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Post by Gokhan on Jan 30, 2009 9:28:18 GMT -8
Sorry to be argumentative, but a few years ago I had an epiphany that this Valley-Westside line would probably have to be a subway of some sort to get quickly through the Sepulveda pass. I've not yet changed my opinion. So, perhaps a light-rail line with a bored subway section under the mountains, like the Eastside Light-Rail Line with a bored section under Boyle Heights?
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gregd
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Posts: 17
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Post by gregd on Jan 30, 2009 11:38:28 GMT -8
I'm curious why a subway would be required. Could an above grade line be installed right along the hillside straight up the 405 frwy? There seems to be quite a bit of hillside and open space? Is it an engineering problem to intalls supports along a hillside?
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Post by Gokhan on Jan 30, 2009 16:12:09 GMT -8
I'm curious why a subway would be required. Could an above grade line be installed right along the hillside straight up the 405 frwy? There seems to be quite a bit of hillside and open space? Is it an engineering problem to intalls supports along a hillside? I've checked the grade of the 405 freeway on NavigateLa.lacity.org. It's 4% on the south and 5.5% on the north side of the hill. Typical grade for the LRT underpass/overpass ramps is 4%. They sometimes go up to 4.5% and I guess they could go a little higher. But this is near the borderline. Also, anything above 5.0% is not ADA-compliant. Moreover, I don't know if the LRVs and/or the traction power substations have the enough juice. You certainly have difficulty with braking downhill as well. One good thing about electric trains is though, they generate the exact same amount of electricity when they go downhill in comparison to the electricity they consume uphill. In that sense if there are two trains, one going downhill and the other uphill, the downhill train would generate all the electricity the uphill train needs. Note that this is the same way regenerative braking works. On the other hand, a tunnel would be at least a mile shorter, saving distance both vertically and horizontally, and probably not that much more expensive, if not cheaper, since there would be no stations under the hills. The single most expensive part of the subways are the stations, which are giant underground structures. Tunnel boring is hardly expensive.
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Post by kenalpern on Jan 30, 2009 17:46:22 GMT -8
Gokhan, I really and truly do not know if a LRT that has a subway segment (like the Eastside LRT project) is needed, or a HRT is needed with a higher capacity. All I know is that if we had a FAST train between Wilshire/Westwood and UCLA and the Expo Line on one side, and the Valley on the other side, people would use it.
Hence the desire for a high-capacity HRT is what I lean to...yet there may be regions between the Expo and Purple Lines, and regions south of the Expo Line that would do well with street-level or elevated lines which favor LRT.
Overall, however, a speedy line that went under the very busy (and relatively narrow) Sepulveda Blvd. would, to my way of thinking, probably require underground operations as the ideal way to carry many people fast between the Valley and LAX.
If someone put a gun to my head and asked me to choose, I'd say HRT as a subway (like the Wilshire Subway). Since no one is putting that gun to my head, I'll just say I favor HRT but I'm open to partially-tunneled LRT.
I know that Darrell Clarke has put a lot of time and effort to establishing a LRT that is above ground and goes through the Sepulveda Pass adjacent to the 405 freeway. I just think that the underground route would be faster and utilized bigtime by a whole lotta commuters in ways that the above-ground plan never could.
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Post by darrell on Jan 30, 2009 18:36:52 GMT -8
I'm curious why a subway would be required. Could an above grade line be installed right along the hillside straight up the 405 frwy? There seems to be quite a bit of hillside and open space? Is it an engineering problem to intalls supports along a hillside? I've envisioned (as Ken cited) that a light rail right-of-way could be cut into the east side of the I-405 slopes over Sepulveda Pass. To cope with the steeper grade on the Valley side it could be on an aerial structure to stretch out the grade before finally coming down to ground level around the LA River. South of Sunset along the 405 (even for columns of an aerial structure), and especially getting across the Veterans Cemetery to a likely station at Wilshire & Veteran, would be a tight fit. Conversely that would be a significantly longer tunnel than the North Hollywood Red Line tunnel. I expect when they start studying this route -- which is on the Measure R list -- we'll know more about costs and feasibility.
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Post by JerardWright on Jan 30, 2009 21:12:54 GMT -8
... I really and truly do not know if a LRT that has a subway segment (like the Eastside LRT project) is needed, or a HRT is needed with a higher capacity. All I know is that if we had a FAST train between Wilshire/Westwood and UCLA and the Expo Line on one side, and the Valley on the other side, people would use it. Hence the desire for a high-capacity HRT is what I lean to...yet there may be regions between the Expo and Purple Lines, and regions south of the Expo Line that would do well with street-level or elevated lines which favor LRT. What is the difference between the Light Rail vehicles (LRV) that are in the tunnels and aerial structures compared to heavy rail vehicles (HRV)? They cost same to bore a tube and build the elevated structures. The only difference is their maximum train length at stations LRV's max out at around 270' or 3 car length @ 90' per railcar, The HRV's at 450' or 6 car length @ 75' per railcar. There is one way to do it that blends the two together, and to start thinking about it. We should consider a combination of both concepts by having a 'heavy LRT' with longer LRV trains at least 4 to 5 cars in length. I remember a thread on our old discussion board a while back about the differences between a 450' long light rail train (5 LRV's) and a 450' long heavy rail train (6 HRV's). The difference between the two was that the LRT had more seated capacity when at a 450' long train yet moved about the same (+/- 50 passsengers) of the full consist of the heavy rail trains used on the Red/Purple Line trains. Considering that at the south end we have the Green Line LRT infrastructure, in the mid section we have the Expo Line LRT and the north end we have the Orange Line and that may or may not get converted to rail. We may need these pieces of infrastructure for potential routing purposes and or the more likely scenario to share maintenance facilities. In key sections; such as between Van Nuys and Expo Line, we'll need a full length train to handle the demand (5 LRV cars); in other areas such as the Valley they can manage with at-grade running with shorter train lengths (2-3 LRV cars). The one element that will impact the feasibility of the options is the vehicles electrical power and where to locate the electrical substations.
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Post by ieko on Jan 30, 2009 22:51:23 GMT -8
Why not make this an entirely different line?
I think we really should look at the bigger picture here, there is a signifficant amount of people who travel north/south everyday on the 405 between Long Beach & the San Fernando Valley. If we keep going in the direction we're going we will end up with a service that is ineffecient for anyone who wants to travel between the regions.
For example, if someone wanted to travel from Long Beach to the Westside they'd have to take a harbor sub train, transfer to the crenshaw line, then transfer to an expo or a bus. That'll take much longer than driving... From my experiance whenever you have to transfer between trains you're going to end up there for at least 5-20 minutes depending on what time of day it is. That time spent waiting can be a serious deal breaker for many, both in the aspect of wasted time and in the general uncomfortably that can cause for someone who prefers their car but chose to use mass transit.
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Post by Gokhan on Jan 31, 2009 10:42:30 GMT -8
Comparison of LRT with HRTCapacity: 221 passengers per LRV 180 passengers per HRV 3-LRV train: 663 passengers 4-HRV train: 720 passengers 4-LRV train: 884 passengers 6-HRV train: 1080 passengers 5-LRV train: 1105 passengers Power supply: LRVs are fed with copper overhead catenary wires. HRVs are fed with steel third rail. Copper is much more conductive but much more expensive as well than steel. Conductivity for a given cross section varies directly proportional to the cross-sectional area. The conductivity you need depends on two factors: (1) How much power you need, which is determined by the top speed, hills, and number of L/HRVS. (2) How closely spaced your traction power substations are. That's because conductivity for a given length varies inversely proportional to the length. In summary, more and faster the LRVs, thicker the copper wide and more closely spaced the traction power substations. More and faster the HRVs, thicker the third rail and more closely spaced the traction power substations. In principle, you should be able to use either third rail (HRV) or overhead catenary (LRV) by varying the cross section of your wire or third rail and putting more closely spaced traction power substations. If you don't have thick enough wire or third rail or closely spaced substations, there will be too much voltage drop on the power line because of too little conductivity and/or too much electric current (Voltage = Current x Resistance = Current / Conductance) and the result will be LRVs or HRVs moving like turtles or stalling completely. Speed: LRVs in Los Angeles (Gold Line) are rated at 75 MPH and HRVs (Red Line) are rated at 70 MPH. But near the non-grade-separated sections, CPUC limits the speed to 55 MPH, regardless of whether you have LRV or HRV. So, basically there is not that much different between LRT or HRT systems. In fact, in Europe, they don't distinguish between LRT and HRT and they simply call them both "Metro." They do distinguish between high-capacity and high-speed LRT and HRT systems and low-capacity, 35 MPH, low-floor LRT systems. They call such systems "Tram." Hence, there is no light-rail or heavy-rail in Europe but only Metro vs. Tram. All Metro Rail Lines in Los Angeles would fit into the Metro category. We still don't have any low-floor, 35-MPH-throughout "Tram" lines in Los Angeles. LRT systems have considerable more flexibility and economic benefits. But the HRT systems have somewhat more capacity and speed, mainly because of complete grade separation, which is required as a result of the electrified third rail. This said, I would like to see LRT in this north - south line because: (1) This will help the BRT in the Valley to be converted to LRT one day. If they build the north - south line as HRT, this won't be compatible with LRT and it won't encourage the conversion of BRT to LRT in the Valley. (2) HRT would not be compatible with the Expo Line. (3) There is already HRT from the Valley to the LA Downtown and LA Westside, that is the Red Line and planned Red Line extension.
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Post by ieko on Jan 31, 2009 11:15:29 GMT -8
I don't really see a good reason to interface with the expo line unless you wanted to route trains to go from the San Fernando Valley directly into Santa Monica, but even then that seems unnecessary. Even if light rail connected to the Orange line wouldn't it be better to just extend the Red line? That seems like a better 'one seat ride' arrangement than an expo-orange line combination. At-grade HRT is very possible by the way, I've seen it done in Chicago and it seemed to work quite well, although I admit I'm not aware of all the details on the system.
Also, I'm worried that an LRT car wouldn't be insulated well enough to protect patrons from wind noise while going through a tunnel. A good example of this is the blue line going through to 7th st. Metro Center, it's really unbearable.
That being said LRT would be a good option for interfacing with lines south of expo, like the Crenshaw, Green, and Blue lines.
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Post by kenalpern on Jan 31, 2009 12:23:48 GMT -8
I'm not sure if I'm reading you right, ieko, but I don't see a problem with an underground or above ground train 405 Corridor train intersecting with the Expo Line at Exposition/Sepulveda any more than I'd have a problem with an intersection with the future Purple Line at Wilshire/Westwood.
It's still possible that an above-ground train like Darrell is proposing is the correct plan, but it would be interesting to see if we couldn't get more capacity with a LRT that had tunnel portions along the 405/Sepulveda Corridor.
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Post by darrell on Jan 31, 2009 14:14:54 GMT -8
Seattle is probably the "heaviest" new rail line using LRT equipment. Downtown Seattle will use the existing bus tunnel plus new tunnels, and if I recall, they plan for four-car trains. That and other lines are precedent for LRT tunnel sections.
I've imagined LRT over (or under) the Sepulveda Pass either turning west on Expo Line tracks, then south along the Lincoln corridor to the Green Line, or continuing south along the 405, again to run on Green Line tracks to the South Bay. Those are reasons for LRT equipment.
As long as the Purple Line may be extended west of Westwood it also seems a conflict to consider those trains turning north to the Valley.
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Post by Justin Walker on Jan 31, 2009 18:57:16 GMT -8
I have similar visions of the Sepulveda Pass line as LRT. I would expect the Green Line to run along the 405 up to the SFV and for the Crenshaw line to operate to the South Bay.
The exact operating plan, of course doesn't matter at this point in the game. Yet, most of us seem to agree that LRT would link up better with existing lines on the Westside.
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Post by ieko on Feb 1, 2009 23:39:55 GMT -8
I'm not sure if I'm reading you right, ieko, but I don't see a problem with an underground or above ground train 405 Corridor train intersecting with the Expo Line at Exposition/Sepulveda any more than I'd have a problem with an intersection with the future Purple Line at Wilshire/Westwood. It's still possible that an above-ground train like Darrell is proposing is the correct plan, but it would be interesting to see if we couldn't get more capacity with a LRT that had tunnel portions along the 405/Sepulveda Corridor. What I mean is this line should of course intersect with the purple & expo lines, but I don't believe it should be a part of them. I think the train should be underground, because I feel it'd be a real pain to put it above-grade or at-grade. Not to mention faster and probably need less power, I would like to see a Getty Station in any form though. LRT is the best overall option, but I just hope the cars they use are better protected from wind noise like I mentioned before. Hope that clears things up a bit.
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Post by kenalpern on Feb 2, 2009 4:45:09 GMT -8
Thanks, ieko. It sounds to me like we're all on the same page that LRT would be preferred, with a lot of underground and other grade separations. I imagine that a setup of four-car trains to carry the large load of riders would be critical to making this a cost-effective investment, and that the establishment of both an Expo and Wilshire line that reaches the 405 are precursors to this line becoming a reality.
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Post by JerardWright on Feb 2, 2009 14:25:53 GMT -8
Also, I'm worried that an LRT car wouldn't be insulated well enough to protect patrons from wind noise while going through a tunnel. A good example of this is the blue line going through to 7th st. Metro Center, it's really unbearable. Have you been on the Gold Line trains when they run between Del Mar and Memorial Park? They are fairly well insulated and not as loud.
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Post by bobdavis on Feb 2, 2009 15:00:25 GMT -8
When it comes to running "light rail" underground, let's not forget Boston--they've been running trolley cars underground on what is now their Green Line for over a hundred years. They also have their Blue Line, which runs high-platform subway-type (more or less "heavy rail") trains underground on third rail power downtown and at grade level with overhead wire starting around the Airport station. Regarding grades on electric railways: I'm not sure if any of the "light" or "heavy" cars in LA are designed for regenerative braking. Most light rail cars have dynamic braking, where the motors change to generators and the energy is dissipated in resistor grids (same as most diesel locomotives). Regenerative braking is much trickier to use in the real world; ideally trains will have a "virtual counterbalance" or "electric funicular" operation, but this requires special control systems in the trains and the substations. Also, if there are long, steady upgrades, this may require more robust motors to resist overheating, an argument for a "straight shot" tunnel under Sepulveda Pass. Regarding an underground station serving the Getty complex: Consider the Portland Zoo elevator on the MAX line, or Forest Hill in SF MuniLand.
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Post by ieko on Feb 2, 2009 18:22:52 GMT -8
Also, I'm worried that an LRT car wouldn't be insulated well enough to protect patrons from wind noise while going through a tunnel. A good example of this is the blue line going through to 7th st. Metro Center, it's really unbearable. Have you been on the Gold Line trains when they run between Del Mar and Memorial Park? They are fairly well insulated and not as loud. I have been in that tunnel on both the old and new cars and to be honest I can't recall much about it, if I remember correctly the Gold line didn't seem to go as fast as the Blue line in the tunnel, but I might be wrong. I'll have to check it out again to compare.
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Post by Gokhan on Feb 2, 2009 19:08:08 GMT -8
I know that the Red Line and any HRT in general is very noisy inside the train, because of the sound echoes from the narrow bored tunnels.
I don't remember the Blue Line inside the cut-and-cover section being any noisier than the Red Line -- the same for the other HRT and LRT lines I've ridden.
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Post by Gokhan on Feb 3, 2009 16:44:00 GMT -8
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Post by bluelineshawn on Feb 3, 2009 21:11:40 GMT -8
I made a point to conduct some unscientific noise surveys while riding the red and blue lines today. IMO the blue line is definitely louder underground than the red/purple lines. The red line is actually fairly quiet when not either crossing a switch or traversing a curve. The blue line is very loud, but is more or less similar to the red line while in the curve. But something else that I noticed was how the blue line makes noise. As the train travels the line it gets louder and louder. This is true from either direction. Then when power is cut back it immediately quiets. It's almost like the noise builds up like some sort of feedback loop. I don't know exactly what it is, but it's more than just an echo from the walls.
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gregd
New Member
Posts: 17
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Post by gregd on Feb 21, 2009 21:17:30 GMT -8
They could run the rail along the 405 east side up to about the getty exit. at that point go underground all the way to ventura blvd. seems like that would be the least instrusive to all the homeowners and probably the cheapest, easiest.
heck, if the valley residents who worked at ucla, century city, and the va would use it, it would be worth it for that alone. Just need to link it up properly.
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Post by ieko on Feb 21, 2009 23:42:40 GMT -8
Is there room for that? Seems like any room there may be now is going to be taken up by the northbound carpool lane when they get around to building it.
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