GWR Class 800

[Mintona]

GWR and Network Rail are apparently working on new sectional running times at the moment to finalise the draft timetable for next January but I fully expect GWR to deliver the promised fastest journey time between London and Worcester of two hours, with other services taking five to 10 minutes more, depending on calling patterns.

Apart from all the extra Bristol off-peak services (and I think the third South Wales service each hour in the peaks) that will be introduced next January and will, er, run non-stop for long distances at sustained high speed between Paddington and Bristol Parkway

The biggest challenge is going to be finding fast paths in amongst the stopping paths. Presumably you’ll want the Bristol trains departing Paddington every 15 minutes; it will be tight to keep the stopping train ahead (supposing stops at Reading, Didcot and Swindon) by the time the fast train reaches Wootton Bassett Junction. I have little doubt that it can be done technically, but in real life, particularly with the bottleneck that is Didcot East Junction, it’ll require things to run pretty much perfectly. And that’s before you add in 2 South Wales trains and 1 to Cheltenham using the first 77 miles of track, never mind freight and other bits and bobs.

Very interested to see how the new timetable will fit in.

 

[Railperf]

PpppPp0

OK, so technically no problem.

However, the reason the 802s were specified with the full 940 hp available was to cope with the gradients in Devon and Cornwall. These are comparitively low speed sections, so if the 800s are already delivering this in the low speed ranges, why should the 802s be configured any differently? Presumably the issues involving maintenance of the engines will be the same, even if someone else is paying.

The 802's also have to run between Reading and Exeter at speeds of up to 110mph in diesel mode. So more power at the upper end of the speed range would be good.
The Devon banks and Cornwall should not be underestimated. Line speeds are 60 to 80mph..and an 800 currently seems to have less acceleration than a HST above 40 to 45mph. Ask any HST driver to drive the route in Notch 3 over 40 to 45mph and you will absolutely lose time on the schedule.

 

[paul1609]

I think that with distributed 3ph motors a 800 should have a lot more power available at the wheels than a HST. It's only above about 60 mph that the HST will have an advantage on diesel.

 

[D1009]

PpppPp0

The 802's also have to run between Reading and Exeter at speeds of up to 110mph in diesel mode. So more power at the upper end of the speed range would be good.
The Devon banks and Cornwall should not be underestimated. Line speeds are 60 to 80mph..and an 800 currently seems to have less acceleration than a HST above 40 to 45mph. Ask any HST driver to drive the route in Notch 3 over 40 to 45mph and you will absolutely lose time on the schedule.

A good comparison of actual perfomance will be Hemerdon on the up, but I doubt that the difference overall between Plymouth and Totnes between an HST and an 800 on its current power settings would be significant. I'm not sure that even in their publicity GWR have claimed that timings will be improved as a result of the difference in performance of the trains.

 

[JN114]

I'm not sure that even in their publicity GWR have claimed that timings will be improved as a result of the difference in performance of the trains.

In fact to go a step further - GWR have very specifically lauded the improved London to __________ times; and there is no mention or publicity around improvements of point to point times where one of those points isn’t London. There is a fallacy going around that new = better; when speed has never been the objective - capacity has. Improved journey times were a stated benefit of Electrification, not IEP.

 

[Railperf]

That is not entirely true .. see the text accompanying GWR's promotional video ..

 

[jyte]

That's the slowest departure I've ever seen an HST make.....

 

[samuelmorris]

Indeed, lots of people have suggested that demonstration was rigged.

 

[D1009]

We'll come on you amateur film makers, show us the truth!

 

[gwr4090]

I am curious to know if Class 800s on diesel will maintain the best scheduled HST times on Cardiff-Swansea start to stop, (including calls at Bridgend, Port Talbot and Neath), and the climbs of Llanharan, Stormy and Skewen banks ? Is there any evidence yet ? Is there any penalty for cancellation of electrification of this stretch ?

 

[D365]

Is there any penalty for cancellation of electrification of this stretch ?

Penalty to whom?

 

[Rob F]

Penalty to whom?

Time penalty, I assume.

Rob

 

[Dai Corner]

I am curious to know if Class 800s on diesel will maintain the best scheduled HST times on Cardiff-Swansea start to stop, (including calls at Bridgend, Port Talbot and Neath), and the climbs of Llanharan, Stormy and Skewen banks ? Is there any evidence yet ? Is there any penalty for cancellation of electrification of this stretch ?

There's lots of evidence in the public domain via Realtime Trains et al though I haven't seen an analysis yet.

@Railperf ?

 

[Mag_seven]

Time penalty, I assume.

Rob

I read it as a financial penalty - bearing in mind the DfT cancelled it then there isn't anyone to fine.

 

[paul1609]

I am curious to know if Class 800s on diesel will maintain the best scheduled HST times on Cardiff-Swansea start to stop, (including calls at Bridgend, Port Talbot and Neath), and the climbs of Llanharan, Stormy and Skewen banks ? Is there any evidence yet ? Is there any penalty for cancellation of electrification of this stretch ?

I'd have thought that the 800s power operated doors would represent more potential time saving over the HST than any marginal time saving/ loss on a 800 on diesel v electric on a sub 100 mph line.

 

[jyte]

Don't know if anyone has seen this from GWR.

That start out of paddington, takes off like a rocket!

 

[Railperf]

That is one of the faster starts.. but not exceptional and has been achieved on other scheduled services. The key to this timing was a completely clear unchecked run right the way through to Reading.
It is the fastest run between Paddington and Reading this side of the Ladbroke Grove disaster since the speed limits between Paddington and Ladbroke Grove were severely reduced to just 40 and 50 miles per hour from 60 and 100mph.

 

[D1009]

Don't know if anyone has seen this from GWR.

That start out of paddington, takes off like a rocket!

I watched this earlier today, and I had to turn the sound off after a bit because the music was so repetetive. Can anyone try to guess what train or what time of day it was filmed? The amount of freight around suggests it was a weekday, but I was surprised how little passenger traffic there seemed to be in the opposite direction. I also noticed it overtook a class 332 Heathrow Express between Hanwell and Southall.

 

[387star]

Yes that music is awful!

 

[HowardGWR]

That is one of the faster starts.. but not exceptional and has been achieved on other scheduled services. The key to this timing was a completely clear unchecked run right the way through to Reading.
It is the fastest run between Paddington and Reading this side of the Ladbroke Grove disaster since the speed limits between Paddington and Ladbroke Grove were severely reduced to just 40 and 50 miles per hour from 60 and 100mph.

What, do you think, would be possible, if those speed limits were reintroduced? Was there a logical reason for the lowering, or was it just panic?

 

[Wilts Wanderer]

From memory I believe it was the 0945 London Paddington-Swansea? Or something close to that time.

 

[Wilts Wanderer]

What, do you think, would be possible, if those speed limits were reintroduced? Was there a logical reason for the lowering, or was it just panic?

After Ladbroke Grove severe restrictions were placed on the routings that ARS could call, to prevent some of the more ‘unexpected’ weaves and eliminate SPAD traps, and provide the missing flank protection. Some time later, the Ladbroke-Padd section was resignalled again replacing 4-aspect L-shaped signal heads with 3-aspect conventional signals. By removing the double-yellow aspect you halve the available braking distance, thereby making the 40-50mph emergency speed restrictions the new permanent arrangement.

I can see the line speed being raised in the future (the alignment was designed for 80mph I think?) but not without in-cab signalling, ie ETCS.

Edit - if you could get the linespeed up, I suspect it would only knock 30 secs maximum off the 3 mins that are allowed between Padd and Ladbroke Grove, due to the mandatory running brake test that occurs in the region of Westbourne Park. Probably not worth the effort.

 

[Railperf]

The Railway Performance Society (www.railperf.org.uk) have conducted mass timing days - before and after the Ladbroke Grove disaster.

If I recall correctly, they concluded that for HST's - the lower speed limits to Ladbroke Grove added about 1 minute to previous timings (that may include running brake tests too). The very fastest 2+7 HST runs could pass Ealing Broadway in a tad under 5 minutes compared to the 5 mins 25 seconds achieved by the Class 800 run. So i think a minutes difference is a fair reflection of that. By Southall the 800 has closed the gap even further to an original unrestricted HST run. In terms of todays running - the Class 800's make up almost a minute on HST's due to their superior acceleration to 125mph.

Also, the vast majority of fastest times had been set by HST sets made up of 2 power cars and 7 trailers, whereas most current sets have 8 trailers. The additional trailer seems has a detrimental effect on acceleration to the tune of 30 seconds over the 2+7 sets. I think it was also noted that braking into Reading tended to more cautious than before, - and todays running sees HST's causing at anything between 121-123mph , whereas it was common in earlier days to see cruising at 126/127mph.

Certainly today's safety equipment (TPWS and ATP) - defensive driving techniques and energy saving advisory systems have also seen an increase in average journey times. Schedules in the 1980's were around 22 minutes, whereas todays schedule is a gross 25 minutes - made up of a 24 minutes net running time - with an additional minute for Temporay Speed Restrictions out of course slowing etc.

Today a good / clear HST timing is better than that - around 23 minutes. probably 30 seconds less for a 2 + 7 set. So drivers have at least one minute to dissipate if trying to aim for the 24 minute schedule, and 2 minutes to dissipate if they leave Paddington on time and wish to arrive at Reading in the 25 minutes gross timing.
Another factor is traffic. As was noted - many services are closely spaced behind one another - and so drivers will run a little easier if they know another HST or Heathrow Express service is only a few minutes ahead. Accelerate too quickly and you run the risk of hitting double yellow signals. Better to let those trains sail into the distance and not have to slow unnecessarily.
I wonder if the Heathrow Express service in the video had been moved to the relief lines in order to give this 'speed' run a chance of making a fast time.

 

[Railperf]

What, do you think, would be possible, if those speed limits were reintroduced? Was there a logical reason for the lowering, or was it just panic?

I have had a look at the timings and it seems this run could have been even quicker. The 3 mins 40 from passing Twyford to a stop at Reading are not as quick as some of the fastest recorded times of 3 mins to 3 mins 20 sec.
A better braking rate of 6% might have saved 25 seconds, 7% would have saved a possible 30 seconds, but I am not sure where the ATP speed profile intervenes. The exit to Ladbroke Grove under the older pre-Ladbroke Grove speed limits could possibly have been up to a minute quicker. And then the 800's - we know - cruise at 'only' 200kph (124mph). Over the 22 miles from Southall to Twyford - an average 125mph as opposed to 124mph saves around 6 seconds - improve to a 126mph average - your save 11-12 seconds. Add all those small time savings up, and we could have been looking at a sub - 20 minute timing. Even under the current speed limit profile _ i am sure a slightly higher (but legal) cruising speed (126/127mph) plus better braking at the Reading end - may just have threatened the 20 min 46 second HST record. Who knows - they may just give it another go!

 

[Peter Mugridge]

From memory I believe it was the 0945 London Paddington-Swansea? Or something close to that time.

Any clues from the experts at deciphering fuzzy indicator screens? It does look about the right length to read "Swansea". At the end of the clips there's a couple of people taking photos; might they be on the forum?

As to the date:

Weather-wise... the only crystal clear days we've had like that lately were immediately ahead of the Siberian snowstorm arriving and there are further clues on the date: 800 101 is at North pole, and there seems to be a double stoneblower movement being prepared. I'm not sure how common a double movement is, but put that together with the Azuma being present on the same day...

 

[Envoy]

GWR VIDEO PAD > RDG: It’s a pity that they did not have the real sound instead of that awful music. I would also have liked to have seen the real speed that the train was actually doing - in addition to the speed limit sign in the top right.

I wonder if anything can be done to increase the speeds in south Wales? The sections of line between Cardiff and Newport and Newport & Severn Tunnel Junction are relatively straight and the slow stuff is on the reliefs. (I think the HST limit is 95mph)?

 

[Mintona]

I wonder if anything can be done to increase the speeds in south Wales? The sections of line between Cardiff and Newport and Newport & Severn Tunnel Junction are relatively straight and the slow stuff is on the reliefs. (I think the HST limit is 95mph)?

Very few passenger trains use the reliefs between Severn Tunnel Jn and Cardiff. It’s mostly only used for freight. The line speed on the main is 75 from Severn Tunnel Jn to Magor, HST 90 Magor to Llanwern West, 75 again for a short while and 40 then 30 into Newport. It’s then 50 at the east portal of Newport Tunnel and 75 from Ebbw Junction. It only increases to HST 95 at Pheasants Curve (near ADJ depot) and drops again to 75 before Pengam. The relatively short distances and diesel acceleration would probably make line speed improvements fairly pointless, as you’d probably only be able to cruise at 110 (for example) for around 2 minutes before having to ease off again.

In reference to the video above, a good HST will do it in less than 23 minutes, provided there’s no obstacles en-route.

 

[Peter Mugridge]

GWR VIDEO PAD > RDG: It’s a pity that they did not have the real sound instead of that awful music. I would also have liked to have seen the real speed that the train was actually doing - in addition to the speed limit sign in the top right.

Fully seconded.

 

[Noddy]

Very few passenger trains use the reliefs between Severn Tunnel Jn and Cardiff. It’s mostly only used for freight. The line speed on the main is 75 from Severn Tunnel Jn to Magor, HST 90 Magor to Llanwern West, 75 again for a short while and 40 then 30 into Newport. It’s then 50 at the east portal of Newport Tunnel and 75 from Ebbw Junction. It only increases to HST 95 at Pheasants Curve (near ADJ depot) and drops again to 75 before Pengam. The relatively short distances and diesel acceleration would probably make line speed improvements fairly pointless, as you’d probably only be able to cruise at 110 (for example) for around 2 minutes before having to ease off again.

In reference to the video above, a good HST will do it in less than 23 minutes, provided there’s no obstacles en-route.

Appreciate there’s less point after stopping at Newport but surely the line speeds as far as Newport could (should) be raised given that the acceleration/braking of the 800s in electric mode (from 70 in the Severn Tunnel) would allow a fairly significant stretch of say 110mph running?

 

[Dai Corner]

Appreciate there’s less point after stopping at Newport but surely the line speeds as far as Newport could (should) be raised given that the acceleration/braking of the 800s in electric mode (from 70 in the Severn Tunnel) would allow a fairly significant stretch of say 110mph running?

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).