TTC: Flexity Streetcars Testing & Delivery (Bombardier)

[DSC]

I've noticed this even in newly rebuilt junctions. For example, southbound on Spadina at College, I often see the drivers come to a complete stop before entering the intersection even though they have a green signal. Seems very strange.

They may be waiting for the switches to reset. I don't think that the automated ones reset instantaneously they get the signal from the streetcar - better to wait a moment than derail!

 

[smallspy]

I've noticed this even in newly rebuilt junctions. For example, southbound on Spadina at College, I often see the drivers come to a complete stop before entering the intersection even though they have a green signal. Seems very strange.

The rule for all specialwork calls for all trains to stop at facing-point switches and visually check them, and then proceeding over the specialwork at 10km/h (there is even a blue light on the dash that lights under that speed). Its been like this for about 10 years now.

It has nothing to do with the condition of the specialwork itself, and everything to do with a couple of really bad, high-speed split switch incidents.

Dan
Toronto, Ont.

 

[Duck]

What is "specialwork"? It sounds like something from 1984.

 

[DSC]

What is "specialwork"? It sounds like something from 1984.

Streetcar track that is not just rails - used for switching from one line to another.

 

[TheTigerMaster]

The rule for all specialwork calls for all trains to stop at facing-point switches and visually check them, and then proceeding over the specialwork at 10km/h (there is even a blue light on the dash that lights under that speed). Its been like this for about 10 years now.

It has nothing to do with the condition of the specialwork itself, and everything to do with a couple of really bad, high-speed split switch incidents.

Dan
Toronto, Ont.

Cant the TTC figure out a way to reduce the number of these incidents without forces streetcars to slow down? Trains on the subway have no problem going over switches at full speed.

 

[W. K. Lis]

Cant the TTC figure out a way to reduce the number of these incidents without forces streetcars to slow down? Trains on the subway have no problem going over switches at full speed.

The railways and subway (and later the light rail lines) are using double-point switches. The streetcar lines use single-point switches.

Single-point switch on a streetcar line:

Double-point switch on a railway line:

 

[the lemur]

I'd assume they were testing the signage, and the communication of the vehicle back to transit control. Used to see this occasionally in the NextBus data with cars heading up and down Bathurst, and on St. Clair with cars not yet in service.

That makes sense. I couldn't tell how many people were on board but if it wasn't making any stops it'd be pretty apparent it was not in service.

 

[crs1026]

http://www.theglobeandmail.com/repo...-train-business-a-decade-ago/article27169984/

When the Globe and Mail describes an enterprise as a "chronc underperformer", it's not a good thing.

- Paul

 

[smallspy]

Cant the TTC figure out a way to reduce the number of these incidents without forces streetcars to slow down? Trains on the subway have no problem going over switches at full speed.

Subways travel over the switches at full speed, but subways also operate with a signal system that locks and checks the direction of the points, and then indicates their safe position to the crew running the train. There is no such thing on the streetcar system.

The fact of the matter is that there's really nothing wrong with the switches on the streetcar system - it just took a couple of bad apples to ruin it.

Dan
Toronto, Ont.

 

[crs1026]

The fact of the matter is that there's really nothing wrong with the switches on the streetcar system - it just took a couple of bad apples to ruin it.
.

Is the issue misrouted switches - ie operator not observing point position and integrity - or 'picked' switches - ie looks fine, one truck goes one way but the other truck(s) go the other way?

Switch design really hasn't changed much in the last century - for switches set in pavement, and run over by autos, there is huge potential for foreign material to lodge in the points and allow the points to open at the wrong moment. Is there data - has this been more of an issue with CLRV/ALRV than in the days of PCCs or Witts? Flexities are heavier on a per axle basis, I wonder if it will be different again.

- Paul

 

[Duck]

The Flexities also use fixed bogies, which put a much higher flange load on any curves, since the axle is now responsible for pivoting the entire mass/inertia of the car body above it.

 

[smallspy]

Is the issue misrouted switches - ie operator not observing point position and integrity - or 'picked' switches - ie looks fine, one truck goes one way but the other truck(s) go the other way?

The issue in both of the situations was operators driving far faster than they should have been considering the circumstances, and simply not taking to the time or care to ensure that the switches were set in the correct direction. In both cases, they were set for the diverging, and the car was travelling at such a rate of speed that it changed while the car was over top of it.

Switch design really hasn't changed much in the last century - for switches set in pavement, and run over by autos, there is huge potential for foreign material to lodge in the points and allow the points to open at the wrong moment. Is there data - has this been more of an issue with CLRV/ALRV than in the days of PCCs or Witts? Flexities are heavier on a per axle basis, I wonder if it will be different again.

- Paul

Up to this point, the new cars don't seem to be any more prone to derailments than the older ones. There have been a couple of derailments, but one was in an area known to be problematic (and has since been changed), and another was due to material build-up in a track that hadn't been used in some time.

The Flexities also use fixed bogies, which put a much higher flange load on any curves, since the axle is now responsible for pivoting the entire mass/inertia of the car body above it.

Again, the trucks are not fixed. They do have a couple of degrees of movement versus the body.

Dan
Toronto, Ont.

 

[Duck]

Again, the trucks are not fixed. They do have a couple of degrees of movement versus the body.

That's the first I've heard of that. I thought that the wheels were rigidly affixed to modules 1, 3, and 5, and Module 1 and 2 have a Yaw link, Module 2 and 3 have a Yaw and Pitch link, and module 3-4-5 are the mirror of that, around the centreline of Module 3. This fully defines the position of any module tangent to the track that it is traveling on. Is that not the case? If any of the bogies can yaw relative to the module that it is affixed to, as you're suggesting, then the module position is undefined and it will not track correctly.

 

[Duck]

(I forgot to mention that I believe the wheel frame/bogie in module 1 and 3 can pitch slightly, but that's it - this is how a train can move over a short slope, since 1-2 and 4-5 is yaw only)

I appreciate that you know more about these trains than anyone Dan and I am eager to understand the geometry if I haven't got it right.

 

[smallspy]

That's the first I've heard of that. I thought that the wheels were rigidly affixed to modules 1, 3, and 5, and Module 1 and 2 have a Yaw link, Module 2 and 3 have a Yaw and Pitch link, and module 3-4-5 are the mirror of that, around the centreline of Module 3. This fully defines the position of any module tangent to the track that it is traveling on. Is that not the case? If any of the bogies can yaw relative to the module that it is affixed to, as you're suggesting, then the module position is undefined and it will not track correctly.

It's a bit more complex than that - the joints at 1-2, 2-3 and 4-5 are the same, and only rotate predominantly in the x with some limited y-axis rotation. 3-4 is a special joint that also allows for a very limited z-axis rotational movement, but also allows for additional x- and y-axis rotation beyond what the other joints are capable of. For all intents and purposes, the car is configured as a 3-module car connected to a 2-module car.

The bogies have a limited amount of rotation in the x- and y-axis themselves, as Siemens (and the rest of the industry) found out that fixed bogies will cause serious structural issues in the long run.

The module position itself is monitored and adjusted by active dampers. That's the only way that it could be done safely.

Dan
Toronto, Ont.