[lrt's friend]

Before you think I am nuts, please read.

One of the chief complaints about LRT to the suburbs is that many consider it a glorified streetcar. There are too many stops on the way to downtown.

One of the benefits of BRT is that buses can leapfrog each other and express buses do not need to stop at every station. In fact, Ottawa is considering express Transitway buses that go nonstop or almost nonstop from the suburbs to downtown.

High frequency LRT cannot do such things. It must stop at every station, whether riders are embarking and disembarking or not.

I recently read that one of the lines servicing Coney Island in New York had a third set of tracks, the third set originally used for express trains. That third set of tracks is no longer used for that purpose (mainly because of the decline of Coney Island from its heyday) but it presents an interesting concept nevertheless.

We are now planning our rail network. We still have a lot of choices. Would it advantageous to triple track certain parts of LRT lines where non-stop express trains would be desireable? Triple tracking would not be needed for the whole line. It would not be needed downtown as every train would stop at every station. It would not be needed at the far end of the line either. It would be middle portion that would be considered for triple tracking.

The express trains using the third set of tracks would run in the peak direction. This would also provide extra redundancy when rail maintenance was taking place.

Also consider that construction costs would likely not be enormously different for triple track compared to double track. There would be extra rail and the extra power systems, and bridges and tunnels would have to be a little wider. It would certainly be cheaper to do it at the beginning than trying to retrofit everything later.


What do you think? Can you think of other pros and cons? Is it a ridiculous idea? Is it overkill for a city the size of Ottawa? Will the faster service make it worthwhile?

[Aylmer]

I like the idea but I think that city council would freak out because of costs.

[Deez]

I'm not sure if you've ever been to NYC (I hadn't until this December...), but most of the subway tracks in midtown and downtown Manhattan are quad tracked for express train purposes (which still run).

[lrt's friend]

I like the idea but I think that city council would freak out because of costs.

Perhaps to keep start up costs down, we could provide space for the third track and add it later as ridership grows. Nice to think towards the future even if we can't afford everything up front.

I'm not sure if you've ever been to NYC (I hadn't until this December...), but most of the subway tracks in midtown and downtown Manhattan are quad tracked for express train purposes (which still run).

Good to know there is an actual working example. Nope, I have never been to New York. Some day!

I was thinking of triple track on an east line (converted Transitway) from Montreal Road to Hurdman, on a west line (converted Transitway) from Moodie to Tunney's Pasture, and on a south line from Leitrim to Bayview. Additional 'local' trains could be short-turned at the far extremity of the third track.

[c_speed3108]

Before you think I am nuts, please read.

One of the chief complaints about LRT to the suburbs is that many consider it a glorified streetcar. There are too many stops on the way to downtown.

One of the benefits of BRT is that buses can leapfrog each other and express buses do not need to stop at every station. In fact, Ottawa is considering express Transitway buses that go nonstop or almost nonstop from the suburbs to downtown.

High frequency LRT cannot do such things. It must stop at every station, whether riders are embarking and disembarking or not.

I recently read that one of the lines servicing Coney Island in New York had a third set of tracks, the third set originally used for express trains. That third set of tracks is no longer used for that purpose (mainly because of the decline of Coney Island from its heyday) but it presents an interesting concept nevertheless.

We are now planning our rail network. We still have a lot of choices. Would it advantageous to triple track certain parts of LRT lines where non-stop express trains would be desireable? Triple tracking would not be needed for the whole line. It would not be needed downtown as every train would stop at every station. It would not be needed at the far end of the line either. It would be middle portion that would be considered for triple tracking.

The express trains using the third set of tracks would run in the peak direction. This would also provide extra redundancy when rail maintenance was taking place.

Also consider that construction costs would likely not be enormously different for triple track compared to double track. There would be extra rail and the extra power systems, and bridges and tunnels would have to be a little wider. It would certainly be cheaper to do it at the beginning than trying to retrofit everything later.


What do you think? Can you think of other pros and cons? Is it a ridiculous idea? Is it overkill for a city the size of Ottawa? Will the faster service make it worthwhile?


Much of the New York subway has at least 3 tracks with express service that uses the inside tracks (or sometimes an above and below arrangement) Express stations (about every 4th or so) would have an express platform while local stations do not and the express trains fly through at VERY high speeds.

The MetroNorth in the area North of NY (one of the most awesome commuter railways I have ever seem) uses 4 in most places.

Another interesting idea they have used in New York is skip-stop service as a way to speed things up coming down from Harlem and the Bronx. In skip-stop service basically two train routes follow the same path (use the same tracks) and make alternate stops with odd common stop at a larger transfer stations.

I have often thought it might be interesting to try this in certain sections of the Transitway in Ottawa. It would be advantageous since it discourages people using the Transitway routes for short trips. The disadvantage is that it makes the system a fair bit more complex to use. The speed gain however could help make express bus service less attractive. Otherwise the express service is going to have to continue no matter what gets built...IMHO


Now back to the trackage....

I imagine cost would make it a non start. Also some of the corridors are only so wide..I think. One idea is that if longer trains are used, the trains would then be further apart allowing more space (time) to pass with appropriate signaling.

Or even just add a passing track at the stations the way the transitway was built.

I imagine there would have to be provisions for trains to cross over to the opposite track anyway (with the signaling to make it safe) since a disabled train would screw up everything.

[lrt's friend]

I am glad that my idea is bringing out other ideas that haven't come out in past LRT debates. Hopefully our transit planners and our politicians are looking in at what is being discussed. Maybe something practical can be found in it all.

[Aylmer]

Should we triple-track the tunnels?

[d_jeffrey]

I am glad that my idea is bringing out other ideas that haven't come out in past LRT debates. Hopefully our transit planners and our politicians are looking in at what is being discussed. Maybe something practical can be found in it all.

From the Ottawa Transit site :

The top speed of your metrO cars is 110km/h, but stations are so short in between, that will never be attained? As you may have noticed, Transitway stations have 4 lanes between each side. With efficient rail construction, additional rail lanes should be set up in place to allow express metrO service, bypassing stations along the way. That is why the 110km/h was brought up.



;)

[lrt's friend]

:previous: Good! :)

[lrt's friend]

Well, I sent my suggestion to the transit committee and got a fast response back from Marianne Wilkinson. She said that it would be too expensive to build a third set of tracks initially but there was merit in making the ROW wide enough to add it later. Somehow, I think the idea will simply be pushed aside and forgotten.

[d_jeffrey]

Well, I sent my suggestion to the transit committee and got a fast response back from Marianne Wilkinson. She said that it would be too expensive to build a third set of tracks initially but there was merit in making the ROW wide enough to add it later. Somehow, I think the idea will simply be pushed aside and forgotten.

And yes it will, basically only the stations need a third rail, if we can automatic put trains and switching, when the fast train arrives at a station, it has the choice of going into the station or going straight ahead. You don't need to triple track everything, unless you want a separate line with separate stations.

[lrt's friend]

And yes it will, basically only the stations need a third rail, if we can automatic put trains and switching, when the fast train arrives at a station, it has the choice of going into the station or going straight ahead. You don't need to triple track everything, unless you want a separate line with separate stations.

I guess you can do that but doesn't this present a lot of signalling complications at every station? Besides, train braking is different from buses, and if we are talking about frequent trains, there will be really limited opportunities for express trains to move at a fast speed without longer stretches of a third set of tracks. I guess I am saying, why do it at all, if an express train has to slow down because the local train in front of it is braking to exit onto a siding at a local station. Maybe there are ways to make this efficient.

[d_jeffrey]

I guess you can do that but doesn't this present a lot of signalling complications at every station? Besides, train braking is different from buses, and if we are talking about frequent trains, there will be really limited opportunities for express trains to move at a fast speed without longer stretches of a third set of tracks. I guess I am saying, why do it at all, if an express train has to slow down because the local train in front of it is braking to exit onto a siding at a local station. Maybe there are ways to make this efficient.

The only way to make it really efficient is automation. Even with great signalling, with trains running at 100km/h, you can't assure great service or safety with switching tracks that often.

[lrt's friend]

:previous: Exactly, and then we get into a circular argument because automation is extremely expensive, much more expensive than simply building the third set of tracks.

[d_jeffrey]

:previous: Exactly, and then we get into a circular argument because automation is extremely expensive, much more expensive than simply building the third set of tracks.

Actually automation is not expensive at all, it is easily recovered by the operation costs going down. There are reasons why most new systems are automated (Canada Line, Lausanne M2...)

[lrt's friend]

:previous: As I have said months ago, the extra costs come with right of way construction which must meet much higher security standards than for LRT and total elimination of all level crossings.

[d_jeffrey]

:previous: As I have said months ago, the extra costs come with right of way construction which must meet much higher security standards than for LRT and total elimination of all level crossings.

Yes it comes at extra cost, but it's all about cost differences. If you save 30M$ a year in operation costs, I would say do automation, if it's only 3M$, I would say not. Especially for the new plans, most of the tracks are in dedicated ROWs already.

Also, I was wondering, with at grade crossings, if we have 3 minutes headways, both ways it gives a minimum of 90 seconds for each train to pass, is that feasible? What are the requirements for the gates to come down?

[Dado]

Considering that the Transitway is wide enough (as built) for three tracks (four at stations), then this is definitely an option worth having/designing for.

[youngregina]

Ir would only make sense to design a third track in with the ulimate plan. Even if for later implementation.