Why the attraction to splitting and joining services at various GWML stations?

[irish_rail]

Mod Note: Posts #1 - #8 originally in this thread.

All my experiences over the last few years of living in Swansea give me the ability to say: Yes. The HSTs were usually standing room only if you didn't have a booked seat. And heaven forbid you travel on a commuter time service with no booked seat... Hah.

The suggestion from the previous poster that the units are wasted between Swansea and Cardiff is absolute drivel.

Eh??? Off peak these trains are dead. I use them semi regularly. Obviously peak times needs a 9 car but not for the entire day when the 9 cars would be far more suited to the west of England restaurant trains.

 

[irish_rail]

The population west of Cardiff is greater than that west of Plymouth. The 800’s are therefore pretty full during the main commuting times.

Agreed at commuting times of day they need 9 cars just not rest of the time.

 

[Termy]

Eh??? Off peak these trains are dead. I use them semi regularly. Obviously peak times needs a 9 car but not for the entire day when the 9 cars would be far more suited to the west of England restaurant trains.

We seem to be in different worlds, then. I've never experienced a GWR service between Paddington and Swansea not being full.

Besides, logistically it's not feasible to run 10-cars for rush hours, and not in the other times. That would displace units in the worst of cases, and just cause a general logistical nightmare organising it all in the best.

 

[irish_rail]

We seem to be in different worlds, then. I've never experienced a GWR service between Paddington and Swansea not being full.

Besides, logistically it's not feasible to run 10-cars for rush hours, and not in the other times. That would displace units in the worst of cases, and just cause a general logistical nightmare organising it all in the best.

No I am saying the Swanseas off peak should be a 10 set as far as Cardiff then split and 5 run onto Swansea. This is what we will have to suffer in the south west and I'm making the point why is it acceptable here and not in South wales. I am in no way suggesting 5 car sets should leave London for Swansea at any time .

 

[CMRail]

May I ask why individuals on this website have a particular like to splitting when it is a hassle and unnecessary?

Only place I can see it being useful is on Penzance at Plymouth.

If you were to split at Cardiff, I’d have a right laugh watching the signaller try it and still
keep a time schedule

 

[irish_rail]

May I ask why individuals on this website have a particular like to splitting when it is a hassle and unnecessary?

Only place I can see it being useful is on Penzance at Plymouth.

If you were to split at Cardiff, I’d have a right laugh watching the signaller try it and still
keep a time schedule

Well why is it acceptable to delay the train at Plymouth and not Cardiff? ? WTF?

 

[59CosG95]

Is there any reasonable evidence that the coupling/uncoupling causes delays? Commuter services in Kent, Sussex and Wessex etc. seem to manage fine coupling/uncoupling on a daily basis. And given the spiel on here that the 80x trains are glorified commuter trains, GWR's already on its way to managing it operationally too.

Besides, services tend to wait quite a bit at Plymouth before proceeding to Penzance, due to the single-track section over the Royal Albert Bridge. Not sure if similar waits are booked in at Cardiff.

 

[Thunderer]

No I am saying the Swanseas off peak should be a 10 set as far as Cardiff then split and 5 run onto Swansea. This is what we will have to suffer in the south west and I'm making the point why is it acceptable here and not in South wales. I am in no way suggesting 5 car sets should leave London for Swansea at any time .

What advantage would the operator or passengers have by splitting a ten car train at Cardiff? The other set would just hang about in Cardiff waiting for its return service from Swansea doing nothing for nearly 2 hours, or the even more impractical alternative is to run the other set ECS eastbound to at least Swindon, where it may or may not be beneficial or used, leaving a later Swansea to Paddington short-formed. Then you have to consider coupling and uncoupling twice at Cardiff (they have had enough issues already doing this at Swansea with Carmarthen services twice a day). Basically there is no operational benefit (diagramming) or passenger benefit by splitting trains at Cardiff. Services between Swansea and Cardiff are busier now than they have ever been in the 35 years that I have been using them. Yes there are quieter times, but even they are getting busier. A few Friday's ago I caught the 14:48 GWR service to Swansea from Cardiff, it was short formed with 800005. I just managed to get a seat from Cardiff and there were quite a few people standing, all this before the actual Rush Hour at Cardiff. For me, the common sense answer is more 9 cars should have been built for all the long distance services with a smaller fleet of 5 cars for services to Bedwyn/Oxford.

 

[irish_rail]

Correct. I am only making the point that the company or government wouldn't dream of splitting services on the Welsh route and all the accompanied confusion and delay it entails yet are quite happy to do it on the route to the south west.
I don't think trains should split at Cardiff I'm just saying that they could and it is double standards that Cornwall was considered not worthy of full length trains but west Wales is.
A large fleet of 9 car trains is what should of been ordered from day one , pretty much everyone agrees that , shame first group didn't see that when procuring the 802 fleet as mainly 5s.

 

[Llanigraham]

May I ask why individuals on this website have a particular like to splitting when it is a hassle and unnecessary?

Only place I can see it being useful is on Penzance at Plymouth.

If you were to split at Cardiff, I’d have a right laugh watching the signaller try it and still
keep a time schedule

Because there are too many people on here who do not look at the signalling side of the railway, or the physical layout of the stations in relation to things like storage line access.

 

[Llanigraham]

Well why is it acceptable to delay the train at Plymouth and not Cardiff? ? WTF?

Does it actually cause a delay? If so how long is that?

 

[Bletchleyite]

Besides, logistically it's not feasible to run 10-cars for rush hours, and not in the other times. That would displace units in the worst of cases, and just cause a general logistical nightmare organising it all in the best.

Have you ever been to Northampton? LNR/WMT operate 8/12 car south of there, and 4/8 north of there, because there are large commuter loadings south of it and far lower loadings north of it. Think Reading commuters (though there really needs to be a plan to get enough 12-car fast EMUs running and get them off the ICs entirely).

That said, 5/10 is a fairly blunt instrument, 4/8/12 provides more useful granularity.

 

[swt_passenger]

Have you ever been to Northampton? LNR/WMT operate 8/12 car south of there, and 4/8 north of there, because there are large commuter loadings south of it and far lower loadings north of it. Think Reading commuters (though there really needs to be a plan to get enough 12-car fast EMUs running and get them off the ICs entirely).

That said, 5/10 is a fairly blunt instrument, 4/8/12 provides more useful granularity.

5/10 seems to have worked fine at Bournemouth since the 442s were new. If it fits with the relative loads either side of the proposed split point I don’t see the problem.

 

[jimm]

Correct. I am only making the point that the company or government wouldn't dream of splitting services on the Welsh route and all the accompanied confusion and delay it entails yet are quite happy to do it on the route to the south west.
I don't think trains should split at Cardiff I'm just saying that they could and it is double standards that Cornwall was considered not worthy of full length trains but west Wales is.
A large fleet of 9 car trains is what should of been ordered from day one , pretty much everyone agrees that , shame first group didn't see that when procuring the 802 fleet as mainly 5s.

You really need to brush up on your West Country railway history.

Cornwall was not 'considered worthy of full-length trains' for donkey's years - portion working west of Plymouth continued under the original GWR and BR right up to the time HSTs first appeared in late 1979.

For the simple reason that the numbers of passengers travelling through the Royal Duchy did not justify provision of a complete train for large parts of the year, which is still the case now. The summer timetable would then see alterations to take more complete trains all the way to the end of the line. I expect the same will happen in future as well.

In the period before the HST services to Penzance began there was quite a debate in the letters pages of railway magazines about the wisdom of doing this, with some people even suggesting providing an intermediate driving position to allow splitting and joining of half-trains at Plymouth. Presumably hopelessly impractical technically, but people were very well aware of the disparity in loadings west of the Tamar outside the holiday season.

Who is 'pretty much everyone'? The same 'everyone' going on about the seats?

If shown passenger loadings on off-peak trains through Cornwall on a wet Tuesday afternoon in January - especially once the 2 trains per hour frequency through Cornwall starts operating - 'everyone' might just ask one or two questions about the economics of providing a 650-seat fixed-formation IET to do that job. Same as they would on the Cotswold Line or to Cheltenham off-peak pretty much any day of the year, or when boosting the London-Bristol frequency.

What advantage would the operator or passengers have by splitting a ten car train at Cardiff? The other set would just hang about in Cardiff waiting for its return service from Swansea doing nothing for nearly 2 hours, or the even more impractical alternative is to run the other set ECS eastbound to at least Swindon, where it may or may not be beneficial or used, leaving a later Swansea to Paddington short-formed.

If it was ever decided to split and join formations at Cardiff, a set would not have to wait two hours for the other one in a pair that had travelled out from London to return from Swansea - it would just couple to the next eastbound set from Swansea, as you would design the timetable around such an operation to provide time for coupling.

 

[irish_rail]

Yes Jimm which is why I make the point again why will Swansea get full length trains all day every day despite much of the day only carrying fresh air after Cardiff. The point is trains run throughout the UK not fully loaded for their entire journeys and it's not the end of the world.
Unnecessary risk and delay is added by introducing coupling and uncoupling at Plymouth not to mention the inconvenience for travellers many of whom may be non regular or elderly who will need to move sets If and when they are in the wrong portion.

 

[Cliveblackpool]

Pre HST at Plymouth, remembering back to the late 70's - something like 2 first class coaches, Restaurant car, Kitchen car, Buffet car, 1 second class were removed/added, leaving something like 8 coaches to Cornwall (Penzance)
This saved pulling forward at stations like St Austell, and reduced the weight. When the full length train ran to Penzance (engineering at Plymouth etc) it was considerably slower.
A lot of people get on/off at Plymouth, but also a lot get off/on at Plymouth, which is very popular for work and shopping for Cornish residents.

 

[Envoy]

Yes Jimm which is why I make the point again why will Swansea get full length trains all day every day despite much of the day only carrying fresh air after Cardiff. The point is trains run throughout the UK not fully loaded for their entire journeys and it's not the end of the world.
Unnecessary risk and delay is added by introducing coupling and uncoupling at Plymouth not to mention the inconvenience for travellers many of whom may be non regular or elderly who will need to move sets If and when they are in the wrong portion.

Swansea has a population of around 300,000 (inc. Gower). Plymouth by comparison has a population of 261,500 (2014). Throw in the population of Neath/Port Talbot = 141,000, Bridgend = 139,000 and Llanelli = 50,000 approx and you have and you have 630,000 people living in south Wales - west of Cardiff and near the main line. The population of the whole of Cornwall is about 536,000. The population in south Wales only thins out once you are west of Llanelli. It is only once you are west of Swansea that the term ‘west’ Wales is usually applied. Bridgend, for example, would not be regarded as west Wales. So, going by population figures, it is easy to see why Swansea would justify longer trains than those going into Cornwall.

Another factor that needs to be considered is seats provided by non-London services. Cornwall has a limited number of Cross Country trains - some going all the way to/from Scotland. Plymouth has regular Cross Country Trains. South Wales, on the other hand, has drawn the short straw and has no Cross Country Trains west of Cardiff. Even Cardiff only has a limited Cross Country service with hourly Turbostars (170’s) going to Nottingham via Gloucester & Birmingham. Perhaps, ideally, a Cross Country service should run from Swansea to Cardiff > Gloucester >Birmingham and up to York and Newcastle? The only other long distance service to serve Swansea is the west Wales to Manchester hourly Transport for Wales trains. Overcrowding on these trains (normally 2 or 3 coach 175’s) means that new operator Keolis have ordered new 5 coach trains for this route - which is the shortest & quickest way to Scotland via a change at Crewe. (These trains will split/join at Swansea).

With such a high population along the south Wales coastal strip, it is all the more galling that electrification west of Cardiff was cancelled - especially as local stopping trains could also have been electric - along with the 800’s.

Of course, it is not just about the population figures alone. Cornwall has a much greater tourist trade than south-west Wales so greater numbers of seats would be needed to meet the seasonal demand.

 

[irish_rail]

You are being a little selective with your figures on population if you include greater plymouth (as you have Swansea ) then pop is more than 260,000. I would certainly dispute swansea being a bigger city than Plymouth not quite sure that can be correct. Wikipedia suggests Swansea is 240,000 but anyway going off track a bit now I know.

 

[irish_rail]

My other big bug bear with the pairs of 5s is the minute there is a set shortage for a Bristol Oxford Cardiff or wherever a set will inevitably be pinched from the 10 car wofe train making these services more vulnerable to future short forming. Rather than everybody jumping to the defence of lots of 5 car trains (the one I just drove up required 6 catering staff) why can we not all accept for more 9 car sets should of been ordered with just a small proportion of 5s required.

 

[jimm]

My other big bug bear with the pairs of 5s is the minute there is a set shortage for a Bristol Oxford Cardiff or wherever a set will inevitably be pinched from the 10 car wofe train making these services more vulnerable to future short forming. Rather than everybody jumping to the defence of lots of 5 car trains (the one I just drove up required 6 catering staff) why can we not all accept for more 9 car sets should of been ordered with just a small proportion of 5s required.

Why? Because we don't all share your opinion, that's why.

Some of us can see a bigger picture, as opposed to your regularly-expressed one-eyed view of things, focused on one route, though this is a view which apparently doesn't extend to acknowledging the long history of portion working on London-Cornwall services. Many of the reasons for that method of operating have not actually changed since the practice was ended by the arrival of fixed-formation HSTs in 1979-80, such as the population of Cornwall.

What counts as a 'small proportion', I have no idea, but when FGW had all 14 Class 180s, that was not a big enough fleet for all the jobs that trains of that size were well suited to back then, never mind now.

The full new GWR timetable calls for five-car 800s to pick up all those sorts of jobs (and account for more frequent services operating on the Cotswold Line since the 180s' first stint ended in 2009), take on other work like Paddington-Bedwyn and provide more services for Cheltenham and Exeter all day and Bristol off-peak - oh, and replace HSTs where they were being used because they were available, rather than because they were the size of train that was needed. All of which adds up to a pretty sizeable fleet of five-car sets being needed, even before you add on Carmarthen portions and planned splits/joins on Weston and Taunton services at Bristol.

Any pinching of trains at Paddington is far more likely to be a nine-car diagrammed to go to Oxford/Hereford/Cheltenham being used to cover for a poorly 2x5 formation supposed to go to Bristol, Cardiff or the West Country - the same as what has happened for many years with HSTs - than a five-car being nicked to go the other way.

Sure, a healthy five-car split off a poorly one might be sent to Hereford instead of a pinched nine-car that goes to Plymouth, but please stop trying to make out that the West Country services have been singled out for some sort of special persecution by comparison with other parts of the GWR network.

Or being selective about population figures yourself, when Envoy did not even mention the populations of Cardiff and Newport (and adjacent areas that feed passengers into GWR's London services at those points), or the north of Bristol, which of course is also served by the Cardiff and Swansea trains.

 

[RPI]

Correct. I am only making the point that the company or government wouldn't dream of splitting services on the Welsh route and all the accompanied confusion and delay it entails yet are quite happy to do it on the route to the south west.
I don't think trains should split at Cardiff I'm just saying that they could and it is double standards that Cornwall was considered not worthy of full length trains but west Wales is.
A large fleet of 9 car trains is what should of been ordered from day one , pretty much everyone agrees that , shame first group didn't see that when procuring the 802 fleet as mainly 5s.

Have you seen how much hassle it is running 10 to Penzance? I work these services and the amount of people overcarried from liskeard on the up and other stations where only 5 cars or less fit on the platform is becoming a joke and yet 5 cars on most of the weekday services is more than adequate.
Admittedly though the first train to start joining at Plymouth is from this Saturday the 0900 Penzance to pad which on a Saturday is rammed through Cornwall with people bound for Primark in Plymouth .
Will be less of a problem when the 2 trains per hour start on the Cornish mainline.

 

[irish_rail]

Have you seen how much hassle it is running 10 to Penzance? I work these services and the amount of people overcarried from liskeard on the up and other stations where only 5 cars or less fit on the platform is becoming a joke and yet 5 cars on most of the weekday services is more than adequate.
Admittedly though the first train to start joining at Plymouth is from this Saturday the 0900 Penzance to pad which on a Saturday is rammed through Cornwall with people bound for Primark in Plymouth .
Will be less of a problem when the 2 trains per hour start on the Cornish mainline.

Correct which is why I think services should be predominantly 9 cars and not pairs of 5s for precisely these kind of reasons. Just because some trains don't justify 9 carriages in Cornwall in my view isn't a reason to introduce the risk and complication of splitting and joining at Plymouth which from an operational point of view could be difficult.

 

[irish_rail]

Why? Because we don't all share your opinion, that's why.

Some of us can see a bigger picture, as opposed to your regularly-expressed one-eyed view of things, focused on one route, though this is a view which apparently doesn't extend to acknowledging the long history of portion working on London-Cornwall services. Many of the reasons for that method of operating have not actually changed since the practice was ended by the arrival of fixed-formation HSTs in 1979-80, such as the population of Cornwall.

What counts as a 'small proportion', I have no idea, but when FGW had all 14 Class 180s, that was not a big enough fleet for all the jobs that trains of that size were well suited to back then, never mind now.

The full new GWR timetable calls for five-car 800s to pick up all those sorts of jobs (and account for more frequent services operating on the Cotswold Line since the 180s' first stint ended in 2009), take on other work like Paddington-Bedwyn and provide more services for Cheltenham and Exeter all day and Bristol off-peak - oh, and replace HSTs where they were being used because they were available, rather than because they were the size of train that was needed. All of which adds up to a pretty sizeable fleet of five-car sets being needed, even before you add on Carmarthen portions and planned splits/joins on Weston and Taunton services at Bristol.

Any pinching of trains at Paddington is far more likely to be a nine-car diagrammed to go to Oxford/Hereford/Cheltenham being used to cover for a poorly 2x5 formation supposed to go to Bristol, Cardiff or the West Country - the same as what has happened for many years with HSTs - than a five-car being nicked to go the other way.

Sure, a healthy five-car split off a poorly one might be sent to Hereford instead of a pinched nine-car that goes to Plymouth, but please stop trying to make out that the West Country services have been singled out for some sort of special persecution by comparison with other parts of the GWR network.

Or being selective about population figures yourself, when Envoy did not even mention the populations of Cardiff and Newport (and adjacent areas that feed passengers into GWR's London services at those points), or the north of Bristol, which of course is also served by the Cardiff and Swansea trains.

I agree the Bedwyn, cotswold, Bristol off peaks etc etc should be 5 cars. However we have a fleet of 58 5 car trains rather more than is necessary for the amount of trains which should be formed of 5 cars.
10 car trains should in my view not be running at all. It should either be 5 or 9 , nothing else (after all capacity on a 10 is.virtually the same as a 9 anyway) .
The wastefulNess of huge crewing costs between Plymouth and London of double manning both sets will soon bite GWR on the backside, indeed I took 6 catering staff to London yesterday (would of been 2 on a HST) surely this cancels out any cost savings of running shorter trains in Cornwall? ???

 

[jimm]

Correct which is why I think services should be predominantly 9 cars and not pairs of 5s for precisely these kind of reasons. Just because some trains don't justify 9 carriages in Cornwall in my view isn't a reason to introduce the risk and complication of splitting and joining at Plymouth which from an operational point of view could be difficult.

I agree the Bedwyn, cotswold, Bristol off peaks etc etc should be 5 cars. However we have a fleet of 58 5 car trains rather more than is necessary for the amount of trains which should be formed of 5 cars.
10 car trains should in my view not be running at all. It should either be 5 or 9 , nothing else (after all capacity on a 10 is.virtually the same as a 9 anyway) .
The wastefulNess of huge crewing costs between Plymouth and London of double manning both sets will soon bite GWR on the backside, indeed I took 6 catering staff to London yesterday (would of been 2 on a HST) surely this cancels out any cost savings of running shorter trains in Cornwall? ???

We are still waiting for the full fleet of IETs to enter service, never mind the short HSTs and the new timetable. We're in a transitional period, so things are not likely to be straightforward, are they?

If no 10-car formations were allowed, how exactly would you propose to meet the GWR pledge to provide all long trains into Paddington in the morning peaks and all long trains out in the evenings and boost capacity in the peak periods on routes where five-car sets are fine to meet demand the rest of the day? Lots of nine-car sets running round most of the time half-full or less than half-full would never pass a basic test of a business case.

The five-car sets provide the flexibility to do that, and boost frequencies in various places, which is why plenty were ordered in the first place. After their return to FGW in 2012, the 180s were deliberately diagrammed to keep them off services reaching Paddington at the height of the morning peak or leaving in the evening peak, as they weren't big enough to handle passenger numbers on fast services at those time, thus not making best use of capacity on the main lines. The 180 used on the 17.18 semi-fast to Oxford was in effect a surrogate Turbo that had the advantage of being able to run at 125mph and keep up with the main line services out to its first stop at Maidenhead, where it switched to the relief line.

 

[philthetube]

I agree the Bedwyn, cotswold, Bristol off peaks etc etc should be 5 cars. However we have a fleet of 58 5 car trains rather more than is necessary for the amount of trains which should be formed of 5 cars.
10 car trains should in my view not be running at all. It should either be 5 or 9 , nothing else (after all capacity on a 10 is.virtually the same as a 9 anyway) .
The wastefulNess of huge crewing costs between Plymouth and London of double manning both sets will soon bite GWR on the backside, indeed I took 6 catering staff to London yesterday (would of been 2 on a HST) surely this cancels out any cost savings of running shorter trains in Cornwall? ???

Two catering staff to provide first service and buffet sounds a bit short, There is no logical reason why an increase of 150% is needed, 100% still is an improvement in the staff to customer ratio.

 

[Master29]

If, as defenders of the 800 are so fond of telling us as to why the splitting is supposed to make sense ( which admittedly in some cases perhaps does)then why is the situation not the same with LNER. The majority of their 800`s are 9 car so the "if one unit breaks down there will at least be a spare" does kinda fall a bit flat as an argument.

 

[Master29]

You are being a little selective with your figures on population if you include greater plymouth (as you have Swansea ) then pop is more than 260,000. I would certainly dispute swansea being a bigger city than Plymouth not quite sure that can be correct. Wikipedia suggests Swansea is 240,000 but anyway going off track a bit now I know.

...And not to mention Devon and Cornwall's population swells by around 5 times in the summer months and as we are now being told these so called holiday periods extend until the end of November until early march so as anyone native to these areas who regularly uses trains to London will tell you (myself included) 5 car trains won`t cut it on most services, especially in the mornings. On most morning trains to London by the time they reach the likes of Bodmin Parkway the first class seats are all but full, so how 5 car units are going to help until Plymouth.....Well. I know they used to split at Plymouth pre HST but most trains now shouldn`t have to do that. I can`t help but wonder if all these consultancies and researches which no doubt account for a sizeable chunk of the 800 budgets have got it wrong; this is the UK after all.

 

[Grumbler]

The problems of catering etc. when splitting trains would not have been a problem had the trains been gangwayed throughout.

 

[jimm]

...And not to mention Devon and Cornwall's population swells by around 5 times in the summer months and as we are now being told these so called holiday periods extend until the end of November until early march so as anyone native to these areas who regularly uses trains to London will tell you (myself included) 5 car trains won`t cut it on most services, especially in the mornings. On most morning trains to London by the time they reach the likes of Bodmin Parkway the first class seats are all but full, so how 5 car units are going to help until Plymouth.....Well. I know they used to split at Plymouth pre HST but most trains now shouldn`t have to do that. I can`t help but wonder if all these consultancies and researches which no doubt account for a sizeable chunk of the 800 budgets have got it wrong; this is the UK after all.

And naturally no one at GWR knows anything about Cornwall's popularity as a holiday destination and there won't be different timetables and rolling stock allocations for the summer, or other peak travel periods - you know, all the things that have been done by the railways for a very long time now.

My regular service home for many years lost its HST every Good Friday, sometimes the Friday before Christmas, and every single Friday in July and August so the set could be used to operate an extra to the West Country on those afternoons.

If we were lucky, we got a 180 instead (though that was at the expense of Thames Valley passengers on the 17.18 to Oxford who in their turn got a Turbo nicked off a formation that was a pair of sets the rest of the week), or if a 180 was not an option then a Turbo (sometimes just a two-coach one) replaced what was normally an HST leaving Paddington shortly before 18.00, so forgive me for not being overly impressed by tales of supposed woe from Cornwall, a place where I have travelled on my fair share of lightly-loaded HSTs at various times of the day over the years.

Perhaps heavy loadings on London trains in the mornings might partly be explained by things like the current gap in eastbound departures from Penzance between 06.47 and 07.41 - a gap which will presumably be filled in future by a short HST soaking up passengers travelling within Cornwall or just to Plymouth.

How about you wait until we see how the whole package of timetable and rolling stock changes in Cornwall beds in before presuming to know how things will look in the long run?

If, as defenders of the 800 are so fond of telling us as to why the splitting is supposed to make sense ( which admittedly in some cases perhaps does)then why is the situation not the same with LNER. The majority of their 800`s are 9 car so the "if one unit breaks down there will at least be a spare" does kinda fall a bit flat as an argument.

Perhaps because the situation on the East Coast, the LNER service pattern and the amount of running on diesel engines will not be the same as on GWR, being a different part of the country, with different passenger flows, overhead wires to all the key destinations bar Aberdeen, etc.

 

[kieron]

I suppose it also helps that the layout at Plymouth is well suited to leaving carriages behind there. There are a few long through platforms to use. There's a double line either side of the station, rather than anything more complicated. And there aren't too many other trains going in and out to get in the way.

If you tried to split a train somewhere like Cardiff Central or Edinburgh Waverley, you would almost certainly need to arrange for a driver to take the second portion out of the station, If you were going to send the second portion somewhere else, you'd need the driver anyway. If not, the driver is another cost to set against the benefit from not taking the portion to (say) Swansea.