kEiThZ
Superstar
We're about to find out if the CIB is actually as apolitical as they claim it to be. Real analysis and decision-making would focus on maximizing ridership and economic benefits.
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VIA Rail
- Thread starter ehlow
- Start date
We're about to find out if the CIB is actually as apolitical as they claim it to be. Real analysis and decision-making would focus on maximizing ridership and economic benefits.
roger1818
Senior Member
The problem with too much straightening is it has the potential of creating enemies. It will add ammunition to the HSR or nothing zealots as the cost will be getting closer to the cost of HSR. On the other side, the airlines (and air fans) will feel threatened by the shorter travel times, and will lobby against the project. HFR needs to find the balance where it is competitive with driving but not too competitive with flying if it has any hope of funding. Once built and there is strong public support, upgrades will be easier.
I don't think you fully understand why electric trains are more energy-efficiently than diesel trains. It is true that regenerative braking (that can be fed back up into the catenary) gives electric trains an advantage, but it is only one small factor. Not needing a diesel generator (with about a 30-35% efficiency) is a much more significant factor. Trains don't just use their motors to accelerate and then coast at their target speed, they use them to overcome friction and keep their speed, which becomes even more pronounced at higher speeds.
While I agree, I also feel that many on this forum have their mind made up on what HFR should look like based on assumptions and guesses and if the plan isn't what they want, the assumption will be that there was political interference. I don't know if the cost of electrifying HFR can be justified, but I would trust a study based on projected fuel and electricity prices over the opinion of some person on a forum. Don't forget that much of the costs of electrifying would be spent in Canada, so as as an act of economic stimulus, it isn't a bad option.
reaperexpress
Senior Member
Yes, obviously if we just randomly spam curve realignments along the line, those could become lost investments with HSR. But as I described earlier, the line is divided into two fairly distinct segments: the relatively straight track through flat land (mostly west of Havelock) and the super curvy track through rocky terrain (mostly east of Havelock). The super-curvy track physically cannot be straightened without abandoning the entire ROW, so that part will obviously stay as is, and would be a prime candidate to be bypassed by a future HSR line. The segments through flat land can mostly be upgraded to 110 mph, and some segments could be aligned for 125+ mph to allow speeds to increase above 110 mph by building grade separations in a later stage. So there is still plenty of opportunity for HSR even with a heavily-upgraded (western half of the) corridor.
As for the threat of airlines, I don't buy the rationale of deliberately limiting the speed of the project to avoid upsetting the competitors. First of all, I'm an air fan myself, and I don't see how reducing the number of flights from Toronto to Ottawa would be in any way negative from that perspective. The GTAA has been saying for years that they're short on capacity, so the slots freed up by cancelling those flights would likely allow for more long-distance flights. And those types of flights are much more interesting to an air fan than an endless stream of Air Canada Airbus A320s.
If the project is built such that it does not impress the public (e.g. travel times similar to today), intercity rail will continue to be irrelevant in the public eye and there will never be any future upgrades.
Do you (or anyone) have any figures on the balance of energy consumption between acceleration and cruising? Because from my experience riding EMUs in the Netherlands, trains maintain speed for an extremely long time while coasting (at 140 km/h), which suggests that it takes relatively little energy to keep the train moving, compared to the energy that was invested to build up that inertia.
I don't buy the "economic stimulus" argument because that can be applied to virtually any construction project. Canada is so far behind in infrastructure that there's no need to include "economic stimulus" as a justification to build a project. If a certain version of a project doesn't have a strong business case, it's fine to reject it because there will be plenty of other versions/projects which do.
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roger1818
Senior Member
Can 125+ speed trains run on single track, or does double track become a requirement at that speed?
Maybe you are right about air fans, but the airlines would not just roll over and accept the loss of revenue (There is a big difference between what the GTAA wants and what the airlines want). Don't forget that in 1991, Air Canada (along with CP Rail) did a study on HSR that, as The High-Speed Rail Story stated, "The results of this study created considerable concern among the airlines, given the huge public investment required to implement high-speed rail. It is believed that the ensuing lobby was a major factor in the lack of support for follow-up action on HRS proposals." So I stand by my argument that to get HSR, we first need strong public support.
IMHO, 3 hours and 15 minutes between Ottawa and Toronto (VIA's busiest route) along with significant improvement in reliability is a significant improvement and will generate significant interest in further rail upgrades.
I don't have information figures on the balance of energy consumption between acceleration and cruising but I will say that since fluid friction increases with the square of the velocity, the energy required to overcome that increases significantly with speed, such that compared to cruising at 140 km/h:
cruising at 177 km/h (110 mph) requires 1.6 times the energy
cruising at 201 km/h (125 mph) requires 2.1 times the energy
cruising at 250 km/h (155 mph) requires 3.2 times the energy
cruising at 300 km/h (186 mph) requires 4.6 times the energy
It is true that it can be applied to any construction project, but I suspect the government will want to spend more stimulus money than there are shovel ready projects that have a strong business case.
nfitz
Superstar
Via's 1980s studies were for 300 km/hr using single track. Though you certainly need a lot of long sidings at such speeds.
reaperexpress
Senior Member
There's no technical limitation to the speed of single track lines. High-Speed Line signaling systems (ETCS etc) are perfectly capable of ensuring safe train separation regardless of speed or direction.
The Bothnia Line in Sweden is a single-tracked railway designed for 250 km/h, though it currently only permits 200 km/h
The Lötschberg Base Tunnel permits 250 km/h and has been single track since its opening in 2007, though work is currently underway to double-track it.
That said, the higher your design speed, the more (net) time you lose slowing down to switch tracks when encountering a train in the opposite direction. To limit this impact it would be really helpful if VIA were to include high-speed switches (i.e. >100 km/h diverging), regardless of HFR or HSR. The wikipedia article for "Flying Junction" describes some switches which permit 220 km/h for diverging trains and 300 km/h for the straight-through route, but unfortunately I can't find any source for that.
Oh yeah, for sure public support is a huge issue, and so is airline lobbying. I'm just saying that we need to make sure that the initial implementation of HFR isn't a flop.
I absolutely agree that's a totally respectable achievement. My thinking is not that we need to aim higher than that, it's that we need to make sure we actually achieve those objectives, even if it means increasing the (rather optimistic) project budget. I have a bad feeling that we'll end up with a line which could theoretically be traversed in 3h15 if there were no other trains on the line, but in practice takes closer to 4 hours given schedule padding required to account for meets. To routinely schedule 3h15 travel times on a single-tracked line, the best case scenario needs to be under 3 hours.
Yes obviously fluid dynamics applies to trains as it does all objects, but the real question is the energy was at 140 km/h in the first place. It should be possible to estimate that by measuring the frontal area of a train and assuming a drag coefficient. Maybe I'll consider doing a back-of-the-envelope calculation this evening.
In any case, your ratios underline the point that we're typically better off eliminating speed restrictions before worrying about increasing the maximum speed.
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crs1026
Superstar
I seem to recall YDS saying at one point that the cost-of-energy analysis was a wash for HFR, it was the carbon reduction that tipped the balance towards electric. Even that informed opinion might need to be revisited and the key data refreshed - is the cost per kg of carbon reduction competitive with what one could accomplish for the same investment in some other sectorj?
We armchair observers don’t have the data to prove one way or the other.....but.....There is certainly some intuitive logic to @kEiThZ ’s observation that a once-hourly passenger train line is not enough energy consumption to extract gains by switching modes - especially given a billion dollar pricetag.
- Paul
We armchair observers don’t have the data to prove one way or the other.....but.....There is certainly some intuitive logic to @kEiThZ ’s observation that a once-hourly passenger train line is not enough energy consumption to extract gains by switching modes - especially given a billion dollar pricetag.
- Paul
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crs1026
Superstar
This.
An hourly service plan equates to a meet every 30 minutes en route. One train takes a minimum 5-minute hit for each of those meets, as it must take siding and await the other train, clearing early enough to not slow the other train. On a 3:15 schedule, that would mean each train needs 15 minutes of wait time just for meets.
Now assume a regulatory-imposed speed restriction in each of Peterboro, Tweed, Sharbot Lake, and Perth. Assume two minutes lost time in each of those. That's 8 minutes.
Now assume that due to regulatory issues there is no improvement in time over today between Ottawa and Fallowfield. And assume that VIA can go no faster than GO between Agincourt and Union (assuming the Scarboro Jct route is used, and not the Don route). And, be pessimistic about the speed through the junctions between VIA and CP at Smiths Falls, and between VIA and CP/GO at Agincourt (the concern about a lowest-cost design). Those segments eat up minutes.
I'm confident that there will be substantial speed achieved in between, even east of Tweed, but there are a lot of "minute eaters" in the plan.
Hopefully the JPO reports will put this concern to rest.
- Paul
kEiThZ
Superstar
I would look at it as opportunity cost. Rail is bloody efficient as is. Electrification isn't going to save substantially on fuel cost and the associated emissions. Especially, compared to what the $2B penciled in for electrification could do for upgrades that yield higher ridership.
I'm happy to wait for a study. But intuitively, I don't think there's a case for electrification until they get into Higher Speed Rail/HSR territory with higher frequencies as well.
roger1818
Senior Member
You are ignoring the option of long sidings. They become less practical with higher speeds, but not impossible. The idea is to make the siding long enough that the trains can pass each other without slowing down. After the train passes the switch, it is thrown in the opposite direction for the oncoming train. To do this, you need to make the siding long enough for:
- time to throw the switch after the oncoming train has passed it, plus
- time to stop the train if the switch fails to throw, plus
- a reasonable amount of time for the oncoming train to be late.
Using some back of the napkin math, you need about 1 minute to throw the switch, which at 177 km/h is 3km, maybe another 3 km for an emergency stop at 177 km/h, and assuming a margin of 5 minutes late for the oncoming train, another 15 km. That is a total of 21km. Given that at 177km/h a train can travel 88.5 km in 30 minutes, that is less than 1/4 of the ROW being long sidings, which is still a lot cheaper than double track and most of the time neither train needs to slow down.
crs1026
Superstar
I'm assuming the precedent of the Ottawa-Brockville line, ie sidings about a half mile in length. And sidings placed about where they were in steam days, to save new grading of the roadbed. At that siding length, turnouts will not be high speed because there isn't any point in them when the train has little room remaining to brake to a safe stop after entering the siding.
The limiting event is that the train taking siding must clear the main line 30 seconds before the train holding the main reaches the "approach signal" (in fixed block mentality). The 30 seconds is the time required to throw the switch and clear the signal. Only then will the train on the main be able to proceed maintaining full speed, ie without ever reaching a restrictive signal.
Before the limiting event, the train taking siding must slow at service application (not emergency application, some safety margin is required) from full speed to turnout speed, transit the near turnout (likely a 30 mph affair) and clear the interlocking.
The train in siding must then wait for the train holding main to transit the approach block, transit the far turnout, and then 30 seconds to reverse the turnout and clear the signal. Then the waiting train can resume its journey, accelerating from zero to full speed.
I agree, a far better approach would be longer sections of double track with high speed turnouts, so meets happen close to full speed for both trains. Those sidings would have to be several miles in length to give adequate contingency. I just don't anticipate that VIA's budget stretches that far.
- Paul
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reaperexpress
Senior Member
I think Ottawa-Brockville is an excessively pessimistic precedent, because it was designed based on quite a different circumstance. Those sidings would have been placed with lower frequencies in mind (and thus less consequence of cheaping out on sidings), and only the vaguest form of schedule adherence (so frequency of sidings becomes more important than length).
I think a more suitable reference case would be the hourly off-peak GO train services that were introduced over the last couple years. These generally use sidings at least a couple kilometres long, with 45mph turnouts.
- The Barrie line started its 75-min service using the 3.3km siding north of Maple. Trains often got stopped waiting for each other and it added 2 minutes to the schedule (in addition to all the schedule padding that schedule already had).
- The current passing place for the Barrie line's 60-minute service is the 6.8km siding between Downsview Park and Rutherford. Trains meet around 100 km/h within the segment and the schedule is not adjusted for the meet (the normal schedule already assumed <45 mph at the locations of the switches).
- The Kitchener line is fully double/triple tracked as far as Georgetown, but the hourly service operates a single-track pattern with a meet at Maple Station. The station stop serves to considerably increase the effective length (in time) of the passing track. But I don't see us double-tracking Peterborough station so that's not particularly relevant to HFR.
Given the above examples I personally think the base case scenario would be sidings a couple kilometres long with 45 mph turnouts in the locations meets are supposed to happen, and a smattering of Ottawa-Brockville style sidings in between (in case a train is off-schedule). But ideally the planned sidings would be more than just a couple kilometres long with turnouts suitable for more than 45 mph.
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crs1026
Superstar
The ROW may be wide enough to place two tracks, so in theory there is no added land cost.....but ..... the grading is the limiting factor. If the line has cuts or fills that were built for only one track, the earthmoving to widen the roadbed may be expensive. This is a factor east of Havelock where the line enters the Canadian Shield. Widening cuts means blasting rock. For this line, in many spots the line is draped onto the side of a slope or around a hillside - so the volume of material to be removed is greater. The other cost is fills through wetlands, which may require a lot of fill to stabilise all the way to the bottom of a marsh. And any bridges or underpasses that were built without future proofing for doubletracking. There are plenty of stretches where doubletracking would have a prohibitive cost, it’s a matter of how much double track is really needed and where it is most feasible.
And of course the cost of track materials and ballast doubles when there are two tracks over one.
- Paul
crs1026
Superstar
If this happens, I will be delighted.
But....baking those preferred passing locations in to the design strikes me as very risky, considering that CN controls timings at the east end and ML may control timings at the other end. One would need an ironclad agreement with CN. What if, for instance, CN abruptly declared that VIA can only have one track at any time east of Coteau? Or changed where in that territory it wanted VIA to hold its meets? That could shift the scheduled meeting points all the way to Toronto. VIA will probably tweak its schedules also with experience. It may start with some specific timing (eg always leave on the hour) but find some other timing is preferable. (On the hour ex Toronto but on the half hour ex Ottawa, as a hypothetical example)
That’s why I would argue for more fairly closely-spaced short sidings throughout the route. With a static service plan and perfect timekeeping, some of those sidings might rarely see a train.... but that gives maximum flexibility to alter the schedule, and the time penalty involved in any shifted meet is small. I had assumed VIA might invest in some extra software in their traffic control to predict actual times so that meets could be optimised.
- Paul
crs1026
Superstar
The same variables are at play, yes. New construction may actually allow steeper grades and a straighter line is also shorter - less track to build and maintain. But rock is rock and swamp is swamp.
The real economic issue for straightening curves on this line is just the sheer number of them, and how close they are together. One doesn’t save much time (or generate ROI) by cherrypicking a few cheap/easy ones....one has to connect enough straight track to achieve a sustained speed improvement over a significant distance. Otherwise one spends millions to save seconds, and the business case isn’t there. I’d predict that the incremental improvements down the road will be packaged as $100-million + chunks of a dozen or more kms in length rather than smaller projects. The ROI only comes when you save increments of 5-10 minutes.
- Paul