[hw621]

With a few power outage along the subway today, it is interesting that GO trains are more reliable partly because they are on diesel...

 

[mdrejhon]

It's always interesting to view the Document Requester List
(the parties that paid $40 to MERX to download the RFI document):

Most parties paid their document download fee on April 2-3-4, with only one last-minute downloader on April 9th.

 

[maxt797]

With a few power outage along the subway today, it is interesting that GO trains are more reliable partly because they are on diesel...

Probably yes but I thought electrified rail vould have backup power station similarly to finch west LRT or eglinton LRT don't remember which one , but read somewhere ethereal will be backup power substation which is battery based .

 

[hw621]

Probably yes but I thought electrified rail vould have backup power station similarly to finch west LRT or eglinton LRT don't remember which one , but read somewhere ethereal will be backup power substation which is battery based .

Why don't subways have backup power?

 

[rbt]

Why don't subways have backup power?

Funding and timing mostly.

Large battery banks wasn't something that was commonly done (other than for telco's) until recently. Given the cost of the backup plant for Eglinton, TTC would require about $1B for a project like that BUT you could cover a small section (like south of Bloor only) for much less.

 

[crs1026]

Makes sense to have backup power that will get every train to the next station so everybody can be offloaded in the event of a power outage. Makes a lot less sense to have the ability to continue to operate the system if there is a city wide blackout. The cost of the latter would be huge.

Also, there's a difference between a blackout at one feed point (very desirable to have multiple and redundant feedpoints) and a city wide blackout. The former happen more frequently, the latter only once in a decade.

- Paul

 

[mdrejhon]

Funding and timing mostly.

Large battery banks wasn't something that was commonly done (other than for telco's) until recently. Given the cost of the backup plant for Eglinton, TTC would require about $1B for a project like that BUT you could cover a small section (like south of Bloor only) for much less.

Or just maybe a few ten million for the the whole system if you only put few trains in crawl motion at a time. Fundamentally, it's just total wattage. Run fewer trains in crawl, just to get all of them to stations, so people are never stuck in tunnels in a power blackout. It would take coordination so not all trains are simultaneously moved, but that might be an easy add-on for the new CBTC signal system.

 

[rbt]

Or just maybe a few ten million for the the whole system if you only put few trains in crawl motion at a time. Fundamentally, it's just total wattage. Run fewer trains in crawl, just to get all of them to stations, so people are never stuck in tunnels in a power blackout. It would take coordination so not all trains are simultaneously moved, but that might be an easy add-on for the new CBTC signal system.

I thought T1 trains already have onboard battery for crawling them into the next station; so I assumed the idea was to sustain normal operations during Toronto Hydro feed problems.

 

[smallspy]

I thought T1 trains already have onboard battery for crawling them into the next station; so I assumed the idea was to sustain normal operations during Toronto Hydro feed problems.

The onboard batteries on the trains are only to power emergency lighting, PA systems and other safety systems.

That said, the loss of traction power does not automatically mean that the train must stop. It can coast quite a distance, gradients and curves notwithstanding of course.

Dan
Toronto, Ont.

 

[ssiguy2]

Certainly one of the benefits of Hydrail is that, like diesel, it is not at the whim over an external power supply giving it greater reliability in inclement weather.

 

[dowlingm]

Certainly one of the benefits of Hydrail is that, like diesel, it is not at the whim over an external power supply giving it greater reliability in inclement weather.

On the other hand, depending on the refuelling method, it could bring new challenges in inclement weather...

 

[Streety McCarface]

As long as Hydrail is only considered for Diesel-only corridors, I'm fine. However, the benefits in electricity cost savings (due to non-peak usage) are pretty much bullshit. Here's why:

If I am correct, at maximum efficiency, hydrail is about 30-50% efficient (quoted from earlier in this thread). Compare this to the 70-90% efficiency from a pantograph. Peak electricity costs are 13 cents, and off-peak electricity costs are 6.5 cents; half the cost. Hydrail is half as efficient as direct pantograph collection, so twice as much electricity is required to get the same amount of work through hydrogen as you would through pantograph collection. There are also unforeseen maintenance costs that are not known.

 

[KevinT]

If I am correct, at maximum efficiency, hydrail is about 30-50% efficient (quoted from earlier in this thread). Compare this to the 70-90% efficiency from a pantograph. Peak electricity costs are 13 cents, and off-peak electricity costs are 6.5 cents; half the cost. Hydrail is half as efficient as direct pantograph collection, so twice as much electricity is required to get the same amount of work through hydrogen as you would through pantograph collection.

Theoretical counterpoint: What's the cost of selling our surplus electricity to neighbouring grids at a loss when green production exceeds consumption (i.e. windy days)? It seems that would be an excellent time to bank hydrogen. That makes sense when hydro is a 100% public utility, not sure how that works out in our present system though.

 

[nfitz]

The onboard batteries on the trains are only to power emergency lighting, PA systems and other safety systems.

Really? As far as I understand it, the specs on the 1960s and 1970s Montreal rolling stock required enough power to make it to the next station.

I'm surprised Toronto hasn't done this 50 years later ... maybe batteries are larger than they were in the 1960s ... inflation

 

[smallspy]

Really? As far as I understand it, the specs on the 1960s and 1970s Montreal rolling stock required enough power to make it to the next station.

I'm surprised Toronto hasn't done this 50 years later ... maybe batteries are larger than they were in the 1960s ... inflation

The Metro isn't capable of moving on battery power either, at least not the MR63s or MR73s. I don't know enough about the Azurs to know whether they have an onboard propulsion battery.

I suspect that what the specs called for was battery power that kept the various sub-systems active long enough to make it to the next station. That's how the Toronto subway cars, and as far as I can tell most others built around that time, were configured.

Dan
Toronto, Ont.