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

[tomh009]

No howling metal wheels, though: a definite difference as compared to the Toronto subway.

[kps]

Question for the mechanically-inclined folks: What would be the least visually obtrusive elevated structure for LRT-scale vehicles — for existing systems or otherwise? (Assuming just rail and structural support, not added walkways and such.) For existing systems, is standard-gauge × whatever necessarily bulkier than a full-scale Hitachi/Alweg beam?

[Canard]

Yes. Elevated LRT has about the absolute worst visual overhead, not only for the massive guideway, but then you have the ugly OCS on top of that. It's a terrible solution.

VAL gets around this by using much smaller vehicles that run at very high frequency. The tunnels are therefore much smaller (less $$$) and the overhead guideway is smaller (prettier).

Monorail (take your pick of what type/tech) always wins for lowest overhead structure - that's probably the biggest advantage. Take a look at some of the earlier discussion in this thread for examples (here, and here). Some of the Japanese monorails aren't perhaps the best examples, though (here) - strict laws around earthquake protection mean they have a higher frequency of support columns.

...but so does everything else there, so it's a moot point.

[timc]

Not that I would like to see elevated LRT, but would/could/should it use a third rail?

[Viewfromthe42]

Or the Bombardier non-Catenary power system that Canard has promoted

[timc]

Oh, I guess if you're talking about ICTS, then I guess some would consider it to be light rail.

[Canard]

I think you're talking about two different things;

PRIMOVE is the catenary-free system available for Light Rail (though technically could be used anywhere - it's been installed on some electric buses in limited deployment).  It uses a track-based coil as half of a transformer to send power to the train.  So yes, you could do this

UTDC ICTS uses a Linear Induction Motor (LIM) for propulsive thrust and third (and fourth) rail for power supply.

Yes, you could build an elevated LRT with bus-bar pickup at ground level.  But why would you do that?  Now I get to play the game.  What advantage would LRT with a ground-based pickup have over, say, ICTS, VAL, Monorail, etc.?  I see only negatives. You'd have a massive overhead structure, can't run it like a tram at ground level, and don't get good acceleration, and you get wheel-rail noise.

One of my favourite videos of VAL is from Lille (the first one) - showing just how crazy short the headways can be:

[timc]

I have no idea why you would do it, other than it would not look quite as ridiculous as OCS over top of on an elevated track.

PRIMOVE seems like it would be really expensive for this situation.

Is ICTS a light rail system? Google tells me that it's complicated.

[KevinL]

Yes, you could build an elevated LRT with bus-bar pickup at ground level.  But why would you do that?  Now I get to play the game.  What advantage would LRT with a ground-based pickup have over, say, ICTS, VAL, Monorail, etc.?  I see only negatives.  You'd have a massive overhead structure, can't run it like a tram at ground level, and don't get good acceleration, and you get wheel-rail noise.

One advantage I can think of is if you want to have a surface section - or if you're expanding a system with surface routes - this vehicle can have a pantograph and a ground pickup, and be able to use either.

I think some tram-trains in Europe do this, in fact.

[DHLawrence]

I expect the Fountain Street/Speed River overpass will use overhead same as the rest of ION.

[jamincan]

Technically it should be possible to run third rail with level crossings, and there seems to be a number of examples of this. I gather the third rail doesn't necessarily have to be continuous.

[danbrotherston]

Yes, there's an example of this in NY.

https://en.wikipedia.org/wiki/Metro-Nort...on_systems

[Canard]

Is ICTS a light rail system? Google tells me that it's complicated.

ICTS is the name given to the concept developed by UTDC in the 80's.  It was a system intended to bridge the gap between Light Rail/Streetcars and full Metro/Subway systems (call it a "mini-metro" or "pre-metro", if you like).  UTDC was owned by the Province and in France at the same time MATRA was developing VAL, so the two were in direct competition with one another.  Both used small, lightweight vehicles running in small trains at high frequency to achieve a reasonable capacity.

While VAL uses rubber tires and conventional electric motors, ICTS uses a Linear Induction Motor which has no moving parts, and produces direct thrust without any friction or contact.  Because the coil on the train (1 mounted in each bogie) interacts directly with the passive reaction rail (an aluminium plate) on the track, traction loss is impossible.  The wheels can therefore be much smaller, the floor height is lower, and the vehicles and tunnels can all be smaller.

The design concept was even more advanced and introduced steerable trucks, intended to allow the cars to navigate very tight turns - typically the types of curve radii that Light Rail/Streetcars can do.  In practice, there were problems with a very tight radius turn in Scarborough (the turnaround loop at Kennedy) which had actually been built already when the line was intended to be serviced by CLRV's... and there the turnaround loop is no longer used and a switch was added, so the trains just back out the way they came.

While the Scarborough rt is often seen by many as a failure and the TTC is doing everything in its power to get rid of it, Vancouver's Skytrain (the second installation) is very successful, and is the longest automated system in the world.

One advantage I can think of is if you want to have a surface section - or if you're expanding a system with surface routes - this vehicle can have a pantograph and a ground pickup, and be able to use either.

I think some tram-trains in Europe do this, in fact.

None that I'm aware of. The Eurostar (Class 373 HSR) is the only system like this I've heard of, where there's a third-rail pickup shoe for operation inside some tunnels or stations within London.

[KevinL]

None that I'm aware of.  

Then allow me to illuminate you: the Rotterdam Metro runs alternately on third rail and overhead. https://en.wikipedia.org/wiki/Rotterdam_...tion_power

[Canard]

Thanks!

VAL is used at Orly airport as a connector between the terminals and the adjacent RER line.