Originally Posted by ByeByeBaby
Siemens' page suggests S70s carry 220-236 passengers versus 150-180 for SD160s, although over a 91-96ft length rather than 81ft. And I'm not sure how one floor height would have different accessibility issues than the other, given that they can both have level boarding. Is it in areas where they didn't build platforms for the low-floor vehicles and that introduces a step?
The economy of scale argument (which I'm a little dubious on; these aren't exactly Big Macs, and they're all built to order) is an argument for low-floor, not against. LRVs are used in other cities besides Calgary; if there's an economy of scale, it's from a couple of dozen transit systems all using the same equipment, not because we also ordered 10 more for an extension on one of the high-floor lines. Looking globally, the most common LRV is (I believe) the Alstom Citadis. The S70/Avanto is approaching the SD160 in fleet size, and with all of the new LRT systems going low-floor, this trend will continue. 30 years from now, the high-floor customer base in North America will be replacement vehicles here, and in maybe three or four other cities. The low-floor market will be a lot bigger and more competitive. Besides, we've never ordered more than 50 LRVs in a single order, and the phased approach from the recent SETWay meetings will prevent a massive bulk order.
In terms of balancing loads on lines, how would that work? The SE line crosses the existing LRT in two places; once on 10th Ave, where the SE is at-grade and the 201 is in a tunnel, and again at 7th Ave, where the SE is in a tunnel and the existing LRT is at-grade. Additional track would be needed to connect the two lines together, which they only do downtown. Do we build a spiral tunnel under Banker's Hall? And for what benefit; do people from the SE only commute on Tuesdays and Thursdays? Flexibility is nice, but it's not free and not necessary. The 201 and 202 are doing fine right now; are there really a lot of cases where bringing in additional vehicles would be a big help? Excluding the rush hours, when the SELRT would be just as busy as the existing lines.
As far as underground and elevated sections, that's mostly between stations. For the two underground stations, sure, the costs are basically the same. (Although, if low floor vehicles can operate with lower catenary, they may be able to use a smaller tunnel, which could save costs, especially if a TBM is being used.) It doesn't matter whether the track between the stations is elevated or not, the floor height only affects station design. For the dozen plus non-underground stations, low floor vehicles should save money. The urban design component is something that will become more valuable as station areas develop, although that may be 40 years from now.
I know the turn from 10th to 2nd St is supposed to be pretty sharp; I don't know if it excludes high-floor vehicles, but it may well. In which case, the discussion is a moot point.
Additionally, if the SETWay plan goes forward, the transitway that is built will be a lot more compatible with low-floor vehicles; the boarding height of a New Flyer Xcelsior 60' is 356 mm, and a Siemens S70 is 350 mm. So the same stations work for both systems; a high floor train would require the stations to be demolished and rebuilt.
The accessibility issues with low floor designs depend on the specific vehicle. Some vehicles aren't level boarding, some aren't 100% low floor (there being a raised platform in the middle of the car over the bogies), or there is some other limitation. There are simply unavoidable tradeoffs when designing vehicles that low. The vehicles that avoid accessibility issues typically result in reduced bogie movement which carries its own share of issues.
The economy of scale issue is precisely because they are built to order. This isn't an issue of the number of cities using each system, except in the rare instance when orders can be piggybacked on each other (as Calgary and Edmonton did once). It is an issue of making orders that are large enough to generate multiple bids and some competition for the work. For instance, Bombardier has stated publicly that our past orders have been too small for them to put in the effort to build vehicles specific to our design needs. We have, until this point, been forced to sole source our orders from Siemens and pay what they ask.
Yes, so far, our orders have generally been small. That won't necessarily hold into the future. At some point in the short term, possibly around the same time that we build the SE LRT, we're going to need to replace the 80 U2s. That could be a very large order. Longer term we will have a fleet of hundreds of vehicles from the combination of longer consists, shorter planned headways, and more lines. Larger orders to replace existing stock will become the norm as opposed to the typical orders we have had for a handful of new vehicles to deal with a small extension. This is a system that will exist for decades if not centuries. Cities with large fleets often make large orders to replace stock being retired. These orders result in multiple bids for purpose built vehicles as opposed to buying off the rack vehicles offered to cities with smaller systems. Splitting our fleet into different, non-compatible batches will reduce our ability to get the same kind of economies of scale. That is without coming into the need to have technicians and drivers trained on different technology platforms.
Likewise the issue of diverting capacity to where it is needed is not a matter of building an active connection so that SE LRT trains can switch routes on Tuesday and Thursday. It is a longer term issue. Moving vehicles between lines would mean loading them on a freight train or truck and taking them over, in much the same way as they are shipped here. That wouldn't be a minor decision to do on a whim but if we found that we had an imbalance in capacity needs between lines we could do it relatively easily. It would simply allow more flexibility in scheduling long term without the need to order more vehicles.
Having a single design standard for all of our rail lines would also add flexibility in other ways. In the future lines could be rerouted into each other or connected in other ways. For instance, if we ever feel the need to build a line to the airport it could be built as a spur off of both the NC LRT and the NE LRT following Airport Trail. If the NC LRT is a continuation of a low floor SE LRT, that would be impossible. Hell, if we were going to build an airport line it would make sense to connect to both the NE and NC even if it operated as an independent line. It would be pretty cheap to have connecting tracks on both ends and it would allow for movement of vehicles between all lines. That and no transfer trains from downtown to the airport on either the NE or NC, whichever routing made more sense.
Again, the only stations that could really be integrated into an urban realm are 10 Ave, which should be grade separated anyway, and supposedly Seton. This is not a streetcar line that pulls up and lets people off on sidewalks. Most of the route is beside freight tracks or isolated on one side of a relatively major road. High platforms will not be an issue with integration in these areas, definitely no more than the acres devoted to parking and bus loops.
The SETWay wouldn't be compatible with any LRT, high floor or low: the roadway would need to be entirely rebuilt to make a trackbed, there likely won't be level boarding anyway but the loading areas won't be as long as train platforms. It is not a matter of laying rails on pavement and calling it a day because the existing infrastructure will handle it.
The two places where Calgary Transit has mentioned issues with turning the turning radius are from 10 Ave to 2 St and somewhere in Seton. Seton isn't built yet and designing the road network to disallow a choice in technology would be fundamentally stupid. The turn from 10 Ave to 2 St could easily be redesigned today away from the existing plans to allow for a wider turning radius. The property needed is currently a surface parking lot. Property acquisition followed by selling the air rights above the tunnel along with the rest of the property would result in little in the way of increased expenses.