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GWR Class 800

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Noddy

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It's about 10 miles from Severn Tunnel Junction to Newport so at best about 2 mins saved even assuming you could do 110mph instead of 75mph all the way (to keep the sums simple).

Assuming that it currently takes 10 min that’s a 20% reduction in time. Not bad!
 
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TwistedMentat

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Assuming that it currently takes 10 min that’s a 20% reduction in time. Not bad!

But you still have to add all the other time. So your 205 reduction suddenly become a fraction of 1%. I've always found it interesting how such jumps in speed turn out to be essentially pointleess unless you can sustain it. It all comes down to the average speed, not the point peak.
 

Waverleystu

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How many GWR 800’s are in service now? I’m guessing that there’s only a couple left to enter traffic?
 

Noddy

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But you still have to add all the other time. So your 205 reduction suddenly become a fraction of 1%. I've always found it interesting how such jumps in speed turn out to be essentially pointleess unless you can sustain it. It all comes down to the average speed, not the point peak.

I’ve always found it interesting how a minute here and minute there, can save 10 or 15 min over the length of a journey....
 
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dp21

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How many GWR 800’s are in service now? I’m guessing that there’s only a couple left to enter traffic?

Pretty sure they've still got a boat load to come. They're set to have 57 of the things and from this thread and my general observations there are definitely nothing close to 57 so much as delivered let alone in service.

Then of course remember the 36 802s as well.
 

Dai Corner

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Pretty sure they've still got a boat load to come. They're set to have 57 of the things and from this thread and my general observations there are definitely nothing close to 57 so much as delivered let alone in service.

Then of course remember the 36 802s as well.

Also, none of the 9 car 800 sets have been delivered yet, as far as I know.
 

Dai Corner

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I’ve always found it interesting how a minute here and minute there, can save 10 or 15 min over the length of a journey....

But if you wanted to save even two minutes (itself an overestimate) in this case you'd have to somehow raise the line speed in the tunnels either end of the section to 100mph + and omit the Newport stop.

It's station stops that soak up the time in the GWML. Much of the advertised acceleration from next January will be achieved by running non-stop between Paddington and Bristol Parkway.
 

FGW_DID

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Pretty sure they've still got a boat load to come. They're set to have 57 of the things and from this thread and my general observations there are definitely nothing close to 57 so much as delivered let alone in service.

Then of course remember the 36 802s as well.

Also, none of the 9 car 800 sets have been delivered yet, as far as I know.

The highest numbered GWR 5 car I’ve seen out and about is 800033 so that makes three to go.

The only GWR 9 car I’ve seen out in the wild (although not handed over for service yet) is 800302. That’s been flying about the last couple of nights in the Didcot / Reading area.
 

swt_passenger

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Pretty sure they've still got a boat load to come. They're set to have 57 of the things and from this thread and my general observations there are definitely nothing close to 57 so much as delivered let alone in service.

Then of course remember the 36 802s as well.

The original timescales from the graph shown in the 2015 - 2019 direct award brief (and I think also in tabular form in the franchise spec) had deliveries at a reasonably steady pace, between Jan 17 and Jun 18, although accelerating slightly during the last 6 months. I suspect they are a few months (maybe 3 or 4?) behind the expected delivery dates at the moment, but I don't think any recent forecasts have been given.

My assumption is that the last of the 9 cars will be arriving in the late autumn rather than summer.

(As mentioned above 802 are a separate ball game...)
 

dp21

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They seem to have been arriving at a much faster rate than I had appreciated then.

Given the number of services which still appear to be HST-hauled (if that's the right terminology) will most of those be taken over by the 9-cars and the 802s or are a number of the accepted 800s just not being put into service just yet?

I'm curious as to whether there'll be a point at which the number of IETs starts to exceet HSTs.

My apologies also if this has all been covered extensively already.
 

TwistedMentat

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I’ve always found it interesting how a minute here and minute there, can save 10 or 15 min over the length of a journey....

Sure. And that will likely come from the reduced dwell times at stations. Not from making one bit of line run a bit faster. ;)

But yes, the small things add up if you have a lot of them.
 

59CosG95

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They seem to have been arriving at a much faster rate than I had appreciated then.

Given the number of services which still appear to be HST-hauled (if that's the right terminology) will most of those be taken over by the 9-cars and the 802s or are a number of the accepted 800s just not being put into service just yet?

I'm curious as to whether there'll be a point at which the number of IETs starts to exceet HSTs.

My apologies also if this has all been covered extensively already.
Given that 93 IETs are due to be delivered (36 5-car 800s, 21 9-car 800s, 22 5-car 802s and 14 9-car 802s), and assuming all 5-cars will run together,
that's 18 + 21 + 11 + 14 = 64. GWR had 54 sets at the top of its game, so yes, there is a net gain overall.
When that net gain is remains a mystery - most likely once the wiring to Cardiff/Newbury is complete.
 

dp21

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Given that 93 IETs are due to be delivered (36 5-car 800s, 21 9-car 800s, 22 5-car 802s and 14 9-car 802s), and assuming all 5-cars will run together,
that's 18 + 21 + 11 + 14 = 64. GWR had 54 sets at the top of its game, so yes, there is a net gain overall.
When that net gain is remains a mystery - most likely once the wiring to Cardiff/Newbury is complete.

Sorry I realise I should have clarified in saying when the number of IETs in service exceeds the number of HSTs in service.

However I feel you're probably onto a winner there with regards the Cardiff/Newbury wiring proving to be a catalyst.
 

Noddy

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It's station stops that soak up the time in the GWML. Much of the advertised acceleration from next January will be achieved by running non-stop between Paddington and Bristol Parkway.

Except the majority of the advertised improvements to the journey times to the West Country are not coming from omitting stops but from from the superior acceleration and braking of the units (acceleration probably mostly at the electrified Newbury-London section), plus the improved dwell times (maybe 30 seconds per stop?). All these are marginal gains saving a bit here and a bit there. If the same was done to the line speeds along the (slower) electrified sections (and let’s face it it’s virtually straight track apart from the last curve into the station) it would add more marginal gains.

Anyway I’m sure ‘railperf’ has enough data out of Reading on the 800s electric acceleration and braking curves from 70-110 and 110-70 to tell us whether it would make a difference...
 
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Dai Corner

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Except the majority of the advertised improvements to the journey times to the West Country are not coming from omitting stops but from from the superior acceleration and braking of the units (acceleration probably mostly at the electrified Newbury-London section), plus the improved dwell times (maybe 30 seconds per stop?). All these are marginal gains saving a bit here and a bit there. If the same was done to the line speeds along the (slower) electrified sections (and let’s face it it’s virtually straight track apart from the last curve into the station) it would add more marginal gains.

I had in mind Paddington-Bristol. Are there many slower electrified sections between Paddington and Bristol Parkway? Reading Station, Swindon Station, Wootton Basset Jn, and the much discussed Steventon. Where else?
 

Domh245

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The highest numbered GWR 5 car I’ve seen out and about is 800033 so that makes three to go.

There are also 800001-800004 and 800007 from the lower end of the range to still be handed over to GWR as well AFAIK
 

Noddy

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I had in mind Paddington-Bristol. Are there many slower electrified sections between Paddington and Bristol Parkway? Reading Station, Swindon Station, Wootton Basset Jn, and the much discussed Steventon. Where else?

I’m talking about the advertised improvements to the West Country and by that I meant Devon/Cornwall via Newbury. Ie where they are advertising improvement but not omitting any stops (at least not as far as I am aware). This is an example of what I am talking about by marginal gains add up to quite a bit over a longer journey. Applying this to the slower sections of electrified track as well (where curves are not an issue eg Severn tunnel-Newport)= further gains at relatively little expense.
 

Railperf

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If Network Rail's plan to improve punctuality from 2019 -2024 -with their intention to roll out 'right time' punctuality - pans out..then dwell times will get longer and recovery time will likely get spread among intermediate station stops rather than a large chunk of additional time added on at the end of a journey.
 

Railperf

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Except the majority of the advertised improvements to the journey times to the West Country are not coming from omitting stops but from from the superior acceleration and braking of the units.. plus the improved dwell times (maybe 30 seconds per stop?).
Anyway I’m sure ‘railperf’ has enough data out of Reading on the 800s electric acceleration and braking curves from 70-110 and 110-70 to tell us whether it would make a difference...
I have established that the superior acceleration from rest to 125mph (in electric mode) is worth around a minute's time saving over an HST. Multiply that by the number of stops, and you gain that time saving.
Braking is slightly more contentious - as timetables are based on braking rates of approximately 5 to 6%G - mainly for safety reasons. Although _ i understand - the 800's have better brakes than HST's, I have not read anywhere that drivers are going to be retrained to brake later and harder than they do now. Undoubtedly, as drivers become more confident and understanding of their machinery, and how it performs in good and bad weather, they may be able to utilise the better braking performance when running late. But that is likely to be in isolated cases - as it is now with any train - rather than an widespread policy change. Especially if drivers have to be signed to drive both sets of traction for a period of time.
As an example , GWR's recent 'speed' run took 3 mins 40 seconds from Passing Twyford at speed to a rest in Reading. However, I have seen logs of HST's achieving that in 3 minutes flat. So HST's have pretty good brakes, but likely that braking would not be allowed by today's safety conscious - defensive driving standards to prevent SPAD's and station overruns!

And the braking has to be achieved in both dry rail - and very slippery conditions to ensure reliability of the timetable.

For example, in wet weather - GEML Class 90's suffer terrible wheelslip and have to be accelerated gently to linespeed. In wet conditions - the timetable suffers considerably and a 10 minute late arrival is not uncommon. However, in dry conditions - the 90's can obliterate the timetable easily making up time on every station to station section!
 

jimm

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I’m talking about the advertised improvements to the West Country and by that I meant Devon/Cornwall via Newbury. Ie where they are advertising improvement but not omitting any stops (at least not as far as I am aware). This is an example of what I am talking about by marginal gains add up to quite a bit over a longer journey. Applying this to the slower sections of electrified track as well (where curves are not an issue eg Severn tunnel-Newport)= further gains at relatively little expense.

They certainly are omitting stops on West Country services - from January the Plymouth and Penzance trains will be non-stop between Reading and Taunton in both directions.

The intermediate stations on the Berks & Hants will instead be covered by the two-hourly Paddington-Exeter semi-fasts, and west of Bedwyn by whatever peak extras serve the Westbury/Frome area. In addition, there will be IETs on Paddington-Bedwyn runs and more Paddington-Newbury services once the 387s replace Turbos there.
 

smiffy9373

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The 80X may have superior braking but unfortunately the infrastructure will not allow drivers to make the most of it.TPWS and ATP will intervene. It's just a case of knowing where and when you can use the superior brakes. Didcot and Chippenham spring to mind as 2 potential stations if the signals are green at the end. Reading is definitely a no no as the signal is very rarely off at the other end.
The LTV guys have been caught out a few times by the TPWS on the 387s for exactly that.
 

fgwrich

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Are there any OHLE issues West of Reading at the moment affecting the 800s or are the 800s suffering further issues? I've noticed a significant number of 800s arriving into Reading of late from Paddington, switching on their Diesel engines before heading off to the West. It seems to be happening to most of the Swansea services at the moment, along with the Oxford / Cotswolds (slightly more understandable) - Should / Would they not be dropping their pans in the Moreton cutting area?
 

PHILIPE

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Are there any OHLE issues West of Reading at the moment affecting the 800s or are the 800s suffering further issues? I've noticed a significant number of 800s arriving into Reading of late from Paddington, switching on their Diesel engines before heading off to the West. It seems to be happening to most of the Swansea services at the moment, along with the Oxford / Cotswolds (slightly more understandable) - Should / Would they not be dropping their pans in the Moreton cutting area?

Quite a lot of discussion earlier in the thread. Problem with Axle Counters when running in Electric Mode
 

paul1609

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The 80X may have superior braking but unfortunately the infrastructure will not allow drivers to make the most of it.TPWS and ATP will intervene. It's just a case of knowing where and when you can use the superior brakes. Didcot and Chippenham spring to mind as 2 potential stations if the signals are green at the end. Reading is definitely a no no as the signal is very rarely off at the other end.
The LTV guys have been caught out a few times by the TPWS on the 387s for exactly that.
Talking of ATP which as I understand it gives an in cab indication. Could you not with the necessary pw improvements make a safety case for 140 mph operation of 800s?
 

trebor79

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I was on an 800 Swindon to Paddington yesterday and the engines were switched off at Didcot.
My first trip on one, I was quite impressed other than the seat being horribly hard and uncomfortable after an hour. I was glad to get off for that reason alone. Other than that I thought it was a nice train, pleasantly surprised at the almost barely noticeable engine noise or vibration.
Daft having 5 car sets running in multiple though, and they should give serious thought to coupling the 2 first class ends together. Can't help think they should have just ordered 10 car set and used the additional space for a buffet car! The trolley came through once and people were wandering around trying to find it.
 

D365

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Quite a lot of discussion earlier in the thread. Problem with Axle Counters when running in Electric Mode

Yeah I’ve heard problems are still persisting.

Can't help think they should have just ordered 10 car set and used the additional space for a buffet car! The trolley came through once and people were wandering around trying to find it.

Is that not what the nine car units are?
 

Railperf

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The 80X may have superior braking but unfortunately the infrastructure will not allow drivers to make the most of it.TPWS and ATP will intervene. It's just a case of knowing where and when you can use the superior brakes. Didcot and Chippenham spring to mind as 2 potential stations if the signals are green at the end. Reading is definitely a no no as the signal is very rarely off at the other end.
The LTV guys have been caught out a few times by the TPWS on the 387s for exactly that.
Are there set maximum speeds for passing yellow/ double yellow signals to avoid TPWS / ATP intervention..or does it vary according to location?
 

JN114

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Are there set maximum speeds for passing yellow/ double yellow signals to avoid TPWS / ATP intervention..or does it vary according to location?

ATP is complex - in short, no, there isn’t a specific speed. It continuously works out on the fly the maximum safe speed to be travelling at given line speed, gradient, signal aspect, etc and warns/intervenes the driver as necessary. A train being driven normally shouldn’t see ATP warnings; but in practice it has somewhat hamstrung some of the more “ambitious” drivers.

TPWS grids are set to a specific speed (strictly by the spacing of the arm and trigger grids); and only energised when their associated signal is at danger. Technically, and for obvious reasons, drivers aren’t meant to know the set speeds for them (to prevent them driving to the grids), but I think some of the more commonly tripped ones are known. The speed is usually set low enough that a train being driven “correctly” won’t trip, but an over speeding train can still be stopped before the first conflict point beyond the signal.

“Professional” driving policies and Eco driving seem to be the main detriments to modern performance - “rules” like slowing to 10mph by the AWS magnet for a red signal, not entering platforms over X mph - all are individual to the TOCs and so a bit harder to quantify in such general terms.
 

43096

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“Professional” driving policies and Eco driving seem to be the main detriments to modern performance - “rules” like slowing to 10mph by the AWS magnet for a red signal, not entering platforms over X mph - all are individual to the TOCs and so a bit harder to quantify in such general terms.
FirstGroup have taken this to extremes, though. There has been more and more padding added to GW schedules over the years to take account of this. Crawling into and out of platforms at 10mph is simply not needed.

Interesting to note that SWR are now exhibiting similar driving characteristics with an increasing number of trains being driven like the driver is a frightened old woman going to the shops.
 
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