Talk:North Yonge subway extension/GA1

Lead

• I think the hatnote could be made even clearer by specifying "2020s subway extension to Richmond Hill".
• "This expansion added four new stations, including its new northern terminus at Finch station. In mid-1961, the TTC had drawn up plans to extend the Yonge line to Steeles Avenue." I think this paragraph should be split into two between these sentences. It would give the lead an "introduction paragraph", then a paragraph on the planning and construction history.
• "In mid-1961, the TTC had drawn up plans to extend the Yonge line to Steeles Avenue." -> "In mid-1961, the TTC created plans to extend the Yonge line to Steeles Avenue."
• "while the section to Sheppard would open with the rest of the line to Finch." -> "while the rest of the extension to Finch opened ."
• "A 1971 strike prompted the TTC to initially open the extension to York Mills while the section to Sheppard would open with the rest of the line to Finch. The extension opened to York Mills in March 1973 and to Finch in March 1974." -> "A 1971 strike prompted the TTC to open the extension to York Mills first. Service began to York Mills in March 1973, while the remaining section to Sheppard and Finch opened together in March 1974." And the last paragraph can be merged into this paragraph I think.
• "to extend the Yonge branch still farther north" -> "to extend the Yonge branch further north"
• Is it possible to mention the cost of the extension in the lead?
• And any details about construction methods?

Hey Steelkamp, I've made these edits. For the cost, I just put the initial expected costs and the final cost. For the hatnote, I've added "2030s" as the YNSE will most likely open during that decade. ~UN6892 ^t_c 18:59, 17 May 2026 (UTC)

That sounds good for the costs. One more lead comment below: Steelkamp (talk) 06:50, 18 May 2026 (UTC)

• "A loop extension was proposed in the 1990s but ultimately shelved in favour of the Yonge North subway extension (YNSE), approved in 2021. The YNSE will extend the Yonge branch farther north to near Highway 407 and Highway 7 in Richmond Hill." -> "A loop extension was proposed in the 1990s but ultimately shelved in favour of the Yonge North subway extension, approved in 2021, which will extend the Yonge branch farther north to near Highway 407 and Highway 7 in Richmond Hill."

Background

• Nothing

Planning and design

• "CA$63-million" -> "CA$63 million"
• Is "Willam Archer" mean to be "William Archer"? And is that the same person as William Archer (Toronto politician)? If so, that should be linked.
• Should "Metro Toronto Council" be "the Metro Toronto Council"? Or is it currently correct in local usage?
• Loretto Abbey Catholic Secondary School can be linked.
• "due to its lower estimated cost around $57 million" -> "due to its lower estimated cost of $57 million"
• "after the commission found it would cost $7 to $10 million to add parking at Sheppard." Did it cost less to provide parking at Finch? Is that because the parking at Finch is on cheap hydro land, and they wouldn't have to build a multi-storey parking structure I'm guessing?
• Metro Toronto is linked twice in this section.
• "The tunnel option was selected." Cut-and-cover is also a type of tunnel, so they were both tunnel options. I think this should be clarified.
• "The late decision-making delayed the project." Could this be elaborated on? Like in what way was the project delayed?
• TBH I had to google the term "rough in". Could this sentence be changed to something like this?: "A proposal to make provisions for the future construction of the station was also rejected by Metro Toronto."

My sources generally say "Metro Council" without "the". If it is preferred that I keep with that specific usage, I will make those edits.

It did cost less to provide parking at Finch, I have reworded that section.

Regarding "tunnelling", the sources specify a difference between that term and cut-and-cover. The method (based on my sources) involved a process similar to tunnel boring, but I was unable to find evidence of a boring machine and the workers have been referred to in some sources as "tunnel diggers". How should I clarify this?

Otherwise,  Done. ~UN6892 ^t_c 19:32, 17 May 2026 (UTC)

Maybe something like "mined tunnelling". Fair enough if the sources differentiate the two, but to me, cut-and-cover is also tunnelling. Interesting that TBMs weren't used. They would definitely be used if it were constructed nowadays. Steelkamp (talk) 06:50, 18 May 2026 (UTC)

I found some better images in a primary source I'd been using lightly The first couple of images here. It appears the tunnels were done by a TBM (though they are called "mechanical moles"). Some tunnels were dug manually as the TBMs they could use were unable to go through all types of soil. It appears the source I was using that mentioned the diggers was referring to a part which was done without a TBM (I believe it was related to a strike). I don't have a lot of time this week, I will update the page as soon as I have it. ~UN6892 ^t_c 02:32, 20 May 2026 (UTC)

Some additional engineering info I was unable to find in news sources is also there including the size of tunnels, which ones were bored and which were mined ("manual shield" indicates it was mined), and where the contracts were (but not who the contractors were). The primary source there was made before the TTC decided to go cut-and-cover to Finch but there are no details north of Sheppard as construction there hadn't started yet. ~UN6892 ^t_c 02:36, 20 May 2026 (UTC)

Construction

• "Construction of the project was originally expected to begin at the start of 1968" -> "Construction was originally expected to begin at the start of 1968". IMO the project goes without saying.
• "including at least one in 1968 due to safety concerns." -> "including at least once in 1968 due to safety concerns."
• "Labour disputes delayed the project by around six months by 1971." -> "Labour disputes had delayed the project by around six months by 1971."
• "Costs of the initial section to Sheppard increased by $21 million" -> "Costs of the initial section to Sheppard had increased by $21 million".
• "The decision to use cut-and-cover was credited with keeping costs under control." I feel like this goes without saying right after that previous sentence.
• "Tunnelling was complete to just south of Highway 401". This doesn't make it clear where this is measured from? The northern or southern end of the extension? If from the south, I suggest something like "Tunnelling was complete from Eglinton station to just south of Highway 401".
• I think this section could do with some expansion for criterion 3. In particular, which sections were mined and which were cut-and-cover, what contractors built the extension (if that info's available), and any engineering info, which I find tunnels often have.

Hey Steelkamp, I put in the info I've been able to find. Contractor info seems scant though I was able to find the contract locations and some tunnel design information south of Sheppard. Things get more difficult north of there since they changed the plans after that document was made. ~UN6892 ^t_c 22:25, 21 May 2026 (UTC)

Opening and operation

No comments.

Later Line 1 extensions and plans

• "In the late 1980s and early 1990s, the TTC instead proposed turning the Yonge–University–Spadina line into a circle route, initially to be closed via a hydro corridor north of Finch Avenue but later to instead loop along Steeles Avenue allowing for subway service to York University." -> "In the late 1980s and early 1990s, the TTC instead proposed turning the Yonge–University–Spadina line into a circle route. Early plans had the loop closed via a hydro corridor north of Finch Avenue but later plans ran the loop along Steeles Avenue, allowing for subway service to York University." This makes it clearer that the two routes are two separate plans and not a single staged plan.
• "opened in 2017" -> "which opened in 2017".