The Great Canadian Transit Thread

[Beedok]

I know the new GO station in Hamilton poured concrete into the sewer by accident somehow, so Ottawa isn't alone on the mishaps front.

[eemy]

I seem to recall another mistake with a concrete pour elsewhere as well, though I don't recall exactly where.

It's kind of embarrassing for RTG, but in the grand scheme of things, this doesn't seem like a terribly big deal.

[Innsertnamehere]

construction accidents happen. Reading construction incident reports can be kind of humorous actually, provided it doesn't anyone getting hurt. It varies from trucks getting stuck in mud to porta potties getting knocked over by machinery, etc.

[matt602]

I believe tunnel boring machines were used in the construction of the Sheppard and University subway line extensions and are also being used for the Eglinton Crosstown LRT. I don't recall any of them bumping into underground structures though.

[Metro-One]

Downtown Vancouver used a boring machine (but the stations themselves were cut and cover).

The Evergreen Line is currently using a boring machine.

[SFUVancouver]

We also have the odd "whoopsie doodle" moments with rapid transit construction in Metro Vancouver.

A 300 tonne section of elevated guideway under construction for the SkyTrain Evergreen Line shifted slightly during one night and crushed one of the small temporary concrete spacer supports that sit at the top of the column and allow the guideway to be mounted at the precise angle. Whoopsie doodle! They fixed it without much issue the following day and no damage was done.

Also, the giant gantry crane used to assemble the pre-fab concrete sections into elevated guideways stumbled when repositioning and partially collapsed. Whoopsie doodle! They fixed it the following day and no damage was done.

Now one of the flatbed trucks that carries the pre-fab concrete guideway segments for the tunnel had an accident and the segment fell off and was damaged, possibly beyond repair. Whoopsie doodle! Those are almost always custom formed for the particular segment of the tunnel, so perhaps this one is a problem. If they pour and form another one they would still have to wait 28 days for it to cure to sufficient strength.

http://www.youtube.com/watch?v=SHaZyMxgxpk <-- (Whoopsie doodle Simpsons reference)

[J.OT13]

Thanks! I feel a little better now.

[Innsertnamehere]

then there is always the crane that fell over on the Spadina subway extension and killed a guy..

[1overcosc]

In the case of the Ottawa subway, these kind of accidents are difficult to avoid, because the tunnel is so shallow. The roof of the train tunnel is only 11 metres below the surface, and the stations go even higher--Parliament station's cavern roof is only five metres down. It's very rare for bored tunnels to be this shallow--normally depths like that result from cut and cover construction. And Ottawa is digging out the entire station caverns via boring--which is also unique as even bored subways almost always use cut and cover for the stations. The fact that only two accidents have happened so far is actually quite incredible.

To put things in perspective for people who have difficulty visualizing what 5 metres is--that's the height of three average-sized humans. All it would take is 3 people standing shoulder to shoulder to stretch from the roof of the station platforms to the street.

As for why Ottawa is building a bored tunnel so shallow? Geology. Downtown Ottawa has very shallow bedrock, it starts about 3 metres down in most of the core. Unusual conditions result in unusual construction.

[Doady]

3 metres, wow. Maybe they should have elevated instead.

[Aylmer]

I'm actually a big fan of shallow stations. It may sound silly, but it can reduce the perceived cost in time of transit; all the escalators and stairs can add up to a rather significant addition to the trip, especially if it's short.

Case in point: if, in Montreal, I take a short trip from Métro from Verdun to De L'Église, it might not be worth it since I'll probably be spending five minutes or more getting down to the station and back up again. (Note: I know these are two pretty random stations, but I chose them because of their depth to illustrate a point transferable to any short trip, notably downtown.)

So if we want to encourage short hops downtown on the Confederation Line, it's helpful to have stations which are so shallow that the time needed to get to/from them is as insignificant as possible in relation to the short trip.

[eemy]

One of the earlier plans actually had extremely deep stations so that the line could traverse across blocks downtown. All in all, I prefer the shallower design, even if the odd hole is accidentally drilled into a neighbouring structure.

[milomilo]

I don't think there's any question really that shallower is better - it just usually isn't possible or is just easier to bore far deeper underneath everything. Ottawa appears to be lucky enough to be able to use a drilling method unavailable to most other cities, which is great for them if it's cheaper and allows shallow stations.

[SFUVancouver]

Shallow stations were a value-add design element of the SkyTrain Canada Line design and it was sold as reducing total travel time and perceived convenience of using the line. There's really only two deep-ish stations on the Canada Line: Vancouver City Centre Station and Yaletown-Roundhosue Station. These have a set of vertical circulation (stairs, escalators, and elevators) that lead from street level to the ticket mezzanine level and then a further set of vertical circulation to reach the platform level. The most shallow underground station would arguably be Broadway-City Hall, which takes advantage of the topographical change in grade to convey passengers from the street level ticket mezzanine down to the platform level with only a modest ramp and a single relatively small set of vertical circulation (escalators, stairs, and elevators). One can disembark a train, make their way to street level and be out of the station in the same time it would take passengers disembarking in Yaletown-Roundhouse Station, for example, to make it to the mezzanine level. Both have pros and cons. I do like the deeper stations because they feel like a real subway, however it's also pretty darn convenient to be off the train and out of the station so quickly in the shallow stations. Of course, half the line has elevated stations and these are comparable to the shallow stations for egress time, plus daylight and fresh air are nice perks.

[Chadillaccc]

According to the municipal census, 29.61% of Calgarians now use alternative transportation to get to work. This figure includes public transportation, carpooling, bicycle, and walking.

[caltrane74]

Union Pearson (UPX) trains will be arriving in Toronto shortly...







UPX Facebook

https://m.facebook.com/UnionPearsonExpressEN

[Aylmer]

Perhaps it's the colour scheme or maybe the slightly boxy design, but it doesn't quite look as modern as I would have thought. Exciting that the project is advancing so rapidly though!

[caltrane74]

Looks like they have covered the electrical/air conditioning/pantograph units with some nasty plastic contraption which has taken a lot from the slicked up look of the trains.

[Beedok]

Maybe they're trying to get it to look less new so that when visitors come to the city in a few years they'll think the link has been up for decades and the city is proactive on transit? *conspiracy mode intensifies*

[vid]

It looks innocently surprised! Reminds me of the old Novabus LFSs!