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Because there is nothing wrong with them. The equipment is designed to use them.
I see. It was my understanding the TTC implemented a 15kmh speed limit across switches due to the possibility of derailment on SPS. Do they plan to remove this restriction for newly installed SPS?
And yet the TTC implemented a 10 km/h system-wide speed limit through them, notably due to their insufficient locking... The TTC is so concerned about them that they even limit streetcars to 10 km/h through trailing switches.
Yes, the TTC had to order a custom low-floor design at great expense to accommodate the antiquated system characteristics such as sub-15m curve radii, trolley poles and single-blade switches. The TTC successfully completed a system upgrade to eliminate the need for trolley poles. Why not also start a program to start eliminating single-blade switches and sub-15 curves through attrition?
Double-blade switches do not require changing the intersection geometry. At worse they would slightly adjust the path of the tracks by a few centimetres, but there's more than a few centimetres of asphalt on either side of the tracks anyway, so it certainly would not require intersection geometry changes.
As far as I know, the custom floor design was for the wheelchair ramps that had to go all the way to the road.
Yes that was another aspect that needed to be customized. There was no one factor that was the issue, it was a combination of factors such as the ones I listed and this additional one you named.
Line 6 has Citadis trains (same as Mississauga and Ottawa) and Line 5 has Flexities (same as Waterloo and Edmonton), yet both are built to approximately the same design standards so either model could be used on any of those lines (albeit with some modification to onboard signal equipment). It's worth also considering the benefit of having the option to buy more than one product from one manufacturer for half a century before asking someone to sole-source another new bespoke design solely for Toronto. Indeed it's interesting that the cost per vehicle is so high on those Metrolinx projects, though it's also worth noting that the Citadis is 50% larger than the Flexity.
As we discussed a couple weeks ago (can't remember which thread, maybe this one), Toronto has a handful of curves that are much tighter than curves in other cities with tight curves, which is why we couldn't use those other products during the original procurement of the Flexities. Resolving those few exceptionally tight curves would reduce the effort required for manufacturers to modify their European or North American tight-curve products for use in Toronto. So would (eventually) ending the use of single-blade switches. Eliminating the requirement for trolley poles will also make things a bit easier.
Which isn't related to the TTC Flexities being cheaper than the Citadis. Surely that the Flexity is cheaper suggests that the curves are not a huge issue.
As we've discussed, the curves that were identified for upgrade as part of the first round of bidding (where all bids were rejected) was a lot more than a handful. Recall the Admiral's post (among others).
Okay? Nowhere in that paragraph did say anything about cost. I said the ability to use more than one model of streetcar per half-century is an additoinal benefit worth considering.
Those diagrams are for increasing the minimum radius to 20 metres, which is absurd. And they were about the question of suddenly rebuilding every curve in the network in advance of an imminent equipment order, which is also absurd. Nobody is seriously suggesting we increase the radius to 20 metres nor are we talking about urgently demolishing every switch and curve in the network.
You literally quoted a comment about cost. The comment was follow-up to your own post:
Please don't try and pretend that's not what you said, simply because the facts suggest you were not correct.
Is it? The Blackpool Flexity which was the basis for design, is designed for 25 metre curves on revenue track, and 20 metres, slowly, in a yard.
To what end? I'm not sure that image of yours is up to date - the curve that I see in the wild that seems to cause the most trouble is the one from eastbound King to southbound Sumach.
You mean like were used on Line 6?
Oh right, because Metrolinx is the gold standard for cost-effective vehicle procurement. I'm not pretending that's not what I said, nor am I convinced that the statement "Toronto's streetcars were expensive" is false. That said, I am open to that possibility if you provide convincing evidence.
The Blackpool Flexity is a light rail vehicle designed for a system with wide curves. But like you said yourself:
THOSE are the specifications we should be aiming to be more in line with.
19 metres is also absurd. Most of the curves in the network are around 15.
Currently the TTC's minimum radius is tighter than even the tightest curves on other systems with tight curves. Even just slightly increasing the minimum would bring the TTC in line with other legacy tram systems, allowing us to use their equipment with relatively little modification. For example, 13.5 metres is the minimum radius in Boston, and according to that diagram there may be as few as 8 curves tighter than that in Toronto.
Like the systems used on nearly every tram line built in the past century, yes.
Once again...
Good thing that they don't have a 10km/h limit over the couple of dual-blade switches that do exist on the network.
Upgrading the trackwork would be a terrific idea. What would be a better idea is to replace the N/A system with something that actually works.
They absolutely do. Single-point switches need a steeper departure angle, because the back side of the wheel needs adequate steering in order to follow the appropriate path. A steeper departure angle means a short blade, which moves the point of departure closer to the middle of the intersection. Double-point switches don't act on the back of the wheels, so they can be much thinner and have a much shallower departure angle. But that also means that they need to be much longer, moving the tip of the point several feet further away from the intersection.
Because a simple flip-out ramp is too simple for what was needed in Toronto.
Where are there dual-blade switches on the mainline? I'm only aware of the ones in Leslie barns where the yard limit is 10 regardless of switches.
These are not different ideas. These are two elements of the same idea, which is updating the switch design & control standards. Replacing the switch control system is indeed the more important of the two, but given that switches stay in the ground for half a century once installed, it's also important to talk about the switch geometry at the same time.
In addition to what @smallspy said, if there were only a flip-out ramp long enough to reach ground level at AODA-compliant slope, it would be too long to fit on a lot of the narrow raised platforms such as on St Clair. The ramp for raised platforms needs to be as short as possible to give people room to manoeuvre on the platform.
