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Post by kenalpern on Nov 17, 2008 20:45:40 GMT -8
Jejozwik is correct--remember that Silver Line?
Something to think of when the Gold Lines are done. Remember: after Gold comes Silver!
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Post by crzwdjk on Nov 17, 2008 20:54:37 GMT -8
As far as I understand operations of EMUs, there's no particular reason that long trips need to be avoided. In fact, if you think about it, there's no difference between a train pulling in to 7th/Metro, taking a 30 second break, and continuing on its way versus going back the way it came. The real operational reason for avoiding long lines is service reliability, since delays tend to compound over a train's trip, though that can be dealt with by putting some recovery time in the schedules. As for actual service planning for through service, the main concerns are balancing load on opposite ends of the line, followed by catering to through riders and dealing with rolling stock allocation to depots.
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Post by bluelineshawn on Nov 17, 2008 21:56:09 GMT -8
Train A: Multiply 8 round trips times 120 stops = 960 times trains brake and accelerate Train B: Multiply 4 round trips times 120 stops = 480 times trains brake and accelerate. You misunderstood. Train A: 8 RT x 15 stops = 120 stops Train B: 4 RT x 30 stops = 120 stops I have no idea why you are characterizing shorter lines/runs as having twice as many stops per mile. That doesn't seem to be the case, but even if it were having two lines of equal length doesn't solve anything if one of the lines has twice as many stops per mile.
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Post by JerardWright on Nov 18, 2008 14:58:34 GMT -8
Train A: Multiply 8 round trips times 120 stops = 960 times trains brake and accelerate Train B: Multiply 4 round trips times 120 stops = 480 times trains brake and accelerate. You misunderstood. Train A: 8 RT x 15 stops = 120 stops Train B: 4 RT x 30 stops = 120 stops I have no idea why you are characterizing shorter lines/runs as having twice as many stops per mile. My mistake I misread how you worded it. Crzwdjk makes another point that I made in the earlier posts about schedule reliability, rider destination based on route and again maintenance because they have to budget the money and figure how many mechanics they'll need to service that line to keep it running smoothly and what parts they'll need to stock up on and how often they'll need maintenance.
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Post by crzwdjk on Nov 18, 2008 23:58:57 GMT -8
In terms of maintenance, what I really meant was that each line needs to have appropriate access to storage and inspection yards, preferably at the outer ends of the lines. That's why they're building the temporary storage and inspection facility for Expo, because awkward as that location is in terms of layout, it's still better than running trains back and forth to the Blue Line yard all the time. The reason for the outer end is to be able to start inbound service earlier. In terms of the light rail planned so far, I believe there's going to be a facility in Santa Monica for Expo, the Blue Line has its yard in Carson, Eastside has the Midway Yard, which isn't on the outer end, but it's a short enough line that it's not that huge of a problem. And the Pasadena Gold Line will presumably get extended to Irwindale eventually, where there's room for a relatively big yard, because the current yard arrangement is suboptimal in terms of operations, to the point where they're considering extending the tail tracks at Sierra Madre Villa to be able to store trains there overnight.
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Post by Jason Saunders on Nov 28, 2008 22:30:20 GMT -8
[/li][li]2) The other option for this is creating a Small scale Union Station with multiple tracks and platforms. This could be done by building a new cut-cover tunnel from 7th St until 4th/5th Street and then tie it into the old Pacific Electric Subway that runs just due south of 4th Street. Then modernize the Subway Terminal Building and ( now called Metro417 which is adjacent to the existing Pershing Square Subway Station) which had five tracks and 4 platforms for LRT terminal. Upgrade the platforms for High Floor LRT, add signage, HVAC, Fire Alarm, etc and now that facility is reborn so that all the lines would operate as a main terminal with multiple end tracks and platforms. However the biggest issue of connecting the new tunnel with the old one without having to rebuild the YMCA/Parking Structure, this piece might cost more than the entire Regional Connector. [/LIST][/quote] I'm glad you recognized the cost of a retrofit. While I am impressed that this this tunnel has survived three major earthquakes since it was completed in 1925, I just can't imagine us using a pre-earthquake standards structure for such a key piece of infrastructure. It seems to me a modern TBM with automated wall placement would be less expensive then retrofitting this facility. Not to mention the tunnel has been cut off between Fig and Flower by the foundation of the Bonaventure. Elson Trinidad's Pacific Electric Tunnel Page: www.westworld.com/~elson/larail/PE/tunnel.html
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Post by jejozwik on Nov 29, 2008 7:46:58 GMT -8
I'm glad you recognized the cost of a retrofit. While I am impressed that this this tunnel has survived three major earthquakes since it was completed in 1925, I just can't imagine us using a pre-earthquake standards structure for such a key piece of infrastructure. tunnels, for the most part are the safest place in an earthquake because you are moving with the ground movements. buildings on the other hand are not bound by all sides to such movement and get the wobble effect. but if the ground fractures that could be another story. so its not that amazing that the tunnels are still around
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Post by bobdavis on Nov 29, 2008 20:44:27 GMT -8
Having done construction work in buildings dating back to the 20's, I can testify that if the concrete was properly mixed and placed when the terminal was built, it just gets harder and tougher with age. As I recall, the demolision crew that took out the PE 6th & Main elevated terminal had a major challenge in removing that well-seasoned concrete.
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Post by Jason Saunders on Nov 30, 2008 12:03:07 GMT -8
I am not an engineer. Truthfully I do not know if the eighty four year old Belmont Tunnel is structurally suitable for a modern light rail line. I think it's safe to say, none of us posting here have this knowledge.
I do know that most of the regions earthquake codes were developed post construction of this tunnel. A quick google search tells me that the 1971 Sylmar quake, almost fifty years after the completion of the tunnel, played a major role in seismic code strengthening for our region. At the very least one would have to circumnavigate the closed off portion at the Bonaventure and avoiding the foundations of the numerous nearby office towers.
I would support a study to determine the potential utility of the tunnel, what seismic retrofitting would be necessary and the cost effectiveness of plugging into this tunnel.
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