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Author Topic: Crossrail - The Elizabeth Line - ongoing discussion, merged topics  (Read 272767 times)
a-driver
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« Reply #1065 on: August 31, 2018, 09:54:56 pm »

I travelled parallel to one just yesterday leaving Paddington and was struck with exactly the same observation.  I have never seen a carriage with so much fresh air underneath.  There looks room for a couple of diesel engines under each one!

That is odd. It's hard to comment based on the pictures people post on line, since they are never  taken side--on near the middle of a train. However, I did find some in comments on this somewhat obsessive web page (of The Anonymous Widower), with the comment "There’s some complicated gear underneath".

Seen from past the end, there are obviously plenty of boxes under the first three cars - DMSO/PMSO/MSO. The middle three are two more MSOs and a TSO; obviously the trailer could be almost unladen underneath, and as those motor carriages are omittable they may have not so much either (though I'd expect the odd IGBT or two). "What a lot of motors", you may say - but it's only one bogie per car, and that in itself halves the drive electronics needed relative to a VFD box per bogie.

But maybe it just depends on what you are used to seeing in that area - IETs are about as full of stuff underneath as is possible.

A request - I checked the list of acronyms and abbreviations, and found IET, but none of the others. For the benefit of the dozen or so members of the coffee shop who don't what they all mean, could you enlighten us please? I'll be happy to update the acronyms page, once I and the other 11...

Class 345 trains have two Driving Motor Standard Opens (DMSO), two Pantograph Motor Standard Opens (PMSO), four Motor Standard Opens (MSO) and one Trailer Standard Open (TSO). They will be formed as DMSO+PMSO+MSO+MSO+TSO+MSO+MSO+PMSO+DMSO.

An IGBT is an insulated-gate bipolar transistor.
A VFD is a variable frequency drive
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Four Track, Now!
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« Reply #1066 on: August 31, 2018, 10:04:49 pm »

Thank you a-driver, my education is at last complete. I will update the Acronyms page as soon as an apparent technical difficulty is sorted.

I think I know an IGBT.

Edit: Done 7 September 2018.
« Last Edit: September 07, 2018, 11:10:34 pm by Four Track, Now! » Logged

Now, please!
stuving
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« Reply #1067 on: August 31, 2018, 11:30:06 pm »

Class 345 trains have two Driving Motor Standard Opens (DMSO), two Pantograph Motor Standard Opens (PMSO), four Motor Standard Opens (MSO) and one Trailer Standard Open (TSO). They will be formed as DMSO+PMSO+MSO+MSO+TSO+MSO+MSO+PMSO+DMSO.

An IGBT is an insulated-gate bipolar transistor.
A VFD is a variable frequency drive

Exactly. Mind you, those vehicle type codes are hardly new or unfamiliar (unlike on the IETs, where some news ones have been invented).

In terms of the original context, what goes where and why, the VFD is the motor drive so lives next to a motored bogie. Being variable means it can drive an AC motor, following its frequency as the speed changes. The VFD is where most of the IGBTs live, providing the universal high-power on-off switch that power circuit designers had been having to do without for decades.

There are some more IGBTs in another box, with less consensus about its name: the input rectifier, which naturally lives near the pantograph and its friend the transformer. Here, the magic IGBT switch makes possible a PWM (pulse-width modulation) rectifier. Single phase rectifiers always used to suffer high harmonic current levels and low power factor; the PWM design slays both dragons. So that should mean an end to serious interference problems (though no-one told the IETs about that, apparently).
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bradshaw
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« Reply #1068 on: September 07, 2018, 08:23:38 am »

Excellent analysis of Crossrail dilemma in this article.

https://www.londonreconnections.com/2018/crossrail-a-hole-new-world/

London Reconnections always a thoughtful read
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eightf48544
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« Reply #1069 on: September 07, 2018, 10:09:12 am »

Delay on front page of this weeks Maidenhead Advertiser.

Along the lines of better to get it right.
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Electric train
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« Reply #1070 on: September 07, 2018, 09:29:28 pm »

Delay on front page of this weeks Maidenhead Advertiser.

Along the lines of better to get it right.

One of the things that has come out of the May 18 timetable debacle is a robustness stress test, anjd I agree it is better to ensure the trains, infrestructure, oeprating procedures, time table have been stress tested as far is reasonable before the system if opened for public use.

My guess is the opening West will not see to much delay from its original date.
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« Reply #1071 on: September 21, 2018, 04:28:50 am »

From ITV

Quote
Sadiq Khan said he cannot be sure when Crossrail will be completed.

The Mayor of London said he will talk about a revised timetable at some stage, but only when he has confidence in it.

Quote
Mr Khan previously revealed that he only learned of Crossrail’s delay two days before the announcement.

The mayor was asked on BBC Radio London if he could reassure listeners and Londoners that he has put the checks and balances in place to ensure the current situation would not be repeated.

Mr Khan told presenter Eddie Nestor: “I can’t yet give Londoners the confidence that we will finish the project when we’ve been told by Crossrail with the most recent report.

“What we’re doing now is trying to make sure we have the rigour in Crossrail Limited so we’ve instructed someone to do a report into governance, a very speedy report that will come back in a couple of weeks, in relation to what the governance is like now, what it needs to be, and we’re doing several pieces of work.

“And at some stage I will come out and say what the revised timetable is, but only when I’ve got the confidence in that revised timetable.”
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Lee
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« Reply #1072 on: September 21, 2018, 08:38:13 am »

A very speedy report, eh? Next couple of weeks but they are doing "several pieces of work"...

As a veteran analyser of such reports, I confidently recommend the provision of bigger barn doors and banjos.
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« Reply #1073 on: October 19, 2018, 11:25:39 am »

Class 345 testing/training between Maidenhead and Reading is set to start in earnest next week:

http://www.realtimetrains.co.uk/train/G30024/2018/10/23/advanced
http://www.realtimetrains.co.uk/train/G31017/2018/10/23/advanced
http://www.realtimetrains.co.uk/train/G31025/2018/10/23/advanced
http://www.realtimetrains.co.uk/train/G31019/2018/10/23/advanced
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To view my cab run over the new Reading Viaduct as well as a relief line cab ride at Reading just after Platforms 12-15 opened and my 'before and after' video comparison of the Cotswold Line Redoubling scheme, see: http://www.dailymotion.com/user/IndustryInsider/1
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