlkZUSDkojfntKpu3BBScO0tEd9dauuVTMzDu-i_LoM2lb1eNCLSL_YO4acjEK8ec4TqHtGA

View
Contexts
Context 1
[...] The use of independent wheels certainly represents one of the most ”revolu- tionary” innovation of the last decades. Indeed, it aims at replacing the traditional wheelset which exists for more than one century and is at the root of the bogie guidance thanks to its well-established self-steering capability. [...]

https://www.researchgate.net/figure/The-articulated-bogie_fig2_267830130

Even just the quoted text of the opening page sample mentions "steer" ten times.

Perhaps if you weren't so beholden to calling others out, you could see a world beyond your own, but alas...There's a lot more "steerable" in the world than just the EMD patented term. And in the case of the Transtech bogie, they use *continuous axles*. The bogie frame itself, as they aptly and repeatedly state, 'articulates like the carriages themselves'. As to how that 'articulation' 'pivoting' or 'steering' happens is unique in many cases. It's unique in the case of Transtech bogie, and an exact engineering discussion is proving difficult to find. Somehow they've achieved articulation in all planes with continuous ('solid' by your terminology) axles.

Just because it doesn't fit *YOUR* understanding doesn't mean it doesn't meet established and proven engineering terms and standards elsewhere.

 

[Jonny5]

In the Report to TTC Board on the King Street Project they recommend adding a curve at York:

Streetcar track network enhancements: improving the intersection of York Street and King Street by adding an additional east-to-north movement that allows for more routing options for diversions or adjustments. Layby tracks within the pilot area may also provide an opportunity to provide greater service resiliency with standby vehicles.

It would also add flexibility if the built/rebuilt the tracks on Adelaide, at least from York to Victoria

Diversions are often more trouble than they are worth when the average rider is so confounded by them that their brains shutdown sending their lives into a total meltdown, halting the service while they demand the driver stop and provide a detailed explanation to them of what is happening, and then seven people behind them also demand the exact same explanation be individually provided to them, after which they all spend four or five minutes in the doorway pondering whether or not to get off.

Even the regular daily westbound 503 trips are a nightmare for some people, and these aren't newbie riders, but people who have made thousands of trips on the TTC. You can see them at the back when the bus or streetcar turns at Church Street frantically pulling the cord 50 times in a row, thinking that will make the vehicle stop for some reason. Then when it finally gets to the next stop they will walk to the front to exit, then turn around and walk back past the door they could have exited anyway.

 

[DSC]

Diversions are often more trouble than they are worth when the average rider is confounded by them their brains shutdown sending their lives into a total meltdown, halting the service while they demand the driver stop and provide a detailed explanation to them of what is happening, and then seven people behind them also demand the exact same explanation be individually provided to them, after which they all spend four or five minutes in the doorway pondering whether or not to get off.

Even the regular daily westbound 503 trips are a nightmare for some people, and these aren't newbie riders, but people who have made thousands of trips on the TTC. You can see them at the back when the bus or streetcar turns at Church Street frantically pulling the cord 50 times in a row, thinking that will make the vehicle stop for some reason. Then when it finally gets to the next stop they will walk to the front to exit, then turn around and walk back past the door they could have exited anyway.

I am not suggesting that I like either diversions or short-turns but they WILL happen due to accidents, street closures or schedule problems and my point was that having a couple more options downtown would be good. For 99% of passengers a diversion is much preferred to no service at all!

 

[steveintoronto]

Here's the most detailed pic I've found so far on the TransTech Helsinki trams. They're produced by a Swiss company Prose who make bogies for a number of large names in the rail business.

Still looking for technical/engineering description, but already, the 'steerable elements' are clearly visible in the pic, for both axle geometry and drive compliance for that:

https://www.prose.one/fr-fr/News-and-Events/News/Detail?nid=82

Here's some company promo:
https://www.prose.one/DesktopModules/PRO_CaseHistory/files_ch/7-3_000.pdf
https://designenlassen1.s3.amazonaws.com/5/583738/prose_presentation_standard_e.pdf

 

[thettctransitfanatic]

I am not suggesting that I like either diversions or short-turns but they WILL happen due to accidents, street closures or schedule problems and my point was that having a couple more options downtown would be good. For 99% of passengers a diversion is much preferred to no service at all!

Well, they could also get off the streetcar and walk, if their trips are within the downtown.

 

[smallspy]

That's *EXACTLY* what an articulated bogie does. Call it Fred for all I care. It's steerable. *Even if it has no continuous axles*!

And a reminder as to where your nose got out of joint:

I posted a link to this, obviously you didn't access it, or if you did, you couldn't read it. The authors of this and many articles on the subject are not American, and thus use a different terminology to achieve *exactly as you yourself describe it*:

https://www.researchgate.net/figure/The-articulated-bogie_fig2_267830130

Even just the quoted text of the opening page sample mentions "steer" ten times.

Perhaps if you weren't so beholden to calling others out, you could see a world beyond your own, but alas...There's a lot more "steerable" in the world than just the EMD patented term. And in the case of the Transtech bogie, they use *continuous axles*. The bogie frame itself, as they aptly and repeatedly state, 'articulates like the carriages themselves'. As to how that 'articulation' 'pivoting' or 'steering' happens is unique in many cases. It's unique in the case of Transtech bogie, and an exact engineering discussion is proving difficult to find. Somehow they've achieved articulation in all planes with continuous ('solid' by your terminology) axles.

Just because it doesn't fit *YOUR* understanding doesn't mean it doesn't meet established and proven engineering terms and standards elsewhere.

You seem to have completely missed the point.

You claimed that the Artic cars have steerable axles. They don't. They're bog-standard in that case. The trucks rotate freely. The axles however don't move fore-and-aft in relation to the truck sideframes beyond the very little range of motion the suspension affords them. A steerable axle will have a linkage mechanism built into the truck to allow the ends of each axle to move fore-and-aft in response to curves.

As for the language, well, I guess that's up to you. I'll continue to use the industry-standard nomenclature so that those that actually do know what they're talking about understand the point that I am trying to get across. You're more than welcome to watch from the sidelines.

Dan

 

[DSC]

Well, they could also get off the streetcar and walk, if their trips are within the downtown.

Not all passengers can walk many blocks and if there are no diversionary routes and the ONLY route gets blocked, there will be no service for anyone.

 

[thettctransitfanatic]

Not all passengers can walk many blocks and if there are no diversionary routes and the ONLY route gets blocked, there will be no service for anyone.

That's a good point. But in the core if you are able bodied then you should be able to handle a walk of that nature

 

[DSC]

That's a good point. But in the core if you are able bodied then you should be able to handle a walk of that nature

Well, yes but the point is that not all passengers ARE able-bodied.

 

[steveintoronto]

A steerable axle will have a linkage mechanism built into the truck to allow the ends of each axle to move fore-and-aft in response to curves.

Which is exactly what they have. And more. The question is whether the axle geometry compliance is passive or active.

I

Some enlightenment *might* be had here:

Posted by beaulieu on Wednesday, January 17, 2007 10:46 AM

artschlosser wrote:

Things often get named inappropriately. In this case 'self-aligning' might have been better than 'steerable'.

Depends upon whether or not the self-steering is passive or forced. The EMD HTCR and HTCR II are passive, and self-aligning would be an accurate description. But the "B" truck used under the ABB-SLM "Lok 2000" locomotives is a forced steer design. The axles assume a radial position because the truck is rotated from being aligned straight with the locomotive body. Examples of the "Lok 2000" are the Swiss SBB Re 460 locomotives, and the Finnish Vr2 locomotives.

• http://cs.trains.com/trn/f/111/t/85366.aspx

The ABB design was from PROSE. They detail it in their literature.
As you were...

 

[smallspy]

Which is exactly what they have. And more. The question is whether the axle geometry compliance is passive or active.

Once again.....

No, they don't. There needs to be a linkage between the axle ends of each truck, and the truck itself. These have none of that.

What you are looking at in those screengrabs is the truck sideframe, the "metalastic" primary suspension components, and the swing plank which connects the truck sideframe through the secondary suspension to the bolster of the car.

Dan

 

[steveintoronto]

Once again.....

No, they don't. There needs to be a linkage between the axle ends of each truck, and the truck itself. These have none of that.

What you are looking at in those screengrabs is the truck sideframe, the "metalastic" primary suspension components, and the swing plank which connects the truck sideframe through the secondary suspension to the bolster of the car.

Dan

Keep trying. I think you'd best read the addendum I added to my last post before you dig yourself any deeper. The PMO is envious...

And just a reminder,:

Addendum: Took some time to find more detailed info on the bogies and the "steerable axles" (which is what I thought they meant, but it might be terminology used mostly in the West), and there's a number of really sensible engineering features to these vehicles. Excellent multi-page pdf:
https://www.hel.fi/static/hkl/artic.pdf

[...]
GE has by now come up with its own radial truck -- these things are heavily protected by patents so you have to come up with a different design.

I had asked about the two-axle truck on the Genesis Diesel on another thread. I was wondering 1) who makes that truck (the guesses were Deutz or someone German) and 2) whether that design is radial steer. I talked to some folks in town who were of the opinion that it wasn't.

The interesting thing about the Genesis truck is that it has these long bell crank-like pieces connecting the axle bearings to the bolster, and it looks like it could be a steering truck.

There are also two kinds of steering trucks -- self-steer and forced-steer. The self-steer truck has links to force the axles to either go straight or assume equal and opposite angles relative to the truck side frame, but the main steering force is the self-steer of the coned wheels -- the steering of a pair of axles is coordinated in an effort to prevent hunting. The forced-steer truck uses the pivot angle of the truck with the bolster to provide the steering input. The forced-steer design is more common for high-speed passenger equipment (I believe the Swiss company SIG has such a truck along with their being a Japanese design) while self-steer is more common for freight (the EMD radial truck, the self-steer freight truck of the South African Railway).
[...]

http://cs.trains.com/trn/f/111/t/22695.aspx

Once again.....

No, they don't. There needs to be a linkage between the axle ends of each truck, and the truck itself. These have none of that.

What you are looking at in those screengrabs is the truck sideframe, the "metalastic" primary suspension components, and the swing plank which connects the truck sideframe through the secondary suspension to the bolster of the car.

Dan

I see. You know of only one method, and hold the rest of the world to your limited understanding. I'd have some sympathy for your understanding only North Am methods, save that GE (I presume you're familiar with them?) have this patented method.

I challenge you to indicate where "There needs to be a linkage between the axle ends of each truck, and the truck itself. These have none of that." are on this design:

http://www.freepatentsonline.com/4440094.pdf

Lots more detail exquisitely supplied at that link. Allow me to offer your next excuse: "Oh, but that's for a three axle bogie". There are separate patents for a two axle one.

Readers might find this interesting: http://www.freepatentsonline.com/4285280.pdf Developed in Kingston and assigned to UTDC, albeit it's a simple mechanical actuation, somewhat as Smallspy describes.

 

[smallspy]

Keep trying. I think you'd best read the addendum I added to my last post before you dig yourself any deeper. The PMO is envious...

And just a reminder,:


http://cs.trains.com/trn/f/111/t/22695.aspx


I see. You know of only one method, and hold the rest of the world to your limited understanding. I'd have some sympathy for your understanding only North Am methods, save that GE (I presume you're familiar with them?) have this patented method.

I challenge you to indicate where "There needs to be a linkage between the axle ends of each truck, and the truck itself. These have none of that." are on this design:
http://www.freepatentsonline.com/4440094.pdf

Lots more detail exquisitely supplied at that link. Allow me to offer your next excuse: "Oh, but that's for a three axle bogie". There are separate patents for a two axle one.

Readers might find this interesting: http://www.freepatentsonline.com/4285280.pdf Developed in Kingston and assigned to UTDC, albeit it's a simple mechanical actuation, somewhat as Smallspy describes.

For a guy who doesn't know a bolster from a pedestal liner, you seem to think you know a lot about trucks.

Dan