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IndustryInsider
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« Reply #795 on: August 08, 2016, 15:50:10 » |
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I would presume 5 car.
Certainly some confusion out there. Ollie's been told 9-car, the article Adelante_CCT linked to says 9-car, ChrisB, TrainSpy and Rob T on here say 9-car. However several posters on the wnxx forum are confident of 5-car including Mark Hopwood apparently confirming that to staff yesterday. Looks like the wnxx forum have conceded they are probably wrong, so looking like they'll be 9-car sets. Excellent news. |
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To view my GWML▸ Electrification cab video 'before and after' video comparison, as well as other videos of the new layout at Reading and 'before and after' comparisons of the Cotswold Line Redoubling scheme, see: http://www.dailymotion.com/user/IndustryInsider/ |
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ChrisB
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« Reply #796 on: August 31, 2016, 13:29:16 » |
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I think we'd worked this out already.....from RAILGWR▸ electrification uncertainty raises timetable issues
The ability of Great Western Railway’s Class 800 bi-mode electric multiple units to meet current and future timetables is under scrutiny by the train operator, due to their maximum speed in diesel mode of 100mph.Network Rail’s electrification of the Great Western Main Line is taking place on a discontinuous basis, and the trains will have to run on diesel power between energised sections at potentially lower maximum speeds than the current High Speed Trains, which can operate at up to 125mph.However, uncertainty about exactly which sections will go live (and when) means that planning future timetables when the fleet begins entering service from next year is proving extremely difficult. The Class 802s have a design speed of 125mph under electric traction. |
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broadgage
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« Reply #797 on: August 31, 2016, 19:49:32 » |
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If these additional sets are to be 9 car as now seems probable, then that is indeed good news.
I still have considerable reservations regarding the downgrading from a buffet to a trolley, the reduced first class, and the limited number of tables, but 9 cars is better than 5.
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A proper intercity train has a minimum of 8 coaches, gangwayed throughout, with first at one end, and a full sized buffet car between first and standard.
It has space for cycles, surfboards,luggage etc.
A 5 car DMU▸ is not a proper inter-city train. The 5+5 and 9 car DMUs are almost as bad.
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TonyK
Global Moderator
Hero Member
Posts: 6439
The artist formerly known as Four Track, Now!
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« Reply #798 on: September 05, 2016, 11:49:04 » |
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I think we'd worked this out already.....from RAILGWR▸ electrification uncertainty raises timetable issues
The ability of Great Western Railway’s Class 800 bi-mode electric multiple units to meet current and future timetables is under scrutiny by the train operator, due to their maximum speed in diesel mode of 100mph.Network Rail’s electrification of the Great Western Main Line is taking place on a discontinuous basis, and the trains will have to run on diesel power between energised sections at potentially lower maximum speeds than the current High Speed Trains, which can operate at up to 125mph.However, uncertainty about exactly which sections will go live (and when) means that planning future timetables when the fleet begins entering service from next year is proving extremely difficult. The Class 802s have a design speed of 125mph under electric traction. Acceleration / deceleration will also be an issue under diesel power, presumably. |
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Now, please!
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Gordon the Blue Engine
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« Reply #799 on: September 05, 2016, 14:06:06 » |
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We discussed the issue of journey time being extended when IEP▸ bi-modes take over from HST▸ ’s back at the end of April, in the Across the West – GWML▸ Electrification thread, following my tongue-in-cheek suggested PR▸ line of “here are your new trains, it’s now 10 minutes longer to London”.
An exaggeration of course, and we agreed certainly not applicable to N Cotswold services, but in the early days it may not be far off the truth for S Wales services if IEP’s are used before the wires go live to Bristol Parkway.
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broadgage
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« Reply #800 on: September 05, 2016, 21:52:47 » |
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Acceleration would indeed be slower under diesel power, but surely Deceleration would be the same under diesel or electric ? The brakes should work just the same and would not "know" what power source has accelerated the train.
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A proper intercity train has a minimum of 8 coaches, gangwayed throughout, with first at one end, and a full sized buffet car between first and standard.
It has space for cycles, surfboards,luggage etc.
A 5 car DMU▸ is not a proper inter-city train. The 5+5 and 9 car DMUs are almost as bad.
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eightf48544
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« Reply #801 on: September 05, 2016, 23:39:17 » |
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Acceleration would indeed be slower under diesel power, but surely Deceleration would be the same under diesel or electric ? The brakes should work just the same and would not "know" what power source has accelerated the train.
Not necessarily as I would assume that the IEP▸ would have regenerative braking under the wires. Can you have that under diesel power? |
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ellendune
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« Reply #802 on: September 05, 2016, 23:53:50 » |
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Acceleration would indeed be slower under diesel power, but surely Deceleration would be the same under diesel or electric ? The brakes should work just the same and would not "know" what power source has accelerated the train.
Not necessarily as I would assume that the IEP▸ would have regenerative braking under the wires. Can you have that under diesel power? If you are still running with traction motors you could still have rheostatic braking - where the current generated goes into a resistor (rheostat). Don't know if IEP's do that |
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Tim
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« Reply #803 on: September 06, 2016, 09:32:55 » |
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If you are still running with traction motors you could still have rheostatic braking - where the current generated goes into a resistor (rheostat). Don't know if IEP▸ 's do that
let's hope not. Isn't it the roof mounted rheostats that short out on Voyagers when sprayed with sea water at Dawlish? |
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paul7575
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« Reply #804 on: September 06, 2016, 11:41:27 » |
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AIUI▸ from magazine articles all IEPs▸ will have some resistive braking capability, but the 802s will have higher rated resistance banks as they will be used more on that class.
Paul
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Tim
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« Reply #805 on: September 06, 2016, 15:53:35 » |
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but the 802s will have higher rated resistance banks as they will be used more on that class.
Paul
Please tell me that they will not be on the roof or otherwise in the way of salt spray! |
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paul7575
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« Reply #806 on: September 06, 2016, 16:26:15 » |
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I doubt there's anywhere else they could be - as they need air cooling.
Paul
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stuving
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« Reply #807 on: September 06, 2016, 16:53:41 » |
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I doubt there's anywhere else they could be - as they need air cooling.
Paul
So do people, in the summer, and they are allowed inside. I think the ballast resistance may be quite small, and primarily needed to make the bidirectional inverter work properly, and indeed work without going pop if it momentarily isn't connected to a 25 kV supply. |
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« Last Edit: September 21, 2016, 12:18:59 by stuving »
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TonyK
Global Moderator
Hero Member
Posts: 6439
The artist formerly known as Four Track, Now!
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« Reply #808 on: September 21, 2016, 10:43:07 » |
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So deceleration may indeed be a slight issue...
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Now, please!
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Tim
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« Reply #809 on: September 21, 2016, 11:25:53 » |
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I doubt there's anywhere else they could be - as they need air cooling.
Paul
I agree, There isn't anywhere else obvious to put them. I predict that there will be problems at high tide. |
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