Double-ended LRVs and Crossovers
As we know, the replacements for the existing streetcars in Toronto will be single-ended vehicles, but the Transit City routes will use double-ended vehicles, likely to be an alteration of the other fleet.
A number of discussions have taken place about the benefits of double- over single-ended vehicles, both on this site and on other sites. For a true LRT implementation, double-ended LRVs are the way to go. Several reasons cited are:
- Loops require property or, at best, additional streets for on-street turning.
- Single-ended vehicles can only load and unload to their right side, while double-ended vehicles allow a mix of centre- and side-platformed stations and stops, as needed.
- The TTC’s display materials used at various EA open houses mention the issue of wheel squeal with turning loops and cites crossovers used by double-ended operations as being quieter.
- If work must be done on a track, with single-ended vehicles both tracks must be taken out of service between usable turning loops, often resulting in extensive portions of the line being taken out of service.
I have cited this last point as an important issue, but the flexibility does depend on track layout. Many cities that I have visited only use trailing-point switches, except for at terminals. This means that turning a vehicle back involves passing the crossover, then reversing operation and crossing over to the other track. Trailing-point switches are often preferred for safety, as the operator does not have to take care to ensure they are aligned properly before passing through.
A few cities I have visited have double crossovers that have both trailing- and facing-point switches. St. Louis, Cleveland, and Sydney Australia are three that come to mind. I was in St. Louis back when the Cross County extension was being built and one evening the LRT was operating on only one track around the location where the extension was to be connected to the existing system. No back-up moves are needed to accomplish this with both types of cross-overs.
Oslo is another city that sticks with trailing-point crossovers for the most part. On my recent trip, part of the western line was undergoing track replacement between Ullem (pictured above) and Hoff. That is about a 1 km distance with an intermediate stop in the middle. This part of the line is in its own private ROW and is built with ballasted tie construction, and this made it relatively easy to provide a single-track detour. A temporary switch was laid on the remaining track at each end of the construction zone and the other track was realigned to the switch.
Wiring over pantographs is easily moved over the single track, running parallel to the permanent wire over that track. No wire frogs or anything special like that is needed. Pantographs simply contact whatever wire, or wires, are above them.
Whether single-track operation makes use of existing crossovers, or temporarily installed track-work, this can only be accomplished when double-ended (and therefore double-sided) LRVs are used.
August 22nd, 2008 at 1:43 pm
Hi Calvin:-
For a true LRT implementation, double-ended LRVs are ‘the’ way to go. ‘A’ way to go would be more accurate for ‘the’ way to go is the immanently superior in every way, single ending of a system.
Let’s take the discussion step by step.
Cal interjects: As a matter of policy on this site, I do not censor comments - moderation is used to keep out the spam as I wish to encourage alternate points of view. However, brevity can be a virtue. I recently heard a comment that basically said that if one’s comments to an article requires more words than the original article, then one may have to readdress one’s writing skills. That said, I am leaving this comment in its entirety, adding only brief comments.
• Loops require property or, at best, additional streets for on-street turning.
This statement appears to have been made as a detrimental reason to not have single end. I for the life of me can’t see why an off-street site for a major transit facility would be shunned. The purchase price of the loop property would never go stale in this city. Real estate only grows in value so any property purchase is a win-win for our TTC. If the site is one that can have commercial value in office and/or retail scenarios, then rent or sell the air rites, again win-win. If the site is out in the boonies and of little commercial interest, then its value and established use as a transit node will eventually increase that kind of interest in the area surrounding it.
The safety, convenience and desirability of an off-street transfer point cannot be overstressed. One would hope that Transit City will be the purported catalyst that it claims to be, thus increasing suburban rider-ship and because it’s in the burbs and thus less hemmed in by established development, then what a great opportunity to re-establish the triumphs of the once great TTC. When the Commission took over from the private company, they embarked on loop construction in every quarter of the city. These loop properties were lauded as an important and appealing undertaking of the new Commission by all citizens, unlike the seedy eyesores that lack of commitment and maintenance has turned the remaining sites into. They were once well maintained with manicured lawns and shrubberies. Each generally had an inviting waiting shelter too. What a marvelous chance for our city to regain its once pleasant aura that our streetcar system used to exude.
Pretty picture aside, what of the transferee. Where terminals and major short-turn sites are established, they will be transit nodes. For the aforementioned safety, convenience and desirability reasons, a dedicated facility designed for the benefit of the rider should invite rider-ship increases on all connecting modes. An on street interchange, where the need to dodge traffic, maybe get splashed, get no overhead protection from rain and sleet just to change to a trolley car or dirty old diseasel bus; “well no thanks, I’ll drive instead, thank you kindly”!
In the burbs, where the auto is still king, a great opportunity to mimic one of the TTC’s successes, the ‘Kiss-and-ride’, should be retained as another mode connection. Much more refined than being part of a busy thoroughfare and blocking traffic while the passenger alights from the car.
This terminal site too should have covered and protected waiting areas, newspaper kiosk(s) and possibly even a public potty, besides the essential one for the operator. Said operator, now not having to dodge traffic themselves to take a well deserved tinkle break at the end of a trip, would greatly appreciate the fact that there is a place for them to go. Too, each operator would not have to brave the elements each and every time that a return working would necessitate if double end. Imagine not having to walk the length of their train in slushy, sleety conditions, getting their feet wet and their uniforms splashed by passing motorists (because the turnaround point is in the middle of a busy thoroughfare) merely to go to the opposite control cab. Their bus counterparts are not subjected to this indignity. An LRT operation should be some many steps above that of a diseasel busman’s lot in life. After all, motor persons carry more people on their train than 5 bus drivers can on their freewheelers.
On street loopings at intermediate or emergency turn-back locations is merely one of the ways in which a modern streetcar system can deal with issues of flexibility, so rather than a drawback, it can be seen as one of the positive aspects of what can be done with a genuinely important transit vehicle.
Cal’s comment: This addresses the idea of an off-street terminal facility more than single/double ended operations, which is a whole other issue. While land costs for an off-street terminal for double-ended operations is still there, it tends to be lower because of the sheer space needed for the loop itself.
• Single-ended vehicles can only load and unload to their right side, while double-ended vehicles allow a mix of centre and side platform stations and stops, as needed.
One of the basic tenets and principles of streetcar design and past practices is being badly overlooked here in this statement. That is, the almost limitless way in which a streetcar can be built. Many single-ended streetcars had off-side doors, thus giving access to other than right hand stops. For only surface scratching examples; Boston’s PCC fleet comes first to mind as almost 300 cars were thus built to accommodate Park Street, then latterly, Government Centre stations. Cleveland’s Shaker Heights routes were similarly equipped with PCCs with left hand doors. Mexico City cut left hand doors into its second hand Detroit fleet of PCC cars and their Peter Witts I believe were built that way. All single end cars with the ability to service left hand platform locations. Surely modern car builders can accommodate this feature if required.
Cal’s comment: One argument for single-ended cars has to do with the added cost of two sets of controls and twice the door hardware, and sometimes gets into the loss of seating or standing space resulting from this. Of the two, it is the doors that contributes to this more than the control stands (both cost and space). To suggest that single-ended vehicles with off-side doors is an alternative to double-ended cars rather defeats the argument in favour single-ended cars.
• The TTC’s display materials used at various EA open houses mention the issue of wheel squeal with turning loops and cites crossovers used by double-ended operations as being quieter.
It appears from this statement that the TTC is still running gun shy about neighbours’ complaints of flange squeal at loops. This squeamishness is not reflected in their attitude towards the also noisy and equally obnoxious phenomenon of corrugation, which is ignored and allowed to propagate; for the engineering models say that it will never grow again on the new super track. This cavalier attitude towards TTC’s neighbours in this vein (corrugation has reaffirmed its hold on this new track, whether the TTC wants to acknowledge the fact or not) but not at squealing loops is interesting. But I digress, for the TTC has been successful in minimizing and darned near eliminating this source of pollution and congratulatory recognition of this fact is well deserved. The successful engineering folks that, day to day deal with the existing system, have found a workable solution to flange squeal. Please, PR folks, go to the Main Street Station and see, for you cannot hear, for yourselves the working lubricator and curve grease that has been in place and working for almost two years. Curve noise is for all intents and purposes a non-issue now thanks to the maintenance folks continued investigations to eliminate it.
Now it is possible that a lubricator can fail, but if it does, then it is a simple matter to grease the curves by hand for the period required to get the repairs effected. If a track-switch fails, because that’s the method required to send cars back, then what could be the repercussions of that? It could be as benign as having a point man sited until repairs are made, or for the operator to get out and change the point themselves. If that failure results in something a bit more serious, then injury, damage or line hold ups could be the undesirable result(s).
Until maintenance is required on the switches and crossings, they can be reasonably quiet. But once they’ve been in use for a period of time, then heals start to hammer as well as the crossing frogs. Then bang-bang, bang-bang, bang-bang goes the trolley.
• If work must be done on a track, with single-ended vehicles both tracks must be taken out of service between usable turning loops, often resulting in extensive portions of the line being taken out of service.
Must both tracks be taken out of service? Not if one practices tried and true street railway maintenance methods. Ramp rails and surface mounted track and switches were once employed throughout North American streetcar systems. They are a truly a simple and safe technology that can be employed for the period requiring them in single tracking a line. In Toronto, I was told that the TTC had used them not all that long ago on Coxwell Avenue south of Gerrard Street while the car track was renewed, admittedly in the old method of track rehabilitation, but none the less successfully. Slewing the trolley wire over in span type construction was also a simple task. Quickly installed and safe to use, wow what a concept, and this in an entirely single-ended scenario.
Cal’s comment: The TTC did recently try this for some construction, with mixed results. It is very workable for short sections that have no intermediate stop within it, otherwise we are back to the off-side door issue.
I will be greatly surprised though if the TTC adopts any, even temporary, single line working for TC routes when the time necessitates track rebuilding. By the time tracks need replacing, headways will surely demand that they don’t single track. Again, old methods may well be thought of here to allow reconstruction and still keep the cars running on double track, a highly desirable situation, thus avoiding the single track bottleneck that will be sure to develop. That method is the temporary shoo-fly track. It would be on the surface of the roadway and allow the cars to run on a parallel line, leaving the centre section free for the track-work.
IN ADDITION:
Single-end cars are less costly to maintain and build. Also Murphy’s laws always play rampantly on more complex systems than on simpler ones. I think it is law number seven. Anyhow, the second control space on each and every car cuts down on passenger capacity per vehicle, as the public will surely not be allowed to ride there. Increasing passenger capacity should be a concern as it makes each vehicle and thereby the whole system more efficient. If one controller is out of use, then the car is out of use and there is a 100% greater opportunity to have this happen with 100% more cars requiring double end packages.
Cal’s comment: Where does your information on the cost of single-ended cars come from? Modular construction has two identical end sections for both ends of a double-ended car, making me wonder just how much less expensive two different modules would cost, even if one lacks a control stand.
Track maintenance is lessened, thus again thwarting Mr. Murphy, if fewer moving parts are necessitated. Cleaning switches of snow and ice is also a bug-a-boo and can and will slow service. Been there, done that and I’ve still got the parka and frostbite scars to prove that cleaning switches is not a jolly job! Snow covered switches have also contributed to accidents, definitely not a desirable occurrence.
Changing ends and then reversing back into service is the least efficient way to run a system. Most of the heavily used streetcar systems in North America were not double end and if they once were and survived into the PCC era, soon changed their routes to using loops. Chicago, the once largest street railway in the world did so. Why, because it made so much sense to eliminate the throttling need to wait for a car to clear the terminal before heading back. There are ways to increase capacity at a stub terminal, but why go to the extra expense of complexity and the real estate eating demands that would be required to retain a less than optimal operating plan. For discussions on the minimum time requirements to satisfy a safe interlocking clearing move at stub terminals, look at Steve Munro’s web site when the discussions are about our existing subway. Loops can allow cars to enter, offload, load and then be outta there in the shortest possible time, thus being the best scenario. Quoting the optimal headways that TC is supposed to be running under and then stating that with that as a basis there is plenty of time to clear a x-over before the next car arrives could be valid if you don’t ever want to increase capacity to greater numbers than initially forecast. And what of the inevitable bunching? Loops would be the best way to contribute to clearing a backlog where x-overs could do nothing but exacerbate the problem.
My aversion to double ending is one that I’ve developed over many years of experience and observation. True as a trolley fan, I really enjoyed the Toonerville aspects of the double-ended Philly Suburban, but even there, the heavy demands at its subway/elevated connection at 69th Street they employ a loop. Overall the system, at present, is not conducive to improving turnaround times at the outer terminals. The greatest streetcar systems that daily carried millions of riders in North America, (Toronto, Montreal, Chicago, Boston, Cleveland, Detroit, Birmingham and Pittsburgh to name merely a few) were by and large single ended, or adopted single ending for many more than one reason. The tight fisted, profit driven Toronto Railway Company, although exceptionally cheap among its peers in the industry, refused to double end any of its routes, for you know, it’s less costly laddie!
Dennis Rankin
Cal’s comment: There is a place for single-ended and a place for double-ended operations. Transit City is supposed to be a true LRT implementation, and hopefully it will be. I do have strong suspicions that it will need to show itself as something more than “just a streetcar line”. One of the premises of this site is that many people in the GTA have this idea that LRT is “just streetcars”. Its success will be partly due to breaking this image and double-ended operation will play a part in that.