Light Rail Vehicles - LRT, ICTS, Monorail, and more

[danbrotherston]

Which is a bonus for university students, who tend to be the majority users of transit outside major urban centres.

Out of curiosity, what is a bonus?

Also, are students actually the majority of users?  I suspect they probably form the largest (semi-)visible group, but I doubt university students actually represent >50% of riders on GRT.

[ijmorlan]

How does CityVal handle this? It seems to be rubber on concrete but running mostly outside.

CityVal (you're only mentioning it because I pointed out I was excited for its launch in Rennes in a couple of years, a few pages ago), and it's predecessor VAL, aren't built in places with snow.

As for the comment about it running "mostly outside" - there is no relationship between the guideway alignment/type of grade separation and the technology.  It can be underground, elevated, or at-grade - your choice.

Morgantown's PRT is about the only [rubber-tired] AGT system I can think of that operates in an area with regular snow, and there, the entire guideway is heated (at great expense). The upshot is that it always works, even when the roads are completely impassible...

I remembered your reference to it from before, and wondered about it when you mentioned that Montreal’s system needed to be covered for snow protection. So I think what I’m understanding is that CityVal cannot run in snowy conditions, which in most of Canada means it would have to be fully enclosed (or with heated guideway). Which I think pretty well means it is not suitable for Canada, because anywhere that full enclosure is cost-effective, it will be a high-traffic line that needs to be a subway, not a medium-capacity system like LRT, ICTS, or CityVal. At least, that is my immediate reaction — I welcome correction.

I don’t quite understand your statement that there is “no relationship”. It seems to me that CityVal requires grade separation — is there a way of building a level crossing? Of course it can be at-grade regardless, but as I understand it anything crossing it has to go above or below. More generally, it seems clear that some technologies are incompatible with level crossings, while others (e.g. 3rd rail) make level crossings strongly not preferred although still possible. Other technologies allow level crossings, but obviously every technology can be installed on a fully isolated right-of-way with no crossings.

Also I’m not really aware of the climate in France, at least not in detail, so I didn’t understand that Rennes is snow-free. Looking on Wikipedia, it says that it averages 9 snowy days a year, which to me suggests that it will probably melt almost immediately. So not entirely snow-free but pretty well ignorable.

[KevinL]

Which is a bonus for university students, who tend to be the majority users of transit outside major urban centres.

Out of curiosity, what is a bonus?

Also, are students actually the majority of users?  I suspect they probably form the largest (semi-)visible group, but I doubt university students actually represent >50% of riders on GRT.

They were specifically discussing Morgantown and its reliable PRT (it's a university town).

[jwilliamson]

Canard, isn't the ATS at Chicago O'Hare a VAL system? Do you know how they keep the track clean?

[Canard]

It is, shoot! VAL 256, with half its fleet from Jacksonville. I've even ridden it a handful of times. I don't know how they keep the snow off the track, but their guideway is fairly "transparent" if I recall correctly. It's not just a big concrete trough, so maybe accumulation isn't so much of an issue.

I actually really love that system. I call it FatVal

[kitborn]

The choice to go with rubber-tire tech for the system means it can never go above ground, due to the weather.

They'll never have AC in Montreal because the stations don't have the capacity to remove the heat generated by the units on the trains.  It would be a monumental effort to retrofit it all in now.

The stations don't need air conditioning but how about the trains?

[Canard]

Air conditioners make one side cold (the inside of the train), and one side hot (the outside). The hot has to go somewhere... which is the tunnels and stations. The trains would all be heating the stations, which then has to go somewhere. The metro is already very hot (some say it's because of the tires, but I don't really totally buy that), so, in short, they'll never install AC.

[Viewfromthe42]

Fun to imagine the heat transfer going on there, in alternative scenarios. Cooling stations and trains, but having the trains shut off their heat-generating capacity while within the station areas, with something to attempt to remove residual heat from their equipment, all the while finding a way to let the tunnels absorb and/or shunt the heat from the active system encountered therein.

[Canard]

The tunnels would still get hot and it would all balance out. It's energy - has to go somewhere!

[plam]

Fun to imagine the heat transfer going on there, in alternative scenarios. Cooling stations and trains, but having the trains shut off their heat-generating capacity while within the station areas, with something to attempt to remove residual heat from their equipment, all the while finding a way to let the tunnels absorb and/or shunt the heat from the active system encountered therein.

Montreal metro trains aren't heated either. It really is supposed to be all the heat generated by the rubber tires.

[jamincan]

People can be significant sources of heat on their own. As for the trains, I'm sure the rubber tires would produce more heat than steel wheels, but so would the motors and VFDs

[danbrotherston]

Fun to imagine the heat transfer going on there, in alternative scenarios. Cooling stations and trains, but having the trains shut off their heat-generating capacity while within the station areas, with something to attempt to remove residual heat from their equipment, all the while finding a way to let the tunnels absorb and/or shunt the heat from the active system encountered therein.

The heat is transferred to the air, and given there are trains moving through the tunnels, the air would just be pushed into the stations.  Heat in stations is apparently a big issue, some stations I've been in with air conditioned trains were quite unbearable, sauna like temperatures.

[tomh009]

Need heating ducts from station ceilings up to the ground level, and pump the hot air up, up and away. Whether it's practical to retrofit such ducts really depends on the specific station.

[Canard]

They looked at it during the concept design phase of the MPM-10 trains, and decided no.

[KevinL]

How to build in VERY high density: http://www.telegraph.co.uk/news/2017/03/...tain-city/