News   Apr 26, 2024
Sustainability Month: ReHousing — A Multiplex How-To Guide Explores What’s Possible in the Yellowbelt
 1.2K     4 
News   Apr 26, 2024
Mattamy's Soleil and Mile & Creek Condos in Milton’s Flourishing Landscape
 299     0 
News   Apr 26, 2024
Galleria on the Park Soon to Welcome First Residents of Masterplanned Community
 847     0 

TTC: Flexity Streetcars Testing & Delivery (Bombardier)

salsa said:
This line in the beginning of the article makes no sense to me.

"A TTC streetcar derailed at King and University to avoid hitting a car that went through a red light at 6:50 a.m. this morning."
Click to expand...
I just commented exactly same in another thread. (edit, THIS thread, two posts above) Must be the secret "derail right" button unbeknownst to anyone but BlogTO writers. If it ain't food or fashion, they're out of their depth.

Addendum: Looking at the impact marks on the SUV, and where the impact damage was on the Flexity, the soft skirt *appears* to have contributed to the derailment by the impacted vehicle lifting the frame/chassis of the first Flexity segment as the vehicle was captured underneath it. Something as simple as a 'lower chassis attached bumper' that would prevent getting jammed under the chassis overhang (the impact of which is clearly visible half-way up the SUV door) and thus deterring lifting forces under the Flexity chassis. Those soft, plastic replaceable skirt cowls might be well-intentioned for pedestrian impact, but might have to be revisited. What you see on the front of the Alexander-Dennis latest low clearance DD buses is much more apt.

The down-side would be greater deflection of impacted vehicles, but given the risk of damage from a vehicle being deflected, vs tram derailment, it's a no-brainer. There's also the consideration of impact detritus sliding under the frontal area to then derail the trucks (bogies).
189933
Click to expand...
Compare that to:
189934
Click to expand...
https://www.blogto.com/city/2019/06/king-streetcar-accident-toronto/

Springs or absorptive 'buffers' could be used behind a front 'bumper' to reduce any and all forces that would otherwise contribute to deflection and derailment.

Note the distinct impact line/indent across the damaged area: (that's the height of the Flexity frame, a dangerous height for impacted vehicle passengers as it intrudes *above* the wheels and suspension). A double decker bus bumper impacts at axle height, much safer for all concerned.
189942
Click to expand...
https://www.blogto.com/city/2019/06/king-streetcar-accident-toronto/
 
Last edited:
EastYorkTTCFan said:
I wonder once 511 is fully new streetcars if we will see pans go up on it. I know that later this month a mix of clrv, and lflrv are scheduled along with the remaining serviceable alrvs which could be substituted with lflrvs to start apering on 511 probably for the reminder of the summer or until the bridge work gets scheduled.
Click to expand...

511 from what heard will be mostly CLRV and Flexity with the POSSIBILITY of ALRVs going onto it in addition.
 
gabe said:
I will walk/TTC/cycle/crawl, before i will get in a ride share vehicle or taxi. Too many crazy drivers.
Click to expand...
I tried Uber for a few rides. I gave up after about the third trip. The driver passed my turn off Lakeshore Blvd. because the GPS told him to continue straight through eastbound to Leslie Street. I instantly figured out that the GPS had mistakenly placed him up above on the Gardiner, not down underneath on Lakeshore. The driver refused to believe me and insisted the GPS was the correct route which even then showed he would be mnaking a giant loop back to where we already were.

When it was then obvious he was wrong the driver offered in his defence: "I didn't know. I only arrived here in Canada yesterday."

Which.. uh........
 
steveintoronto said:
Something I'd written in my prior post but erased was that I doubt a CLRV would have derailed as easily. Mass and where the mass is concentrated would have a large part to do with that, but one also wonders on wheel flange depth (reach).
Click to expand...

A CLRV may not have derailed as easily, but that has as much or more to do with physics acting on a single rigid body versus the Flexities where each body is somewhat independent of each other. But there have certainly been numerous derailments to CLRVs caused by accidents over the years.

As for wheels, the wheel profile of the Flexities is basically the same as that of the CLRVs. Running larger flanges would not be a good idea, as the trackwork is already designed for a specific wheel profile and flange depth.

steveintoronto said:
Just as the 'Shiner Skirts' were necessary (albeit mostly for pedestrian safety) on the CLRVs to help prevent 'riding up' on the object of collision (think cow-catchers and plows on locomotives to do the opposite) similar *might* need to be considered for the Flexities. On the other hand, analysis might show the crumpled skirt to have absorbed impact.
Click to expand...

The FRP body panels of the Flexities are designed to allow for some measure of impact absorption. On top of that, the "bumper" on the ends of the car below the lights are designed to act more-or-less like a bumper on an automobile, with additional impact-absorbing capabilities.

steveintoronto said:
The derailment is one thing, throwing the LRT in front of a heavy truck or another LRT coming head-on could have proved disastrous, as I suspect the side impact strength of those vehicles is a fraction of what the CLRV or PCC is. I'm projecting on that, but someone will and should be asking those questions.
Click to expand...

PCCs are well-known to be built like tin cans. Operators were frequently noted to evacuate the front area of the car if a major impact was imminent.

The CLRVs were built with heavy steel underframes and generally fare extremely well in an accident, but I certainly don't feel unsafe in a Flexity. There is a lot of structure underneath the windows that is designed to take a lot of force in a side impact. There are huge structural tubes located behind the corners of the windshields at the front and rear of the car to provide those spaces with the strength needed.

steveintoronto said:
It could well be that nothing is possible to render the Flexities safer, but it must be considered. It seems to me, again without having numbers handy, that the Flexities have been derailing at a higher rate than what they're replacing. And it doesn't seem to take much of an impact to do it.
Click to expand...

Again, it's physics. It will always be easier to derail a Flexity - there's not really anything that can be done to resolve this, unfortunately. A car with fewer, larger articulated sections may be less susceptible to derailment, which may be something worth looking into for the next streetcar order.

On the bright side, when they do get damaged they are out of service for less time than the CLRVs because of how everything is designed. Panels and glass are easily replaced. There is seldom any damage to the underside of the car.

Dan
 
^Take a look at the front right wheel of the impacted vehicle. It jammed under the Flexity frame, and a very good chance it lifted it. I stand by my claim, that clearance gap is another derailment waiting to happen. Those SUV wheels are slightly higher than most sedans' but crushing onto the top of a sedan's slightly smaller wheels will also render a lifting force.

Perhaps you are replying to the earliest version of my posting? I added points and pics w/ observations in addendums. I also came across a pic of the analysis of the OC-Transpo DD crash, and cross-sectional detailing of the impact zone of the A-D DD. I'll try and refind it later. The A-D and other manufacturers of low clearance buses have all put special emphasis on the placement of front bumpers with controlled crush characteristics.

I will detail and post later. The vehicle impacted today is typical in many ways of many passenger vehicles on the road. Passenger vehicle safety has put emphasis on side beams in doors the last gen or so. How that vehicle dealt with it with that Flexity, and vice-versa I'm sure will be a point of interest to engineers. A tweak for the Flexities will be a relatively easy fix.
 
A large, v-shaped plow on the front would be helpful to prevent both derailments and also provide self-clearing of the tracks in the event of a collision or even parked cars blocking. Something like this:
 
steveintoronto said:
^Take a look at the front right wheel of the impacted vehicle. It jammed under the Flexity frame, and a very good chance it lifted it. I stand by my claim, that clearance gap is another derailment waiting to happen. Those SUV wheels are slightly higher than most sedans' but crushing onto the top of a sedan's slightly smaller wheels will also render a lifting force.
Click to expand...

How much more would you like the TTC vehicles to have cost? While the TTC didn't take them with the retractable Scharfenberg couplers found on the Crosstown / ION Flexity Freedoms, their Outlooks were based on the same common design which allows them. Designing a bespoke cab structure just so they'd fare slightly better when t-boning a red light running vehicle would not have been good value for money.
 
Some reference might be helpful, you can start here, but then again, it is Toronto and Region:

189990

http://onlinepubs.trb.org/onlinepubs/IDEA/FinalReports/Transit/Transit77.pdf

[...]
189992

[...]
189993

[...]
189994

[...]
Click to expand...
This paper if 30 pages, be warned, it might cause thinking and introspection.

But of course, it couldn't/wouldn't work in Toronto and Region. The Forces of Nature are different here....maybe in another generation...maybe not at all at this rate. Think of the cost! Think of the whole vehicle going on its side. Think of how it might show Toronto is far from being perfect...
 
Last edited:
Well it has happened where they derailed without being rammed. But correct, when I read it this morning I figured it derailed on its own. That being said they really need a TPS task force to lay down some kind of extreme transit-priority measures during situations like this. Both the 504 and 501 were a complete mess. So basically two lines down not one, due to diversion. All south downtown cross-travel is ruined and virtually a standstill. Every intersection seeing this diversion should have dispatched officers waving streetcars through with priority.
 
nfitz said:
Given how amazingly far that streetcar seems to be from any streetcar tracks, I'd guess that the vehicle in question was travelling on University not King.
Click to expand...
It must have been travelling at a hell of a pace. I can't really understand this. What a mess on the granite pavers.
 
You must log in or register to post here.

Back
Top