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Post by jejozwik on Aug 28, 2008 8:04:13 GMT -8
today, while rushing to the am red line to north hollywood, i was a bit late and rushed into the first train car. while it was standing room elbow to elbow for the first few stations, by 7th and metro it mostly cleared out.
so i took my normal standing spot by the wheel chair space. this being the first time i have ever been in the lead car, i noticed you could look out that little window and actually see the tunnel ahead of you!
i was amazed by this and watched out the window for the entire trip.
so my first question, judging by the angles of the tunnel service lights, i noticed that for the majority of the north hollywood spur the tunnels generally raise in elevation immediately before a station, then dip down in elevation immediately after.
the only ones i can remember not seeing this were on the hollywood and vine till noho stations.
what is the reason behind this?
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Post by JerardWright on Aug 28, 2008 11:21:58 GMT -8
...So my first question, judging by the angles of the tunnel service lights, i noticed that for the majority of the north hollywood spur the tunnels generally raise in elevation immediately before a station, then dip down in elevation immediately after. the only ones i can remember not seeing this were on the hollywood and vine till noho stations. what is the reason behind this? I remember from a video clip about the Metro Rail construction during the 90's that it was for energy efficency. By going up in elevation before a platform and then breaking is making the use of all it's power and makes the train breaking a lot smoother and easier. Then going down in elevation after the station uses very little actual electrical power but takes advantage of the trains mass and weight to push the train forward and keep it going.
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Post by Justin Walker on Aug 28, 2008 11:23:07 GMT -8
This is an energy-saving measure. Trains naturally coast downhill to gain speed as they leave stations and are slowed down as they roll uphill into each station.
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Post by Justin Walker on Aug 28, 2008 11:26:45 GMT -8
Jerard, Simul-posting! But I did find that clip at the beginning of this vid: These old transit videos sure are fascinating.
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Post by jejozwik on Aug 28, 2008 11:48:57 GMT -8
oo nice video, though it leaves me asking for more!
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Post by bobdavis on Aug 28, 2008 17:49:16 GMT -8
This could be a "urban transit legend", but this concept is said to have originated on the Chicago South Side Elevated, back in the days when the trains were powered by small steam locomotives. Same idea--use the upgrade to slow the trains coming into the station and the downgrade to help accelerate leaving.
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Post by Jason Saunders on Nov 6, 2008 17:16:22 GMT -8
Roger Snoble on Airtalk this morning said some property aquisition would need to happen near Wilshire and Western to lower the tunnel boring machins below ground. What do you suppose is the most likely acquisition is? The Wiltern is a historic Landmark and the other three corners have towers built on them. Is the Rite Aid property on the wrong side of the tracks? maps.google.com/maps?f=q&hl=en&geocode=&q=3799+Wilshire,+Los+Angeles&sll=34.061699,-118.30856&sspn=0.002049,0.003455&ie=UTF8&ll=34.061975,-118.308908&spn=0.002049,0.003455&t=h&z=18
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Post by JerardWright on Nov 6, 2008 18:07:51 GMT -8
The station box is between St. Andrews and Oxford Street on Wilshire because the mezzanine is directly on the eastside of the Wilshire/Western intersection. My guess is that they do a short cover-cut tunnel to tie in the current subway with the new one between St. Andrews and Wilton Place. Then start the TBM at Wilton Place because there are one or two strip malls with a lot large enough to work as a staging site for setting up a TBMs.
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Post by antonio on Nov 15, 2008 0:55:21 GMT -8
This question is for anybody but I presume Jerard knows the answer. I understand that our subway stations have 6 car length platforms but I was wondering if there are any provisions for expansion (or if it would be ridiculously cost prohibitive) to extend those to 8 car lengths. I'm thinking for the future here because this Wilshire extension will be the spine of our system and it since its just a two-track tunnel with no express tracks, it will fill up to capacity within 25 years. Just look at DC's metro, specifically their Red Line (and they have 8 car platform lengths!). I'm wondering this because if they are expandable to 8 car lengths then we should lobby to have the Wilshire extension be built to 8 car lengths. Same question goes for the Eastside tunnel and its expandability to 4 car lengths, and building the DTC and Crenshaw tunnels at 4 cars.
Also Jerard, where in the system do knockout panels exist (including in the Blue Line tunnel at Olympic, if that exists)?
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Post by JerardWright on Nov 15, 2008 10:05:14 GMT -8
This question is for anybody but I presume Jerard knows the answer. I understand that our subway stations have 6 car length platforms but I was wondering if there are any provisions for expansion (or if it would be ridiculously cost prohibitive) to extend those to 8 car lengths. No, originally they were going to use the DC Metro's 8 car length platforms as the model to operate and build our subway but that was eliminated due to costs and oddly enough accelleration/capacity. If you think about it, a longer train requires more distance between trains to break and accelerate. The only DC Metro line they run an 8 car train is the Orange Line in peak direction to Vienna because it's not running as frequently and it shares it's central tunnel with their Blue Line. Thus the 8 car trains (600' in length), which DC Metro doesn't operate on their busy Red Line despite their provisions for the stations they will not run because they lose capacity by running the longer units in an urban Metro. There is a threshold for this and interestingly enough it is right between 450' (6 car trains) and 550' in length. This is dependant on the weight and acceleration of the equipment, a lighter 500-550' train will give you a similar performance as a heavier 450' train. Beyond the 550' train length the longer train length you have, the longer the frequency. The subway line that operates the longest trains most frequenty in the US is the (7) "Flushing-Queens"trains in NYC with a 2 minute rush hour headway with 550' (that is an 11 car unit). With the use of computer controlled train movements, moving block signals and Automatic train operation (ATO) they do a better job of moving vehicles and improving operational efficencies couple this with the 'lighter 6 car train' and improved accelleration on the trains this provides the best of both worlds. Here's another related analogy, think of Southwest Airlines. They only operate Boeing 737 planes because they acheive a higher operating efficency by allowing being able to land, unload passengers and luggage, load new passengers and luggage and takeoff again within 30 minutes and gain more of a profit because of that efficency. On some corridors they could operate a large plane like a 757 or 767 however they don't gain too much from that because those planes take a longer time to perform that same task which means there is a limit to how many routes, passengers and how frequent service is operated. We could go to Toronto's subway and they are over capacity, but they are doing some simple and effective measures to improve and increase capacity. * TRAIN OPERATIONS: Toronto will be adding Moving block signals and ATO to more efficently manage their subways. This move alone doubles capacity, without a single sticth of additional tunnels or platform extensions. * INTERIOR LAYOUTS: Toronto will also have a new train design in which their full 6 car train are all linked together with articulation (like LRV's), the layout of the trains are mostly seats along the walls and the doors are wider. How does this improve capacity? You don't have to operate a transit system to know this one, maybe an architecture degree ( ;D). The reason is because space is used more efficiently. Improving circulation of passengers going in and out of trains and the standee space that is needed. With our subway the next step is to order a new batch of train cars with; * 4 wide doors, * Increase standee space by reducing the number of seats and * Instead of married pair, go with articulation.Another place in the world we could venture to is Calgary, Alberta, Canada. I love their system for their methodical approach to the design of their C-train Light rail system. BTW, they carry over 250,000 riders on their 25 mile LRT network of at-grade in urban areas and highway median running on the outer edges with strategic grade seperations over highways, where trains turn and major waterways but that is not the reason I bring them up. * BOARDING LOCATIONS: I bring them up because they looked at the designs of their train stations and the boarding psychology of the passengers along the course of a line and realized that they need to mix up where the platform entrance are located at the stations. If all the boarding entrances are at the same exact location at every station what will happen is the train car closest to the entrance will be packed like sardines while the other vehicles aren't as full. So with the Wilshire subway they need to look at where to place the stairs/escalators/elevators in relation to the other stations along the corridor. * PEAK TRAVEL DIRECTION: Another thing Calgary system points out is of peak direction. Their system in the inner core is at 50/50 meaning there are just as many people travelling in as they are travelling out. Now with the current buses on Wilshire, there is a 60/40 peak direction of Westbound in the AM, Eastbound PM. This is stat is important as to how our system will operate. If we had a dominate CBD and a traditional low density suburb area, the loads will be very heavy in one direction and empty the other direction. How Wilshire is situated and most of the Westside for that matter it will be a closer 50/50 relationship meaning we wouldn't need to worry about trains being excessively full in one direction and empty the other meaning we squeeze more capacity out of our system with a minimal infrastructure compared to other networks. If all of these things occur and it's still over capacity, I guess that means we build another rail corridor parallel to the over-crowded one or a perpendicular rail that will move the capacity from one line to another nearby line. Sounds good to me!
New Yorkers are looking at that fate and are planning and building the Second Avenue Subway to relieve pressure on 4/5/6 on Lexington through Manhattan's East Side.
Back here at home, Santa Monica Blvd corridor planning would be a great start, getting Crenshaw Corridor to Wilshire/La Brea would help, begin discussion of the 405/Sepuveda Pass transit corridor. All these things will improve the capacity of the network for Wilshire once that fateful day we realize; "OMG, Wilshire is over capacity" For Eastside, they only went with 3 car trains because that is the max. length of the street blocks. However if that line goes over capacity, so what? There is Whittier corridor subway that will finally get built to relieve those capacity strains. Again the trick here is that even if Wilshire or Expo or whatever line goes over capacity, that's not an issue because there will be another corridor in it's place either parallel or perpendicular to it to shift the loads and spread out the ridership, the key thing is to begin planning for it as stated in a previous paragraph. Crenshaw their street blocks are longer than the 3 car LRV train and if operated independently of Expo they could theoretically be built and operate as a 4 car unit because of this fact. The Blue Line at Olympic is the only major tunnel that has that because it was built as a cut-cover and not a bored subway. That is the trick of the bored tubes in that once the circular hole is cut and unless you build it for the full buildout of the system, going back and extending platforms will not happen because you'd have to build it twice.. All the other locations of knock-out panels are at the Subway station mezzanines for future expansion. I'll have to look at the actual as-built construction drawings for those to verify which stations have them. I can make some guesses though, Hollywood/Highland, Universal City and North Hollywood all look like they have knockout panels at their mezzanines for future portal entries.
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Post by bluelineshawn on Nov 15, 2008 12:54:31 GMT -8
We seem a long way from needing to worry about lengthening red/purple line platforms, which as Jerard pointed out isn't going to happen. There is room in the schedule to run a lot more trains. Probably almost twice as many if we should ever need to.
Light rail is a different issue because the lack of grade separation and the priority that cars get means that we're limited to about 12 tph.
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Post by darrell on Nov 16, 2008 17:40:55 GMT -8
Good discussion, Jerard.
I asked one of the engineers about their 6-car lengths at a Red Line public meeting c. 1980, remembering BART's 10-car platforms. He assured me that was sufficient, and the cost savings of a shorter station box were significant.
Despite its long trains BART manages to run 21 trains per hour under Market Street (westbound, 7-8 a.m. weekdays), an average of just under 3-minute headways, compared with our Red / Purple Line 5 minute headways.
On the earlier topic, I also recall the energy savings of the track dipping down between stations being mentioned back then.
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Post by darrell on Nov 16, 2008 18:14:51 GMT -8
Light rail is a different issue because the lack of grade separation and the priority that cars get means that we're limited to about 12 tph. Here are examples (posted here 2/16/08 with photos) of downtown at-grade light rail over 12 tphpd: Dallas - 17 (Akard station) Portland - 16 (Pioneer Square) San Francisco - 16 (Embarcadero & Folsom) Denver - 14 (16th & California) They may never get this close, but this map (posted here 3/20/08) illustrates Blue and Expo Line trains spaced around 3 blocks apart at 2-minute combined headways ( 30 tphpd). There is still queuing space to make up for off-schedule trains.
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Post by bluelineshawn on Nov 16, 2008 18:15:39 GMT -8
Although the parts about the braking make sense, I doubt that the savings would be significant. Starting downhill might save a little more. It still doesn't seem like it would add up to much compared to the cost of construction, but maybe it didn't cost much more to build it that way.
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Post by bluelineshawn on Nov 16, 2008 18:32:10 GMT -8
Normally headways are understood to mean one direction, not both. So when I say 12 tph I mean 24 total trains in both directions per hour. I only checked the numbers that you listed for Dallas and Denver, but those two numbers are for two directions so they're even less than I said would work for light rail. Denver's 3 lines combine to about 7-8 tph at rush hour and Dallas has one line at 4.5 tph and the other at 6 tph for a combined 10.5 tph. About the same as the blue line. I think that Houston also has a similar headway to the blue line.
Under certain circumstances, like transit plazas and such we could squeeze more trains into certain spots. I only meant that for longer street running portions we only target a max of 12 tph. That's how we're building our system. IINM we don't even have enough substations to run more than that.
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Post by darrell on Nov 16, 2008 19:04:24 GMT -8
I only checked the numbers that you listed for Dallas and Denver, but those two numbers are for two directions so they're even less than I said would work for light rail. Denver's 3 lines combine to about 7-8 tph at rush hour and Dallas has one line at 4.5 tph and the other at 6 tph for a combined 10.5 tph. No, my numbers are per direction. Here are the schedule times I used last spring: Dallas, Akard station, southbound: Red Line -- 7:03, 7:13, 7:17, 7:22, 7:27, 7:33, 7:37, 7:43, 7:47, 7:53, 7:57 = 11 trains/hour Blue Line -- 7:10, 7:20, 7:30, 7:40, 7:50, 8:00 = 6 trains/hour Total = 17 trains/hour/direction Denver, 16th & California, northbound: D Littleton -- 7:01, 7:16, 7:26, 7:31, 7:46, 7:56 = 6 trains/hour H Nine Mile -- 7:06, 7:21, 7:36, 7:51 = 4 trains/hour F Lincoln -- 7:13, 7:28, 7:43, 7:58 = 4 trains/hour Total = 14 trains/hour/direction
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Post by bluelineshawn on Nov 16, 2008 19:30:45 GMT -8
My mistake then. Sorry about that. We'll have the same thing on Flower when Expo opens. But headways refer to the time between trains on a single line, not multiple lines and that's what I originally meant. We're not using the same terminology.
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Post by darrell on Nov 16, 2008 19:39:13 GMT -8
We'll have the same thing on Flower when Expo opens. But headways refer to the time between trains on a single line, not multiple lines and that's what I originally meant. We're not using the same terminology. Fair enough. I tried to capture that idea with "combined headways", but would appreciate a better term. I still need to follow up with the current status of Metro Operations about turning trains at 7th Street, probably the biggest constraint.
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Post by JerardWright on Nov 16, 2008 21:15:58 GMT -8
I still need to follow up with the current status of Metro Operations about turning trains at 7th Street, probably the biggest constraint. Conceptually, that constraint can be relieved in one of two ways; - 1) Build the Regional Connector and take a page from San Francisco's Muni Metro Embarcadero Station -which was notoriously trouble prone with delays due to this before - by adding a long storage track in between two passing tracks so that can hold many trains with multiple switches. Embarcadero Muni Metro Station (EML and EMR on image below)between the Embracadero Portal and the station as a reference to highlight this point, that is the indigo box.
- 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.
However, the current idea of dynamic scheduling and flipping of trains at 7th Street Metro between Expo and Blue Lines sounds like that will work for a short period of time.
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Post by antonio on Nov 16, 2008 22:07:23 GMT -8
I've mentioned this a couple of times before, but we should extend that storage track to the 5th/Flower station that they are building for the DTC (it'll end right before 5th anyway) and use that center track as a terminus for Foothill (Gold) trains. They will have such a long run that it doesn't make sense to route them all they way to Long Beach or SM because there isn't anywhere else in DTLA where they can be turned around.
The other lines would be Long Beach-East LA (Blue) and Expo-SMV (Aqua)(or Duarte because its the last station before the big Irwindale yard) with some peak Expo trains terminating at Chinatown, using the Midway Yard to turnaround because they can't easily be turned around at LAUS. Under this routing all three light rail lines would be about the same length (nice for the operations people), Aqua at 32 miles (38 to Duarte), Blue at 29, and Gold at 39. If the MTA had their way we'd have two totally uneven lines (shown at DTC meetings), the Blue at 59 miles and Aqua at 20 miles, which would be a nightmare for cars working the Blue Line, which would wear out far faster, and for the operations people who have to keep to schedules for such a beast.
Edit: End to End travel times would also be similar about 80 minutes each for Blue and Aqua and 75 for Gold, which is also good for operations
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Post by antonio on Nov 16, 2008 22:26:45 GMT -8
Also, I've made a future 2025 Metro Map, after realizing that with Measure R we can get things done. Some things aren't currently on Metro's radar but they do use funds that metro already has programmed, like N-S Valley Transitway, etc. in a better way Follow this link to view the map.
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Post by JerardWright on Nov 16, 2008 22:47:35 GMT -8
I've mentioned this a couple of times before, but we should extend that storage track to the 5th/Flower station that they are building for the DTC (it'll end right before 5th anyway) and use that center track as a terminus for Foothill (Gold) trains. They will have such a long run that it doesn't make sense to route them all they way to Long Beach or SM because there isn't anywhere else in DTLA where they can be turned around. .... You're not the only one who've thought of this. ;D ( 05.02.08 ) ( 05.20.08 ) ( 06.18.08 )
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Post by antonio on Nov 16, 2008 22:55:16 GMT -8
Sorry I forgot to credit you also Jerard, we have been saying the same things since we used to be on the old board.
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Post by JerardWright on Nov 16, 2008 23:08:05 GMT -8
A couple of things I like in that plan. One I've always thought about is that East Valley Blvd/Alameda Corridor East between El Monte and Pomona that hits up all the major centers not yet served either with LRT or Commuter. The other change would be to eliminate the Red Line subway to CSULA and just have the multiple EMU/Commuter Lines operate in frequent service between Union Station and CSULA, it's easier to find the ROW for that section to make it double track. Then instead of continuing the Red Line north, though that would be usable, I would turn it west to Van Nuys to relieve the crowding on the Orange Line so that the ridership would shift to end at Van Nuys where a number of riders transfer at Van Nuys Blvd. The one thing I wonder is with Measure R, is it possible to make these changes without the EIR's and the State Legislation's approval, I call it the Oropeza Rule for the one who wanted that as protection for the Green Line to LAX.
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Post by wad on Nov 17, 2008 5:27:05 GMT -8
A couple of things I like in that plan. One I've always thought about is that East Valley Blvd/Alameda Corridor East between El Monte and Pomona that hits up all the major centers not yet served either with LRT or Commuter. Commuter would be better, but an express bus wouldn't be shabby in a pinch. There's only one major destination, Puente Hills Mall, in the area. Otherwise, it would be industrial/suburban park & ride. The line looks like the Metrolink Ventura County Line between Burbank and Chatsworth. Agreed here, but also have some kind of bus terminal center either at Van Nuys Civic Center or Sepulveda. This would be a place where most of the local buses in the Valley can converge. Also, it would turn the remnant of the Orange Line into something similar to the Dadeland station where the Metrorail and the busway meet in Miami. For instance, the local buses can originate at this terminal, run on the busway, then continue as north-south services. In the case of the Canoga busway, east-west buses would originate from either Chatsworth or Warner Center.
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Post by bluelineshawn on Nov 17, 2008 9:12:53 GMT -8
I'm not sure that the end to end distances are an important concern. At least not as far as equipment wear is concerned. One line at 60 miles and another at 20 miles only means that the trains on the shorter line travel the same route more often.
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Post by JerardWright on Nov 17, 2008 14:07:46 GMT -8
Believe it or not they are very important and it's the same reason for the trains as they are for buses, Wheel wear, brakes and maintenance.
Even if you theoretically operated the shorter 20 mile run more often, unless that 20 mile run required the vehicles to stop every 1/2 mile you'd still have less wear on either the 20 mile run or the 60 mile run depending on how far apart the stops are. That is means theres more braking and accelerating and continual train runs for one run compared to the other. That means one set of equipment will wear out a lot quicker than the other one.
Another way to offset this is by fleet rotation where after every week a new set of trains are rotated to another train line to keep the overall maintenance of the vehicles even and more consistent.
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Post by bluelineshawn on Nov 17, 2008 18:51:05 GMT -8
Believe it or not they are very important and it's the same reason for the trains as they are for buses, Wheel wear, brakes and maintenance. Even if you theoretically operated the shorter 20 mile run more often, unless that 20 mile run required the vehicles to stop every 1/2 mile you'd still have less wear on either the 20 mile run or the 60 mile run depending on how far apart the stops are. That is means theres more braking and accelerating and continual train runs for one run compared to the other. That means one set of equipment will wear out a lot quicker than the other one. Another way to offset this is by fleet rotation where after every week a new set of trains are rotated to another train line to keep the overall maintenance of the vehicles even and more consistent. No, it's the total miles traveled by the train and the number of stops that the train makes. And that has nothing to do with how long the individual runs are. If Train A runs 8 round trips on a 25 mile line and makes 120 stops, it's exactly the same as Train B that makes 4 round trips on a 50 mile line also making 120 stops.
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Post by JerardWright on Nov 17, 2008 19:45:08 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.
So on that calculation if continued over a length of time, There will be twice as much brake wear on Train A as it is on Train B because of more runs and more stops within that run, based on those assumptions.
The mileage plays a factor in basic warranty maintenance of other parts of the vehicles and to determine how many trains we will need to cover the route, which factors into how many mechanics are needed. If under the same perameters Train A operates more frequently than Train B, we may have a lot of Train A's wear out a lot quicker than they should, becuase within that roundtrip Train A will require more runs than train B.
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Post by jejozwik on Nov 17, 2008 19:51:07 GMT -8
If under the same perameters Train A operates more frequently than Train B, we may have a lot of Train A's wear out a lot quicker than they should, becuase within that roundtrip Train A will require more runs than train B. i cant solve my high school math problem with out a "train A leaves tulsa at ##:##" as far as the el monte line commuter rail thing. come on people! silver line!
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