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Post by class411 on Apr 8, 2018 9:07:41 GMT
There are places where the negative rail is at 0V, usually where track is shared with NR trains. But surely any requirement for on board supply at less than line voltage is taken from the main supply using a potential divider, not by a separate feed from one or other rail? As for the effects of electricity on the human body, it depends more on thevroite it finds through the body and therefore which muscles are triggered than on whether it's AC or DC. A shock to the leg muscles can make you hurl yourself across a room. To the fingers can cause you to be unable to release your grip. To the heart can stop it. You can also get severe burns. The amps are relevant, but the current flowing through you will depend largely on the electrical resistance of your body (and anything between you and the electric supply or the ground, such as your shoes). If the short circuit from rail to ground passes only from toe to heel of one foot, the resistance is low and the current therefore high. You will get a very nasty burn but the current will only pass through your foot. If it passes from one foot to the other the resistance will be greater and the current less- but it will pass through more vital organs (and those powerful leg muscles) Actually, the resistance between any two (external, skin covered) points of the human body is pretty much constant. This is because once the current is through the outer layer of the dermis it very quickly find some hot salty liquid (a.k.a. blood) that offers a very low resistance, and proceeds to flow along that. This is why you can kill yourself with a 9v battery if you connected one side to each arm through broken (and still bleeding) skin. Fortunately this is not something that's at all likely to happen by accident. And can we lay this "it's not the volts" myth to rest: The volts will kill you. Yes, you need enough current available (something that's not [or is] a problem with the mains, or a railway's traction supply), but you need the volts to drive it. So you actually need both the volts to drive the current and the available current, in order to do the damage. (The reason that people saying "it's the current that kills you" is annoying is that whilst in one sense it's a tautology, in another it's plain wrong, as having 1 billion amps available will do you no harm whatsoever if the available potential difference is only one volt.)
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class411
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Guards
Apr 5, 2018 6:53:50 GMT
Post by class411 on Apr 5, 2018 6:53:50 GMT
Guards were supposed to monitor the platform until one third out of the platform, to ensure safe departure. the red handle above the guards panel is an emergency brake handle which was pulled down to stop the train, hence the expression "pulling him down"
Interestingly the guard acts incorrectly at the five minute point, you see him push the button to close the guards door as the train moves off then continue to watch the platform, presumably keeping the door open with his shoulder or foot.. He should not do this for safety reasons. Should he happen to fall off the train the door would close and might trap his foot dragging him along the platform, if button not pushed then he would just fall clear.
I remember seeing many a guard do this on the Northern - I thought it was standard practice!Does anyone know what the advantage of the non standard procedure would have been? (Apart, I suppose, of stopping a truly desperate commuter from trying to barge in [or worse, out] past the guard?)
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class411
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Guards
Apr 4, 2018 13:19:37 GMT
Post by class411 on Apr 4, 2018 13:19:37 GMT
In the entire history of the underground, is there any record of an accident caused by this practice in the hundreds of thousands of times it was performed? I remember a post on the forum years ago about a Northern liner guard who lost his head doing this, having forgotten about the Hendon to Colindale tunnel Presumably he missed out the 'looking carefully in the direction of travel' bit. When I posed the question, I thought that the only likely accident would be not holding on properly and falling out. Possibly colliding with a passenger if they were being really careless.
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Guards
Apr 4, 2018 7:48:31 GMT
Post by class411 on Apr 4, 2018 7:48:31 GMT
Not on the same level but I remember as a kid travelling on the Central line from Epping in the guards car and thinking, (in the 60s) what a primitive system to operate the doors, never guessing that 30 years later I would be doing that job on the Northern. I couldn't believe that people were allowed to hang out of trains like that, it would be even less believable now. Hope this dosent take the thread off topic. I only remember guards on the Central and Northern lines in the mid 90s, but what makes me feel old is that, describing the way guards used to hang out the door to someone in their early twenties, they were astounded. Can you imagine the risk assessment? I would say the risk is relatively low. Certainly lower than the risk to someone using a crutch and having to get out of a train in the rush hour at the least favourable point on a very curved platform. You have an able bodied man (back then) with something specifically designed to hold on to, undergoing a reasonably linear acceleration, and looking carefully in the direction of travel. A lot safer than some of the things builders do from time to time. In the entire history of the underground, is there any record of an accident caused by this practice in the hundreds of thousands of times it was performed?
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Post by class411 on Apr 1, 2018 14:10:25 GMT
Many years ago I christened this the 'kettle' syndrome..... <snip> ....(although not necessarily with every minor element of it.) I only spotted this because "April 1st syndrome" has put me on edge. Very droll. I don't suppose anyone will believe me but I swear to God that that was unintentional. It's not that they break (well, one did but everyone who had the same model had the same problem: the lid mechanism failed after a couple of years). No, the problem was/is that every different type kettle has at least one niggle (switch/lid/spout/water gauge, etc.), and yet instead of instead of each manufacturer fixing the niggle, they go in for a complete redesign every couple of years, and never manage to get it 100% right.
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Post by class411 on Apr 1, 2018 8:50:29 GMT
Beat me to it. If you follow the software analogy there are plenty of examples of people buying into and regularly using "bug riddled software" - I have lost count of how many "updates" have been made to Windows 10 let alone Windows 7, Windows ... Inherently if it reaches the standard required by whatever specs were agreed between supplier and purchaser then the fact it cannot handle other stuff which were not covered in the spec may be unfortunate but probably never going to result in compensation to the customer. If there are evident areas where the spec is not met then legal action is often the worst solution. Almost inevitably both sides then harden their positions and the potential for a practical compromise or just reaching a deal on equitable compensation often goes out the window. Often lawyers are the only real winners. Staying slightly off topic for a moment, the trouble with consumer software (and particularly Windows) is that just as it's really well bedded down, with most of the important bugs ironed out, they scrap it and foist a new, bug ridden, effort on the general public. Many years ago I christened this the 'kettle' syndrome: We've had electric kettles for many decades now, and it ought to be possible to make them nigh on perfect. What happens in practice, however, is that a manufacturer brings out a kettle, and instead of bringing out a revision that addresses it's faults in a couple of years, brings out a completely new design with its own niggling faults. At least with the railways, they do tend to stick with a major system for many years once it's well 'bedded in' (although not necessarily with every minor element of it.)
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Post by class411 on Apr 1, 2018 8:42:24 GMT
I thought that I read somewhere (probably on here) that the JL had slack built-in to its timetable (or maybe that the timetable's assumed max speed was (say) 10% less than max linespeed) so that in the case of a particular dwell time being longer than expected, that the train would run at higher than timetabled speeds until it had caught up. I suppose that running at 97% (say) max speed gets more TPH than (say) 90%, but are we running so need max capacity that a few seconds extra dwell time in a central station leads to "bus bunching"? I think this is an excellent point. It's absolute madness to run a system that it is known will partially break from time to time (and, in this case, that includes so many passengers trying to e/ingres that dwell time goes outside allowance), at maximum theoretical throughput. With a railway system, though, if you look at any line as a whole, it may be desirable to accept a certain amount of bunching in the busiest sections and provide the slack elsewhere. Determining the balance to get the highest sustainable throughput is the magic skill.
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Post by class411 on Mar 28, 2018 8:22:35 GMT
"or not" presumably means the image was not loading. "nvm" = never mind "smh" = shaking my head Whilst these are all now prevalent abbreviations/text speak, and so within the letter of the forum rules, they're probably not quite in the spirit as they are more at the 'younger' end of Internet users. As always, members are reminded to avoid the use of abbreviations/acronyms/initialisms without an explanation, particularly unusual or specialist terms. If in doubt, spell it out. Thanks.I'm still not clear which image he's got a problem with. Assuming he's referring to my post, one of the images doesn't display and one does. I've checked this now with PC (edge/chrome/opera), Android, and iOS, and it's the same with all of them. So it would be really helpful if he could make clear exactly to what the 'or not' refers. And does the NVM/SMH mean he's worked out what he was doing wrong and is shaking his head at his own ineptitude, or that he's decided he no longer cares, and has lost the will to live?
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Post by class411 on Mar 28, 2018 7:56:48 GMT
or not edit: nvm it wasn't loading smh That is as about as unclear as it's possible to be. To what does the 'or not' refer? And what are 'nvm' and 'smh'?
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Post by class411 on Mar 27, 2018 11:46:20 GMT
I'd really love to see this now! Have you any pics or is it possible to scan it for us to see? I don't have any pics at the moment. The link I linked to is to the TfL site. If you can masquerade as a 3-yr old, I'm sure TfL will send you one... If it's possible to put pics on here without a needing a flickr etc account, then I'll try and get some up, but won't be for a bit I'm afraid. You can use the Imgur site to post one-offs without creating an account. Here's one I did just to prove (to myself) that it works. As you can see it doesn't. However you can post a link to the picture: Link to a pictureOr, you can right click on your picture as shown on the Imgur site, click 'copy image address', and use that url to add an image here, as below.
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Post by class411 on Mar 27, 2018 8:14:07 GMT
I'd really love to see this now! Have you any pics or is it possible to scan it for us to see? I don't have any pics at the moment. The link I linked to is to the TfL site. If you can masquerade as a 3-yr old, I'm sure TfL will send you one... If it's possible to put pics on here without a needing a flickr etc account, then I'll try and get some up, but won't be for a bit I'm afraid. You have to wonder why TFL are being so Secret Squirrel about it.
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Post by class411 on Mar 26, 2018 10:15:36 GMT
They get on at wood lane, and it's a good recognisable illustration of a picc line extension station. With Victoria Line stock in the station (detailed down to the active door sensor wasp stickers on the door edges...)... I'm boggling at how they managed that. If the artist had drawn it from life, that couldn't have happened, if he'd got a pic of the station with train in, it couldn't have happened, if he'd just googled it, it would be unlikely to happen. Someone had to actively go out of their way to do that. In the grand scheme of things it's not the end of the world, but if they've gone to the trouble of drawing a recognisable tube station and a recognisable train, why couldn't they match...? My guess is that it's deliberate and done so that as many people as possible find something to recognise in the picture. Not sure how well they've succeeded, though.
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Post by class411 on Mar 16, 2018 10:43:36 GMT
That fact that the seats appear to be harder than previous is disappointing. I wonder when the days of bringing ones own cushion will arrive (especially if you have a bad back- although a firmer seat can be beneficial!)? They may well 'bed in' after a few weeks.
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Post by class411 on Mar 12, 2018 14:25:50 GMT
In 'Key Lines and Symbols', 'Northern' is missing it's first 'r'.
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Post by class411 on Mar 10, 2018 10:26:57 GMT
I worked at Watford Met and Croxley. I don't think anybody ever got on that last train to Ricky. There was never anybody about. Anyway it would have been lamped out and announced Ricky only if anybody was going to get on it. The north end of the Met was and maybe still is a different world. What does the underlined part mean?
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Post by class411 on Mar 10, 2018 9:18:09 GMT
The big problem with South Eastern is that the were promulgating false information on the 'live departures' board.
It made it look as if the restricted service was running well.
If trains that are (normally) formed from stock that is completing a ~2 hour journey are described as 'on time', it is reasonable to assume that they are running and in their expected positions.
This is what SE did for virtually all of Friday morning. Only when you got to Victoria and saw no trains at all on platforms 1-8, and found the information screen did you, after it had displayed up to three other pages, get the information that the conductor rails were iced up and nothing was running south of Swanley.
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Post by class411 on Mar 9, 2018 10:52:15 GMT
The PM system is there for personal communication, but I hope you won't mind my commenting as you've made this a public post. It's very easy for the mayor to give directions to entities that are under his direct control. He does not, however, have the power to impose restrictions on individual citizens unless that power is enshrined in law. This is where it would require legislation which is not a straightforward matter.
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Post by class411 on Mar 9, 2018 9:54:29 GMT
Does the New York experience translate to London? The issue in the UK has to be political - can anyone make the equivalent “snow day” process happen? Does the Mayor of London have the legal power to declare the London equivalent of a “snow emergency”. I suspect not…. It would almost certainly not be worth the planning, provisioning, and legislation involved for something that happens so infrequently.
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Post by class411 on Mar 8, 2018 15:07:22 GMT
I knew I was missing something obvious. Doh! Ha ha, go and have a lie down now class411 Feeling better, now. Wibble.
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Post by class411 on Mar 8, 2018 9:43:42 GMT
I don't think the issue is for people going to Hainault, more for those that actually wanted to alight at Wanstead, Redbridge &c... I knew I was missing something obvious. Doh!
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Post by class411 on Mar 8, 2018 9:37:40 GMT
I'm completely bemused.
I assume you are talking about people boarding at or to the south of Leytonstone.
In which case the two options after Leytonstone are:
Snaresbrook South Woodford Woodford Roding Valley Chigwell Grange Hill Hainault
or
Wanstead Redbridge Gants Hill Newbury Park Barkingside Fairlop Hainault
If passengers don't like the route and detrain at Snaresbrook they then have
Cross bridge Wait for next train Leytonstone Detrain Wait for next correct Hainault train Wanstead Redbridge Gants Hill Newbury Park Barkingside Fairlop Hainault
Is there some sort of 'Edgeware of the North' on the Hainault via Woodford run where trains stop and wait indefinitely? Or am I missing something much more obvious?
ETA: Looking at some older diagrams it appears that something odd happens at Woodford but it's not entirely clear what.
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Post by class411 on Mar 7, 2018 10:06:25 GMT
Also, unfortunately, some people consider it a sign of personal weakness not to attempt to get to work if there is the tiniest possibility that they can make it. (The same sort of people who come into work with streaming colds and infect everyone else.)
And there are others who feel that if they show that work can carry on in their absence they will be deemed permenantly unnecessary.
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Post by class411 on Mar 3, 2018 13:23:43 GMT
Excellent analyses, Chris.
It's all very well for the authoritarian, holier than thou, types to adopt a counsel of perfection attitude, but the railways are transporting people, not sheep.
One thing that the railway companies (inc tfl) never seem to learn is that providing constant, timely, accurate, information is often key to managing these events, as well as less serious ones where the train is held for a long time at a station.
I suffered one major hold up and two abandoned journeys over the last three days, and in two cases the information being peddled by the train companies amounted to outright lies.
I have absolutely no problem at all with any of the delays or cancellations.
What I do have a problem with is the companies indicating that trains are running and 'on time', when they are not, in fact, running at all.
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Post by class411 on Feb 27, 2018 15:15:42 GMT
To be pedantic, the question is whether there is anything that the company could reasonably have done. Such as implementing a new ticketing system that was more easily able to negate lost or stolen tickets, or imposing a less swingeing penalty for such lost and stolen tickets, perhaps. LOL, I'm not sure if that's a serious comment, but the law doesn't work like that. The judge is not expected to consider why the plaintiff acted recklessly. Would you expect her/him to find for the plaintiff if the rail company had run his train late the day before and he'd been threatened with the sack if he turned up late again that week? Although, in general, I'd agree that train companies have been given far too much power to 'punish' travellers for not correctly handling their convoluted ticketing systems and rules and regulations, particularly as it is their desire to save money by removing ticket collectors and such like that necessitated such swinging penalties in the first place.
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Post by class411 on Feb 27, 2018 14:00:39 GMT
I'm not sure the judge is qualified to say that the current procedure is adequate for safe dispatch. The judge can only comment on one particular case, and in this one the judge says that there is no action the company (s) could have taken which would or could have prevented the tragic and traumatic injury. To be pedantic, the question is whether there is anything that the company could reasonably have done. Obviously they could install a marshal for every carriage at every station, but that would hardly be a 'reasonable' expectation. Had the plaintiff's barrister been able to show that that particular company operated in some way that was less safe than the industry norm or the the industry as a whole had not implemented some cheap and easy procedure/equipment set-up, then the case might well have succeeded.
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Post by class411 on Feb 23, 2018 19:18:04 GMT
The 'Newspaper' article is quite misleading, Alex Johnson did not unveil a range of driverless trains. He had a few speculative drawings manufacturers did on a computer. Ah, so a train is a driverless train when there's no driver in it. So, for many hours at a time LU have quite a lot of 'driverless' trains. Fewer on Friday and Saturday.
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Post by class411 on Feb 4, 2018 12:19:37 GMT
On a purely technical note, real time computer analysis is now well up to the task of observing the input from cameras along the edge of a train and detecting if anything alongside the train is accelerating with it. Repeatedly saying people shouldn't do x and y is pretty pointless if they've been doing it for decades and there is no way to stop them. The sensitive edge equipment on the S stock seems to achieve this, all be it in a very different way from described. Indeed, but it will be many, many, years before all trains are so equipped. I haven't heard of any plans to retro-fit such equipment to the current - non S stock - fleet. (Which doesn't mean it's not being considered, of course, but I imagine it would be difficult in a number of ways.) Of course, fitting cameras above a few hundred platforms and linking them up wouldn't be a walk on the park.
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Post by class411 on Feb 3, 2018 13:55:15 GMT
It's sooo annoying when people misuse words. Every time I see it happen I'm literally beside myself. My ex-missus used to hate it when I corrected her spelling or grammar. I only did it because I didn't want people to think she was thick and try to get one over on her. Anyway, I did stop eventually when she angrily turned to me and said "Every time you correct my grammar, I love you just a little bit fewer." That is absolutely BRILLIANT!!
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Post by class411 on Feb 3, 2018 9:07:52 GMT
I worked as a Station Assistant from December 1997 until August 2002 and I've never seen or heard of a UTS gate paddle falling off even when someone had forced their way through the gates. I doubt if you are in any way to blame for the gate but I believe you could be subject to a £1000 fine for blatant misuse of the word "literally"....... It's sooo annoying when people misuse words. Every time I see it happen I'm literally beside myself.
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Post by class411 on Feb 3, 2018 9:05:22 GMT
On a purely technical note, real time computer analysis is now well up to the task of observing the input from cameras along the edge of a train and detecting if anything alongside the train is accelerating with it.
Repeatedly saying people shouldn't do x and y is pretty pointless if they've been doing it for decades and there is no way to stop them.
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