ssiguy2 said:
They are exactly the same trains except they get they power on top as opposed to underneath.
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In gist, yes. In practice, 'vanilla subway trains' have massive and heavy bogies that modern 'metros' don't. There's a reason that so many cities are using them, and light weight is one. Overhead catenary also allows (in higher voltage supplies, especially 15 and 25 kVAC) a much lower 'source impedance' for the motors. The easiest analogy for most in understanding this is running a table saw on 120v, and noting the time it takes to accelerate to speed from start, and then rewiring it 240 v. Startup time is a fraction of what it was, roughly 1/4 all other parameters remaining equal. Now scale that accordingly up to 25kV from 600-750 VDC third rail. Although AC and DC won't scale in most scenarios in a linear product against each other, the scale factor of 33.3 (or more) should give you an idea. Reformed DC at best will halve that, so 17+ times squared inversely applied to the 'source impedance'. There's good reason things have moved forward.

There is always the option of 1500 VDC catenary as is used for Metrolinx LRTs, and is used on some metro systems (IIRC, Montreal's REM is being built this way) and the older Oz city systems and other nations use it still, but it's a legacy of older times.

What Metrolinx has indicated for "RER" is 25 kVAC, the de-facto international standard for modern electrification of trains.
 
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44 North said:
And again, systems like Cleveland's Red Line don't inter-operate with mainline trains so your idea that we can operate subway trains on GO tracks and vice versa is not realistic or relatable.
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That's not what I read him stating.

To make the discussion neutral, use the term and model "metro".

Addendum: Metro North run some trains on both 15 kV AC catenary, and 750 VDC third rail, mostly the Connecticut cars, if not all. They run *far faster and efficiently when the third rail 'runs out' and the catenary begins*. The UK had this situation with the early tranche of Eurostars. running them on 25kVAC for the high-speed stretches (attaining full power) and running third rail into Waterloo Int'l at 'slow speed (and 'sucking down' the third rail supply doing it). It was a makeshift fudge to get them into any London main station at the time.

There's is no compromise of that sort now, they run on 25 kVAC to St Pancreas, the way they always should have run, and the 'third rail Eurostars' are now retired. A massive catenary build program in the UK made it possible.
Eurostar third rail operations meet their Waterloo! - Southern Electric ...
 
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As to the 'length' of the Aventra (Crossrail) coaches...it's a meaningless claim, for whatever purpose it serves. It's available in the length the client states. But since it is an issue somehow:
Description[edit]
The train has been designed to be lighter and more efficient, with increased reliability.[3] It will have lightweight all-welded bodies, wide gangwaysand doors to shorten boarding times in stations, and ERTMS.[2] The design incorporates FlexxEco bogies which have been used in service on Voyagers and newer Turbostars.[4] The gangway is designed to allow maximum use of the interior space and ease of movement throughout the train.[5][6]

Orders[edit]
As of December 2017, 2,618 vehicles have been ordered for six operators:

Crossrail[edit]
The first order for Aventra trains covered 65 Class 345 nine-car EMUs (with an option for 17 more) for the London Crossrail project. These will be operated by Crossrail concession holder MTR Crossrail.[7] A second order was placed with Bombardier in March 2018 calling off an additional 5 9-car units from the existing options, leaving 12 option units.

London Overground[edit]
London Overground has ordered 45 four-car trains (Class 710), with an option for 24 more, similar to those being used for Crossrail. They will replace Class 315, 317 and 172 on London Overground Lea Valley and Gospel Oak lines as well as replacing the Class 378s currently operating on the Watford DC line and will be operated by London Overground concession holder Arriva Rail London.[8]

Greater Anglia[edit]
In August 2016, Greater Anglia was awarded the new East Anglia franchise, and announced an order with Bombardier for 22 ten-car trains and 89 five-car trains (a total of 665 carriages) as part of a full fleet replacement programme.[9]

South Western Railway[edit]
On 20 June 2017, Bombardier was awarded a contract to build 750 cars for South Western Railway. These will be formed into 30 five-car and 60 ten-car sets and replace its 455, 456, 458 and 707.[10][11]

West Midlands Trains[edit]
On 17 October 2017, Bombardier was selected to provide a total of 333 Class 730 EMU vehicles for West Midlands Trains. These will be formed into three separate types; 36 three-car high capacity 'Metro' units, 29 five-car units for outer suburban services, and 16 five-car units for London-Birmingham services.[12]

c2c[edit]
In December 2017, c2c ordered six 10-car Aventra units, to come into service in summer 2021.[13][14] These will displace six 4-car Class 387 units leased from 2017.[15]

upload_2018-9-4_22-45-36.png
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https://en.wikipedia.org/wiki/Aventra

And this is just one of BBD's models, let alone the massive competitions'. And then there's the 'metro' stock...lots of options to choose from, world leading. But hey, if Toronto wants to buy "vanilla subway cars" with someone else's money...

I'm sure the rest of Ontario will just love that.
 

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steveintoronto said:
As to the 'length' of the Aventra (Crossrail) coaches...it's a meaningless claim, for whatever purpose it serves. It's available in the length the client states. But since it is an issue somehow:

https://en.wikipedia.org/wiki/Aventra

And this is just one of BBD's models, let alone the massive competitions'. And then there's the 'metro' stock...lots of options to choose from, world leading. But hey, if Toronto wants to buy "vanilla subway cars" with someone else's money...
Click to expand...

If we're going single deck and fully segregated from freight, then Toronto would be hard-pressed to find a cheaper and more reliable option than Toronto Rockets with minor design change for a pantograph instead of 3rd rail.

It's it's not fully segregated from freight then almost nothing mentioned in this thread is actually an option (under current rules).
 
rbt said:
If we're going single deck and fully segregated from freight, then Toronto would be hard-pressed to find a cheaper and more reliable option than Toronto Rockets with minor design change for a pantograph instead of 3rd rail.
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It depends on the length of train contemplated. With the plan for "four car trains" a much cheaper option would be LRTs. And it may be also for the later "six car trains". The LRTs could also be through-running to existing and future street running LRTs routes. Even though LRTs are available in high platform versions (Edmonton and Calgary both have now gone this route) that would raise costs of building the line.

But where is the funding coming from for *any* form of Relief Line? He who pays the funding picks the tune...
 
steveintoronto said:
It depends on the length of train contemplated. With the plan for "four car trains" a much cheaper option would be LRTs. And it may be also for the later "six car trains". The LRTs could also be through-running to existing and future street running LRTs routes. Even though LRTs are available in high platform versions (Edmonton and Calgary both have now gone this route) that would raise costs of building the line.

But where is the funding coming from for *any* form of Relief Line? He who pays the funding picks the tune...
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I highly doubt high floor LRT lines will every be built again in Canada due to accessibility and aesthetic reasons. Only existing extensions would be force to chose such option.

Surrey's network plans and Calgary's green line would be low floor.
 
Steve X said:
I highly doubt high floor LRT lines will every be built again in Canada due to accessibility and aesthetic reasons. Only existing extensions would be force to chose such option.

Surrey's network plans and Calgary's green line would be low floor.
Click to expand...

High floor LRT has several advantages - better capacity within the vehicles, for example, and fully level boarding. There's so much wasted floor space with low floor models, and there's a lot less seating, in fewer workable configurations. High floor works great with LRT at the high end of the spectrum, where the line is grade separated with proper stations. Low- floor does make sense for LRTs at the lower end of the spectrum - median operation and street-running sections. I understand why the new Calgary and Edmonton lines will be low floor, as they're new builds, and will be operating in the outer ends without full grade separation. It even makes sense for Eglinton.

But I wish Ottawa's LRT was high floor - even the Phase 2 extensions will be fully grade separated, so there are no accessibility or aesthetic reasons.
 
steveintoronto said:
Btw, your claim on '24 metre coach length' being unique to the Class 345s is off.

https://www.railengineer.uk/2018/04/03/northerns-trains-from-spain/
Click to expand...

I didn't say unique, I said non-standard. Very, very few of the EMUs scheduled to be built for service in the UK use 24m carbodies - and the ones that do are only going to be used on lines that have been more recently rebuilt to allow for the longer carbodies.

Look at the standard designs - the Class 350s, 800s and variations, the 379s and descendants - they all use 20m carbodies.

steveintoronto said:
In gist, yes. In practice, 'vanilla subway trains' have massive and heavy bogies that modern 'metros' don't. There's a reason that so many cities are using them, and light weight is one. Overhead catenary also allows (in higher voltage supplies, especially 15 and 25 kVAC) a much lower 'source impedance' for the motors. The easiest analogy for most in understanding this is running a table saw on 120v, and noting the time it takes to accelerate to speed from start, and then rewiring it 240 v. Startup time is a fraction of what it was, roughly 1/4 all other parameters remaining equal. Now scale that accordingly up to 25kV from 600-750 VDC third rail. Although AC and DC won't scale in most scenarios in a linear product against each other, the scale factor of 33.3 (or more) should give you an idea. Reformed DC at best will halve that, so 17+ times squared inversely applied to the 'source impedance'. There's good reason things have moved forward.
Click to expand...

Except that isn't how it works with any device that requires the line voltage to be dropped down to something usable. A transformer designed to convert 25kV to 600Vdc is going to be just as efficient as one designed to convert 1500V to 600Vdc. A better analogy would be the power block for your notebook - one may be designed for North American service and another designed for Europe, but at the end of the day they will be be outputting the same 19.5Vdc that the computer needs.

Dan
Toronto, Ont.
 
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ShonTron said:
High floor LRT has several advantages - better capacity within the vehicles, for example, and fully level boarding. There's so much wasted floor space with low floor models, and there's a lot less seating, in fewer workable configurations. High floor works great with LRT at the high end of the spectrum, where the line is grade separated with proper stations. Low- floor does make sense for LRTs at the lower end of the spectrum - median operation and street-running sections. I understand why the new Calgary and Edmonton lines will be low floor, as they're new builds, and will be operating in the outer ends without full grade separation. It even makes sense for Eglinton.

But I wish Ottawa's LRT was high floor - even the Phase 2 extensions will be fully grade separated, so there are no accessibility or aesthetic reasons.
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Yeah, it's a bit odd to think of LRT as 'high-floor' but they're gaining credibility and favour in some locales, and losing it in others.
Calgary, Edmonton adopt low-floor approach - Railway Age

They aren't as efficient in maximizing passenger load per vehicle length as subway, but are cheaper to buy, run, more energy efficient...and *vastly more flexible* in terms of where you can run them and utilizing on-road running to connect into existing LRT routes and situations like York Region's, where they want their pudding without paying for their dinner. Relief Line North could run north of Steeles to Richmond Hill on-road if necessary, and/or beside one.

How much 'heavy lifting' can an LRT do?
[...]
As of the Fourth Quarter (Q4) of 2013, the average weekday ridership on the San Diego Trolley system was 119,800,[3] making it the fourth busiestLight rail system in the United States. Taking overall track length into consideration, the San Diego Trolley transported 2,239 daily passengers per route mile in Q4 2014, making it the twelfth busiest Light rail system on a per mile basis over this time period. Weekday ridership on the Trolley has been relatively high since Q3 2013 (see table at right).

In all of 2014, the San Diego Trolley provided 39,731,900 unlinked passenger transits according to the American Public Transportation Association (APTA).[3] MTS reported that there were 39,694,197 trips on the Trolley in Fiscal Year 2014 (FY 2014), a 34% increase over Fiscal Year 2013.[35] Of the Trolley's three lines, the Blue Line has the system's highest ridership with 15,094,878 riders during FY 2014, followed by the Green Line with 13,673,926 FY 2014 riders, and the Orange Line with 10,896,289 FY 2014 riders.[35] The Silver Line, operating only mid-days just four days a week (and with some service interruptions during the year), carried 29,104 passengers around the downtown loop in FY2014.

The following ridership data for the San Diego Trolley was obtained from the American Public Transportation Association's (APTA) Ridership Report Archives:[36]
[...chart and text continue...]
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https://en.wikipedia.org/wiki/San_Diego_Trolley

Edmonton and Calgary (with very similar systems, vehicles, history and success to SD) wouldn't dream of building a 'vanilla subway'. Nor would many cities. There's better ways to serve the purpose all things considered.
 
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smallspy said:
Except that isn't how it works with any device that requires the line voltage to be dropped down to something usable. A transformer designed to convert 25kV to 600Vdc is going to be just as efficient as one designed to convert 1500V to 600Vdc. A better analogy would be the power block for your notebook - one may be designed for North American service and another designed for Europe, but at the end of the day they will be be outputting the same 19.5Vdc that the computer needs.
Click to expand...
You completely miss the point on transmission losses. And switching power supplies are a whole other discussion I can but won't enter into here.(And Siemens have spent years and big money engineering a new core material for smaller and even higher efficiency traction xfrmrs)(which predicates AC use)
[...]
Third Rail:

The advantages

  • Low visual impact in sensitive landscapes
  • Simple infrastructure installation
  • Compatible with conversion of existing lines with low tunnels and overbridges.
The disadvantages

  • Electrically inefficient. The 3rd rail has to be strong enough to withstand the downforce of the pickups, so it is made of steel rail profiles. These have to be supported on short pot insulators at frequent intervals
    • The shortness of the insulators limits voltage to arround 600V. Overhead power is typically 25,000V. Thus the current in 3rd rail distribution is much higher, leading to vastly increased transmission losses.
    • Further losses are caused by leakage to earth theough the huge number of pot insulators (which are never clean) and other accumulated debris.
    • For historic reasons 3rd rail systems tend to be DC which cannot have transformers. Infeed systems are more complex, particularly on long routes.
  • Mechanically awkward. There have to be gaps in 3rd rails at road crossings and rail junctions, and these require careful planning.
  • Danger. People crossing, working on, or tresspassing upon the railway need to avoid the live rail. Also hazardous in the event of an incident requiring trains to be evacuated.
The Germans have a system whereby the third rail is about half a metre up, under a safety and weather cover, with the pickups below the suspended rail. This mitigates some of the problems but introduces others, mainly mechanical awkwardness.
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https://www.quora.com/Why-do-railway-networks-use-overhead-wires-insted-of-third-rails-Wouldn’t-it-be-less-expensive-to-install-and-maintain

Third Rail is yesterday's way of doing things. Side valve engines have their uses too (the low head compression means they can run on very low octane fuel)...but for some odd reason internal combustion vehicles don't use them anymore.

There's lots more online, mostly too technical for this forum, on the technical and cost efficiencies of AC pwr xmssn.
A transformer designed to convert 25kV to 600Vdc is going to be just as efficient as one designed to convert 1500V to 600Vdc.
Click to expand...
An xfrmr is AC in, AC out. You miss the needed rectification and (sometimes) filtering. (In practice, unfiltered DC renders higher torque in a motor, albeit motors nowdays are much preferred to run triple phase AC by reformation of the rectified AC).

I cut you some slack in your lack of electrical engineering where-with-all. I'll see what I can link later.

Low voltage DC catenary does offer a large advantage in the respect of not needing a 'traction xfrmr', they use choppers and switching supplies, on which there's been huge strides in the last gen or so. I'll detail more later on solid state 25kVAC conversion to motor feed *without* using an xfrmr at all! UHV DC pwr xmssn has made all of this impossible. And btw folks, Hydro Quebec hosts one of the world's most advanced examples, albeit with Swedish and Swiss know-how. You can thank the ice-storm for forcing that conversion.
 
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steveintoronto said:
Almost all have had massive renos to accommodate this, including, wait for it, the 'Circus' stations where the ticket halls have been massively renoed. Some stations have 'lift' (elevator) only access from the ticket hall to Crossrail, the tunnels are so deep.
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To the ticket halls and mezzanines perhaps. But I'm not aware of any lines that had widened platforms - which are surprisingly narrow in some stations, especially the deep level tubes. I certainly didn't notice anything last time I was there. And it would be there, I wonder what the impact would be of these very large Elizabeth line trains loading a lot more people, onto already crowded platforms.

But who knows, perhaps they've got the frequencies sorted out, that this won't be a problem. And (unlike Union GO trains), not everyone will be getting off the Elizabeth line at one stop.

Compare to the District/Circle line platforms at Westminster station, where they they did rebuild the platforms when they built the Jubilee line.

Interesting to see that suddenly the Elizabeth line opening through central London is delayed 9 months when they were supposedly so close to opening. I guess the grass is not always greener.

https://www.standard.co.uk/news/tra...-not-be-ready-until-autumn-2019-a3924386.html
 
steveintoronto said:
You completely miss the point on transmission losses. And switching power supplies are a whole other discussion I can but won't enter into here.(And Siemens have spent years and big money engineering a new core material for smaller and even higher efficiency traction xfrmrs)(which predicates AC use)
Click to expand...

I'm well aware of the issues with power transmission, and the reason why railroads are generally switching to higher voltages. I'm referring however to the specific instance of dealing with voltage on the vehicle.

There are of course other things at play as well. For instance, if you are using a 600Vdc power system - such as on the TTC's streetcar and subway fleet - there is no need to use an onboard power transformer on the vehicles. This has advantages in terms of your ongoing maintenance, as that is a heavy device that you no longer have to lug around on each train, saving wait and a little bit of wear-and-tear. Yes, you have more substations that are required to feed the network - but does that additional cost get negated by the long-term savings?

(This of course has changed with the advent of AC traction, although it comes with a weight penalty as well. Is the savings in maintenance of an AC motor worth the weight penalty that comes along with the use of the additional hardware required to make it run?)

For the record, as much as Siemens may be at the forefront for a lot of industrial power design, I'm not sure that they are when it comes to switching power supplies/multi-voltage transformers in railway use. They do good work, sure - but so have a lot of other companies, such as ABB and Alstom.

Dan
Toronto, Ont.
 
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