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Post by lexlexlex on Feb 20, 2010 9:37:26 GMT -8
I do apologize if this is a silly question, but I can't find the answer anywhere and thought someone here might know:
If one were to add a catenary wire to the top of a red line/heavy rail tunnel, could light rail vehicles use the tracks and/or stations? Is the rail gauge the same? Is the platform height and track distance within acceptable limits?
I ask because more and more, it would seem to make sense to share tracks. For example: where the proposed Crenshaw line could conceivably tie in with the Red line at Wilshire.
Anybody?
BTW, I am in Germany for about six months on business and they have driverless subway trains here - with large front windows. Kids love them! (and I'm rather fond of it myself.) I'll post some pics later.
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Post by bluelineshawn on Feb 20, 2010 10:01:37 GMT -8
No, because the light rail trains are over a foot narrower than the subway trains. There would be a large gap at the platform. Plus even thought they are shorter I think that the pantograph, plus wire would be too tall for the subway tunnels as constructed.
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Post by lexlexlex on Feb 20, 2010 10:13:21 GMT -8
OK, well if one were to consider this possibility, could you envision a situation where some sort of conveyance extends from either the train or the platform? Here in Germany they have this thing that pops out of the side of the train at a stop, completely closing the gap and allowing you to roll luggage or wheelchairs with no danger of slipping. As for the pantograph, I have seen those things collapse completely - see this pic: en.wikipedia.org/wiki/File:Overhead_rail_P1220601.jpgEven if it were not possible now, with modification could it be achieved? Perhaps going forward with the new stretch of the red line? It just seems a shame that we have two different types of rolling stock - very limiting in some respects and I'm sure, expensive: more parts to keep in stock, techs to train, etc
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Post by jeisenbe on Feb 20, 2010 23:23:30 GMT -8
Our current LRT vehicles cannot work on the Red/Purple line tracks due to the different platforms, as bluelineshaw mentioned. Even with new vehicles with ramps at the doors, the different platform height might make it problematic to share platforms. The cantenary could probably be replaced with an overhead beam in the tunnels, however.
I would question the need to share the tracks, even in the distant future. The Crenshaw line is really a cross-town route, and would be most useful if extended north to Hollywood rather than turning at Wilshire. With high expected ridership on the Wilshire Metro line (Purple line) in the future after the extensions to Santa Monica and thru West Hollwood are built, there will not be enough space in the schedule for another line to share the tracks at rush hour. Passengers headed to Downtown LA or the Westside would be able to transfer.
If you are imagining a system with light rail heading east-west from Hollywood or in the mid-Wilshire area, it might make sense to plan for new routes. Santa Monica Blvd and Venice Blvd could both have the density to support a new rail line in the future.
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Post by jeisenbe on Feb 20, 2010 23:44:08 GMT -8
The main reason for having "Light" rail and "Heavy" rail here is that the "Light" trains are designed to operate on street medians with tight turns, short blocks and ungated crossings, as well as with exclusive right of way. They also are designed to carry fewer passengers in the peak hour. For example, the loop in Long Beach could not be easily negotiated by a "Heavy" metrorail train due to the tight turns, 100 meter blocks and somewhat narrow streets. The subway trains work well on grade-separated lines with long stations and no sharp turns. So it makes sense for LA to have both types of trains.
If we could upgrade trains and stations, I would vote to change the Red, Purple and Green lines to automated operation, like the Vancouver Skytrain or the new Paris Metro lines, so we could have higher frequencies throughout the day, and even late at night. Since we already paid for fully grade-separated routes, we might as well set up operational savings in the future. Upgrading the light rail lines to metrorail/heavy rail standards would be much more expensive and would only have a small effect on speed, though reliability would improve. In fact, I wonder why our subway and the Green Line were not planned to be automated from the start, since the technology was already proved and working elsewhere with good results.
(*LRT vehicles are often heavier than metrorail venhicles, due to articulation points and multiple operator cabs, so I'm told.)
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Post by ieko on Feb 21, 2010 1:35:28 GMT -8
The main reason for having "Light" rail and "Heavy" rail here is that the "Light" trains are designed to operate on street medians with tight turns, short blocks and ungated crossings, as well as with exclusive right of way. They also are designed to carry fewer passengers in the peak hour. For example, the loop in Long Beach could not be easily negotiated by a "Heavy" metrorail train due to the tight turns, 100 meter blocks and somewhat narrow streets. The subway trains work well on grade-separated lines with long stations and no sharp turns. So it makes sense for LA to have both types of trains. If we could upgrade trains and stations, I would vote to change the Red, Purple and Green lines to automated operation, like the Vancouver Skytrain or the new Paris Metro lines, so we could have higher frequencies throughout the day, and even late at night. Since we already paid for fully grade-separated routes, we might as well set up operational savings in the future. Upgrading the light rail lines to metrorail/heavy rail standards would be much more expensive and would only have a small effect on speed, though reliability would improve. In fact, I wonder why our subway and the Green Line were not planned to be automated from the start, since the technology was already proved and working elsewhere with good results. (*LRT vehicles are often heavier than metrorail venhicles, due to articulation points and multiple operator cabs, so I'm told.) I think the Green Line was planned to be automated but then someone somewhere became angry. I think the Green Line would benefit the most if the trains were to become automated because you'd likely need to install Platform Screen Doors. Waiting on a freeway/elevated platform would such a better experience if we had those right now.
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Post by bobdavis on Feb 21, 2010 1:44:36 GMT -8
The Green Line was originally planned to be "driverless", as I recall, Siemens cars MTA 301 and 302 (usually used on the Gold Line) were to be "test bed" cars for automated operation. They were refitted to match the 200-series cars, and any modifications for driverless operation were reportedly removed. Pressure from the transit operators' union, and general misgivings among Metro and local politicians about the suitability of driverless operation for the Los Angeles environment were given as the reasons for dumping the idea. Does anybody have specifications for the "light" and "heavy" cars that would confirm or correct the comment about their relative weights? Both gross weight of cars and weight per passenger would be useful.
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Post by Justin Walker on Feb 21, 2010 4:39:01 GMT -8
It just seems a shame that we have two different types of rolling stock - very limiting in some respects and I'm sure, expensive: more parts to keep in stock, techs to train, etc Such a disconnect partly stems from the Red Line and Blue Line having been constructed by what were largely rival agencies... Many years later, we are stuck with their decisions. As I posted in an earlier thread, it was originally planned to have the proto-Blue Line interline with the proto-Red Line. The difference then, however, was that both were to have been heavy rail. It isn't necessarily bad the systems ended up apart; interlining would have meant longer headways for individual lines. Once we have the Regional Connector, we'll have two strong rail corridors through downtown rather than funneling several rail lines into one corridor (a la SF's Market Street). I think the Green Line was planned to be automated but then someone somewhere became angry. Way back when they nixed Green Line automation, Metro claimed that "ridership projections...through FY 2015 do not warrant a reduction in headway to the point of justifying automated operation." They lay out all the pros and cons of automation they considered in this 1995 board report. Does anybody have specifications for the "light" and "heavy" cars that would confirm or correct the comment about their relative weights? Both gross weight of cars and weight per passenger would be useful. According to Elson Trinidad's site, the Red Line cars each weigh 82,000 lbs and the Blue Line cars each weight 94,000 lbs. Normalizing the weights for length, I get: -Red Line- 1,093 lb/ft -Blue Line- 1,044 lb/ft (Weight per passenger would depend on which passenger counts I use.)
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Post by bluelineshawn on Feb 21, 2010 13:54:23 GMT -8
If we could upgrade trains and stations, I would vote to change the Red, Purple and Green lines to automated operation... The red and purple lines have been running under ATO for over a year. Not sure about the green line, but if anyone rides they can can look in the cab and see.
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Post by bluelineshawn on Feb 21, 2010 14:07:52 GMT -8
Elson's weights don't take into account that there are two types of cars (with and without cabs). Also "light" and "heavy" have more to do with type of car, grade separation, and maximum passenger loading and not really the physical weight of the car. Using light rail vehicles will be enough to label a line "light rail" even when it is completely grade separated like the green line.
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Post by Justin Walker on Feb 21, 2010 17:43:47 GMT -8
Elson's weights don't take into account that there are two types of cars (with and without cabs). I'm not sure I understand what you're getting at. All the Red Line and Blue Line cars are essentially identical. The Red Line cars each have a cab at one end and the Blue Line cars each have a cab at both ends.
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Post by bluelineshawn on Feb 21, 2010 18:22:42 GMT -8
Elson's weights don't take into account that there are two types of cars (with and without cabs). I'm not sure I understand what you're getting at. All the Red Line and Blue Line cars are essentially identical. The Red Line cars each have a cab at one end and the Blue Line cars each have a cab at both ends. My mistake.
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Post by bobdavis on Feb 21, 2010 20:40:14 GMT -8
I think the Red Line cars normally operate in "married pairs", although they can be uncoupled at the shops, so you don't always see two cars back to back with consecutive numbers. "Light Rail" cars in most systems are articulated with two car bodies sharing a center truck. As far as incompatibility between lines, I think Boston holds the record, with four different series of cars for four different lines. New York has narrower, shorter cars for the ex-IRT lines, while the ex-IND lines share dimensions with the ex-BMT. Philly even has two different gauges in the SEPTA system. Chicago is more rational; any car can run on any line, but it took a while; some lines ran with mostly with third-rail and switched to trolley poles at the outer ends.
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Post by pithecanthropus on Sept 28, 2010 22:45:23 GMT -8
Elson's weights don't take into account that there are two types of cars (with and without cabs). I'm not sure I understand what you're getting at. All the Red Line and Blue Line cars are essentially identical. The Red Line cars each have a cab at one end and the Blue Line cars each have a cab at both ends. Really? I haven't been on any of the trains for nine months, but I thought the the Red Line cars were noticeably wider, and certainly heavier than the Blue Line cars. The peculiar, the odd, the giggle-inducing. Wandering In L.A
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Post by Justin Walker on Sept 28, 2010 23:15:48 GMT -8
I'm not sure I understand what you're getting at. All the Red Line and Blue Line cars are essentially identical. The Red Line cars each have a cab at one end and the Blue Line cars each have a cab at both ends. Really? I haven't been on any of the trains for nine months, but I thought the the Red Line cars were noticeably wider, and certainly heavier than the Blue Line cars. The Red Line cars are certainly not the same as the Blue Line cars. What I meant (and wasn't sufficiently clear about) was that all the Red Line cars are identical and all the Blue Line cars are identical (but not to each other).
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Post by trackman on Sept 29, 2010 5:28:27 GMT -8
No. Red Line cars are wider, shorter, faster and DO NOT have a cab on each end (although married-pairs do). Married pairs are 150 feet long.
Blue Line cars ARE NOT identical to each other as several different models are operated on the line. They are also taller and have roof top equipment - pantograghs, AC, etc.
Floor heights may also be different, although each are considered high level boarding.
Nevertheless, Red Line tunnels may be to small to fit light-rail cars, pantographs, and include the over-head contact systems.
The two systems are incompatible.
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Post by James Fujita on Sept 29, 2010 10:54:36 GMT -8
Part of the confusion may stem from the fact that you can run light rail trains in subway tunnels. That is what we are attempting to do with the Regional Connector (underground light rail) and that is what they do on Market Street in San Francisco with Muni Metro on top of BART. A similar situation exists underneath Aoyama Dori in Tokyo with the Ginza (3rd rail) and Hanzomon (pantograph) lines. You could dig a light rail tunnel underneath or alongside the Red Line on Wilshire, but you could never run the two different kinds of trains in one tunnel. That's probably just as well, as we are quickly discovering with the Regional Connector the disadvantages of having too many routes share the same tracks.
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Post by Gokhan on Sept 29, 2010 11:19:15 GMT -8
Los Angeles LRVs are 8.7-ft-wide and have a platform height of 3-1/4 ft from top of rail. Los Angeles subway cars are 10-ft-wide. I don't know their platform height. If the platform heights are the same, you would still have to use some extenders to fill the short gap to maintain ADA compatibility.
In addition you would have to install overhead wires (assuming there is sufficient clearance) and probably install new train-control equipment on the LRVs.
So, it would be rather difficult, if not impossible.
But certainly you can run any railroad vehicle on any railroad tracks (subway, freight, light-rail) as long as they have the same track gauge. And the track gauge is standard (4 ft 8.5 in) throughout Los Angeles. That doesn't mean that though it's practical to do so, as I explained above.
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Post by James Fujita on Sept 29, 2010 12:28:01 GMT -8
But certainly you can run any railroad vehicle on any railroad tracks (subway, freight, light-rail) as long as they have the same track gauge. And the track gauge is standard (4 ft 8.5 in) throughout Los Angeles. That doesn't mean that though it's practical to do so, as I explained above. I'm sorry, but I can't read this without cracking up. Because the little kid in me wants to see if a standard-size boxcar can fit into the Red Line tunnel. ;D (Probably not a hi-cube boxcar, but I betcha you could squeeze an old-time cattle car into the subway. Just add "platform extenders". High-capacity! Lower costs! )
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Post by Justin Walker on Sept 29, 2010 17:19:46 GMT -8
Los Angeles LRVs are 8.7-ft-wide and have a platform height of 3-1/4 ft from top of rail. Los Angeles subway cars are 10-ft-wide. I don't know their platform height. FYI, the height of our subway car floors is 44.7 inches above the top of the rails.
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Post by bobdavis on Sept 29, 2010 18:50:55 GMT -8
There are two different gauges used in specifying railway cars: Track gauge and loading gauge. Track gauge is the distance between the inner faces of the rails. Everything presently running in Southern California is "standard gauge" (56.5 inches), unless you include the steam railroads at Knott's and Disneyland, which are 36" gauge. Orange Empire Railway Museum has preserved LA Railway cars that are 42" gauge. Loading gauge is the measurement of clearance of wayside structures, tunnels, etc. I tell the story of the time my daughter visited England for a "semester abroad" at a college near Oxford. One of the first things she did was go to the local railway station to check out the action. Along came a British Railways passenger train, like something out of a PBS "Mystery", and she had to restrain herself from saying, "This is cute, but where do you keep your full-size trains?" American locomotive builders have had some success selling diesels to British operators, but they have to be specially engineered to fit in tunnels that were excavated over 150 years ago. When the Gold Line opened, more than one railfan harked back to the days when Santa Fe executives would park their business cars in Pasadena for the Rose Parade, and wondered if this could be done with the new line. I replied that there is a connection to the Metrolink track near the maintenance facility, but main line railroad cars would get to Chinatown or the Ave. 26 platform, and there would be an awful crash as wide car met narrow platform. Had we not had so many different governmental entities involved, it might have been possible to design an LA Metro system that used one standard of cars. Since all the LA light rail lines have high platform loading, it wouldn't have been that difficult to build them to the same loading gauge as the Red Line, and use one type of car. Pacific Electric used to run main-line-railroad-sized "Blimps" on the streets of Long Beach, so it's not like there wasn't enough room for wider cars. Seems like we alway have to do things the hard way here in California. (oh, well, nobody elected me Supreme Potentate and All-Seeing Philosopher-King)
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Post by Gokhan on Sept 30, 2010 13:40:56 GMT -8
Los Angeles LRVs are 8.7-ft-wide and have a platform height of 3-1/4 ft from top of rail. Los Angeles subway cars are 10-ft-wide. I don't know their platform height. FYI, the height of our subway car floors is 44.7 inches above the top of the rails. Hmm, that's a very uneven number. That is 5.7 in more than the light-rail's 39.0 in. An easy solution to run both light-rail and subway cars in the same tunnels and using the same platforms would be to install a new pair of tracks for light-rail cars next to the subway tracks that are 5.7 in higher and 7.8 in offset sideways toward the platform. But then there is little reason to run the light-rail cars in the Red or Purple Line tunnels and stations if any. This tunnels can barely take the Red and Purple Line traffic, let alone several times more traffic on top of that. The long story short, we would still need the Downtown Connector even if you modified the Red Line tunnels to coexist with light-rail.
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Post by James Fujita on Oct 2, 2010 11:59:26 GMT -8
FYI, the height of our subway car floors is 44.7 inches above the top of the rails. Hmm, that's a very uneven number. That is 5.7 in more than the light-rail's 39.0 in. An easy solution to run both light-rail and subway cars in the same tunnels and using the same platforms would be to install a new pair of tracks for light-rail cars next to the subway tracks that are 5.7 in higher and 7.8 in offset sideways toward the platform. But then there is little reason to run the light-rail cars in the Red or Purple Line tunnels and stations if any. This tunnels can barely take the Red and Purple Line traffic, let alone several times more traffic on top of that. The long story short, we would still need the Downtown Connector even if you modified the Red Line tunnels to coexist with light-rail. You know, I think Gokhan's got it exactly right. Having a "standard car" or making sure that the platforms line up right or that the tunnels or the right width or the right turning ratios would be nice. But that's not nearly as important as making sure that the system works efficiently to make sure that people can get to their destination quickly. One obvious way to do that would be to limit branches and LIMIT, not expand, opprtunities for rail lines to interconnect. Every "multi-purpose" line has to divide up service by the number of lines that it serves. In other words, more time spent waiting for the right train to show up. I think the Regional Connector is great, but at the same time, I think we may ultimately find that its greatest strength is not in its ability to connect Pasadena with Long Beach, as useful as that may be, but rather in its ability to get people to Bunker Hill or to the Financial District (which is why I really hope that station doesn't get cut). [ I predict it will also get a lot of "convention center shuttle" traffic as visitors go from Pico to the Bonaventure or other hotels. ] All Muni Metro trains end up underneath Market Street. That makes sense, because of the geography of the city and the density of Market. But it is also annoying to wait for a J-Church train when all the trains seem to be headed for Ocean Beach. Tokyo, interestingly, has several different track gauges at work. Subway train lines do interconnect with commuter train lines, but that typically occurs at the "end of the line," out in the suburbs. Even then, the subway train often operates as the local service, while the parallel limited/ express train pulls up to a different platform. Within the Yamanote loop, each individual subway line is completely separate from the others, and Tokyo has 13 of them.
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