drum118
Superstar
Wasn't applying it to you, but to Steve. Sorry for that.
|
|
|
Metrolinx: Bombardier Flexity Freedom & Alstom Citadis Spirit LRVs
- Thread starter W. K. Lis
- Start date
steveintoronto
Superstar
I'm fully aware of it. It's fraught with problems, and Spain has accepted the need to adopt to standard gauge on any new-builds, especially those that go cross-border. Russia and China do something similar on the Trans-Siberian express, which is anything but 'express' but I digress.
Changing wheels on the Trans Siberian railway - Nomadic Boys
Meantime:
Since 1992, all high-speed rail lines in Spain have been built to standard gauge, 1,435mm, providing direct connections without break-of-gauge with the French railway system. The high speed line that was projected to run from Madrid to Lisbon was also to have been built at this gauge.
Track gauge in Spain - Wikipedia
https://en.wikipedia.org/wiki/Track_gauge_in_Spain
As for the automatic wheelset waist trimming and nail clipping machine, is this really in your realm of arguing your point?
I take your "3rd year" to mean third inception? The TTC is also stuck with much tighter radii than standard UIC practice and grades that many suppliers don't build for. Even if the TTC had standard gauge track and flexibility in voltage scaling and control systems, it would only mean TTC stock could run through onto other systems, and highly unlikely that could be reciprocated. It would greatly help with running onto the LRT lines, however.
And for the subway, standard gauge could greatly assist interlining with LRTs and mainlines, as is done in other cities in Canada, and many in Europe.
Of course they'd use standard gauge given a fresh start. I've made it very clear prior though that it's too late to change what's already been done, they're bound to their heritage choices.
My point has always been the extra costs of having made that choice and the straight-jacket of expanding into interlining with other systems, sharing track and buying equipment.
Last edited:
nfitz
Superstar
Spain has nothing to do with TTC and Metrolinx's Bombardier Flexity vehicles.
Enough with the endless irreverent comments!
steveintoronto
Superstar
It seems you have your irrelevance misdirected.
nfitz
Superstar
No.
It's not necessary for someone to post every irrelevant comment - merely the most recent ... or the worst offender. Or both ...
Last edited:
smallspy
Senior Member
There is no traction xfrmr on DC vehicles. That is one of the previous advantages to DC traction. With modern xfrmr design (Siemens is far ahead of the competition with core configuration) that weight penalty has been all but eliminated. Switching power supplies also minimize the difference (the higher the conversion frequency, the smaller the core necessary, albeit other factors limit the highest freq that can be used without significant core losses).
In the case of DC to DC, a simple switching stack is all that's necessary. The basic circuit is very simple and cheap.(The voltage sensing is just done with inexpensive but 'fast' diodes) For a streetcar/LRV, the unit would be about the size of a suitcase including all the automatic sensing to do the switch instantaneously. The unit will also double as a 'clamp-regulator' on voltage variations on the line. This is very similar to computer power supplies that can be plugged into 120V or 240V sources with no change needed other than the plug, or the plug-in chargers for cell/i phones and devices.
In the event, older pre solid-state control motors will run just fine on a variance of 600-750V. The higher voltage will render 1.3X more traction torque and power, all other things staying the same. When mainline third rail trains in London run on the Underground lines (still done to this day) they do so on the lower Underground voltage (660v vs 750v). That's a perfect illustration of interoperability as I describe earlier, not available to Toronto due to the track gauge difference.
Shared Service Routes - Railfanning London's Railways
A transport enthusiast's guide to where it is possible to travel between the same stations via different trains.citytransport.info
Here's another:
Third rail - Wikipedia
en.wikipedia.org
There's a lot more examples, but that suffices to make the point...to those that care to see.
I'm not sure what any of that has to do with the Flexity cars, both the ones for the legacy system and the Flexity Freedoms. They are using AC traction motors, not DC.
Dan
steveintoronto
Superstar
A traction motor uses reformed AC from a DC source. A "traction transformer" is used to...I'm short on time, here's a published explanation:
Traction transformers - Special application transformers (Transformers) | ABB
ABB supplies traction transformers for all applications: high-speed, commuter and regional trains, locomotives, tram-trains and AC metros offering different designs offering different designs in terms of size, weight and power ratings.
new.abb.com
In fact Siemens have the edge right now, but I digress. (As to how they've gotten it down to the size they have is a company secret)
A traction transformer is specifically designed to transform power from the locomotives overhead power that is delivered to the electric motors. The motors turn the wheels of a locomotive. Those are called the traction motors because the turning of the wheels uses the friction or resistance of the surface of the wheel in order to “grab” the surface of the rail. That is simply traction.
What is a traction transformer?
Answer (1 of 2): A traction transformer is a large single phase transformer fitted in the locomotive to feed power to traction motors and other auxiliaries. It takes 25kv AC from overhead line as primary voltage. This voltage is then stepped down to say 1500volts and fed to a rectifier for runnin...
www.quora.com
You can't put DC through an xfrmr, save in special instances where core saturation is the intention (edit: With caveats, the DC must be superimposed on a carrier AC)(resulting in massive power loss in the form of heat). (The purpose of this is usually for regulation at the expense of efficiency).(It's done magnificently nowadays with solid-state control either side of the xfrmr, and then the DC is reconstituted into AC for motor use.
DC systems, almost invariably used on streetcars and subways, don't use "traction transformers". They have solid state 'multivibrators' (an old term still used from the days of electro-mechanical devices) to turn the DC into a form of AC, in modern traction motors, almost invariably three phase AC...the same way solar cell arrays do for use as house and street current (the phase form is selectable, either single or triple) and the motor speed is controlled by both "chopping" of the applied voltage and synchronous variability in terms of the frequency of the reconstituted AC from DC.
Ironically, in the now almost universal single phase AC catenary use, it's rectified after the traction xfrmr! into DC, and most often reconstituted before or after (sometimes both) the control circuits, and then applied to the traction motors.
There's many incredibly good engineering papers on-line.
I'm most familiar with toroid transformers, being deeply involved in their design, manufacture and distribution, albeit my emphasis is on audio output ones. Power circuits are mundane to audio nerds. What Siemens are doing (any modern traction xfrmrs are a form of toroid) is intriguing. I leave it at that.
Lots here:
The point is that running a DC powered vehicle eliminates the need for a traction transformer, albeit there are prototypical exceptions to that. And traction transformers, early ones being a massive weight, are now much smaller, and the reconstitution of the line frequency from, say, 60Hz to 600Hz before it's even transformed reduces the size/weight of the core geometrically. (Computer 'switching' supplies do this, to make them small and light, but still offer isolation from the line for safety)(some failing on the latter, btw)
That's the reason why aircraft control systems have used much higher line frequencies, It not only reduces the core size/weight of needed xfrmrs, it does for the motors too.
Why we use 400Hz Power Supply in Aircraft?
Last edited:
TOareaFan
Superstar
Allandale25
Senior Member
^ And using Flexities would really add that much more time to Eglinton? Has a comparison time ever been put forward?
nfitz
Superstar
Do we even know what the door configuration for Finch West is? I thought Citadis Spirit units were customizable. Looks to me that a 30-metre Citadis Spirit has 4 doors, like the 30-metre Flexity.
If they use the same configuration as Ottawa, you get 7 doors on a 48.5-metre car. That would be equivalent to 4.3 doors on a 30-metre car.
Surely 4 doors instead of 4.3 doors is "slightly lower alighting speeds" not "way lower alighting speeds".
I'd be tempted to say "imperceptibly lower alighting speeds"!
Is there an indication somewhere that this will be a problem?
nfitz
Superstar
Given the very small difference, it would theoretically mean a small increase.
It was the "way more" I was objecting too ... it's a rounding error, surely.
That's not what I'm seeing. I regularly still take both, and the amount of time for people to climb the stairs is significant. Especially in the front, by the time the person gets from behind the white line, all the way down the stairs, and then those there have to come in, and up the stairs. It's not much better in the back - especially as the back doors can't even close until after everyone has gotten off the stairs!
Kyle Campbell
Active Member
Maybe I'm confused then. An s70 in a 30m configuration like say in San Diego, Portland, or any other variety of American cities also only has 4 doors. How is it any different than a 4 door flexity or citadis, other than being 70% low floor
Or is your point that because there's a single door at each end module rather than a double it's worse? I don't think it will make a massive difference, although it's less optimal. Really the distance between where you're sitting/standing and the nearest exit makes the biggest difference in people getting off the train and the next group getting on.
Last edited:
smallspy
Senior Member
What is the width of the doors on the S70, though? I can't seem to find any information on them online.
To my eye, they don't appear to be as wide as the double-doors on the Flexities. But without an actual measurement I'm not willing to claim that one is bigger than the other.
Dan
jordanmkasla2009
Active Member
So... Why is Metrolinx still so infatuated with Alstom?
Here in KW with Bombardier vehicles we haven't had these kinds of issues.
'Unreliable' LRT trains can't handle Ottawa winters, internal reports reveal
'Unreliable' LRT trains can't handle Ottawa winters, internal reports reveal | CBC News
The $2.1-billion light rail system that was supposed to be completed by the end of this month appears to have significant issues, CBC has learned — especially when it comes to surviving Ottawa winters.www.cbc.ca
Here in KW with Bombardier vehicles we haven't had these kinds of issues.
Steve X
Senior Member
I remember them advertising that they are built for -40C Canadian weather.