And now crumple zones are evil are they?
No, they aren't evil, health & saftey requirements generally aren't. But don't you admit it seems silly to have more of them than you need (one at each end of the train)?
No, you just have the problem of lugging around a half-empty train much of the day if you use nine cars, wasting energy, which is something you used to go on about a great deal.
Well 2x5-car would also be lugging arround the equivelant of an empty carriage so that's also wasting energy. And, because of my concerns about waste, I pondered whether you could put some 7-car or 8-car sets in the fleet, maybe even a handful of 5or6-car sets as direct 180 replacements, to save running 9-car all the time.
The trouble with your idea is that it would completely remove the ability to couple and uncouple trains to reflect variations in demand and would produce seven-car trains that were too big for lots of jobs, which won't need 450 seats, and too small for lots of others, which will need more than 450.
Removing the ability to couple is an intentional outcome of my proposals.
It's not a diagramming problem
Why not? You said above that 7-car trains would be too short for lots of jobs. That's why it is a diagramming problem, you'd need to be able to keep them off the jobs they aren't big enough for.
it's a meeting demand sensibly problem
Which is why you have different length sets that you sensibly diagram on services as appropriate. Just like the 180s at present, diagram a short train where you can and a long one when at least one service in the diagram needs it. Just, if there's a demand break (like east/west of Oxford on the Cotswolds services) don't try to solve the problem with portion working. It means not meeting the demand at the busy end sensibly (running 10 coaches with the capacity of 9) and potentially not meeting demand on the quieter bit either (running 5 coaches when you need 6).
And on the subject of meeting demand sensibly, you were told the following about the impact of the increased service frequency with IEP on capacity between London and Bristol
...
Similarly, from Oxford, if there are 3 IEPS an hour, plus assorted 100mph-plus emus, there will also be a huge leap in capacity there, same as an hourly 5-car IEP to/from Cheltenham and Gloucester tots up to rather more capacity than an HST every couple of hours.
Not all routes are going to see a frequency improvement though are they? Bristol might be ok with shorter sets, as might Cheltenham, but what happens when a 5-car goes to south Wales or east of Reading? Also, where did 3 IEPs an hour to Oxford come from. My diagramming estimates are based on just one IEP an hour (the Cotswolds service). If you add 2tph PAD-Oxford on top that's another five or six diagrams, which would at least mean they couldn't do portion working as there wouldn't be enough trains.
What is the point of running nine coaches all the way west of Oxford or Swindon, if there are fewer than 300 people on that leg of the journey, whereas demand east of those points is higher, so by splitting and joining sets you balance the capacity against the demand on each section of the journey?
Because, assuming there are peaks where you do need to carry more than 315 passengers on the western leg, you will need enough long trains to cover those services anyway? Because if you order trains assuming you're doing that, you may have some services where you have to run a 5-car beyond Oxford/Swindon because that's the pattern but 5-car isn't enough further west on that service? Because it has the potential to inconvienance passengers? Because running two 5 cars in multiple only gives you the capacity of a 9-car set and puts the train length at 10-cars meaning there's less (if any) scope for lengthening?
If I were to suggest (and I'm not going to, because it is silly and conflicts with my rules for passenger-friendly services) running short fixed formation LHCS trains with a loco and DVT and use them for portion working, without detatching either loco or DVT when the sets are joined, you'd probably rightly point out that it's silly. Ok the two crumple zones in the middle of a 2x5-car IEP wouldn't be quite as much wasted space as having a loco and DVT in the middle of the formation, but it's still quite a bit and still prevents passengers walking through between the joined sets.
If you want more capacity you, er, buy more coaches, which is what has happened with Pendolinos or 333s in West Yorkshire - unless those cases are in some way different to buying more IEP coaches.
The difference between lengthening 390s and lengthening 5-car IEPs is that 390s were/are not worked in multiple. That means you can stick extra coaches in them without much of a problem. With 5-car IEPs, lengthening them would stop them working in multiple which means you end up with more sets than you need (or spare driving vehicles if you use intermediate coaches to lengthen other sets). Far better, when dealing with 125mph stock, to only have the number of driving vehicles needed to run each service with a single unit.
I do love all this stuff about coupling short trains. What is it that you and Rhydgaled know that train operators the world over have clearly failed to grasp, so they persist in doing it, day in, day out?
That depends. Coupling short trains, in my view, makes perfect sense if they don't require large crumple zones for saftey reasons and comply with the following:
- All units serve every station on route (so no portion working and at least one door on each unit able to open at every station), unless passenger-gangways are provided between units
- Catering, if provided at all, is available to all passengers in the same form throughout
- And probably one or two other things that I can't remember right now
Operators which don't do this may just have been landed with rolling stock that isn't fit for purpose and are doing the best they can in the circumstances.
Rhydgaled's various justifications for why IEP cannot work (too late now, I appreciate).
It isn't that IEP cannot work, it can. It's just been rather poorly executed and could be improved significantly.
The only way to buying more IEP coaches would be to convert some 5-car sets into 9/10 car sets, because you can't double up 6-car formations without requiring hideously expensive platform extensions.
This leaves you with a surplus of sets with nowhere to put them.
ECML will be swimming in IEPs, GWML will be swimming in IEPs. MML and XC will be the only place to send them really
And XC, I'm assuming, will be fairly well supplied with Voyager family units. That just leaves the MML, which will probably have wires and need new units before additional coaches to lengthen IEPs can be ordered and built. Much better to get it right first time than lengthen later. As said above, keeping the IC225s could provide the additional IEP vehicles needed to eliminate 5-car IEPs on GW and perhaps enough to cover the requirement for new MML stock too, since they can have the IEP vehicles ordered to replace the IC225s.