[Amare]

I'm not sure if the derailment was caused by the switch, but if that was the case this is a prime reason the TTC needs to figure out their switch issues. Enough of the stop and proceed non-sense, and single pointed switches.

Maybe we should send Tory all the photos and videos so he can take a good look at all this chaos- which we may be able to partially attribute due to a lack of funding.

 

[EastYorkTTCFan]

I'm not sure if the derailment was caused by the switch, but if that was the case this is a prime reason the TTC needs to figure out their switch issues. Enough of the stop and proceed non-sense, and single pointed switches.

Maybe we should send Tory all the photos and videos so he can take a good look at all this chaos- which we may be able to partially attribute due to a lack of funding.

I really don't get where people have gotten this idea that the switches are all broken. Not all of them are powdered because they don't need to be because they aren't used a lot. The reason they stop at them is because there is no signal for the driver to tell them which way a switch is set. This derailment was caused because there was some muck in the less used section of the switch that got washed into it because of the rain.

 

[Amare]

That makes no sense. There aren't even 62 cars on the entire 504+514 lines combined.

Keep in mind that the 501 is on diversion through this stretch of King as well.

I really don't get where people have gotten this idea that the switches are all broken. Not all of them are powdered because they don't need to be because they aren't used a lot. The reason they stop at them is because there is no signal for the driver to tell them which way a switch is set. This derailment was caused because there was some muck in the less used section of the switch that got washed into it because of the rain.

That's really not entirely true. Some of them arent powered since they are known locations for potential derailments (ie: the intersection immediately outside of Broadview station). Other powered switched were removed many years ago, and were never powered again for whatever reason.

 

[EastYorkTTCFan]

That's really not entirely true. Some of them arent powered since they are known locations for potential derailments (ie: the intersection immediately outside of Broadview station). Other powered switched were removed many years ago, and were never powered again for whatever reason.

yes but people keep saying all of them are broken because the TTC wants to be safe and have the drivers check that the switch is set right.

 

[drum118]

If 4404 was pushing a disable car, how is the driver going to know if there an issues with the switch with limit space they have in front of the ???

Moreso, why did it take 9 hours to re-rail the car, as it has never taken this long to fix the problem before??

Having 3 routes totally shut down is a case for the anti streetcar to call for their removal.

TTC has a switch problem and this made be what is needed to deal with the issue finally. Mr Tory should setup and noticed what his cost cutting to TTC is doing to the system as a whole, not building more white elephants.

 

[crs1026]

Warning: pure speculation ahead.

The cause that TTC offered was foreign material in the unused leg of the switch, deposited by heavy rain.

If this is accurate, the Flexity never reached the curved portion where the debris was said to be. Rather, it was the ALRV that hit this debris. I'd speculate that the debris added resistance to movement, already high given the ALRV was on a sharp curve, and the ALRV became an immovable object. If we assume the rail was wet and the Flexity was likely to have encountered wheel slip, possibly the front wheels lost power and only the rearmost wheels were applying force. Effectively, the articulated ALRV and the articulated Flexity became a piece of rope that was being shoved from the rear. Even we non-engineers know what happens when you push a rope.

In this scenario, even a new, well maintained switch becomes a probable point of failure.... the geometry makes it the easiest point in the curve for the 'rope' to pop out of alignment.

I bet the TTC is rewriting their manual on pushing vehicles with a Flexity under wet weather conditions. I doubt this particular scenario got much testing or training up til now. It's likely a 'learning opportunity' after all.

(But I also wonder whether any other vehicles had made that turn yesterday morning.....the 'debris' bit isn't completely credible, IMHO)

Again, pure speculation.

- Paul

 

[ProjectEnd]

From about 3:30pm yesterday:

 

[crs1026]

That big yellow spacer bar is interesting.....clearly the designers recognized there will be times when the flex in the articulation is not desirable. Looks like there are purpose-built points on the carbody to attach a bar to make the joint rigid.

- Paul

 

[smallspy]

The actual cause of the derailment is a known issue - physics. More specifically, the physics involved with a Flexity pushing a CLRV around a curve. This is not the first time this has happened, and if they're not careful it won't be the last, either.

Much like Drum, I am very interested in finding out what took them so long to rerail the car, as they've seemingly never had an issue with doing it before.

Paul, those holes that the bar slides into are the jacking holes. They are reinforced and tied in to the frame of each module to allow them to lift up the module - or in this case, prevent side-to-side movement and rotation.

Dan
Toronto, Ont.

 

[AlbertHWagstaff]

Warning: pure speculation ahead.

The cause that TTC offered was foreign material in the unused leg of the switch, deposited by heavy rain.

If this is accurate, the Flexity never reached the curved portion where the debris was said to be. Rather, it was the ALRV that hit this debris. I'd speculate that the debris added resistance to movement, already high given the ALRV was on a sharp curve, and the ALRV became an immovable object. If we assume the rail was wet and the Flexity was likely to have encountered wheel slip, possibly the front wheels lost power and only the rearmost wheels were applying force. Effectively, the articulated ALRV and the articulated Flexity became a piece of rope that was being shoved from the rear. Even we non-engineers know what happens when you push a rope.


- Paul

One of the news stories showed 4156 in front of 4404, not sure if this was the disabled car or not, but in any case how much debris was in the rail to make a CLRV or an ALRV "an immovable object"? The flangeway isn't that large and unless it was a piece of rock a streetcar should be able to push through muck or wet sand.

The re-railing process was more of the issue in terms of the length of time to clear the car. Even rerailing an ALRV with a derailed centre truck doesn't take that long unless the car has jack-knifed or something.

They were probably reading the manuals on how to rerail the car while doing it.

 

[44 North]

At least the Flexity didn't push the older car onto its side, which has happened before:

 

[the lemur]

I heard there were Queen cars on King as well because of a diversion. Also, he may have counted the double length ones as two.

I get that there were more streetcars on King than usual because of the diversion, but at what point would it have occurred to the TTC to start rerouting them to Dundas via Shaw and Queen?

 

[Kitsune]

The debris issue happened last year for a eastbound streetcar on queens quay turning (by accident) onto Spadina.... the TTC needs to better maintenance on these switches.

 

[KevinT]

That big yellow spacer bar is interesting.....clearly the designers recognized there will be times when the flex in the articulation is not desirable. Looks like there are purpose-built points on the carbody to attach a bar to make the joint rigid.

It could even have been used to adjust the articulation to the angle necessary to get the wheels back on track -- they are fixed bogies after all.

 

[JamesKoole]

Taken around 4:55pm. Comparing the two images it looks like the strategy was to jack the first section, then rotate it to straight vs. on the switch track and set it down.

There were switch maintainers out this morning walking cars through the switch. It's also the case that the special work in this area seems pretty worn - the depth of the track seems pretty low compared to other areas. Perhaps that contributed to the derailment given the car would be riding on the flange through that and would perhaps have an easier time climbing up and over with a worn track.