tag:blogger.com,1999:blog-8419444332771213285.post6363238016630756007..comments2024-03-17T12:42:36.234-07:00Comments on Caltrain HSR Compatibility Blog: Station Design 101Clemhttp://www.blogger.com/profile/01374282217135682245noreply@blogger.comBlogger109125tag:blogger.com,1999:blog-8419444332771213285.post-23213938287515338822014-11-30T21:55:46.099-08:002014-11-30T21:55:46.099-08:00FTA planner: blended station designs may benefit B...<a href="http://www.greencaltrain.com/2014/11/fta-planner-blended-station-designs-may-benefit-bay-area/" rel="nofollow">FTA planner: blended station designs may benefit Bay Area</a>.<br /><br />(Maybe they would. But maybe they <i>wouldn't</i> benefit the engineering-concrete transit-industrial complex.)<br /><br />"Railvolution"<br /><br />Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-57274593671875010952014-05-07T04:20:19.975-07:002014-05-07T04:20:19.975-07:00A common platform for trains with different platfo...A common platform for trains with different platform elevations above tracks can also be achieved by putting tracks at different levels, i.e. caltrin tracks some half-meter above HSE tracks.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-77522626884348633462012-02-25T23:55:02.642-08:002012-02-25T23:55:02.642-08:00While you guys were talking about it, the French w...While you guys were talking about it, the French would have had the stations built already. The right way.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-62576802406599266782011-10-30T10:02:11.241-07:002011-10-30T10:02:11.241-07:00Clem is correct. It's called strict liability,...Clem is correct. It's called strict liability, and intent is not required.Peterhttps://www.blogger.com/profile/00326948451529910432noreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-36042751472391493472011-10-29T20:35:32.288-07:002011-10-29T20:35:32.288-07:00The aim of Proof of Payment enforcement isn't ...The aim of Proof of Payment enforcement isn't to be perfect.<br /><br />It's to be <i>good enough</i>.<br /><br />So ... once in a while somebody somewhere gets away with something. Oh dear.<br /><br />So .... so what?<br /><br />If you're saving millions of dollars a year in maintenance costs and if you're saving tens of millions a year (or much more!) in <i>capital opportunity costs</i> from not having wasted billions on the concrete "architecture" of fortress barrier stations, and if you're gaining revenue and riders because trip time, <i>that includes station entry and egress time</i>. becomes faster, well, you're a long way ahead indeed.<br /><br />Good engineering and good design is about being good enough, about delivering more benefits than costs, about when to pay attention to more important things, and about how to understand <i><b>orders of magnitude</b></i> of effort and cost.<br /><br />PS Everybody knows how to dodge BART's fare gates, and many do. What measures do you propose implementing to reduce the evasion rate down to the only acceptable figure of 0.00000%?Richard Mlynarikhttp://www.pobox.com/users/mly/noreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-88252265736783372802011-10-29T15:56:19.528-07:002011-10-29T15:56:19.528-07:00I'm really not sure why one needs to prove int...I'm really not sure why one needs to prove intent when fining someone for not producing proof of payment.<br /><br />"I didn't know" just doesn't cut it.<br /><br />Does a cop need to prove intent to exceed the speed limit? Intent to park beyond the two-hour limit? No, of course not. You get fined, and you suck it up unless you want to go through the rigamarole of showing up in court.Clemhttps://www.blogger.com/profile/01374282217135682245noreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-23009742977148239142011-10-25T12:26:27.193-07:002011-10-25T12:26:27.193-07:00The trouble with POP is that it's almost impos...The trouble with POP is that it's almost impossible to set a penalty that is at the same time high enough to stop chancers from preferring to pay the penalty every time they're caught, while low enough so that passengers making innocent errors don't feel like they're being gouged (in some cases even a request for the full ordinary fare is enough to attract the attention of the media!),<br />unless you have nearly complete ticket inspection anyway. (Not that fare gates prevent dodging, they just make the dodgers buy a one-stop ticket for each end instead of no ticket at all...)<br /><br />If you try to have a higher penalty for deliberate fare dodging, you'll quickly find it difficult to enforce, as this higher penalty will require that intent be proved beyond reasonable doubt. Worse, normally-honest passengers who forgot or made a mistake end up saying the wrong things to the inspector, and end up convicted, while habitual dodgers tend to get away with not paying unless extreme measures (e.g. detectives, skipping certain stations, or special ticket inspections at certain stations) are taken.<br /><br />I'm not sure what the right solution is. Full ticket inspections after every station are unlikely to be tolerated (and "tickets from X" calls are routinely ignored by dodgers, especially on busy trains) and don't (except on very quiet trains) stop passengers buying a short distance ticket and travelling much further. Prosecution for wilful fare dodging doesn't help much as you have the same problem with proving intent.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-60480158249381739682010-12-16T14:38:22.168-08:002010-12-16T14:38:22.168-08:00That's a (rather dated) rendering of the insid...That's a (rather dated) rendering of the inside of the Transbay Terminal. And if you look closely, HSR and CalTrain aren't even on the same platform.Joeyhttps://www.blogger.com/profile/16406340564037825796noreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-39817400119876872752010-12-16T11:31:33.440-08:002010-12-16T11:31:33.440-08:00As of today, the CA High Speed Rail website has a ...As of today, the CA High Speed Rail website has a banner showing cross-platform access between HSR and (presumably) Caltrain, copied at <a href="http://flic.kr/p/92nvsZ" rel="nofollow">http://flic.kr/p/92nvsZ</a>mattwigwaynoreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-82506979842641512832010-11-06T16:41:59.307-07:002010-11-06T16:41:59.307-07:00According to The California High Speed Project Sys...According to The California High Speed Project System Requirements Data Base Report the 25,000 VAC contact wire’s required nominal height above the rails is 17’0” (page 852). The recommended clearances between energized and grounded parts are 12.6” static plus 8.7” dynamic (page846). Allowing for a 0.7” contact wire diameter the required nominal clearance between the rail surface and the bottom of an overhead bridge would total 17’ + 12.6” + 8.7” + 0.7” = 18’ 10”. The rail car heights of CHSR selected train sets are 9’ 10”, 10’10”, 11’6”, and 11’10”. Assuming that for open cut rail grade separations the cost of providing for a given rail clearance is proportional to the square of height of that rail clearance the cost of open trench grade separations for a 12’ 6” rail clearance approaches 44% of the expenditure required to construct a 18’ 10” rail clearance open trench grade separation.<br />Is the cost of below grade road rail separations actually proportional to the square of the rail clearance height? If a circular tunnel is applied the amount of material removed is directly proportional to square of the diameter. The length of the tunnel wall per linear foot is proportional to the diameter plus the added tunnel liner strength needed is also proportional to the diameter. So the liner thickness must increase in proportion to the tunnel diameter. Therefore a function describing the tunnel liner mass and expense will likely be close to proportional to the square of the tunnel diameter. Will open cut grade separation costs exhibit the same square of the rail clearance height expense function likely for tunnel structures? More heavily constructed plus higher retaining walls are required the deeper the trench. The distance required to climb above stream crossings rise the deeper the trench. Water table and underground streams rapidly become problems the deeper the trench. Another aspect of shallow trench grade separations is that retaining wall and overhead bridge pier construction and removal of center fill without significant delays to weekday rail traffic is more likely to be accomplished.John Baconhttps://www.blogger.com/profile/06487111497340132298noreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-69510969902386884782010-11-04T18:59:44.935-07:002010-11-04T18:59:44.935-07:00If you feel you need turnstiles, it's quite co...If you feel you need turnstiles, it's quite common to use turnstiles which accept any ticket, as a supplement to POP.<br /><br />The number of people willing to bother to buy a commuter ticket in order to attempt to ride free on a intercity train is miniscule.<br /><br />I think your proposals do not preclude that. At all.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-38561296143963716712010-11-03T19:09:39.115-07:002010-11-03T19:09:39.115-07:00No need to look at UK practice. You can look up t...No need to look at UK practice. You can look up the CHSR requirements in the resources section of this blog. SR 6-09.1 requires 320 mm of static clearance / 220 mm for dynamic clearance.<br /><br />Or in God's own units, 1 foot and 19/32 inch.Clemhttps://www.blogger.com/profile/01374282217135682245noreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-72101989479249376632010-11-02T22:57:09.524-07:002010-11-02T22:57:09.524-07:00John, you can look up clearance standards for 25kV...John, you can look up clearance standards for 25kV electrification somewhere on the UK Network Rail site. I think it's somewhere under a foot for wire to structure clearance and similar for wire to train roof clearance. The issue of arcs from the inductive load of the motors is simply not addressed by the train-wire interface: that's the job of the main breaker in the train. For neutral sections and the like, there are trackside magnets to open the main breaker automatically at the appropriate time. If an AC-powered train lowers its pantograph under load, there's actually a pretty good chance that there will be a pan-to-wire arc that will persist until it melts the wire in half. That's one of the reasons for all the grounding requirements for structures around AC electrified lines. And the main breaker on an AC locomotive is a pretty fancy device, which literally blows out the arc using compressed air.crzwdjkhttps://www.blogger.com/profile/06394805356595604336noreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-79769653426714141102010-11-01T17:50:36.484-07:002010-11-01T17:50:36.484-07:00"Clearances required for the proposed CHSR 25..."Clearances required for the proposed CHSR 25,000 VAC electrification would be greater than 3 feet ..."<br /><br />Somebody take a look at the clearances above NJ Transit's 25 kV catenary. Isn't it a foot or less at Summit, e.g.?Timnoreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-84299405794989375312010-11-01T08:37:05.355-07:002010-11-01T08:37:05.355-07:00Any railroad’s externally applied electrification ...Any railroad’s externally applied electrification system has a highly inductive load from its traction motors and, especially on long power supply lines, its power source. The practical effect is if the power circuit is broken the collapsing magnetic fields in the circuit’s inductive sections will instantly produce a voltage across the break that tends to drive current across the expanding break at a magnitude close the same level that existed before the break was initiated. I have observed extremely bright flashes likely generated by such locally produced voltage spikes on an 84 mph third rail powered train in rainy weather and in another case during a 15% power application on trolley busses across breakers. These observations suggests these voltage spike magnitudes were many times their 600 VDC power supply. Thus for electric system integrity or personal safety distance and/or insulation effectiveness must be well in excess of that required for nominal voltage supply levels.<br /> William D. Middleton’s book The Pennsylvania Railroad Under Wire says on page 34 that during an 11,000 VAC electrification during the early 1930’s overhead bridges were raised as much as “3 feet to provide adequate catenary clearance”. Clearances required for the proposed CHSR 25,000 VAC electrification would be greater than 3 feet because of the higher nominal voltage and today’s greater concern for safety enforced by more stringent regulation. The cost of excess vertical clearance in the present case appears to be quite high. On October 28, 2010 a $715 million federal stimulus grant to build HSR infrastructure was offered for a stretch down the center of the San Joaquin Valley. With the availability of enough money to complete construction of the current CHSR proposal in serious doubt a well-constructed but isolated electrified passenger railway section at this location would be of little use to anybody. <br />If that $715 million was used to construct passing tracks along a central portion of Caltrain’s SF to SJ right-of-way, for example continuous passing tracks through San Carlos to Millbrae, a material improvement in service speed and reliability with less noise at the same operation cost with currently used rolling stock would become feasible. But no doubt people in Washington have heard about Peninsula Community law suits objecting to the present CHSR proposal. The motivation behind this opposition is the appearance and noise emanating from an elevated right-of-way, Open cut grade separations would sharply reduce these esthetic objections and a lower track overhead clearance requirement would reduce the construction cost in proportion to the square of this clearance height. <br />In one important aspect the interest of Nimby’s and rail transit advocates are the same. The more attractive or less repulsive the rail structure is the more likely people will build high density communities near the right-of-way. Therefore more passenger traffic is likely to appear to pay fares and support tax subsidies.John Baconhttps://www.blogger.com/profile/06487111497340132298noreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-24650009985768016412010-10-31T23:24:55.324-07:002010-10-31T23:24:55.324-07:00Was that what we talking about?
I thought so. Si...<em>Was that what we talking about? </em><br /><br />I thought so. Silly me thinking "Caltrain" on a blog titled "Caltrain HSR Compatibility Blog"Adirondacker12800noreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-59044436935733588842010-10-31T23:06:48.855-07:002010-10-31T23:06:48.855-07:00There isn't any. Was that what we talking abou...There isn't any. Was that what we talking about? I thought we were just discussing the technical possibilities of DC versus AC power collection systems. So theoretically, it's plausible to make a reasonable DC power system for Caltrain, but I don't see any compelling argument one way or the other for Caltrain in isolation, and combined with HSR, I think AC wins over DC pretty handily, since the HSR mainline pretty much has to be AC, and having just a single standard for mainline electrification is much, much better in lots of ways even if it's slightly suboptimal in some specific cases. If nothing else, there's a pretty big pool of 25kv-powered locomotives on the East Coast, and a large amount of expertise adapting models from the much larger European fleet to operate in the US.crzwdjkhttps://www.blogger.com/profile/06394805356595604336noreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-70233286361138344232010-10-31T18:12:57.408-07:002010-10-31T18:12:57.408-07:00The line in China was opened sometime in the past ...<em>The line in China was opened sometime in the past decade, I believe in Guangzhou. I have no idea why they went with third rail for that one, as all the rest of their lines use overhead.</em><br /><br />They must have had an overriding technical reason. Or the designers were BARTophiles and wanted to make the line as BART like as possible. What's the overriding technical reason to use third rail on the Peninsula, other than to make it BART like?Adirondacker12800noreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-41203614024094509162010-10-31T17:51:34.663-07:002010-10-31T17:51:34.663-07:00The line in China was opened sometime in the past ...The line in China was opened sometime in the past decade, I believe in Guangzhou. I have no idea why they went with third rail for that one, as all the rest of their lines use overhead. But an aluminum third rail does have a pretty high current carrying capacity, and isn't as susceptible to wind as overhead wires are, and it's easier to install on an elevated structure than an overhead contact rail. So which solution works best really depends on what you're trying to accomplish.<br /><br />As for the Swiss electric kettles, that was a very logical solution: they were surrounded on all sides by enemies, and getting petroleum or coal into the country was quite a problem. But they had lots of hydropower, and all the mainlines were already electrified, but not all the sidings. Plus, they had a fleet of steam locomotives that were still perfectly good aside from not having any fuel. Presumably the electric boiler solution wasn't too inefficient, and it was certainly cheaper than building a fleet of battery locomotives (which would probably require lots of fancy metals) or wiring all the sidings (which would take lots of time, and also require lots of copper).crzwdjkhttps://www.blogger.com/profile/06394805356595604336noreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-10189406761594876432010-10-31T10:56:59.927-07:002010-10-31T10:56:59.927-07:00But 1500 VDC third rail has been done in China, so...<em>But 1500 VDC third rail has been done in China, so clearly that's a solved problem one way or another.</em><br /><br />There are many solutions to dragging trains around. One of the original ones, and very usable in tunnels, is using a horse. You wouldn't want to do that in 2010. There's also fireless steam locomotives. There's even odder solutions - during World War II the Swiss had trouble getting fuel for steam locomotives or electric locomotives that could run on hydropower. So they converted some of the steam locomotives to boil the water with electricity. <br /><br />Third rail looked like a good idea when suburban railroads were electrifying in 1900. It may not be the best idea in 2010.Adirondacker12800noreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-75790729872141322522010-10-31T09:36:47.027-07:002010-10-31T09:36:47.027-07:00On-EMU transformers aren't strictly necessary ...On-EMU transformers aren't strictly necessary for 25kVAC. There are solid-state solutions for handling high voltage AC power conversion.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-69787905289335725312010-10-30T23:36:25.337-07:002010-10-30T23:36:25.337-07:00About half an inch. If the required clearance for ...About half an inch. If the required clearance for 25kV AC is 10 inches, and and arc length is proportional to voltage. Plus of course divide by the square root of 2, because 25 kV is RMS voltage, but for dielectric breakdown it's the peak voltage that matters. The problem is not so much arcing to the ground but insulating the structures supporting the third rail. But 1500 VDC third rail has been done in China, so clearly that's a solved problem one way or another.<br /><br />And if you look at what John Bacon is saying, he mentions nothing about Caltrain being "unique", he's just comparing AC powered Caltrain cars to DC powered BART cars and wondering why the former are so much heavier per passenger. The EMUs in Switzerland (and Germany and Austria and Sweden) have even heavier transformers, because they use 16.7 Hz power, rather than 50 or 60, and transformers get lighter and more efficient at higher frequencies (that's why airplanes have 400Hz power).crzwdjkhttps://www.blogger.com/profile/06394805356595604336noreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-27593943966229716712010-10-30T20:53:46.665-07:002010-10-30T20:53:46.665-07:00Perhaps a 1500 VDC third rail would be good for de...<em>Perhaps a 1500 VDC third rail would be good for delivering enough current, but it would still pose some clearance issues for freight.</em><br /><br />How high does this wonder have to be to prevent arcing to the <em> ground </em>?Adirondacker12800noreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-57196395297579941462010-10-30T19:28:39.870-07:002010-10-30T19:28:39.870-07:00@ arcady
So, what you're saying is that every...@ arcady<br /><br />So, what you're saying is that every electric train has the "added" weight that john bacon is implying is unique to Caltrain's as-yet-non-existent design.Peterhttps://www.blogger.com/profile/00326948451529910432noreply@blogger.comtag:blogger.com,1999:blog-8419444332771213285.post-59894434778555650032010-10-29T22:52:24.196-07:002010-10-29T22:52:24.196-07:00Um... John Bacon actually knows what he's talk...Um... John Bacon actually knows what he's talking about. ALL electric and diesel-electric trains have some DC in them somewhere. The incoming high voltage AC is stepped down in the main transformer to a lower level, generally around 700 volts, rectified to DC, and then converted to variable-frequency AC to drive the motors. In a diesel-electric locomotive, the prime mover drives an alternator, which is connected to a rectifier to produce DC, which is fed to a power converter. A DC powered train omits the transformer, which is quite heavy. Of course, the downside is that DC voltages are low, and thus currents are high. Both 1500 VDC overhead and 750 VDC third rail systems have had problems delivering enough current to power long, air conditioned suburban trains running at close headways, and a 1500 VDC system means the DC link voltage inside the train has to be higher. Plus of course you need many more substations: Caltrain was planning only two substations and something like 6 paralleling station for the entire electrification project, while the South Shore Line (a 1500 VDC system) has substations every 2-4 miles in the heavily used parts of the line. Perhaps a 1500 VDC third rail would be good for delivering enough current, but it would still pose some clearance issues for freight.crzwdjkhttps://www.blogger.com/profile/06394805356595604336noreply@blogger.com