GWR 802s to Plymouth - Where do they switch from Electric to Diesel?

[pdeaves]

Do they ever run on diesel from London Paddington?

If there are OLE issues, or if the unit is barred from electric running for any reason, yes. Not normally, though.

 

[paul1609]

I was on a service with only 2/3 power struggling to reach 40mph on those gradients! Any slower we would have been going backwards Lol.
Scenic route but too slow!

I've been on a HST running on one power car that couldn't make it from Totnes to Plymouth and was eventually rescued by a class 47.
I notice that on the rail performance society's website the fastest HST time Plymouth to Ivybridge has already fallen to a 802.
802s are also sniffing at the fastest HST from Plymouth to Totnes only 9 secs off, its only a matter of time!

 

[mpthomson]

It is often to do with the infrastructure too. The OHLE at Colton Jnc isn't designed for trains panning up on the move so the swap over is done at York. Presume to keep it simple it is done in reverse there too. This has also been an issue in Greater Anglia with the new bi-modes. Extending the electrification to Church Fenton will include OHLE designed for pan-up on the move meaning the change over location for TPE Bi-modes (and the daily Leeds - Aberdeen Azuma) will move southwards.

Most of the TPE trains that pass the end of my garden just south of York and heading north are pan down when they pass.

 

[hexagon789]

No it isn't, that myth regularly appears. It's the same tension throughout the GWML Series 1 electrification (which is higher than used elsewhere in the UK). The locations simply have to be plain line wire - no overlaps, neutral sections or junctions. They are at specific locations so that NR can monitor wire wear and condition more closely than elsewhere. Raising the pan at other locations is only permitted below 20mph I believe.

So regularly that even drivers are spouting it!

20mph is the restriction I was thinking of, interesting that there is no strengthening, the only thing preventing linespeed pan-ups else where then is trying to restrict heavy wear to specifically monitored locations

 

[robbeech]

I think the confusion sometimes arises because some companies (e.g. TransPennine Express) didn't allow changeovers while moving. I don't know if that's still the case there. The rolling stock is quite capable of it.

I think for example (of course things may have changed) that the LNER Hull service lowers the pan at Temple Hirst on the move but raises it at Doncaster whilst stationary but the Hull trains services raise and lower at Doncaster whilst stationary in each direction.

 

[Railperf]

I've been on a HST running on one power car that couldn't make it from Totnes to Plymouth and was eventually rescued by a class 47.
I notice that on the rail performance society's website the fastest HST time Plymouth to Ivybridge has already fallen to a 802.
802s are also sniffing at the fastest HST from Plymouth to Totnes only 9 secs off, its only a matter of time!

That is not surprising - the speed limits are only mainly 55 to 60mph except for the 80mph climb up Hemerdon. 802's can build up a fair advantage 20 to 30 seconds to 50/60mph over an HST. And the Class 802 braking is seemingly more precise and responsive.
HST's suffer from slow releasing brakes and drivers generally not being able to apply full power from rest.
The 2+4 HST times could be better.. they romp up Hemerdon, getting ahead of time..and drivers tend to take the braking easy for the stop. Some blame it on the fact that many ofthe drivers on these services are ex-unit drivers and not HSS who are more used to the HST brake.

 

[800001]

I think for example (of course things may have changed) that the LNER Hull service lowers the pan at Temple Hirst on the move but raises it at Doncaster whilst stationary but the Hull trains services raise and lower at Doncaster whilst stationary in each direction.

LNER Hull service pans up and down at Temple Hirst in both directions, and Lner Leeds - Aberdeen and return also change over at Colton as they have the APCO (auto power change over) track balises installed.
The train should automatically preheat the engines ready for change over

 

[irish_rail]

That is not surprising - the speed limits are only mainly 55 to 60mph except for the 80mph climb up Hemerdon. 802's can build up a fair advantage 20 to 30 seconds to 50/60mph over an HST. And the Class 802 braking is seemingly more precise and responsive.
HST's suffer from slow releasing brakes and drivers generally not being able to apply full power from rest.
The 2+4 HST times could be better.. they romp up Hemerdon, getting ahead of time..and drivers tend to take the braking easy for the stop. Some blame it on the fact that many ofthe drivers on these services are ex-unit drivers and not HSS who are more used to the HST brake.

2+4 will blow an 802 out of the water plymouth to totnes. Just a shame most of plymouths jobs on 2+4s head west and not east or youd get some really decent runs on them I imagine.

 

[hexagon789]

The 2+4 HST times could be better.. they romp up Hemerdon, getting ahead of time..and drivers tend to take the braking easy for the stop. Some blame it on the fact that many ofthe drivers on these services are ex-unit drivers and not HSS who are more used to the HST brake.

Used to Step One-ing it in a Sprinter with tread brakes rather than using the middle steps in a disc-braked HST?

 

[irish_rail]

Used to Step One-ing it in a Sprinter with tread brakes rather than using the middle steps in a disc-braked HST?

That is now the youngsters are taught nowadays....probably for the best I suppose

 

[Thatcham Xing]

If you watch the recently released GWR "last day of HST Plymouth-Paddington" in-cab video on YouTube, you can see the lineside "pan up" signage just east of Newbury Racecourse at Kennet Viaduct. The linespeed drops from 110 to 100 (eastbound) at the same place.

 

[hexagon789]

That is now the youngsters are taught nowadays....probably for the best I suppose

Maybe that'll change when the last Sprinters get replaced and a new train with fully variable brake control, WSP and load compensated disc-brakes comes along.

I get the impression that drivers are much more sure with the 80x brake performance at least.

 

[JonasB]

They shouldn't be panning up at all West of York until Manchester Victoria. It's not worth it to run electric on the tiny bit between Neville Hill Depot and Holbeck Jn.

I think the people waiting at the platforms in Leeds appreciate a bit less diesel exhaust at the station.

 

[hexagon789]

I think the people waiting at the platforms in Leeds appreciate a bit less diesel exhaust at the station.

And given SNCF will switch it's bi-modes to electric even for just standing time at a station on am otherwise mostly unelectrified route you wonder why such isn't the norm here given the desire to reduce emissions

 

[Wyrleybart]

Which is probably why the later order of the 802s have their engines higher rated to ensure that they can, as opposed to the 800s, which clearly would have had a problem given the change was made.

I think all the GWR 800s and 802s now have the same engine ratings, and are effectively the same except for software versions and the 802s having "proper" rheo pods on the roofs. Hitachi and DfT have done a lot of work after realising the 800s wouldn't cut the mustard in original form. Still don't think you can run them in multi though due to the different software versions.

 

[Class 170101]

Do they ever run on diesel from London Paddington?

Under control instructions if there is a problem with the pantograph I expect.

 

[Class 170101]

Last week I saw a class 802 TP Arrive in Leeds with pan up coming from the York direction so they have been panning up on the move unless stopped at a signal on the way in?

Was it a depot starter?

 

[_toommm_]

Was it a depot starter?

TPE's 802s don't use Neville Hill unless for an emergency - they're maintained at Doncaster Carr IEP Depot.

 

[Class 170101]

TPE's 802s don't use Neville Hill unless for an emergency - they're maintained at Doncaster Carr IEP Depot.

Electric from Doncaster to Leeds but the path might have been required to run through Leeds with a reversal east of there before shunting back in - all on electric of course.

 

[4REP]

Was it a depot starter?

Another possible reason the engines might have failed outside Leeds then switch to electric to enter the station then terminate.
I were walking under the station bridge when I noticed the pan were up so would not have known if it would of terminated or maybe gone to Doncaster Iep depot

 

[SouthEastBuses]

It is often to do with the infrastructure too. The OHLE at Colton Jnc isn't designed for trains panning up on the move so the swap over is done at York. Presume to keep it simple it is done in reverse there too. This has also been an issue in Greater Anglia with the new bi-modes. Extending the electrification to Church Fenton will include OHLE designed for pan-up on the move meaning the change over location for TPE Bi-modes (and the daily Leeds - Aberdeen Azuma) will move southwards.

Isn't that line planning to be electrified anyway as part of the Transpennine MainLine electrification from Manchester to York (part of the Northern Hub scheme), which is due by 2022?

 

[SouthEastBuses]

They are usually started shortly before the traction changeover. They are switched off when running on electric.

It's a while since I've been on an 80x doing a traction change but IIRC, westbound Oxford fasts (not stopping at Didcot) would have the engines running between Goring and Cholsey for the switch to the non-wired avoiding lines at Didcot East Junction. Further west, trains to Bath and Bristol TM have the diesels running between Wootton Bassett and Christian Malford for where the wires run out east of Chippenham.

The diesel engines are always switched on approach to Didcot Parkway. I know because I've commuted on this service to go to uni.

The train would also slow down to something like 20 mph in order to allow the changeover to happen.

 

[Mollman]

Isn't that line planning to be electrified anyway as part of the Transpennine MainLine electrification from Manchester to York (part of the Northern Hub scheme), which is due by 2022?

TPML electrification is still not fully defined. The latest funding announcement was for Huddersfield - Leeds electrification with an option of full reout electrification. As for the completion date, answers on a postcard please.

 

[Mintona]

The diesel engines are always switched on approach to Didcot Parkway. I know because I've commuted on this service to go to uni.

The train would also slow down to something like 20 mph in order to allow the changeover to happen.

Down Oxford fast trains don’t slow down to 20mph to changeover from electric to diesel.

However they do often get signal checked at the same location as the changeover, waiting for a path over all the other lines.

 

[hexagon789]

Down Oxford fast trains don’t slow down to 20mph to changeover from electric to diesel.

However they do often get signal checked at the same location as the changeover, waiting for a path over all the other lines.

Changeover can happen at linespeed can't it?

 

[Wilts Wanderer]

2+4 will blow an 802 out of the water plymouth to totnes. Just a shame most of plymouths jobs on 2+4s head west and not east or youd get some really decent runs on them I imagine.

Currently the 2+4s are planned using 158 timings (or occasionally 150) which means there is a fair bit of slack in the acceleration profile, which encourages / allows easy running and gentle braking.

From this December the 2+4 diagrammed workings have their own specific set of timings based on the actual capability of the train, so it will be interesting to see whether the performances improve, and if some drivers initially get caught out by the quicker timings!

 

[Mintona]

Changeover can happen at linespeed can't it?

Yes.

 

[Jimini]

Yes.

Is the switch over point still Moreton Cutting, where the temporary limit of electrification was a couple of years ago while they were still building the OLE I think? Cheers.

 

[irish_rail]

Currently the 2+4s are planned using 158 timings (or occasionally 150) which means there is a fair bit of slack in the acceleration profile, which encourages / allows easy running and gentle braking.

From this December the 2+4 diagrammed workings have their own specific set of timings based on the actual capability of the train, so it will be interesting to see whether the performances improve, and if some drivers initially get caught out by the quicker timings!

I do hope the new timings don't require the use of notch 5 when departing stations, as one plymouth driver found out to his cost last year when the speedometer couldn't even keep up with the acceleration! I havent heard if anything was put into writing about drivers not using notch 5, and haven't seen anything official, but personally I won't use notch 5 much these days for the above reasons.

 

[Wilts Wanderer]

I do hope the new timings don't require the use of notch 5 when departing stations, as one plymouth driver found out to his cost last year when the speedometer couldn't even keep up with the acceleration! I havent heard if anything was put into writing about drivers not using notch 5, and haven't seen anything official, but personally I won't use notch 5 much these days for the above reasons.

Under normal running, at what point is Notch 5 usually applied? Say if accelerating to 100mph from rest.

Is the switch over point still Moreton Cutting, where the temporary limit of electrification was a couple of years ago while they were still building the OLE I think? Cheers.

Yes, although in theory a service towards Oxford calling at Didcot Parkway (for instance on Sundays) can perform the power changeover while stopped in Didcot Parkway platform. There is little benefit in doing so, however.