eightf48544
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« Reply #345 on: January 30, 2018, 15:52:36 » |
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Might be different rules for running on full diesel power between 800s and 802s
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mjones
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« Reply #346 on: January 30, 2018, 17:48:11 » |
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Just watched a London bound IEP▸ leave Reading with pantographs up but a distinct diesel engine sound from the end nearest me. Is there any explanation for that other than ongoing problems with switch over?
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stuving
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« Reply #347 on: January 30, 2018, 17:53:26 » |
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Just watched a London bound IEP▸ leave Reading with pantographs up but a distinct diesel engine sound from the end nearest me. Is there any explanation for that other than ongoing problems with switch over?
The fans cooling the input transformer do make quite a racket, though it's not exactly diesel-like. The transformer in one end carriage, while the diesels, of course, are only in the middle three. I watched one going through Reading yesterday - definitely electric in and out.
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« Last Edit: January 30, 2018, 18:55:50 by stuving »
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mjones
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« Reply #348 on: January 30, 2018, 18:24:47 » |
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No, this was definitely engine noise from the diesel coach next to the transformer coach, ie the second along from the end. I think other ones were running as well, but couldn't be sure. I had walked to the end to see if the pan was up because I was curious about the noise.
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drenahmeti22
Newbie
Posts: 9
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« Reply #349 on: January 30, 2018, 20:45:49 » |
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I saw 800204 go past me on Platform 6 today with its pan up and on electric.
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Adelante_CCT
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« Reply #350 on: January 30, 2018, 21:13:31 » |
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I sure hope it was not using Platform 6 at Reading with its pan up
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devonexpress
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« Reply #351 on: February 06, 2018, 20:20:41 » |
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Does anyone know whether the different Class 800 variants are considered to require separate traction knowledge? I am thinking in particular of the version for the Plymouth and Penzance trains.
From the RMT▸ letter that was posted elsewhere on the forum, I believe all IEP▸ 's have to be operationally the same. Of course if there are differences, GWR▸ will provide training courses to drivers as and when needed.
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mjones
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« Reply #352 on: February 09, 2018, 17:27:58 » |
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Does anyone know how IEP▸ introduction is going compared with what was planned? My impression from the last couple of weeks is more consistent with HST▸ introduction and IEP withdrawal!
Edit- just seen one at Reading,.London bound running on diesel...
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« Last Edit: February 09, 2018, 17:43:50 by mjones »
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WelshBluebird
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« Reply #353 on: February 21, 2018, 16:14:37 » |
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Other fora suggesting there is going to be some sort of IET▸ journey time record attempt between PAD» and RDG‡ this morning Unconfirmed at 21 mins. Seems this was to show what can be achieved within permitted line speeds. It's going to feature in the next series of the Paddington "fly-on-the-wall" documentary, apparently. Seems like GWR▸ are using this as part of their social media talk! (For anywho can't or doesn't want to go to the Facebook link, its a speeded up cab view of the run). https://www.facebook.com/gwruk/videos/10155136262406806/
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stuving
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« Reply #354 on: February 22, 2018, 17:37:58 » |
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We had reports earlier of electric-mode IETs▸ upsetting axle counters, and I rather dismissed this when it was raised on the grounds that these axle counters were designed to cope with electric traction and have met a lot of different varieties already. But I heard it last month being described as still happening, and now I see the same on RailUK forums today. So could it really be direct EM interference with the sensors, rather than comms cables (which was also reported before as affecting the axle counters)?
I already knew that the Thales Zp30 sensors work at around 30 kHz, which seems safely above any mains harmonics that should escape filtering. But, of course, the trains have other power frequencies, to drive the motors and within the inverters. AIUI▸ the motor drive (DC▸ to three phase, and the reverse) and the input rectifier/converter (which works in reverse as a DC to single phase inverter for regeneration) will be PWM IGBT▸ inverters. Exactly what that means doesn't matter here, except that the IGBT switches are turned off and on many times per cycle of the power frequency, and that switching frequency is a potential source of interference well above 100 Hz.
You can hear this frequency: most modern trains sing (even diesels, though you can't hear it). Some sing with a wide vibrato, 800s without - I went to audition one last week in Reading. I've never been any good at "name that tone", so my judgement of the frequency as about 1 kHz may be wildly out. I didn't think to record it, and I don't seem to have anything (audio or mainly video) that would cope with this rather quiet sound. If anyone happens to have a recording of one, maybe it could be looked at.
If there is interference from a harmonic of the inverter frequency, who's responsible for stopping it? I reckon the train is. That frequency has no reason to be outside the black box with "inverter" written on it; it only has any function inside it. It should be filtered out - after all, one reason for putting it much higher than the power frequency is to make such filtering easier. So I can see two fixes for this: add some more/modify the filtering, or shift the switching frequency a little to move all the harmonics to new safe positions.
The rules about this are in a technical standard (EN 50121), Railway Group Standards GE/RT8015 and GE/RT8270 about who does what, changes, and resolving conflicts. The infrastructure controller (NR» ) draws up lists of the emissions levels the various bits of his lineside equipment can tolerate versus frequency. Similar lists are needed for trains' susceptibility to infrastructure (and each other!), which can be route-specific. These lists are then an implied part of any rolling stock or infrastructure equipment procurement.
In this case the trains are new, and so is the widespread use of the axle counters. Which was known about first and could be listed as pre-existing it's hard to say, and I can't see anything on those RGSs about setting aside a band for future use and protecting it from EMI. So it probably comes down to the same kind of pragmatic engineering that EMI always has - you all just have to ignore the lawyers, dive into the can together, and wrestle those worms.
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Surrey 455
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« Reply #355 on: February 22, 2018, 21:19:46 » |
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In this case the trains are new, and so is the widespread use of the axle counters. Which was known about first and could be listed as pre-existing it's hard to say, and I can't see anything on those RGSs about setting aside a band for future use and protecting it from EMI. So it probably comes down to the same kind of pragmatic engineering that EMI always has - you all just have to ignore the lawyers, dive into the can together, and wrestle those worms.
EMI means something very different in Hayes. They had a large employment base by the railway line manufacturing vinyl records, medical instruments and possibly other stuff.
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stuving
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« Reply #356 on: February 22, 2018, 23:46:17 » |
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In this case the trains are new, and so is the widespread use of the axle counters. Which was known about first and could be listed as pre-existing it's hard to say, and I can't see anything on those RGSs about setting aside a band for future use and protecting it from EMI. So it probably comes down to the same kind of pragmatic engineering that EMI always has - you all just have to ignore the lawyers, dive into the can together, and wrestle those worms.
EMI means something very different in Hayes. They had a large employment base by the railway line manufacturing vinyl records, medical instruments and possibly other stuff. Most things do mean something else if you want them to (and if you don't). And EMI did far more than that - TV (Schoenberg's system, which really worked), radar, stereo records, etc, etc. I did visit Blyth Road, Hayes, a couple of times. It would have been more but by the time EMI 'joined' us in Thales they were already planning to move to Crawley. There they met up with MEL again, having split a bit earlier, so that TPWS▸ became one of their products again. That work was always done a Crawley (no, it's a lovely place, really).
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« Last Edit: February 23, 2018, 07:57:33 by stuving »
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stuving
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« Reply #357 on: February 23, 2018, 00:36:41 » |
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Anyway, I was talking to one of my informants* tonight, and apparently the proposed cure for this IET▸ vs axle counter issue is to replace one of the cables with a fibre-optic one. I don't know if that's been tried, and may be the replaced cable there was talk about earlier.
Of course you can't just replace a cable - it has to be a link, including the bit that goes inside the box at each end. And that's only going to work for digital links, so not the cable from the rail-mounted sensor to the electronics unit (yellow mushroom). From there to the ACE (grey box) is not a standard data link - it's actually ISDN, with power supplies too. But it can be replaced by another physical link, as can those from an ACE to the neighbouring ACEs or into the signalling system.
That would mean that the problem is not so much due to being an axle counter, but having to be close to the track and joined with long cables. That's true of other equipment, so why just a few of these AzLMs and one train type should be giving so much trouble remains unclear.
* I should make clear that I don't have any internal Thales information on this - I was referring to alternative local sources of rumours.
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« Last Edit: February 23, 2018, 08:01:31 by stuving »
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TonyK
Global Moderator
Hero Member
Posts: 6594
The artist formerly known as Four Track, Now!
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« Reply #358 on: February 23, 2018, 12:48:43 » |
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That work was always done at Crawley (no, it's a lovely place, really).
Sounds creepy to me...
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Now, please!
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4064ReadingAbbey
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« Reply #359 on: February 26, 2018, 19:11:24 » |
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In this case the trains are new, and so is the widespread use of the axle counters. Which was known about first and could be listed as pre-existing it's hard to say, and I can't see anything on those RGSs about setting aside a band for future use and protecting it from EMI. So it probably comes down to the same kind of pragmatic engineering that EMI always has - you all just have to ignore the lawyers, dive into the can together, and wrestle those worms.
EMI means something very different in Hayes. They had a large employment base by the railway line manufacturing vinyl records, medical instruments and possibly other stuff. Most things do mean something else if you want them to (and if you don't). And EMI did far more than that - TV (Schoenberg's system, which really worked), radar, stereo records, etc, etc. Alan Blumlein worked there, I believe. And somewhere I have seen a video of GWR▸ freight train shot from an EMI window with the sound in stereo. I did visit Blyth Road, Hayes, a couple of times. It would have been more but by the time EMI 'joined' us in Thales they were already planning to move to Crawley. There they met up with MEL again, having split a bit earlier, so that TPWS▸ became one of their products again. That work was always done a Crawley (no, it's a lovely place, really).
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