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ARG1 said:
Wait so we're doing the whole "each service gets its own half of the ROW" thing like they're now going to do in the shared Stouffville/LSE corridor? That seems extremely silly...
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It may sound that way, but I doubt it will be operated in that extreme a fashion, and I'm sure an awful lot of modelling will have been done by now to inform the design. And redone - the spec's probably changed as things like the East Harbour station were reworked thanks to the Ontario Line becoming part of the design.

When ML decided to abandon the planned flyunder at Scarborough Jct, and retain a "flat" junction, they accepted the need for one direction of the Stouffville line to cross somebody's LSE path. The least intrusive pattern is to have the two northernmost tracks carry the Stouffville traffic... probably interleaved with some part of the LSE traffic. Since the two southernmost tracks don't face any routing conflicts, it does make sense that they be through LSE tracks, likely carrying most of the express trains.

As headways are reduced with both LSE and Stouffville moving to 15 minute (or better) service, the fewer trains that need to cross over, the better.

- Paul
 
reaperexpress said:
Thanks to the SmartTrack station consultations over the past few weeks, we now have a full end-to-end picture of the track configuration that Metrolinx envisages for the Weston Subdivision.

I have combined the conceptual track layout from the New Track and Facilities EA (massive PDF here) with the illustrated platform layouts from the St. Clair/Old Weston (Stockyards) and King/Liberty (Liberty Village) public consultations to create a diagram of the tracks proposed by Metrolinx for the relatively near future:

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In general I am very pleased with this proposed design, as it will be able to support a substantial amount of service. My biggest concern is that Metrolinx does not seem to be rationalizing the 4 tracks in to express/local pairs. This creates a number of problems:
1. Providing platforms on all 4 Kitchener Line tracks at Liberty Village requires eliminating at least 1 of the planned Barrie Line and Milton Line tracks. The conceptual site plan from the 18 November public consultation shows the Milton line being reduced to a single track, rather than the double track which had always been planned until now. Furthermore it shows the northbound Barrie Line track crashing into the north pier of the station's overpass at Sudbury Street.
View attachment 369759

2. As I have described before, mixing high-frequency local and express services on the same tracks severely limits the speed and reliability of express services. If local service runs every 15 minutes, then the express service can be at most 7 minutes faster than it before catching up to it. Today's express service is already 12 minutes faster than local services, and the number of local stations is only going to increase further. At a service planning level, Metrolinx does seem to be aware of this limitation, given that on Page 28 of the 2021 Kitchener Expansion Business Case analysis it states that all trains continuing west of Pearson junction (Wice) will operate express.
View attachment 369760
This, combined with the lack of talk of a rail-to-rail grade separation at said junction, suggests that the concept is for the north pair of tracks to serve express services, while the south pair is primarily used by a local service to the airport.

Here is how I would rationalize the track configuration to better suit that arrangement. I have reduced the two SmartTrack stations to a single island platform on the local tracks, to reduce construction costs and ensure that all 8 tracks can be maintained at Liberty Village. I have also slightly altered Pearson (Wice) and Bramalea (Halwest) junctions to reduce conflicts.
I have coloured the "express" pair in a much darker shade of green, purely to illustrate the typical use of each track.

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Here's a conceptual service pattern which could operate on my slightly-adjusted track layout. I have increased the variety of services compared to the pattern described in the Business Case. Their stopping patterns were probably oversimplified since service details east of Bramalea are not yet required at this stage of that project which is focused on the tracks west of Bramalea.

In my service concept:
- Trains coming in from Kitchener or London should not stop at Malton, due to its lack of regional importance. However they should stop at Mount Dennis and/or Bloor-Dundas due to their rapid transit connections.
- Given that there are 3 tracks west of Pearson Junction, it is possible to run 2 local trains per hour to Bramalea, providing some extra connectivity and frequency to local stations. If the quad track were extended west through Malton station, it would become possible to run 4 tph local to Bramalea, providing an interleaved 8-minute service east of Pearson Junction. The at-grade conflict at Pearson Junction is not a problem with two 4tph services as long as the services are regular and reliable (which the local services would be).

Split lines represent peak-only services
View attachment 369764
Click to expand...
I love this, great work! One question. Have we confirmed that another platform is to be added at Mount Dennis? Currently the station is only set up to serve 3 tracks.
 
crs1026 said:
It may sound that way, but I doubt it will be operated in that extreme a fashion, and I'm sure an awful lot of modelling will have been done by now to inform the design. And redone - the spec's probably changed as things like the East Harbour station were reworked thanks to the Ontario Line becoming part of the design.

When ML decided to abandon the planned flyunder at Scarborough Jct, and retain a "flat" junction, they accepted the need for one direction of the Stouffville line to cross somebody's LSE path. The least intrusive pattern is to have the two northernmost tracks carry the Stouffville traffic... probably interleaved with some part of the LSE traffic. Since the two southernmost tracks don't face any routing conflicts, it does make sense that they be through LSE tracks, likely carrying most of the express trains.

As headways are reduced with both LSE and Stouffville moving to 15 minute (or better) service, the fewer trains that need to cross over, the better.

- Paul
Click to expand...

Maybe the grade seperation will still happen if VIA HFR needs it :)
 
ARG1 said:
Wait so we're doing the whole "each service gets its own half of the ROW" thing like they're now going to do in the shared Stouffville/LSE corridor? That seems extremely silly...
Click to expand...

I don't have any reputable source confirming the preferred distribution of services across the 4 tracks, that's just what I'm guessing given that GO stated that all Kitchener Line trains operating west of Pearson Junction would operate express. If they were planning to use a track layout where the express and local tracks for each direction were next to each other, then this wouldn't be necessary.

Like @crs1026 mentioned, the colour coding in the diagram is simply an illustration of the typical users of each track. In practice any train could use any track.

Capture6.JPG


Here's another diagram, but this time showing an arrangement with express on the outside and local on the inside (E-L-L-E). The only physical change to track layouts here is that the platforms at Stockyards and Liberty Village stations are now on a different pair of tracks.
Capture1.JPG

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Since express and local tracks for a given direction are now adjacent to each other, trains are now able to switch between them without conflicting with oncoming trains. This brings a number of benefits:
- Less chance of cascading delays as a result of deviating a train from its usual track
- There could be 4 local trains per hour to Bramalea, since one of the tracks through Malton can be shared between local and express services without creating a mess of crossing conflicts.
- There are convenient cross-platform transfers available between express and local services at Pearson Junction and at Bloor

The fundamental disadvantage is that it doubles the number of eastbound trains conflicting with westbound Airport-bound trains. If everything runs according to schedule this wouldn't make any difference since the express trains could pass through simultaneously with the local trains, but doubling the number of trains also doubles the chance that one of them is late and delays the airport train (or vice versa). And actually it's more than double the risk, since the express trains are coming off the CN line where they are far more likely to experience delays than the local trains starting at Bramalea or Pearson Airport.

The L-E-L-E arrangment that crs1026 describes for the LSE/Stouffville corridor would basically operate the same as E-L-L-E, but with the following advantages and disadvantages:

Advantages:
- At Pearson Junction, avoids the conflict between eastbound airport locals and eastbound expresses

Disadvantages:
- At Bramalea, creates a new conflict between terminating local trains and through express trains
- Requires additional platform at Liberty Village, which reduces the Milton line to single track


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I think L-E-E-L is out of the question due to the excessive conflicts at both Pearson Junction and Bramalea, and E-E-L-L is out of the question because it places trains from London and Kitchener on the local tracks.

The elephant in the room for any discussion of track arrangements is the Union Station Rail Corridor. How they pair up services for through-running will have a profound effect on conflicts at the inner end of all GO lines, which could flip decisions about the ideal track usage. As I understand it, the final track configurations for the USRC (and by extension the track allocations along LSE/Stouffville, LSW, and Kitchener) are still up for discussion with the consortiums responding to the OnCorr RFP, which may explain why the stations are all being designed with platforms on all tracks. It's easier to delete a platform from a station design than add a new one in at the last minute.

Allandale25 said:
Maybe the grade seperation will still happen if VIA HFR needs it :)
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Once the layout for the USRC is decided, the track assignments are pretty much set in stone. The decisions of the OnCorr consortium will have almost irreversible effects on the GO network. If the Scarborough Junction grade separation were built later after the USRC is already reconfigured, it would put trains on the wrong tracks in the USRC. So all the conflicts you avoid in Scarborough would be cancelled out by new conflicts in the USRC.
 

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Allandale25 said:
So the track would be added at a future date? Is this part of the ProjectCo OnCorr work?
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I don't know for sure; but that's certainly the way it sounds; this work appears to do vegetation control, retaining all construction, conduits and track bed construction.

At the very least, the 4th track is left to a future contract from someone.
 
the way i understand the oncorr construction in relation to the early-works like the stouville corridor early works is that just the track bed is being installed. the oncorr contract will do the tracks
 
generalcanada said:
the way i understand the oncorr construction in relation to the early-works like the stouville corridor early works is that just the track bed is being installed. the oncorr contract will do the tracks
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That seems to be the case. Makes sense in that it relieves the oncorr bidders of the complexity (and risk) of all the civil preparation activity…. geotechnical, hydrological, environmental assessment and design…and basic civil construction.. Plus, ML retains the public interface for the major impacts and inevitable concerns.
Opens up the civil work to local contractors who may not have railway construction expertise, making the bid process more competitive.
A bit like getting new a new kitchen or bathroom….. the framing contractor delivers a set of clean, square walls with the underlying utilities roughed in, and then the cabinet designer/installer shows up. to put in the fixtures.

- Paul
 
WB lanes at Rutherford Go grade sep are open! New station building is also open but still a good amount of work to be done around the existing station building. There is currently a detour through the parking garage to get to the platforms which are nearly complete.

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At Maple GO - is this going to be a tunnel that connects the new bus loop elevator building to the existing tunnel that was installed a few years back to get to the eventual second platform?

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