|
Post by zbang on Feb 16, 2019 18:43:00 GMT
So while you'll have no problem finding a helpful member of staff at Oxford Street or Victoria you might not be so lucky at Buckhurst Hill or West Hampstead. From the sound of things, no article clothing will help with that. (Are any stations truly unattended or do they all have at least one person on duty when open? Perhaps that's a separate topic.)
|
|
|
Post by zbang on Feb 15, 2019 17:16:11 GMT
As someone who isn't a regular rider, this really sounds like a solution in search of a problem. (I can't recall ever having to hunt for help, if anything, the stations seem better staffed than the ones around here (San Francisco etc) although that's usually a low bar.)
|
|
|
Post by zbang on Feb 10, 2019 5:49:21 GMT
IPSO was, iirc, supposed to define such a beast but, like describing an elephant, each TOC / ownership group used the spec in its own way. Hitting one of the oldest problems in, well, almost any computer-based system- spec conformance vs actual inter-operability; the industry is rife with examples of this (e.g. OSI vs TCP/IP or iSCSI vs Fibre-channel), the one that inter-operates best tends to be the winner. Of course, that does depend on the vendors wanting to inter-operate, and that's a separate problem.
|
|
|
Post by zbang on Jan 1, 2019 2:27:52 GMT
If that was in London, would the cat flap have an Oyster reader? Don't cats ride for free (I'm sure they think so) or do they have "mouser" concessionary cards? (side note- friend has a cat flap that's unlocked by the cat's microchip, other cats can't come in and eat the food)
|
|
|
Post by zbang on Nov 8, 2018 2:51:04 GMT
Its being demolished for HS2 along with the Bree Louise Loved that pub! The same; I stop there every time I'm in London.
|
|
|
Post by zbang on Oct 20, 2018 21:34:59 GMT
Isn't an out-of-service third escalator also known as a "parts donor"?
|
|
|
Post by zbang on Sept 25, 2018 16:04:38 GMT
I'd just like to point out that the actual computers were not at fault [...]. Rather it would be the software, or ancillary hardware that was at fault. Definitely. I've worked with computer systems for almost 40 years; what passed for production software "back then" was often poorly designed, poorly tested, and the concept of "exception handling" was practically unknown. Or, it was un-cared-about. (We had two older systems in a steel mill, one for a blast furnace and another for a basic-oxygen-furnace. They would metaphorically wander off into the weeds probably once a week and need someone to go poke the data to rights.) Still curious about how they were set up, their actual tasks, etc.
|
|
|
Post by zbang on Sept 24, 2018 21:21:18 GMT
The X signals between Manor House - Turnpike Lane, Wood Green - Bounds Green are not data collections signals. They were introduced to protect the PEECS (Piccadilly East End Computer System (Metal Micky/Evil Edna)) system. When the computerised signalling system was introduced there were so many problems. Trains were taking 30/40 minutes to travel between Wood Green and Cockfosters, it was an absolute nightmare. The computers kept losing data and instead of having the correct number on the diagram each train was labelled '000' as it's data was lost. So... about that machine...(those machines)... There's a thread from 2005 (http://districtdavesforum.co.uk/thread/1473/metal-mickey-mummy-bear-daddy), but I can't find anything else. Are there some souper-sekret pages about them (containing only public info, of course)?
|
|
|
Post by zbang on Sept 3, 2018 2:52:05 GMT
Sounds amazing, will definitely need to try it when I get home next week.
|
|
|
Post by zbang on Aug 13, 2018 1:14:42 GMT
Sounds a bit like a "flag stop" (train only stops when a flag is displayed or a passenger tells the guard/conductor.) AFAICT, a stopping place is a "halt" because it doesn't handle goods. Or it doesn't have any points associated with it. Or a platform. Or is staffed, (occasionally). Or because it has "halt" in the name, sometimes .
|
|
|
Post by zbang on Jun 23, 2018 22:58:45 GMT
Thales have a bit of a history of providing something which doesn’t do what it should, then leaving it down to the client to identify issues. You make them sound like Micro$oft... (actually, like a great many vendors these days) It amazes me that organizations will set up things like this- let's get everyone together to watch the new system fall over. I do hope nobody dresses you down for doing what they said.
|
|
|
Post by zbang on May 14, 2018 4:54:41 GMT
They're putting up amber panels??? How 1990s. (They look like the existing BART display panels.)
|
|
|
Post by zbang on May 13, 2018 2:08:34 GMT
(pulling up an older topic) I often wonder when I see things like this why they don't move the existing code to an emulator on a more modern platform. Few or no operating code changes, just a more modern platform.
(I did a similar project around 1993 to replace a 25 year old Westinghouse computer which operated in the critical path of a steel-making process. We didn't make any changes to the existing code other than for the new terminals (simulated the old ones), and those were heavily vetted and tested. It worked well; took six+ months, but it worked.)
|
|
|
Post by zbang on May 3, 2018 3:11:35 GMT
Grumble, I'm on the wrong side of the pond this year.
|
|
|
Post by zbang on Apr 22, 2018 4:07:34 GMT
When it goes wrong, it will be Furious Rail. Slightly wrong would be Vexed Rail?
|
|
|
Post by zbang on Apr 15, 2018 3:05:35 GMT
(I hope I'm not further splitting the subject) 15v through the running rails if memory serves Until you take the relay connection off, when it goes to 100v! It's been a long time since I thought about the minutia of track circuits, but do you mean the open-circuit voltage is 100v and the relay drags that down to 15v (and an occupied block would be down close to zero). That must be a fairly high ballast in the feed circuit. I'd expect a feed supply of maybe 10-15v and an relay which doesn't load that down much. OTOH, I'm more thinking of main-line practice than the short blocks of urban transit. Still, 100v will get your attention!
|
|
|
Post by zbang on Apr 11, 2018 3:12:17 GMT
That makes some sense, the skin effect at 33.33 Hz about 13mm whilst at 125 Hz it's only 7mm (approximate). There's probably also some bio-electrical effects that I'm not aware of, too.
|
|
|
Post by zbang on Apr 7, 2018 3:55:14 GMT
you just need to provide a path from one to ground To be pedantic about it, you have to provide a path back to the source, not to "ground" (or earth). It happens that the traction current source is bonded to "ground" so there is a path from the running rails (and the concrete around them). Also, since I'm being that way, electricity doesn't take the path of least resistance, it takes all paths in proportion to their impedance. I don't plan on watching the video, either.
|
|
|
Post by zbang on Apr 3, 2018 3:16:45 GMT
Modern systems usually have a UPS (Uninterruptible Power Supply) to maintain the supply if there's a power loss. That wouldn't have been practical back when the District was signalled though (1950s?) Even in the 1950s, battery stacks were common in railroad signaling systems. More likely that some bright-eyes thought the electric supply was reliable enough (ahem, cough) or they didn't like the cost of enough batteries and maintenance. Or... did they use AC track circuits at the mains frequency? Come to think of it, none of the books I have about UK signalling practice, not that I have many, mention backup power. is the District line signalling based on AC or DC circuits? (Which sends me at various web sites to find out.)
|
|
|
Post by zbang on Mar 31, 2018 5:12:57 GMT
I would expect some amount of batteries involved to maintain the signals and a bit of distributed feeds. No? Seems like close to a single point of failure here.
|
|
|
Post by zbang on Mar 24, 2018 22:27:58 GMT
Yep, its my go-to map. Downside is that it's a bit large to open on some portable devices.
|
|
|
Post by zbang on Mar 24, 2018 21:24:50 GMT
Nice to see it's all so simple . I was expecting a "but if it's Wednesday or Thursday" somewhere in there. (Off to the maps looking for loops and triangles.)
|
|
|
Post by zbang on Mar 14, 2018 16:29:34 GMT
That'll be because of the broken bit of kit. Did they ever announce which piece of equipment was out-of-sorts?
|
|
|
Post by zbang on Mar 13, 2018 1:16:59 GMT
If -I- win... save me a few pieces.
|
|
|
Post by zbang on Mar 13, 2018 1:04:09 GMT
What happens to the lever frames & interlocking equipment when the cabin is decommissioned? Spares for other cabins, museum exhibits, or scrap?
|
|
|
Post by zbang on Mar 10, 2018 23:27:16 GMT
My understanding is that the lathes can easily switch profiles. Mainline railways often use different profiles on their various rolling stock and it wouldn't make any sense for the the device to be locked to a single shape.
Also, I can't speak to UK practice, but in the USA it's common to swap the entire axle & wheel unit if either wheel needs work (which, of course, requires enough spares). That or they turn the wheels while still on the bogie, which is probably easier than axle-swapping when there's a traction motor involved.
How frequent is wheel turning on the DLR or LU trains? I wonder it there's another piece of specialized equipment that's out of service, such as a drop-table (for entire bogies), or a crane.
|
|
|
DRICO
Mar 9, 2018 17:15:48 GMT
Post by zbang on Mar 9, 2018 17:15:48 GMT
Weren't these wires also used to discharge the traction current? Or was that a separate set?
|
|
|
Post by zbang on Mar 3, 2018 3:34:01 GMT
Curious... does Armstrong refer to the location, a person, or that it was operated by strong arms (in the vein of interlocking lever frames that are entirely human powered).
|
|
|
Post by zbang on Mar 2, 2018 4:29:24 GMT
Now at the moment the stations are a long way from PPE free (PPE means Personal Protective Equipment i.e. orange hiviz, hard hats and boots) so I'd guess these open days are a couple of months away at least. I'd be happy with a PPE-required tour, and I'll even bring my own.
|
|
|
Post by zbang on Mar 1, 2018 7:07:39 GMT
Steam engines could cope with a bit of paddling, but third rail electrification is a different matter! Hmm, I wasn't aware of the drainage problem and for some unknown reason, I was thinking of overhead electric, not third rail (which should have been obvious). You also have the possibility of water getting into the traction motors. (goes off to look up more info about the tunnel)
|
|