[BurlOak]

One of biggest issue of Sheppard West extension is crossing West Don Valley - require new bridge or deep tunnel dip under Don Valley West river. Now you're adding those sharp 90 degree subway turns at Sheppard & Bathurst along with Bathurst & Wilson will be difficult and really restrict where a subway station platform can actually be built to service those intersections.

Sheppard Subway Line 4 already has WYE subway turning tunnels onto Yonge Subway Line 1 - yes, eastbound train will actually have to reverse to service Sheppard-Yonge station!

Image looking north along Yonge at Sheppard:
View attachment 137818

So existing Sheppard Subway Line 4 would interline with Yonge Subway Line 1 between Sheppard-Yonge Station and Highway 401 where it heads west under Highway 401.

Now to cross the West Don Valley cheaply,.... use the "unoccupied" lower deck of Highway 401 Hoggs Hollow Bridge just west of Yonge Street,.... why does this sound familiar??? Oh, that Bloor Viaduct being built in 1918 with empty lower deck not being used until Bloor-Danforth line went in during 1960's!
View attachment 137819
https://en.wikipedia.org/wiki/Hogg's_Hollow_Bridge#/media/File:Hogg's_Hollow_Bridge_-_South.jpg
https://en.wikipedia.org/wiki/Hogg's_Hollow_Bridge#/media/File:Hogg's_Hollow_Bridge_-_South.jpg
http://www.uerev.com/index.php?pageid=galleryimage&itemid=1051

Warning: Getting MTO to agree to anything is next to impossible,... under our current Premier,... but hmmmm,... anyone hearing "subway, Subway, SubWay, SUBWAY!"

New subway tunnels bored under Highway 401 until it reaches Wilson Ave just east of Bathurst,.. now Bathurst & Wilson will have proper subway station with straight platform below intersection.

First, bridges are (relatively speaking) dirt cheap. If you want a rough number to go by, I'd say $100M/km.
Portals I don't have as good of a feel for (you definitely need 1 on the East side, and likely another if it goes underground on the west as well). I would guess about $25M each.

Second, Hogg's Hollow bridge was not designed for the weight of a subway. Bloor viaduct (and Millwood Bridge) were. If you propose to run with cars filled with Hellium balloons, it may be able to work, but that leaves little space for passengers.

 

[Leo_Chan]

Second, Hogg's Hollow bridge was not designed for the weight of a subway. Bloor viaduct (and Millwood Bridge) were.

It can support the weight of a subway, but it doesn’t have anywhere to put it without modifications?

 

[idc24]

Maybe a seperate subway exclusive bridge south of the existing Sheppard Hoggs Hollow bridge could be a solution like the Line 2 Bridge over the Humber at Old Mill.

 

[idc24]

 

[idc24]

Line 2 Old Mill, elevated station structure

http://enacademic.com/dic.nsf/enwiki/650699

 

[sunnyraytoronto]

Second, Hogg's Hollow bridge was not designed for the weight of a subway. Bloor viaduct (and Millwood Bridge) were. If you propose to run with cars filled with Hellium balloons, it may be able to work, but that leaves little space for passengers.

Highway 401 Hogg Hollow Bridges are actually made up of 4 parallel bridges:

- The two in the middle are Double Truss Bridges - upper deck for roadway and lower deck for structural support and currently under-utilized (somewhat similar to Bloor Viaduct is Double Truss with Arc support):
--- one built in 1929 (@ $1million when bread was 5cents a loaf, factor in today's $5 a loaf and I guess you get $100million per bridge!) as Yonge Blvd Viaduct as detour to avoid steep valley hills on Yonge Street - now host 401 westbound express lanes
--- the other double truss built in 1952 for MacDonald-Cartier Freeway - now host 401 eastbound express lanes

You would be right in that,.... these lower deck are NOT weight bearing - they can barely support catwalk - won't support subways! Really just rust flavoured jello!

- The two outer bridges are Girder bridges (like elevated Gardiner Express) built in mid-1960s as MacDonald-Cartier Freeway converted to today's Higway 401 Express-Collector system:

These 2 Girder bridges can host a subway line hanging from it's load bearing deck similar to this:

The new large single deck built between the two Double Truss Bridges (westbound & eastbound express) can also host a subway line hanging from it's load bearing upper deck (space is about 20 feet high and 25 feet wide):

Thus,.... no Hellium or Hot Air required!

 

[BMO]

I think ideally the Sheppard West extension would end at Sheppard West station with stops at Senlac, Bathurst and Faywood. From a network connectivity perspective, It'd be nice to have the line interline with the TYSSE extension to connect to the Barrie GO line and York University, but I think the ~2-4 minute transfer wait at Sheppard West would be acceptable for most people.

Ultimately, having the Sheppard subway eventually reach Pearson would be ideal and I think having the line go south just past Allen on a Wilson Ave alignment would touch on some pretty important trip generators, and a GO Train intermodal station at Etobicoke North would be great for connections to the airport reducing the need for transfers at Weston station to UPX.

I'd rather focus on just getting it extended to Sheppard West station first to fill in the gap in the system and provide a good measure of redundancy to the rapid transit network so that the eventual delays won't be as bad as they are today. Having Sheppard, Eglinton and Bloor connect to the Spadina side will hopefully improve the system's resiliency and flexibility in the event of delays on the Yonge line.

 

[W. K. Lis]

They couldn't even put a bridge for bicycles under the Yonge-401 bypass.

 

[Leo_Chan]

Having Sheppard, Eglinton, Bloor, and Queen connect to the Spadina side

FTFY.

I agree that up to Sheppard West Station is already very good, as any more west is just a complete fantasy. And the transfer should be acceptable as interlining will cost more for the tunnels and "people will get confused". However, the tunnel for going south will probably already be built, as it is needed to get to Wilson Yard, which opens the opportunity for interlining southwards might be more necessary compared to north.

Thinking more about this, it actually would make more sense to interline Line 1 with Line 4 instead of Line 4 with Line 1 Extension, as the frequencies north Sheppard West are a bit lower, and so are frequencies on Sheppard. So having half of the Line 1 trains go to Vaughan, and the other half go to Don Mills might actually make a bit of sense. Though, the problem is if Sheppard West will be an interchange station or a bypass.

 

[sunnyraytoronto]

They couldn't even put a bridge for bicycles under the Yonge-401 bypass.

Wow,.... and you're telling me??? Gee, I wonder who's the genius who came up with that absolutely brilliant idea??? Hmmm,....

Anyways,... Local Councillors, City Staff, area ratepayers associations, community groups, advocates, etc,... all love the concept,.... but,... we can't get an off-road multi-use trail or any hanging structures through there,... because it's MTO property and infrastructure. And after countless request including as part of Yonge-401 Environmental Assessment and REimagining Yonge EA,... MTO refuse to be a partner,... that's why I previously mentioned:

Warning: Getting MTO to agree to anything is next to impossible,... under our current Premier,... but hmmmm,... anyone hearing "subway, Subway, SubWay, SUBWAY!"

​

https://urbantoronto.ca/forum/threa...xtension-proposed.20503/page-135#post-1317623

 

[W. K. Lis]

Wow,.... and you're telling me??? Gee, I wonder who's the genius who came up with that absolutely brilliant idea??? Hmmm,....

Anyways,... Local Councillors, City Staff, area ratepayers associations, community groups, advocates, etc,... all love the concept,.... but,... we can't get an off-road multi-use trail or any hanging structures through there,... because it's MTO property and infrastructure. And after countless request including as part of Yonge-401 Environmental Assessment and REimagining Yonge EA,... MTO refuse to be a partner,... that's why I previously mentioned:

​

https://urbantoronto.ca/forum/threa...xtension-proposed.20503/page-135#post-1317623

MTO "took" the Yonge Street Boulevard (Hoggs Hollow) bridge to be used for some of the 401 lanes of traffic.

From link. Pedestrians and cyclists now have a l-o-n-g way to get around.

 

[Hopkins123]

I think ideally the Sheppard West extension would end at Sheppard West station with stops at Senlac, Bathurst and Faywood. From a network connectivity perspective, It'd be nice to have the line interline with the TYSSE extension to connect to the Barrie GO line and York University, but I think the ~2-4 minute transfer wait at Sheppard West would be acceptable for most people.

Ultimately, having the Sheppard subway eventually reach Pearson would be ideal and I think having the line go south just past Allen on a Wilson Ave alignment would touch on some pretty important trip generators, and a GO Train intermodal station at Etobicoke North would be great for connections to the airport reducing the need for transfers at Weston station to UPX.

I'd rather focus on just getting it extended to Sheppard West station first to fill in the gap in the system and provide a good measure of redundancy to the rapid transit network so that the eventual delays won't be as bad as they are today. Having Sheppard, Eglinton and Bloor connect to the Spadina side will hopefully improve the system's resiliency and flexibility in the event of delays on the Yonge line.

If Sheppard Subway is ever extended westward, it could be aligned like this to maximize its utility as Albion Centre, Humber College and Westwood are major nodes. Could even be elevated in parts:

[/URL][/IMG]

 

[sunnyraytoronto]

MTO "took" the Yonge Street Boulevard (Hoggs Hollow) bridge to be used for some of the 401 lanes of traffic.

From link. Pedestrians and cyclists now have a l-o-n-g way to get around.

Technically, the Ontario government paid for that first Hogg Hollow Bridge (Yonge Blvd Viaduct); so maybe it was theirs to take!

Anyways, here's a 1952 image of that first bridge plus it's twin for the new MacDonald-Cartier Freeway.

Notice:
- Yonge interchange (as most including Avenue Road interchange) was originally Four Leaf Clover Interchange design
- Southeast of Yonge interchange was St.Andrews Golf Course,... being transformed to residential use!
- Southwest of Yonge interchange was a large park (former William Carson farm), after Hurricane Hazel (October 15, 1954) caused massive flooding and damage in the Don River Valley West area, the park was converted to Don Valley Golf Course in 1956; one reason was lost of nearby St.Andrews Golf Course! Now with City's Golf Course review, maybe conversion back to parkland???
- Further upstream, northwest of Don Valley Golf Course area you could see part of York Downs Golf Course which in 1975 became Earl Bales Park,.... ever wonder why that park has so many lines of trees set up like golf fairways?!?!?
- Oh, and North York Centre,... nothing but brand new post-war bungalows and 2-storey strip plazas along Yonge Street

 

[sunnyraytoronto]

First, bridges are (relatively speaking) dirt cheap. If you want a rough number to go by, I'd say $100M/km.
Portals I don't have as good of a feel for (you definitely need 1 on the East side, and likely another if it goes underground on the west as well). I would guess about $25M each.

When I last checked over a year ago, mainly due to the technical challenges of crossing the WestDonValley, a westward extension of the Sheppard STUBway line from Yonge (actually Senlac tailtrack) to the current Downsview Station at Allen Road with only one new station at Bathurst was estimated by City Staff to cost $2.3 Billion.

The current 50+ year-old bridge isn't engineered for subway and would require a new bridge,.... and I'm hearing estimates of about $1 billion for the bridge!

Your $100 million per km bridge is sort of in line with our infamous Southbound Yonge to Eastbound 401 Fly-Over ramp,... really a one lane bridge spanning about 600m with estimated cost of $50 million (5 years ago).

Bridge prices will of course vary on height, length, design, material, load requirement, etc,...

The current Sheppard Bridge is a cheap half-bridge in that (as any cyclist is aware) the roadway goes halfway down the valley where you find a shorter and lower bridge,... VS the ridge-to-ridge Hoggs Hollow Bridges on Highway 401 that's so flat you're not even aware you're on a bridge (unless you notice the valley). Subway will prefer a very flat bridge.

With this bridge cost, this will likely reopen that Subway VS LRT debate,... and if Sheppard STUBway should be converted to LRT, and will Sheppard East be LRT or Subway,... hmmmm,... of course all this will be settled on the first day Doug Ford becomes Premier! Three more months to go!

 

[44 North]

That's an interesting suggestion, but I'd change two aspects:

1) Would consider changing the type of trains, to something smaller and with less imposing footprint, to reduce the construction costs. If we expect this line to never exceed 15,000 or 20,000 pphpd, there is little reason to spend money on infrastructure capable of carrying 35,000 or 40,000. Still fully grade-separated for speed, with wide station spacng, but not as expensive per km.

This is my view. I'm not exactly a supporter of extending Sheppard, but do concede it's a longstanding priority (east, not west). Thing is tho it was stupid as all hell to build a line for 6-car (+30k capacity). Would never have seen half that even in the best case scenario. If the line is ever extended in the future I think there's a lot of unstudied merit to sizing things for shorter trains - e.g the current 4-car setup as the max. Perhaps even retrofitting for narrower trains too.

They couldn't even put a bridge for bicycles under the Yonge-401 bypass.

This seems decent and a good way of connecting the area. Not sure about the hanging bridge below the 401... a new structure might be better. But no question it connects a lot of pockets, and allows NYC to be less of an isolated pocket for those on two wheels or on foot. Wonder if another idea may be a short ped/bike tunnel along Yonge for the section below the 401.