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Post by zbang on May 2, 2024 15:58:05 GMT
I don't know the specifics of the TRV, but replacing bad sensors with newer design is pretty much a solved problem; might involve some signal conditioning (e.g. level shift or freq->voltage) or maybe a box that converts the new sensor's digital signal to the expected analogue of the logging system. It's simply a matter of will and money. I spend a lot of time at an aging steel mill working on this kind of stuff, and it's gotten a lot less expensive in the last 25 years.
In terms of a cant sensor, even high-quality semiconductor accelerometers are quite inexpensive and they easily interface to many (also inexpensive) industrial single board computers; those could be configured to output pretty much whatever is needed. Cost is probably under £1000 for the hardware and under a week for a competent engineer.
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Post by zbang on Apr 26, 2024 23:02:15 GMT
it's possible I missed something along the way, however-
"life-expired track recording vehicle" Does that mean simply that it's old, that parts are failing and can't easily be replaced, or what? (There's plenty of old railway equipment out there operating happily.)
If it's a matter of age.... if the equipment can do the job, why is this an issue? Maybe it needs to be towed by a signals-compliant machine, but that doesn't seem like a large impediment.
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Post by zbang on Mar 20, 2024 15:37:15 GMT
I rather expect that some of the software folks are all over this. Me- "When I do YYY, the system crashes." Programmer- "Well, don't do that." Me- "Don't let me." (actual conversation I've had multiple times with software developers)
I'd also love to hear about the root cause, but that's unlikely.
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Post by zbang on Mar 18, 2024 16:06:37 GMT
IIRC, there was some iphone software that knew enough to say which parts of which platforms were step-free to the train, not sure it's still around.
The general problem is not only knowing where steps/stairs but knowing the rough amount (one, "a couple", "more than a few", etc). "AI" isn't useful*, simply having the information and changing the normal planning algorithms use it would do the job. (Does this info exist, either at TfL or elsewhere?)
*seldom is for this sort of problem
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Post by zbang on Mar 4, 2024 18:17:22 GMT
I think you would also have to correlate that to the actual wheel profile.
Also, my understanding of surface corrugation is that it comes more from an intermittent longitudinal force (from intermittent braking) then from vertical force; we see that in some road surfaces, usually at the end of motorway ramps (there are some prime examples of that not far from me).
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Post by zbang on Mar 2, 2024 17:59:37 GMT
Dunno, -I- wasn't confused. In context, 468m is most likely 468 meters (or metres, if you prefer), not miles of any sort.
As for "standards", there are those codified by an internationally-recognised body and those "because everyone (here) does it that way". Again, context is important.
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Post by zbang on Feb 24, 2024 18:45:48 GMT
I'm still missing something. Do those TSR's pre-date the failure of the TRT? It sounds like they were introduced as consequence of that failure. If the TRT was able to run, I assume the TSRs be removed as the track could be proved to be in order.
Or, are there certain sections that will have a TSR applied if not tested within a certain interval? I don't know the standard practice for TRT use on the Central (or other lines). I could see that for tighter curves or more problematic areas.
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Post by zbang on Feb 24, 2024 16:47:45 GMT
I'm missing the cause/effect connection from the track recording train being defective and the TSRs. Are they because the TRT couldn't re-certify those segments, new conditions that can't now be tested, or something else?
Or is there no connection at all?
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Post by zbang on Feb 18, 2024 16:06:53 GMT
Since there are often discussions of the timetables, how are they created? I imagine that they're initially driven by demand across the system and stock availability but what else goes into the process? Eventually it has to get to allowed driving hours & breaks, driver availability(?), transit time between stations, station dwell, and I'm sure many other factors, then something calculates all of the clock times for everything.
What's the actual process? (I don't recall reading about it in any of my books.)
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Post by zbang on Feb 6, 2024 17:06:01 GMT
Simply on the cost question, there are many cubic meters of dirt to remove then probably half a mile of new road and pavements to construct. _Then_ add in the cost of the crossing and signaling. So "how much"? More than a bridge.
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Post by zbang on Feb 6, 2024 2:58:10 GMT
(.....a few days ago the RAIB issued a report about an occurrence.....)
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Post by zbang on Feb 4, 2024 6:24:23 GMT
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Post by zbang on Feb 3, 2024 6:05:59 GMT
I'm glad you answered! (This is the sort of thing I came here for.)
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Post by zbang on Jan 31, 2024 17:27:53 GMT
A reason? Friction drives are easy. And the friction point is probably the final drive wheel to the handrail itself. (Pure speculation, but then I'm not an escalator mechanic).
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Post by zbang on Jan 29, 2024 23:28:51 GMT
More often I notice that the handrail is running fast, but AFAICT it's common enough all over.
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Post by zbang on Jan 24, 2024 17:57:57 GMT
Unfortunately the latest info/plans regarding Grinding, Pandrol rail fixing replacement, current noise levels etc appear not to be publicly available ... Current noise levels are entirely public , all you need is a sound pressure level (SPL) meter and there are apps for both apple and android phones that work reasonably well. These may not be calibrated, but IME are usually within a couple of db, and that's close enough for most things.
You can purchase a hand-held SPL meter for £20-40 on amazon.
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Post by zbang on Jan 15, 2024 17:41:17 GMT
ISTR that during last summer's visit I tried the TfL planner a few times but went back to goog as it generally produced more sane routes.
Although.... from where I was staying in Lisson Grove it had me using Edgware Rd, Marylebone, or Baker Street depending on some unknown algorithm which probably included the exact second when I pushed Go.
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Post by zbang on Jan 8, 2024 21:43:53 GMT
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Post by zbang on Jan 7, 2024 18:25:20 GMT
BTW, the thread title is a bit misleading- the punctuation implies the dispute is between the RMT and ASLEF, not the two together against another body (TfL etc).
title adjusted to remove Union names Dstock7080
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Post by zbang on Jan 4, 2024 18:35:49 GMT
Which union(s) cover the buses and trams?
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Post by zbang on Dec 29, 2023 1:37:44 GMT
Thanks, I'm more thinking of something on-line I can see from here.
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Post by zbang on Dec 28, 2023 17:14:21 GMT
Have there been a public notices about motor failures? A quick search didn't turn up anything for me.
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Post by zbang on Dec 25, 2023 0:52:50 GMT
... and it ended up counting as two separate journeys. It’ll be annoying if I have to keep contacting TfL for a refund every day I walk to Warren Street during these escalator works! Shouldn't fare-capping take care of that? Or does that not apply to your journey? (Not up here on some of the specifics of how fares are calculated.)
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Post by zbang on Dec 15, 2023 5:26:47 GMT
The term I’ve heard is many trains have “flashed motors” which means motor issues, Assuming these are using DC motors (AFAIK correct), there's an occurrence called a commutator flashover which can destroy the brushes, brush holders, and often part of the commutator (it's not pretty). Basically you take some conductive dust, with maybe water or high humidity mixed in, and smear it on the commutator; it gets pushed between the bars and has a low enough electrical resistance to conduct between the commutator bars and maybe arc to the frame.
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Post by zbang on Dec 8, 2023 3:41:13 GMT
And if so, presumably this required all the P-gates which run off the air main to be replaced at stations? Or to install a small compressed air plant at those stations, probably faster than gate replacement.
Re- invisible legacy systems I've been involved with projects to do just that, although not on a railway, and it can take an amazing amount of resources. In one project, we had to trace every wire and connection to make sure than nothing was using that system. On a similar tack, a colleague spent three months planning and investigating in order to remove power from a data center for 20 minutes. ("Who owns this old computer stuffed in that rack?" "The label says Rick Smith at x2345. "HR says he retired three years ago.")
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Post by zbang on Dec 7, 2023 17:31:35 GMT
I rather enjoy them, and Geoff Marshall's, too.
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Post by zbang on Nov 28, 2023 18:00:45 GMT
I have wondered, however, why LUL staff cannot use them in rail gaps? If you're referring to gaps in the traction current rails, these won't have the current carrying capacity to move a train without melting. There's also a question of the "advisability" of connecting two different sections; quite inadvisable in most cases IMHO.
(My opinion, but probably accurate.)
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Post by zbang on Sept 26, 2023 19:48:37 GMT
@a60stock, if you're really curious, read some of the RAIB reports; pretty much all of them have so-called Learning Points and recommendations at the end. Fortunately, there only seems to be around one report a year in the "Metros" class. (RAIB- Rail Accident Investigation Branch www.gov.uk/raib-reports)
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Post by zbang on Sept 14, 2023 18:43:43 GMT
I was thinking of the same argument John makes- you can't control what gets plugged in. And for what are not would I'd call long distance trains (what's the length of the average Eliz Line journey?), I'm not sure it makes much sense to push for 240v outlets. That said, there are certainly packaged units that have both the BS1363 and two USB-A jack (there are fewer with type C jacks; look at the Screwfix web site).
Don't most of the newer long distance trains have these (240v & USB)?
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Post by zbang on Sept 13, 2023 0:04:25 GMT
High-speed cables don't matter for simple charging, and IME most people carry A->C cables just for charging because most charging outlets are type A. (Sample of one- my phone and tablets are usb-C, I carry an A-C cable to charge them and a C-C cable for data transfers.)
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