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Post by zbang on Mar 1, 2018 4:09:23 GMT
It mustn't be forgotten that the track level through Ryde Tunnel was raised at electrification, I'm curious why one would raise the track in a tunnel. There must be something that I'm missing.
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Post by zbang on Feb 23, 2018 16:52:00 GMT
Rather than re-equip the whole line with new power supplies, batteries could be recharged on the move whilst passing over relatively short sections of energised third rail in the vicinity of a handful of feeder stations which would also significantly reduce the transmission losses which third rail systems typically suffer from on longer routes. I doubt that one could get enough charge into the batteries in a "short section" of 3rd rail, and unless the train was standing at a platform you'd have to supply traction power at the same time as charging power. Battery operation might work if maybe 2/3ds of the RoW was energized (and had sufficient power supply) but I can't see it working with less. Probably not enough to be worth while.
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Post by zbang on Feb 23, 2018 0:35:10 GMT
Some of the San Francisco cable cars are originals dating from 1889, but whether these cars are used daily I don't know. Without diving into the books, outside of museums I don't believe that any pre-earthquake (1907) cars exist unaltered, let alone are serviceable. There are some in service that were built in the 1890s, but AFAIK all of those have been extensively rebuilt in the last 60-80 years. How much original material remains in them is a good question. (Thanks.... now I'll have to go look all this up. There goes a couple of hours .)
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Post by zbang on Feb 9, 2018 19:48:35 GMT
]And alas most of the "fans" that are out there prefer the comfort of being at home with a keyboard to a draughty carriage-shed de-greasing an underframe. They are, of course, missing all the fun that comes after the de-greasing. IME, which is somewhat limited, some heritage sites make it difficult to volunteer; they set up hierarchies so you have to start out sweeping floors, ignore real volunteer skills, and generally throw up roadblocks to anyone that would upset the apple cart of the entrenched folks. They also whinge about how many volunteers they (don't) get. Fortunately, there are also sites that welcome anyone who walks in the door.
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Post by zbang on Feb 9, 2018 2:01:22 GMT
Very interesting topic, but I do have to grab onto an earlier reply: ... but 3 rail is (compared to overhead) inefficient and dangerous... Well.... if the overhead is energized with a far higher voltage than a 3rd rail, it may be a more efficient in delivering power to the trainset, otherwise, and absent other info, I'd call it a wash with the possible advantage to the 3rd rail as a better conductor. (No argument on the more-dangerous part, or on the use of MV for long-distance/main-line trains.) When discussing heritage lines which were probably worked at 600vdc (give or take), I don't think it matters. It may be interesting that the Western Rail Museum near San Francisco has 600vdc wire over about 5.5 miles of track which they maintain themselves, only hiring in help for the 13kv feeders and MV switchgear. z!
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Post by zbang on Feb 6, 2018 17:13:05 GMT
I assume this is done to give drivers a required break. Yes?
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Post by zbang on Dec 14, 2017 6:01:28 GMT
Any suggestions for Android phones?
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Post by zbang on Nov 24, 2017 5:43:37 GMT
2) to alter the public address system volume based on the ambient nkise levels, so it can always be heard without being VERY LOUD when the area is quiet. Unless the technology has greatly improved since I last tried them, they seldom bring the level back down after it's been jacked up. (Usually the time constants are far too short properly adjust to conditions.)
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Post by zbang on Sept 29, 2017 18:54:29 GMT
Saw an announcement for that (on ianvisits?), it's on the must-do list for the next time I'm in London. (15 minute walk? Bah. I've walked 2 miles each way to see a good steam engine .)
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Post by zbang on Sept 25, 2017 17:23:39 GMT
The Future is operating with Severe Delays. That would make an excellent signature line, I may steal, err, re-purpose, it.
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Post by zbang on Sept 19, 2017 3:36:13 GMT
Yes, something like that, thanks. I suppose something similar for the occasional tunnel spaghetti is too much to hope for.
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Post by zbang on Sept 18, 2017 21:31:26 GMT
The discussion about modifying the W&C brought to mind- Besides the set on "See How They Run" (http://husk.org/www.geocities.com/athens/acropolis/7069/stations.html), are there any publicly-available 3D maps of stations and tunnels? I'd love to see something comprehensive but understand why they might not be freely distributed. As an aside of what one can do, maybe to excess- www.pitwatch.org/computer-model-shows-berkeley-pit-butte-mine-tunnels/ (all of those tunnels are filled with rather corrosive water now). z!
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Post by zbang on Aug 21, 2017 5:52:57 GMT
But remember, these "planners" built the southern end of the M1 with just two lanes, didn't think the M25 was necessary and so on. There is quite a long list of theses "planners" legacies which still haunt us today I'm reminded of Gaiman and Pratchett's comments about planners (and the M25) in Good Omens (soon to be a movie, apparently). The same sort of planners who build San Francisco's BART to a broad gauge (5'6") in the 1960's(!), and didn't build in enough cross-overs, etc etc.
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Post by zbang on Aug 19, 2017 4:19:50 GMT
Curious here- Why has bullhead lasted as long as it has? Less-used sections won't have worn much and sleepers & chairs can last a -long- time under the right conditions, but I'm kind of surprised that there's much at all still in the system.
Is it simply a matter of too much work/expense to replace an entire section of track rather than individual parts as they need it?
z!
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Post by zbang on Aug 1, 2017 6:49:15 GMT
In the case of the District line upgrade a lot of points are being removed. Removed because the upgrade makes them redundant or for some other reason? Unless there are non-trivial track realignments I'd assume that the line(s) would still need most of the existing points. z!
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Post by zbang on Jul 22, 2017 6:18:49 GMT
I don't think I've seen this mentioned elsewhere; I saw a flyer for it at the Brunel museum last month- www.ice.org.uk/events/exhibitions/ice-tunnel-engineering-exhibitionICE invites you to visit the hidden world of underground engineering. From the worms that inspired famous engineer Brunel to the mechanical giants burrowing under our modern cities, the art of tunnelling has come a long way. This latest free ICE exhibition takes you on a historical journey that shows you some of the longest, deepest and most advanced tunnels in the world. The exhibition runs for six months at ICE’s Infrastructure Learning Hub at One Great George Street in central London It includes a fair bit about Crossrail, including a special magazine about building the tunnels and a well-done 2m long LEGO model of a TBM; you don't see those every day . z!
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Post by zbang on Jun 5, 2017 2:40:11 GMT
Being pedantic, the PAC doesn't tell the train how many wheel revolutions to the next station. The PAC tells the ATO box on the train the distance (amongst other things), and the ATO figures out the number of revolutions for itself There are no communications or waypoints between stations? I'd expect at least a few, otherwise it would kill the tph count; the train would have to expect the track is clear to the next station. (Or are there other systems that look forward and adjust speed on the fly, as it were?) 345, 346, 347, Hey! that waypoint's at 353 (...skipping mentally to 353...), 354, 355 etc (It's also entirely possible that I don't understand the ATO system in question.) Edit- some of my questions are touched on in the consecutive-stations-closed thread.
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Post by zbang on May 28, 2017 1:31:52 GMT
The rail and wheel profiles have a lot to do with the sound; for a while the BART transbay tubes were just awful, like can't-read-your-newspaper awful, but with recent grindings they got a lot quieter. (Still too loud in my opinion.)
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Post by zbang on May 27, 2017 17:10:59 GMT
The Chiltern train now does South Ruislip - Paddington - High Wycombe since the timetable change last week. Thanks, when does that depart Paddington? I'd been planning to visit the Hellfire Caves anyway. Also thanks for the PSUL link, quite comprehensive; however it doesn't have this train that I can see. (And my virus scanner does not like the Chiltern Trains web site.)
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Post by zbang on May 27, 2017 3:20:39 GMT
I've been reading about parly's (or parlies?)... first ran into them in a history of early railways, although the usage seems to have changed from a cheap workman's train to "We're not really abandoning this route, what makes you think that?" or as a way to keep the drivers familiar with uncommon routes.
By any usage, are there still any around London?
I've seen some older references to a South (West?) Ruislip -to- Paddington, South Ruislip -to- Morden, and Kensington Olympia -to- Wandsworth. Are those still running? Others?
Thx,
z! who might take one if it was convenient, otherwise just curious
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Post by zbang on May 17, 2017 16:51:46 GMT
Since everyone's playing (and using North American terms)- London (Underground & DLR) Boston (all lines, was the first 'subway' in the USA, predates New York) New York (subway) Washington DC (subway) Chicago (elevated/subway) San Francisco (subway & light rail) San Jose CA (light rail) Kansas City, MO (light rail) Portland OR (light rail) San Diego CA (light rail) New Orleans LA (streetcars & light rail)
I have not ridden a camel.
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