GWR Class 800

[Master29]

There is no intention to run 800s to Penzance in passenger service.

Am I being a bit pedantic but are you aware of class 802`s?

 

[TT-ONR-NRN]

Am I being a bit pedantic but are you aware of class 802`s?

You’re not being pedantic, the person who’s post you quoted is.

 

[Master29]

You’re not being pedantic, the person who’s post you quoted is.

Yeah. I do see you`re point there

 

[Master29]

I assume the OP was being sarcastic.

Looking again at the direction of the previous entries before his you`re probably right.

 

[Railperf]

I don't think Noddy was referring to a difference between the blue curve and the green curve, but between the first acceleration phase (in both curves) and the second.

Am I right in deducing that these runs are from Reading to Slough?

Absolutely this is Reading to Slough, and yes the second acceleration phase is AC

 

[Railperf]

You've been told wrong. The GWR 800 units are uprated to 700kW (940hp) but the acceleration rate is governed to 0.7 m s/s and the engine management system adjusted to provide a more even torque. That is what came out of the timing tests done earlier this year, the aim being to find an optimal setting whereby the sets meet the overall HST journey times. The 800 sets in GWR passenger operation also have the larger fuel tanks as they have to be capable of doing up to 900 miles on diesel.

@Clarence Yard How is the fuel consumption affected by the higher power output, but lower acceleration rate? And also I am interested in how the torque curve affects performance. Class 802's for example are said to have a higher acceleration rate at 1m/s/s - but then again i may be misinformed again..

 

[D1009]

Am I being a bit pedantic but are you aware of class 802`s?

As I posted earier, the 802s are NOT part of the Inter City Express Programme, unless something has changed of which I am not aware. They are a GWR project.

 

[aar0]

Looking again at the direction of the previous entries before his you`re probably right.

Should I have added a caveat?

It was, indeed, sarcasm.

 

[Noddy]

I don't think Noddy was referring to a difference between the blue curve and the green curve, but between the first acceleration phase (in both curves) and the second.

Am I right in deducing that these runs are from Reading to Slough?

Absolutely this is Reading to Slough, and yes the second acceleration phase is AC

Cheers, that was what I was trying to understand!

There’s quite a long phase of slowing down/cruising before the AC acceleration starts. Is this required as part of the changeover?

 

[Filton Bank]

There’s quite a long phase of slowing down/cruising before the AC acceleration starts. Is this required as part of the changeover?

The changeover is carried out while coasting (i.e., not taking power, so not accelerating) but is done at line speed. The slowing down might just have been a consequence of something like restrictive signals.

 

[najaB]

The low end of that graph is most enlightening, the IET is significantly quicker off the mark and up to around 40mph than the HST which suggests there's no lack of power or inability to put it onto the rails.

 

[mushroomchow]

Attached is a speed vs distance graph of two IET runs vs Class 180 and HST. Class 180 in red, HST in Orange, the two IET runs are blue and green. THE HST and Class 180 were both stopping at SloughView attachment 36147

Thank you to @Railperf for this data. I've been waiting to see some proper analysis of diesel power on the 80X series for too long, given the amount of speculation flying around and Hitachi's incredibly coy attitude to releasing details.

Do tell me if I'm wrong, but does this data pretty much confirm that the diesel engines on an IEP fail to achieve the acceleration of even a HST? The rates when the switch is made at the wires are good, but up to that point the "old guard" seem well ahead in speed and acceleration terms.

Speaking from my own interests, this should make grim reading for those advocating IEP series bi-mode introduction on the MML if so, not least as the 222s they will ultimately have to keep up with have a superior performance to both 43s and 180s and any introduced IEP will be operating far longer distances "off grid" than is ultimately the case on the GWML.

Side-note: interesting to see that the Adelante appears to have a faster deceleration rate than a HST. How does an IEP compare in this respect? A quick deceleration time can at the very least shave a few seconds off journey times.

 

[D1009]

Side-note: interesting to see that the Adelante appears to have a faster deceleration rate than a HST. How does an IEP compare in this respect? A quick deceleration time can at the very least shave a few seconds off journey times.

Unfortunately TOC "Professional" driving policies will tend to over ride any gain in that respect. Having said that I was very impressed with the speed at which the 1055 Cardiff to Paddington entered the platform at Bristol Parkway this morning.

 

[najaB]

Do tell me if I'm wrong, but does this data pretty much confirm that the diesel engines on an IEP fail to achieve the acceleration of even a HST?

The only conclusion that can be drawn is that in these particular runs the HST and Class 180 reached a higher speed sooner. Since both were stopping at Slough and the IET wasn't it's entirely possible that it accelerated more slowly to avoid being early at its next station call.

 

[HowardGWR]

I will be interested in any data our new colleague (welcome BTW) has on climbing Dauntsey bank. The initial run (0625 (was0600) from Bristol) indicated 'not too well' judging from what I saw on RTT. It lost time to Swindon, IIRC.

 

[Railperf]

You've been told wrong. The GWR 800 units are uprated to 700kW (940hp) but the acceleration rate is governed to 0.7 m s/s and the engine management system adjusted to provide a more even torque. That is what came out of the timing tests done earlier this year, the aim being to find an optimal setting whereby the sets meet the overall HST journey times. The 800 sets in GWR passenger operation also have the larger fuel tanks as they have to be capable of doing up to 900 miles on diesel.

Apparently i am told ( hopefully reliably) that some sets still have engines at 700hp not 940 yet. Is there an upgrade in progress? Plus the increase in power seems to be a bonus as there are reports of at least one engine out within one or both of the double 5 car consists so efefctively 5 engines available rather than 6. Are these engines already having reliability issues?

 

[najaB]

Are these engines already having reliability issues?

I'd be surprised, but teething problems wouldn't be that unusual.

 

[LNW-GW Joint]

Mildly underwhelmed by my first 2 trips on an IEP today (1055 Cardiff-Paddington in coach A, and 1345 return in coach B.
Plus points:
Performance generally, especially on electric and the changeover at speed
Leg room, audio PIS, seat reservations (but why paper labels as well?). No obvious diesel engine noise.
Minus points:
Noisier and wobblier than I expected, especially at lower speeds (eg west of Bristol Parkway) and over S&C - nothing like as good as a 390.
What I take to be a pulsing aircon motor noise in coach A (unpowered).
Too much traction motor whine in coach B, highly intrusive up to about 70mph when it disappears.
Decor too dull, seats too hard - 2 hours max I'd say.
The PIS display looked straight out of a 25 year old Turbo. I was expecting something a bit more exciting!
The seat back table reminded me of the original metal Mk4 version, but at least it didn't squeal on opening.
Early days of course.
But at least it works.

I am typing this in a class 175 seat which is much nicer for a long journey, though leg room not as good as IEP.
While certainly functional, I'm still happier in a 390.
We certainly flashed through Ealing Broadway faster than I have experienced before.

 

[Railperf]

The only conclusion that can be drawn is that in these particular runs the HST and Class 180 reached a higher speed sooner. Since both were stopping at Slough and the IET wasn't it's entirely possible that it accelerated more slowly to avoid being early at its next station call.

Neither of the runs was running that early to warrant a low power setting. They could well be a case that one of those runs even had an engine out as has been reported by several pals of mine.
The dataset does prove what we know and confirm data that we've already recorded that a class 180 is a much faster accelerating train yhan both HST and and IET in diesel mode, certainly judging by the performance of those two IET runs in question. And I think the data confirms everything that Roger Ford has been saying in modern railways magazine, that IET wood have a faster initial acceleration up to around 30 miles an hour but from then on would not have the power to match an HST in diesel mode. And if I recall correctly he questioned quite strongly how these new trains would deliver substantial time improvements over an HST in diesel mode on the non electrified sections of network.

 

[Railperf]

I will be interested in any data our new colleague (welcome BTW) has on climbing Dauntsey bank. The initial run (0625 (was0600) from Bristol) indicated 'not too well' judging from what I saw on RTT. It lost time to Swindon, IIRC.

Hi Howard and thanks for the Welcome. Sadly I haven't recorded any data west of Didcot Parkway. But I know that one of the other members Sean Emmett has done so and I think he posted some snippets of data earlier on this thread.

 

[D1009]

I was on the 1345 Paddington to Swansea today which had an unchecked run from Reading to Swindon in a time of 28 mins 3 secs. We reached 100 mph just before Cholsey, and maintained 103 to 105 mph to South Marston. In terms of speed this was slower than a run I did during the first week, but today we arrived at Swindon 2 mins early. No doubt the Drivers Advisory System was in use, so not much to be learnt 800 performance wise

 

[ChrisHogan]

Neither of the runs was running that early to warrant a low power setting. They could well be a case that one of those runs even had an engine out as has been reported by several pals of mine.
The dataset does prove what we know and confirm data that we've already recorded that a class 180 is a much faster accelerating train yhan both HST and and IET in diesel mode, certainly judging by the performance of those two IET runs in question. And I think the data confirms everything that Roger Ford has been saying in modern railways magazine, that IET wood have a faster initial acceleration up to around 30 miles an hour but from then on would not have the power to match an HST in diesel mode. And if I recall correctly he questioned quite strongly how these new trains would deliver substantial time improvements over an HST in diesel mode on the non electrified sections of network.

I believe the DfT quoted time improvements to Bristol and South Wales only come as a result of the introduction of services that run non-stop to and from Bristol Parkway, and not from the existing 00/15/30/45 semi-fasts from Paddn. I think a couple of 27s/57s in the peaks are supposed to be diverted to South Wales instead of Temple Meads.

 

[Clarence Yard]

Apparently i am told ( hopefully reliably) that some sets still have engines at 700hp not 940 yet. Is there an upgrade in progress? Plus the increase in power seems to be a bonus as there are reports of at least one engine out within one or both of the double 5 car consists so efefctively 5 engines available rather than 6. Are these engines already having reliability issues?

No, all the engines in passenger service today are set to 700kw (940hp). If they weren’t the timekeeping would be appalling. This afternoon there was one set running around with an engine out but I don’t know the reason.

The cl.802 sets will be set up for 0.82m s/s acceleration.

 

[najaB]

Neither of the runs was running that early to warrant a low power setting.

The point is you need to compare apples to apples. I'm not saying it's definitely the case, but it's entirely possible that the IET accelerated as fast as it needed to rather than as fast as it could, seeing as you're comparing a run between station calls to a run without one. The IET doesn't need to be as fast between stations to match end to end timings since it shouldn't spend as long stopped at stations.

 

[Railperf]

The point is you need to compare apples to apples. I'm not saying it's definitely the case, but it's entirely possible that the IET accelerated as fast as it needed to rather than as fast as it could, seeing as you're comparing a run between station calls to a run without one. The IET doesn't need to be as fast between stations to match end to end timings since it shouldn't spend as long stopped at stations.

Thanks for your point. To put this into context, the Blue IET speed trace was on a service that left Reading 5 mins late, while the Green speed trace was recorded on an IET that left Reading on time. The HST run also departed Reading 6.5 mins late, while the Class 180 run was running to time. All of the trains except the Class 180 had every incentive to run up to line speed in full power to avoid further delay. The class 180 has a tight schedule of 12 mins to Slough, so full power is needed to stay within that schedule. in fact the driver achieved this in 11min 6 sec. The HST had a schedule of 13 mins, and the driver achieved this in 12 min 40s. There is no way those times could have been achieved running in anything less than full power settings.

From my experience, drivers tend to accelerate their trains to linespeed regardless of the schedule unless there are operational or technical reasons for them not to do so..I.E slippery rails, adverse signals, TSR's etc. A case in point is Reading to Didcot, where the 13 min schedule is way slower than a HST can achieve - the Railway Performance Society's (www.railperf.org.uk) fastest HST recorded time being just over 11 mins. On the same day that I recorded my IET runs, I recorded a Reading to Didcot section where the HST departed Reading around 1 minute early, accelerated on full power to around 115mph, then coasted down to around 96mph before braking for the station stop - around Milepost 52.5 and still achieving a 12 min 40 time - 20 seconds inside the schedule and arriving just over a minute early. So the tendency tends to be to keep on schedule or ahead of schedule, and dissipate time later in the journey.
Another factor may be that HST drivers tend to keep the power to around notch 3 while the rear power car is within the station canopy / or within the platform / before moving the power controller into full power - notch 5. Apparently this was an instruction in the pre-MTU engine days, but seems like many drivers employ it today too - even though I understand it is no longer a requirement as the MTU's are significantly quieter. Whereas the multiple unit trains such as Class 180 have no such restriction. And with more powered axles - wheelslip should be less of an issue with 180's and Class 800's.

On your point about IET not needing to be run as fast to maintain the schedule, the data we are collecting so far suggests that IET's in diesel mode need to be run much harder to maintain the schedule than a HST. A case in point is the journey from Reading to Paddington where the IET loses almost 30 seconds to an HST by the time it reaches Burnham! And it is also clear that as soon as the Maidenhead to Didcot section is electrified, the IET's will more than easily achieve the current schedules in electric mode, and at that point we hope the schedules will start to be reduced, or else they will be spending more time coasting around the GWML than being driven at full line speed.

 

[Railperf]

No, all the engines in passenger service today are set to 700kw (940hp). If they weren’t the timekeeping would be appalling. This afternoon there was one set running around with an engine out but I don’t know the reason.

The cl.802 sets will be set up for 0.82m s/s acceleration.

Thanks @Clarence Yard , it has been reported to me that at least one set has frequently had an engine out. Not just today.

Interesting that the 802's will be set up for higher acceleration rate, as the DfT specification says that an increased acceleration rate over their specification may be allowed if it can be proved to be compatible with the network. If the 802's can be specced at the higher rate, why not the 800's? is there a technical reason for this? Seems strange to have almost identical trains running with different acceleration rates over the network. Unless the difference in timings is negligible? Can you provide any insight as to how much better the 802's will perform than the current 800's in both diesel and electric mode?

 

[Railperf]

The changeover is carried out while coasting (i.e., not taking power, so not accelerating) but is done at line speed. The slowing down might just have been a consequence of something like restrictive signals.

There was a driver training manager on board one of the runs - don't remember which one - so maybe that may have been a factor - especially if the driver was less experienced. I haven't yet spotted any visible marker boards advising drivers where to raise/lower pantographs and/or apply power.

 

[Railperf]

I was on the 1345 Paddington to Swansea today which had an unchecked run from Reading to Swindon in a time of 28 mins 3 secs. We reached 100 mph just before Cholsey, and maintained 103 to 105 mph to South Marston. In terms of speed this was slower than a run I did during the first week, but today we arrived at Swindon 2 mins early. No doubt the Drivers Advisory System was in use, so not much to be learnt 800 performance wise

That train has a schedule of 29.5 mins, so unless you were running significantly late , it is unlikely that it would have been driven much harder. For the record, the Railway Performance Society's fastest (www.railperf.org.uk) HST record for that stretch is 23 mins 6 secs, posted way back in the 1980's - when the schedule was a mere 24 mins!! (that timing was for a 2+7 HST set). A 23min 14 sec run was achieved in 2012. Fastest time in the last year or so was 24min 36 sec.

 

[Railperf]

Unfortunately TOC "Professional" driving policies will tend to over ride any gain in that respect. Having said that I was very impressed with the speed at which the 1055 Cardiff to Paddington entered the platform at Bristol Parkway this morning.

I'm pretty sure NR rules state that trains can not enter platforms at a greater speed than 35mph - unless the track speed limit is lower. But there are cases when a late running service enters the platform a few mph above that.

 

[Filton Bank]

There was a driver training manager on board one of the runs - don't remember which one - so maybe that may have been a factor - especially if the driver was less experienced. I haven't yet spotted any visible marker boards advising drivers where to raise/lower pantographs and/or apply power.

A significant number (more than half) of the trains in passenger service are currently being worked by a driver with a driver instructor. The power changeover procedure itself is so simple I don't think that would have been a factor here.

Signage is in place - 3 signs in each direction. But they are quite small!