ouest-de-lîle REM - Prolongement vers Dorval

[andre md]

Plus on a de maillage et plus les gens vont utiliiser les transports en commun. Autre choae que l on oublie , c'est si par exemple il arrive un probleme sur la branche du rem qui va  a l aeroport les usagers auraient une alterntive avec une prollngation a la station Dorval

 Le meme principe s applique avec la prolongation de ligne orange jusqu a BoisFrancs. 

[crosbyshow]

il y a 7 minutes, andre md a dit :

Plus on a de maillage et plus les gens vont utiliiser les transports en commun. Autre choae que l on oublie , c'est si par exemple il arrive un probleme sur la branche du rem qui va  a l aeroport les usagers auraient une alterntive avec une prollngation a la station Dorval

 Le meme principe s applique avec la prolongation de ligne orange jusqu a BoisFrancs. 

Exactement André 

[amaist]

7 hours ago, danny12345 said:

and may compromise performance and capacity at YUL, since the tunnel will be single track.  

I don't see how it can compromise either performance or capacity at YUL. Only if they don't add another trainset or two to account for the longer network.

The airport tunnel will be fine at single track. The YUL branch is fed by the mainline that passes through the Mount Royal tunnel. This is where the main capacity limit is set. The airport branch can take at best one third of that capacity maybe a little more with express trains.

What might happen is if the system is a great success, then the planned capacity might not be sufficient for both the airport and Dorval users. Out of all the possible negative factors that one is the most benign.

[dcarrier]

5 hours ago, amaist said:

I don't see how it can compromise either performance or capacity at YUL. Only if they don't add another trainset or two to account for the longer network.

The system would be single-tracked from Technopole to Dorval, which means that the train must enter and exit the tunnel before the headway is over. In peak times, they are planning to have one train every 10 minutes. This means five stations at 30s quoted dwell time each, plus 2*4km to go through. The timing would be extremely tight and would prevent ever running the trains more frequently than once every 10 mins.

[andre md]

Il y a 3 heures, dcarrier a dit :

The system would be single-tracked from Technopole to Dorval, which means that the train must enter and exit the tunnel before the headway is over. In peak times, they are planning to have one train every 10 minutes. This means five stations at 30s quoted dwell time each, plus 2*4km to go through. The timing would be extremely tight and would prevent ever running the trains more frequently than once every 10 mins.

Single track is penny saving construction. Unless you have a long distance track then yes it could worth it to just get one track but on short distance it doesnt make sense. And if a problem occur on the single track you are stuck. 

[Enalung]

On 2019-08-02 at 3:42 AM, andre md said:

Single track is penny saving construction. Unless you have a long distance track then yes it could worth it to just get one track but on short distance it doesnt make sense. And if a problem occur on the single track you are stuck. 

Single track tunnels are way less expensive to build then double track tunnels. Take a look at the purple line for the Los Angeles metro. Notice anything? Yep, that's 2 single track tunnels. If they built one single large double track tunnel using a TBM, the amount of material they would have to remove increases significantly. This is material that they have to truck away and most likely, pay to dispose of. A pair of single track tunnels also offer an escape route in case of emergencies. Assuming the CDPQ does decide that they need more capacity, building a second tunnel parallel to the one that they are building right now is likely the solution that will be retained.
 

 

[andre md]

Il y a 9 heures, Enalung a dit :

Single track tunnels are way less expensive to build then double track tunnels. Take a look at the purple line for the Los Angeles metro. Notice anything? Yep, that's 2 single track tunnels. If they built one single large double track tunnel using a TBM, the amount of material they would have to remove increases significantly. This is material that they have to truck away and most likely, pay to dispose of. A pair of single track tunnels also offer an escape route in case of emergencies. Assuming the CDPQ does decide that they need more capacity, building a second tunnel parallel to the one that they are building right now is likely the solution that will be retained.
 

 

About the metro of montreal they were telling a different story about single tunnel and two tunnel comparing montreal and toronto for their respective metros.  Cheaper 1 big tunnel versus 2 smaĺler one. What is the real cost? 

My point was that if you build 1 track or 2 tracks. Whatever if its a single or double tunnel the cost wont be the double for 2 tracks versus 1 track. 

But if you decide in the future to add an extra track then it would cost a way more. 

[YUL]

2 hours ago, andre md said:

Cheaper 1 big tunnel versus 2 smaĺler one

I read something else for the Montreal Metro - from a 1966 document.

Further to the additional material to truck away, most of the wider tunnels would have required center columns to re-enforce the ceilings.  (Not sure if it's still relevant today) 

Modifié 16 août 2019 par YUL

[Né entre les rapides]

Il y a 2 heures, andre md a dit :

My point was that if you build 1 track or 2 tracks. Whatever if its a single or double tunnel the cost wont be the double for 2 tracks versus 1 track. 

But if you decide in the future to add an extra track then it would cost a way more. 

Right on!

[nephersir7]

11 hours ago, Enalung said:

Assuming the CDPQ does decide that they need more capacity, building a second tunnel parallel to the one that they are building right now is likely the solution that will be retained.

CDPQ ont décidé qu'ils n'auront pas besoin de capacité supplémentaire. Ce n'est pas faisable d'ajouter un deuxième tunnel entre les stations Technoparc et aéroport.