You have just provided evidence that the 1720 or thereabouts from Oxford which is almost certainly the busiest train north of Oxford is fine as a 5 car train, you argue for a 30 min frequency, you argue against Turbos, but aren't in favour of a half hourly 5 car IET?
How are you justifying a 30min frequency of 9 car IETs / HSTs? The current service is half hourly from 1820 to 1920 which looks very over provided, but no service at 1750.
I really do think it is time you stopped poking your stick into operations in areas of the GWR network you clearly know/care nothing about - which appears to be just about anywhere west of Reading.
No, I haven't provided evidence of anything of the sort. The 17.22 from Paddington/18.16 from Oxford is an HST that is near enough full, or over-full most days of the week leaving Oxford - ie rather more people than can fit on a five-car Class 800 - which is why the future equivalent service will be operated by a nine-car or 2x5 formation.
Of course I argue for a 30-minute frequency for the main peak flows, because that is what is needed to handle the number of passengers - a frequency that requires a mix of five-car and nine/2x5 as the various trains have varied loadings for various reasons, such as the numbers of people heading home from London between 5pm and 6.30pm.
The 'peak' period out of Oxford starts after 4pm, not everyone works 9 to 5, schools finish at 4pm, blah, blah... and the current service has departures at 16.25, 16.50, 17.25, 18.17, 18.50 and 19.23. And it is safe to assume that things won't look that different from next year. Nor the varied sizes of the trains provided within that sequence.
I am actually advocating a 500 seat off peak train.
Which is way too big for the traffic on offer between Oxford, Worcester and Hereford outside the peaks, which may just have had something to do with the decision to go for five-coach IETs...
On the basis that what goes up must come down, I am sure that like the coupled 5 car trains, they will both do lots of quite off peak trains.
As would your oversize 10-car single unit formations.
Where the conflict occurs isn't the point. The timetable is so fragile that a small delay to either train will cause the Moreton in Marsh legs to be cancelled, and they often are. The infrastructure cannot reliably support a half hourly service in both directions. This leaves you with some choices to make in the peak:
1) Split a 10 car IET at Oxford which will compound the conflicts and delays already happening there.
2) Run a 9 car IET every 30mins in the peak through to Worcester.
3) Run a 5 car IET from London and waste a precious path to Reading.
4) Run a long train, doesn't really matter to me if it is 12car 387 or IET but terminate at Oxford once an hour.
5) Supplement the above with a low capacity Turbo Oxford - Worcester to improve the frequency.
If you had the infrastructure, which you don't, given how much of the traffic is Oxford - Hanborough and Charlbury a Turbo shuttling up and down to Moreton in Marsh or Charlbury is not unreasonable at all.
Your 'logic', or lack of it is quite astounding at times. The local infrastructure can handle the frequency - but if trains are delayed due to things going bang in the Thames Valley, or the mechanical signalling museum at Worcester plays up, then there are issues. Same as the number of occasions earlier this year when they struggled to find drivers or train managers for this service - since when has that got anything to do with infrastructure?
You wish to deny people the service they already have, ie a half-hourly HST equivalent out of Paddington from 17.22 to 18.22 (also providing seats for the entitled Reading commuters), as the infrastructure can't cope, then on the other hand want there to be a shuttle service running in between an hourly jumbo-IET on the same 'inadequate' infrastructure. Slight contradiction there...
The non-stop run, into an off pattern slot at Oxford is simply proof the timetable doesn't really work, even on paper. The extra train is forced through and anything with a 10% cancellation rate, needs to be removed not compounded by trying to do each hour for the peak.
Since when has the operation of one particular train - in order to get the seats back to Oxford where there is high demand - got anything to do with the overall service pattern? As I already explained, the cancellations are related to things happening before that service ever gets on to the Cotswold Line on the outward working in the first place - so long as it has got to Moreton-in-Marsh, its return run to Oxford presents no great problem.
You seem to oscillate between saying the route doesn't need 550 seats trains, to it must have a 30min service to move the numbers. If a 5 car train can lift the numbers at 1720 from Oxford, a 10 car IET running hourly, without two kitchens easily could, and Hanborough is about 10mins down the line.
I'm not oscillatiing between anything. I am saying that the current timetable is the result of many years' operating experience by GWR and its predecessors. Which will be reflected in the new timetable as well, with a few tweaks here and there. And take into account things like the evidence that making people change trains at Oxford is not a great idea. Passenger numbers and revenue both went up by about 30% in six months in 1993 after the launch of an all-day through service between the Cotswold Line and London using 166s in between the peak HSTs - and both have gone up a whole lot more since then...
An IET with <100 people on, running every 30min between Charlbury and Worcester is in need of pruning. As are off peak Hereford, Paignton, Carmarthen services, the peak West of England services beyond Newbury and anywhere else of the same ilk.
Ah yes, stuff everyone else - Reading-London is all that matters...
If I am wishing these dreadful 387s with 2+2 seating good enough for Heathrow Express on Newbury and Oxford, which was the original intention for them, then I am also wishing them on Reading. What is not sensible is an IET every 30mins from Oxford to Worcester service a 10-20min commuting flow to Charlbury.
I'm afraid you will just have to get over it - and again, your lack of local knowledge shines through - even on a seriously busy day, perhaps 150 people in total get off the HST services at Hanborough and Charlbury, which still leaves rather a lot on board.
Maybe just stick to Reading-London, though even there you refuse to wait and see what the effect of the full new GWR and Crossrail timetables is and just demand jumbo this that and the other right now - informing us that
The new trains are already full
when we haven't even seen seen the new GWR timetable and the full IET fleet has not been delivered, never mind a Crossrail train turning a wheel in passenger service west of Hayes & Harlington.
I expect GWR/future franchisee, TfL and the DfT will all want to take a considered look at how all that lot pans out before they even consider spending a penny piece on extra/longer trains.
The GWR franchise now looks likely to run on until 2022 (or even 2024), unless talks with the DfT break down, by which point there will be plenty of evidence of real world operations available, and potential franchise bidders in 2021 or some later date will no doubt be invited by the DFT to take account of that real world evidence in their proposals.