Broadway Subway - Millennium Line Extension to Arbutus | U/C

[madog222]

It really depends on how much delay contingency they had originally planned for. At this point tunneling has taken five months longer after starting over four months from the original schedule. Late 2026 seems like a real possibility.

The stations were supposed to be finished this summer-fall and are obviously no where close. Though that should be less critical, the can be finished as the main systems are commissioned.

[Jimbo604]

The riskiest part of the project is the tunneling. They drill a multitude of bore holes to see what the soil conditions are underground to get an idea but you never know what problems will come up. Take the Coquitlam extension is example of what unforeseen problems can arise with multiple sink holes that opened up to the surface. Or in Seattle with their viaduct replacement tunnel, they had a damaged drill issue (wikipedia).

Once tunneling is done, hopefully in April, the project will be more straight forward: construction of stations that are accessible from ground level, track and electrical installation, etc.

With this more straight forward construction starting, I predict they will release an updated target date. I'm assuming have been reluctant to do that to date because of the unpredictability before reaching this milestone.

And even then the target date is not cut in stone.

[jollyburger]

Originally Posted by Jimbo604

The riskiest part of the project is the tunneling. They drill a multitude of bore holes to see what the soil conditions are underground to get an idea but you never know what problems will come up. Take the Coquitlam extension is example of what unforeseen problems can arise with multiple sink holes that opened up to the surface. Or in Seattle with their viaduct replacement tunnel, they had a damaged drill issue (wikipedia).

Well in Seattle the TBM ran into a steel pipe that had gone unnoticed from a previous project. Seems more like negligence/incompetency in that case.

[Hooknose]

Originally Posted by madog222

It really depends on how much delay contingency they had originally planned for. At this point tunneling has taken five months longer after starting over four months from the original schedule. Late 2026 seems like a real possibility.

The stations were supposed to be finished this summer-fall and are obviously no where close. Though that should be less critical, the can be finished as the main systems are commissioned.

So there are two intermediate goals .. a) tunnel breakthrough (and TBM dismantle) and b) cover up on the streets (so that we "get our Broadway back").

The second can happen quickly once the TBMS have been dismantled. No reason not to close up everything except arbutus/cypress now.

Then all the finish up work is invisible and, also, not really subject to engineering delays.

[Migrant_Coconut]

Question: at what point is the station "ready" for passengers? Can they do the final touches after it's already open?

[jollyburger]

Originally Posted by Migrant_Coconut

Question: at what point is the station "ready" for passengers? Can they do the final touches after it's already open?

You assume it's when they have all the functional systems in place and finish testing everything. That will all take longer than any "final touches" work so I doubt you see that scenario of them opening "early"

[madog222]

From the March 2024 Project Update.

This explains why we haven't seen photos of Phyllis's breakthrough at Cypress.

For the final two breakthroughs at Cypress Street, TBMs Phyllis and Elsie are breaking into a specialized pressure chamber. That’s because the TBMs are specially designed for the ground conditions along Broadway, which are mostly bedrock. Near Arbutus, however, the soil becomes softer than the rest of the Millennium Line extension’s route. Once the TBMs have successfully broken through, the pressure chamber will then be taken away to allow the final tunnel liner rings to be installed.

Images from Province of BC.

Planned construction activities for the next three months include:

Completing the parapets on top of the elevated guideway and beginning work on the track slab;
TBM Elsie completing her journey to Cypress Street;
Disassembling the TBMs at Cypress Street;
Constructing the concrete bases that will hold the SkyTrain tracks in the tunnels;
Constructing the walls and columns at Great Northern Way-Emily Carr, Mount Pleasant, Broadway-City Hall, Oak-VGH, South Granville and Arbutus stations;
Completing the base-slab foundations at Arbutus station;
Constructing the concourse floor at Great Northern Way-Emily Carr, Mount Pleasant, Oak-VGH, Broadway-City Hall and Arbutus stations;
Excavating the tail tracks at Arbutus Station; and
Excavating and constructing the underground passenger connections between the Millennium Line extension and the Canada Line at Broadway-City Hall.

[jollyburger]

They included a photo but it was the arrival into Broadway City Hall.

The first of two tunnel boring machines building the Broadway Subway has made its final breakthrough in its journey at Cypress Street, reaching the pit of Arbutus Station. Through the Broadway Subway Project Office, the provincial government quietly announced that the tunnel boring machine named Phyllis arrived at the Arbutus Station pit on Wednesday, March 20, 2024. This represents the completion of the tunnel boring process for SkyTrain Millennium Line’s Broadway Extension’s westbound tunnel.

Phyllis began boring her last segment between stations on February 2, 2024, when she resumed her dig from the Granville Street wall of South Granville Station. It took her 50 days to travel the four city block segment from Granville Street to Cypress Street.

Elsie, the other tunnel boring machine, responsible for building the eastbound tunnel, is also now closing in to break through the wall at Cypress Street. Elsie resumed her dig from South Granville Street on March 5, 2024 — 17 days ago, as of today. If she is able to dig at a similar pace as Phyllis, she could reach Cypress Street by the end of April 2024. When Elsie makes her final breakthrough later this spring, this will represent the conclusion of the Broadway Subway’s tunnel boring process by Ghella, which partnered with Acciona Infrastructure Canada to build the project. From Cypress Street, both tunnel boring machines will be disassembled and extracted.

Upon opening, Broadway-City Hall Station will become one of the region’s busiest SkyTrain stations, as it will be transformed into a seamless interchange hub between the Millennium Line and Canada Line. The $2.8 billion, 5.7-km-long extension of the Millennium Line will add six subway stations to the SkyTrain network. A length of five km is underground, but there is also a 700-metrelong elevated segment between the existing VCC-Clark Station and the tunnel portal just before Great Northern Way-Emily Carr Station.

https://www.ghella.com/en/media/news/fir...ubway-reaches-end-tunnel-arbutus-station

[madog222]

^It's still inside the pressure vessel. The photos in that release are from previous segments.

[Alex Mackinnon]

Originally Posted by madog222

^It's still inside the pressure vessel. The photos in that release are from previous segments.

FYI, there's some nice viewing windows from the sidewalk where the TBM is now. You can go see the cutterhead there now.

[Jimbo604]

Re: Broadway back

I had a look down into the station constructions when I was going by this week. Still a lot of work to do to get the station to ground level, even at Main Street station where you would assume it would be more advanced in construction as it was the first tunneled to.

Then they'll have to do a fairly hefty cover on top of the tracks/Broadway vehicle lanes to support the roadway with a bunch of rebar placement and concrete pours.

So not close on getting Broadway back, a good number of months still. And it will get worse before it gets better as they'll have to close lanes on Broadway to get all that rebar/concrete built.

[jollyburger]

Originally Posted by Jimbo604

Re: Broadway back
Then they'll have to do a fairly hefty cover on top of the tracks/Broadway vehicle lanes to support the roadway with a bunch of rebar placement and concrete pours.

So not close on getting Broadway back, a good number of months still. And it will get worse before it gets better as they'll have to close lanes on Broadway to get all that rebar/concrete built.

Isn't it just backfilled to the tunnel/platform level and then just build a new road base? I wonder if they have to move stuff into the station platform level for guideway construction which is why they are still uncovered?

[s211]

Originally Posted by Jimbo604

Re: Broadway back

I had a look down into the station constructions when I was going by this week. Still a lot of work to do to get the station to ground level, even at Main Street station where you would assume it would be more advanced in construction as it was the first tunneled to.

Then they'll have to do a fairly hefty cover on top of the tracks/Broadway vehicle lanes to support the roadway with a bunch of rebar placement and concrete pours.

So not close on getting Broadway back, a good number of months still. And it will get worse before it gets better as they'll have to close lanes on Broadway to get all that rebar/concrete built.

I wonder if we could at least get Cambie mostly back. Has the north-south sewage work been completed? It seems that not much is happening there these past few months.

[madog222]

Pure speculation but given what concourse level construction has happened has been at such a slow rate it seems obvious that the TMB conveyor is a major impediment. Once the tunneling equipment is gone station construction should speed up.

Originally Posted by s211

I wonder if we could at least get Cambie mostly back. Has the north-south sewage work been completed? It seems that not much is happening there these past few months.

There is no room on Cambie. In the past few months they started using even more road space, not less, which forced the bus stop to be closed.

[Jimbo604]

Originally Posted by jollyburger

Isn't it just backfilled to the tunnel/platform level and then just build a new road base? I wonder if they have to move stuff into the station platform level for guideway construction which is why they are still uncovered?

Could be, or fair chance they haven't simply haven't constructed enough yet.

Backfill and road base.. would the city be doing that or the project contractors, I wonder.

[jollyburger]

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[Jimbo604]

Wondering if they are drilling this weekend… 24/7 holidays too?

[Hooknose]

Originally Posted by Jimbo604

Wondering if they are drilling this weekend… 24/7 holidays too?

I have to assume they are drilling.
The contract for workers is, no doubt, union and so will have double triple time rates.

A TBM likely rents by the day or week and it does not pay to shut down if you can keep it going for a few hundred an hour in labour costs.

[jollyburger]

Originally Posted by Hooknose

I have to assume they are drilling.
The contract for workers is, no doubt, union and so will have double triple time rates.

A TBM likely rents by the day or week and it does not pay to shut down if you can kep it going for a few hundred an hour in labour costs.

Seems like they still bore on the weekends since one of the TBMs broke through on a Saturday morning.

[Feathered Friend]

There was no activity, and the lights were out at the Oak/VGH station last night, so it seems they're taking the long weekend off.