Blue Streak 1,
You mention holding a local 1-1/2 minutes for an express to arrive, then to follow it out.
Based on current SEPTA schedules, the end to end run of a Norristown High Speed Line takes 28 minutes (limited stops between Ardmore and 69th Street Terminal). At a line length of 13.4 miles, the average speed is about 28 mph.
The N-5 cars have a high HP per axle rating, but I'd be guessing at the max speed between stations.
I can only speak of the one system I use, but during rush hour our light rail runs every 7 1/2 minutes in each direction. Trying to squeeze an express in there would be a nightmare, and would not save more than a few minutes anyway. It's currently only 25 minutes end to end. That's an average of about 30 MPH including stops. You couldn't possibly save enough time to offset the cost and complexity. It's already faster and far less aggravating than driving the road that it parallels.
Dave
Lackawanna Route of the Phoebe Snow
I have to take exception to the statement that the farther apart [the stops], the less useful [light rail is] as urban transport. I see the flexibility to meet changing land use and development density from urban to suburban to exurban as an advantage.
Light rail has limited capacity compared to heavy rail. LRT can meet lower travel demands in outlying lower density suburban areas without the cost of heavy rail. In some instances lrt has been built as a pre-metro and converted to rapid transit as land use densities increased.
Relatively compact urban centers impose limited and acceptable travel time penalties with surface running while providing high accessibility. The slow travel in the city center is offset by faster running in outlying areas on private rights of way. Development desities often are inadequate to generated any reasonable ridership to support closely-spaced stations. Ridership relies on bus feeder services and parking.
In an earlier posting I submitted what might be the minimal acceptabe curvature standard for a 100 mph LRT service with standing passengers, 5,730 feet. For an example, a more acceptable curve may be 8,511 feet radius. The point in that finding an alignment allowing such broad curves between Minneapolis and Saint Paul would be almost impossible.
People keep arguing about the mechanical capability of light rail.
You need to remember that when running near capacity, 75% of the passengers are standing. Acceleration, deceleration, and curves must take that into account.
Here in Charlotte, the Siemens Low Floor S-70s are stopping about every half mile. There are 15 stops in less than 10 miles. At the far end, they are farther apart, in city center, some of the stops are about twice the length of the train apart. That is what limits the speed.
The farther apart the stops, the faster they can go, but the farther apart the stops, the less usefull they are as urban transport. A balance between the two determines the line's average speed.
The 11 mile, 15 station Central Line suggests distances between stations would allow trains to reach 55 mph. With much of the line in street reservations with frequent intersections and crosswalks, only 40-45 mph may be appropriate. Conversely, if the line eventually will be extended beyond the respective downtowns on private rights-of-way, higher speed capability, 55-65 mph, would be desirable.
The concern for gates not lowering in time ignores predictive activation technology.
At "Gopher Rail" (Univ. of MN model railroad club's annual meet/convention) one of the guest speakers was from the company that is doing the engineering work for the light rail in the Twin Cities. IIRC he said that they had originally planned for the light rail on the Hiawatha line to go 50-55 MPH but ended up settling with 40-45 MPH because there was concern over the road/rail grade crossings...apparently Minneapolis city officials feared if the trains were going too fast, they would get to the crossings just as the crossing arms were fully down, they wanted to have a little more time to be sure the road was clear of traffic. Plus the stops are fairly close together, the train would hardly be getting up to 55 before it would have to brake for the next station.
The line between the Mpls and St Paul downtowns is going to involve some street running so it won't be going too fast. It will probably be about like the current bus service, 20-30 minutes downtown to downtown.
Sure you're not looking at a european speedometer in kph? 120kph=72mph, still not shabby.
Back to Minneapolis-St.Paul, a direct service downtown-to-downtown might save 3-4 minutes at 100mph rather than at 55mph non-stop. Then you need another line to make local stops; and I assume there is a lot of travel demand along the line. The high-speed line could extend beyond the downtowns to numerous outlying terminals over more conventional lines with stations and bus feeder connections.
A 100mph line is the first problem. Allowing as much as 4 inches superelevation and 3 inches underbalance, a 1-degree, 5,730-foot radius curve is the minimum necessary. How much money is there to buy the property and bulldoze a new line across the two cities? You don't want an LRV to hit or be hit by a truck at 100mph; so you need a fully grade-separated line.
The next problem is getting a compitent contractor to build the line. The Dan Ryan and O'Hare extensions were supposed to be 70mph lines that would suck all the riders off the commuter railroads. Instead, the Chicago Transit Authority rail lines deteriorated rapidly and suffered continually developing slow orders for decades. Having watched the track work progress for these extensions, I wasn't surprised by the outcome. The current crisis is only the most recent chapter in this affair.
Another problem is that a 100mph train will take 3-4 times the power and energy than for a 55mph train.
Can anyone point the way to a recent evaluation of light rail and bus rapid transit alternative costs on an annualized basis?
But again, some heavy rail vehicles are lighter than some light rail vehicles. The average Chcicago elevated or rapid transit, CTA, car weighs less than any Portland, OR or Dallas or Houston light rail car. Maybe not on a linear foot basis, because the light rail examples are three truck articulated cars and the CTA car is a 48-foot double truck car. But CTA is heavy rail because it is almost entire (now entirely except for the Brown Line) grade separated, uses equipmen not very well adaptable to street running or at least loading and loading passengers on the street, has very little if any single-car operation and runs long trains, whereas Houston and Portland and Dallas do run on the street, even if the lanes are rail or transit-only, have off-hour single-car operation, very little operation with longer than two-car trains. So it is called light rail. Typically, heavy rail equipment has end doors allowing crew, sometimes also the passengers, to pass from car to car. Typically, light rail had no more need for end doors than a bus. Many of the classic systems had both, sharing the same tracks, including Pacific Electric and Illinois Terminal. One example of heavy rail and light rail shearing the same tracks is between Cleveland Union Terminal and East 55th Street. The East-West rapid Red Line to the Airport is defined as heavy rail, even though has not generated the business to run long trains, and the Shaker Heights blue and green lines are defined as light rail, even if the actual vehicles are probably about as heavy as the red line cars. The red line loads from high platforms and the green and blue from sidewalk level with low-floor cars. Separate platforms are provided at the Terminal and at East 55th Street.
In 1903 the Brooklyn system attempted to extend an elevated line out over the streetcar tracks on Brooklyn and Queens first electric streetcar line from Cypress Street to 168th Street Jamaica. The open gate el cars had traps and steps (and most were probably conversions from steam-hauled coaches.) Some objections due to horses being scared and noise stopped the operation and normal streetcar service returned, lasting until 1947 even after the elevated structure was extended out to 168th above the streetcar tracks. (Now the structure has been cut back and the heavy rapid transit trains, the J and Z lines, routed into a new subway under parallel Archer Avenue with its last stop directly at the Long Island Railroad Jamaica Station.) Meanwhile, on what is now Macdonald Avenue and was Graves End Avenue, streetcars, elevated trains, and summertime steam trains shared the same track to Coney Island.
One point that seems to be misunderstood about "Light Rail" is that the Light refers to the VEHICLE, NOT the weight of the rail. A LRV (Light Rail Vehicle) is a Lightweight rail VEHICLE, as opposed to a heavy rail vehicle such as a locomotive pulled train.
Doug
May your flanges always stay BETWEEN the rails
I remember the Santa Clara Valley Transit Authority (VTA) light rail trains topped out at 70 mph on some routes, notably the route down California 87 from downtown San Jose, CA.
Here in Sacramento, CA, the Regional Transit light rail usually top out at 60 mph.
daveklepper wrote: Al, 99% of your posting is correct, but I must make one correction:Up-to-date high speed electric locomotives, suburban mu cars, metro or subway cars, light rail cars, trams or streetcars, all today, use non-synchronous ac hysterises motors, just like the best (for heavy hauling tractive effort and high overload capacity) EMD and GE diesel locomotives. The main reason is no added maintenance for replacement of carbon brushes in the dc motors that have been familiar up to a few years ago . This is also true of modern trolleybuses and battery buses. Alstom, Semans, and Stadler (or Brown Brovori for Stadler) make these motors, also Nikki Shaaro in Japan. In the USA, the pioneer was Amtrak's AEM-7. Of course the Acela equipment uses it, also the latest CTA, Washington, Pittsburgh, etc. equipment. . . .
Al, 99% of your posting is correct, but I must make one correction:
Up-to-date high speed electric locomotives, suburban mu cars, metro or subway cars, light rail cars, trams or streetcars, all today, use non-synchronous ac hysterises motors, just like the best (for heavy hauling tractive effort and high overload capacity) EMD and GE diesel locomotives. The main reason is no added maintenance for replacement of carbon brushes in the dc motors that have been familiar up to a few years ago . This is also true of modern trolleybuses and battery buses. Alstom, Semans, and Stadler (or Brown Brovori for Stadler) make these motors, also Nikki Shaaro in Japan. In the USA, the pioneer was Amtrak's AEM-7. Of course the Acela equipment uses it, also the latest CTA, Washington, Pittsburgh, etc. equipment.
. . .
Daveklepper, thank you for bringing my early-Metroliner standard of knowledge more up to date. Things are starting to make more sense now . . . even though what I know about electricity could still fit in Reddy Kilowatt's left glove, I am slowly learning, in large part because of helpful advice from people like you. Thanks again for taking the time.
This reminds me that I ought to start traveling to check out the newer systems, now that I have more time. The theoretical often goes down better when it is preceded by the actual! Sadly, I don't think I've been on any public transit system post-MARTA: Tri-Met, the Miami system, Mpls., Calgary, St. Louis and so on -- all virgin territory --I've gotta to some of them!
Just for the [Hades] of it, does anyone out there know where the fastest American LRT lines are? My guess would be that the winner would have the latest technology and also the fewest stops en route -- or is there a clear winner here? Something to think about. - And since these preceding two paragraphs are really a new topic, I'm going to start a thread. I welcome and answer all I.M.s. -- a. s. (al-in-chgo)
Some use this motor in an inside-out manner built into the wheel as a wheel-motor or hub-motor. This is true of some Stadler equipment and some Alsthom equipment, and makes possible a 100% low-floor streetcar or LRV with a low aisle continuing between the powered wheels. Independent suspension of each wheel or virtual truck with a low bolster pvioting under the floor are both possibilities. Las Vegas' Max line has diesel electric articulated buses using this concept.
There is also a varient of this scheme with rotating permanent magnets instead of coils. The manufacturers of these motors are Energy Storage Systems in Derby, England, and Magnet Motor, in Pressburg, Germany. Trolleybuses and low-floor airport diesel electric buses in Europe are the main use but Energy Storage Systems makes a remote controlled tiny railroad shop switcher that is in wide use and is attemting to enter the railcar supply market.
Maybe I shouldn't butt in after all these months of inactivity on this thread, but I think in some of the posts above, a mixing of terms between what constitutes a trolley physically, where and how often it can stop, and what constitutes a proper trolley speed is muddling things a bit.
Take the Karlsruhe, Germany trolley system, which I've ridden. It's a nice set-up even if the fares are a little stiff. Or take their three-car conjoined trainset cousins in Vienna*. Or take San Francisco's Muni Metro, or the San Diego trolley, or L.A.'s east (Blue? Line--not the subway). Also take Toronto's streetcars (I don't know if Canadians officially use the term "trolley" car, though I feel sure they'd recognize it. The trolley is just a part of the main, the pole that gets the juice from the catenary down to the motor, which makes it a kind of living anachronism in the day of the folding pantagraph for even local traffic). If you asked most Americans what a "trolley" is, probably most of them would think first of the clang, clang, clang version. But "trolley" is this country has slowly come to mean as well "beverage cart" as on an airplane, or (and this really kills me) those rubber-tired tourist "trolleys" that are really just open-air buses in disguise, hauling out-of-towners about the downtown area. Don't even get me started on the pseudo-Britannic use of "tram" in places like Las Vegas. *The German word for streetcar or streetcar system is "Strassenbahn," literally "street (rail)way." I don't know if Siemens or ABB or the other European manufacturers have had to concoct a more modern word; but "Strassenbahn" will hold no matter how antique or modern the rolling stock is. Besides, they've used pantagraph collectors, just like electrified rail lines, for generations; so they don't have to worry about that metonymy "trolley."
The Karlsruhe system runs from the country into the city. Vienna's "trolleys," like those of the Muni Metro, duck underground for a while downtown (or at busy intersections) and then emerge to run on the streets like the streetcar systems any good-sized American or Western European town had by ca. 1920. San Diego is an excellent example of what a (primarily) German expertise can do for us here at home wish a fresh start and with about half the stops of the buses they replaced eliminated, in favor of open-air stations with ticket machines (and of course running times much faster). Canada hasn't given up on the use of the term "streetcar," and I'm curious to see how much, physically, the proposed light rail lines are similar to the TTC's vast network of streetcars. The Blue(?) L.A. line goes that one better with dedicated and usually elevated rights-of-way and more elaborate stations as well as automatic ticketing.
Here's my point: technique and tradition may argue for different semantics, but all the cars or trainsets above are brothers under the skin. They are "light rail" in the sense of being relatively lightweight on the rails and therefore not needing the well-over-100-lb. track that is now pretty much the norm for conventional passenger and freight. Also, they all use the same or very similar DC induction motors, which are best at overcoming inertia. Another way of saying this is that streetcars, LRV's or whatchamacallits haul off blazingly from a full stop (0 mph), but gradually lose that efficiency as speed grows, to the point where somewhere around 45 mph (metric 80 kph), they reach an effective top speed. That's probably why some of the above posts offer these speed ranges or their approximates as canonical limit of forward speed. Pre-cybernetics, the motorman's controller would usually define "full speed" as something below the highest possible cruising speed, in order to avoid overheating. In this day of solid-state and cybernetics, I suspect any such governing is more subtle and sophisticated. But this genre of rail public transit (and also most trolleybuses) can push you back in your seat after getting the green light but eventually strain their utmost at parkway speeds or less.
That's why Toronto's streetcars are still plying the streets. From the Sixties until the mid-Nineties, a regular TTC streetcar, even PCC vintage, could race the fastest car from one traffic light to the next -- and would always win, at least until the Porsche Cayenne came along about ten years ago. That's a Porsche in top condition with manual gears and a professional driver. But as good as 100 percent of the time up there, it isn't the streetcar that slows traffic; if anything, its the traffic slows the streetcars. It will be interesting to see how different Toronto's proposed LRT electrics will resemble the by-now "classic" streetcars of the TTC.
Again, in our case it's not so much the need creating the technology as the technology determining the need, or at least begging the kind of infrastructure speedy and efficient light rail demands. Something with a quick getaway but with the ability to stop fairly easily -- but for the sake of overall speed and the passenger's tummies and lumbar vertebrae, not too often. You can see this very clearly in the San Diego system as an improvement over buses and in the L.A. Blue(?) line, which behaves as much as possible like a Elevated or a commuter railway with its relatively few stops. Again, trolleybuses also have much the same energetic starts but middle-range bog down, because they use similar motors.
By these criteria, of course, other "light-rail"-ish candidates emerge: The Shaker Heights Trolley. NJT's diesel LRT. Moreover, again IMHO it's not so much the need creating the technology (ninety percent of what we know about traction we knew by 1915) as the technology determining the need, or at least begging the kind of infrastructural format to offer the most utilitarian combination of speed, service and stopping-places. Something with a quick getaway but with the ability to stop fairly easily -- but for the sake of overall speed and the passenger's tummies and lumbar vertebrae, not too often. You can see this very clearly in the San Diego trolley and to a lesser extent in the others light-rail getups. Also in trolleybuses to some extent because they use very similar motors.
Now if some transit official claimed that his jurisdiction's pantagraph-updated streetcar type of LRVs can reach a speed of 100 mph, he is mistaken. Even the New Jersey diesel LRT can't reach 100 mph. Perhaps he meant that the rail is so heavy it could keep (the right kind of) a train on the tracks at such high speeds. Certainly all manner of rapid-transit, and commuter equipment, gets assigned to the "heavy rail" category. On the one hand, we have the lighter kind of heavy rail: the Brilliners, current CSS&SB interurbans, Chicago's "L", Vienna's "Stadtbahn" ("city rail," which is also elevated and which reminds us that certain kinds of rapid transit, like L or Stadtbahn, are not a strictly suburb-to-city affair). Usually (not always) it is possible to distingish them from heavy heavy rail (BART and the Washington Metro, both built by Bechtel; the New York subway system; Cleveland's rail link to the airport).
Notice that the lighter type of heavy-rail has the advatages of stopping quickly and efficiently relative to the really heavy stuff, but they can't stop all that often for fear of compromising speed, an argument well-made in earlier posts to this thread. Light heavy-rail can cruise much faster than LRT: it is no surprise that the types of motor they employ include legendary modes like the Brilliners or the Chgo-Milwaukee Electroliners, which could hit 85 without breathing hard back in the late 1930s. Even so, it's still a challenge to get this kind of m.u. above about 85-90 mph; notice that in this country in the late 1960s the (heavy heavy rail) Metroliner rarely succeded in cruising at 110 mph with the occasional burst to 125, its stated intention. You'll also notice those original Metroliners were adaptations of suburban m.u.'s, with no locomotive, and their points got blasted so often that it wasn't unusual to see Raymond Loewy's 1930s deco-style GG-1's hauling a fritzed-out Metroliner m.u. or lead unit off to repair.
The advantages of an interurban are that even though it shouldn't stop as often as a streetcar, it can when necessary (think of South Shore Line's street running in Michigan City). And, over a distance, their superior speed (which can reach almost twice that of the simple-trolley category) comes to dominate over time and distance. I think of the South Shore Line's voluntary flag-stops in the dunes segment of the rwy are brilliant: "Passengers use light at night," so no more time is wasted accelerating and decelerating than is necessary.
Another similar but fun argument is to get into distinctions between commuter-based heavy rapid transit (BART) and railroad-based commutation (Metro-North, and notice that they both get energy from a shoe, so means of propulsion alone does not determine). Up until a year or two ago the (ex-IC) Metra Electric line from Randolph St./Chicago down to Governor's State University was the duckbilled-platypus of American rail commutation: fixed schedules but trains run more frequently than its other, diesel-based Metra brethren. Skip-stop or express service, though that could belong to either kind of heavy rail. Tickets bought from machines that were in essence an earlier generation of the "now you may pass" turnstiles like New York subways after the imposition of farecarding. But then Metra closed the ticket machines, brought in more trainmen to check the paper tickets that are rated by zone and can be bought from any Metra vendor throughout the whole system -- so that now, the IC-electric is simply the juiced version of any Metra diesel. - a.s.
Going 100 MPH between Mpls and St.Paul might be possible, but wouldn't make much sense, since they're only about 9 mi. apart (downtown to downtown). There probably aren't going to be any nonstop trains, trains will be making several stops along the way (as they do now between DT Mpls and the Mall of America).
High speed makes more sense for interurban runs - Chicago to Milwaukee for example.
top speed of a normal pcc under load was about 48 mph. in additon to fast acceleration and braking, the latter 4.5 miles per hour per second using the magnetic track brakes, for emergency braking, the pcc was somewhat faster in top speed than most of the older cars it replaced. A typical double-truck birney or other four motored lighweight had four 35hp motors, while a pcc had four 55 hp motors and was just as light if not lighter. a typical double truck lightweight had a top speed of about 35 or 40 mph. then there were the vast fleets of old wood semiconvertables and convertables with only two motors, having a top speed of about 25 or 30 mph. single-truck birneys were somewhere between the two. of course cars designed for interurban service, like the bullets, the red devils, and the indiana high speeds, plus some older heavier cars like the north shore's, were far faster, having balancing speeds of about 80 mph, and having possibilities of even faster running under the most favorable conditions.
does anyone know for certain if the interurban pcc's, pittsburgh railways' charleroi and washington lines, and the pacific electric, had different gearing for higher top speeds and slightly less acceleration? trucks were slightly different. the red arrow postwar lighweights, with pcc style bodies but without resilient wheels, pcc control, and with mcb type drop equalizer trucks, built by st louis in 1949, were not pccs but used the same motors. but their gearing was different and they had a 55 mph top speed.
One of the readers mentioned Karlsruhe, in Germany. They indeed run light and heavy on one set of rails.
The Stadtbahn (city trams) go in town and out to the suburbs and beyond. We were clipping along around 150 kmh (90 mph) through Rastatt to Baden-Baden. The Regiobahn (regional) do not stop at all the small stations like the S-Bahn does. They move out real well.
A side note, I rode the IC and the ICE trains a lot for the month I was in Germany. One ICE went from Frankfurt to Mannheim to Saarbrucken and then to Paris. The digital reader was showing a sustained speed of 280 kmh (175 mph) through France. That was rocking!
In Prague, and then back to Mannheim, the EC trains went along around 120 mph. Europe has been maintaining and upgrading for years, from the S-Bahn up to the ICE-5. They look to the future, while here in the US we complain about the traffic.
Munich, Hamburg, Berlin, and a few other cities have remarkable S- and U-Bahn (subway) systems. Karlsruhe Modell (German for model) have been the examples for a lot of cities getting into urban rail. It works well when politicians stay out of the way.
Enjoy the rails.
Generally, light rail tries to save time by quicker acceleration and deceleration. Typically, the industry recommends 3 miles per hour per second as the upper limit for passenger comfort. In other words, it would take 10 seconds to get to 30 (or ten seconds to stop from 30 mph). However, there is only a certain amount of horsepower, most light rail vehicles can't reach 60 mph in 20 seconds. It's more like 40 or 50 seconds.
Speeds above 50 mph are usually only practical if there is a private right of way (no grade crossings), a long distance between stations (2+ miles) and double track (single track may be practical for the last 5 miles of a line.) But, Light Rail is generally driven by costs, and grade crossings are a lot cheaper than tunnels or elevated structures. And, costs dictate that a new light rail vehicle be similar to existing ones. Which are usually 60 MPH, max.
HiWire wrote: Most light rail in the US is limited to 55mph by regulation I believe. Also there is probably a current practical limit for operation of low floor cars. Without the solid center axles, some cars feel like they are hunting across track at 55mph. I have noticed this in Portland OR. The older high floor cars with regular solid axles seem to run smoother at those speeds on the same tracks.Ron
Most light rail in the US is limited to 55mph by regulation I believe.
Also there is probably a current practical limit for operation of low floor cars. Without the solid center axles, some cars feel like they are hunting across track at 55mph. I have noticed this in Portland OR. The older high floor cars with regular solid axles seem to run smoother at those speeds on the same tracks.
Ron
There is one piece of track on the Rotterdam, the Netherlands, tramway system on my regular commuting route where an operator of RET's Alstom Citadis type LRV's can go easily 70 kph and can push 80 if he or she has a mind to do it (the speed scale goes into the red after 80).
The Citadis type cars have a low floor and accelerate and decelerate rapidly. I have not detected any notable hunting. This in contrast with the older high floor cars of RET series 700 or 800 (build and rebuild by BN of Belgium I believe). They shake and rattle on that piece of track when running fast and I always have the feeling they will come of the track.
Rather than topspeed, wouldn't quick acceleration and deceleration be more usefull?
greetings,
Marc Immeker
Morning everyone.
From what I have read and seem from just skimming, I think I need to bring up the Dallas Area Rapid Transit system (DART). Our light rail trains are rated over 120 mph. Although these light rail trains mainly run in the city there main line max speed is 65 mph. There is no reason at this time to ever get the light rail up to 100 mph. From riding the Dart system it is a great thing to have, but with the operators that are operating the trains, I would not trust riding with some of them. Even at 65 and 70 mph the light rail trains are ruff. I am not sure what the cause for this is, but I dont trust them over 70 mph. I am currently working for DART, and plan to go and start operating the light rail trains, so I will up date more often.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
As a child in Philly I remember several thrillingly high speed rides on the Red Arrow Lines interurban trolleys to the west of Philly. I understand that SEPTA still uses those same right of ways for, I believe, regional rail. Is this correct? If so, what kind of speeds do they hit?
Jack
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