I have, it tells me to get off at Reading have the same wait time as if I changed at Oxford, with the added bonus of telling me the platforms which I need to change between. Although I don't get that on The Train Line I know that I don't need to move between platforms, so for many it could be a more attractive change point (perhaps the reason for the difference in suggested change points)
The Oxford-London GW route has two types of service, fast and semi-fast, so if you use the semi-fast path for your fantasy train, it has to do the job of the semi-fasts, which means stopping between Reading and Oxford, which won't change any time soon.
Which is the same for the (currently) fantasy service between London and Stratford. However there are some trains that call at all the stations (which I think of as slow services) and there are some trains that only call at Didcot (which I think of as semi fast).
There is no guarantee connections would be better with any other service either.
Yes there is (well very nearly anyway) in that the GWR service can not run in the same path as the XC service.
So any GW Birmingham service would be of no use whatever to lots of passengers by going to Moor Street - making focusing on achieving better use of the existing XC paths a rather more sensible use of resources.
True, but then it could be of benefit to some passengers for whom New Street isn't ideal. It would also enable those who are traveling to/from Stratford an optional alternate route at times when the GWR service isn't running by changing at stations such as Lapworth, Hatton or Tyseley.
You wouldn't need a very large percentage of the people who occupy standard class (circa 700 seats an hour) in XC to have a reasonable number of people on the new service. 5% of the 2 XC services (assuming 100% standard class seat occupy) would be something like 35 people each way. That's before you tap any new passengers.
Although 35 is something like 1/5 of what you need to make a service viable given how crowded the XC services can get having a choice of 3+2 seating Vs standing on a 2+2 seat train or only being able to sit next to a load/smelly/fat person as that is the last seat on the train is likely to be attractive for some.
Also there's going to be done for whom they arrive at Banbury just after a XC service and are traveling to Reading or Oxford who will just use the new service.
Again that's before any new passengers and is true of the Stratford services too
And in many cases, modelling on railways has hopelessly underestimated actual demand. But in this case, there is plenty of actual evidence from preparatory work BR did in the 1990s, actual train operations until the mid-2000s, and work FGW/GWR has clearly done since then investigating the London-Oxford-Stratford markets and their potential.
Which is why I didn't say that passenger numbers might be too low, I said that the models are likely to be wrong. However, it is always useful to have a known market that benefits your case.
You would pretty obviously call at Leamington and Banbury for connectional reasons, but they would not be a fundamental function of the service - is it so hard to grasp that? Some people may use such trains as an alternative to XC but they are not key to the concept.
It may not be viable to the service making a profit, but it could be key to the service making a good profit.
But sorting out GWR's rolling stock fleet is key to cascades both internally in GW-land and getting stock to other TOCs. XC's rolling stock isn't.
The 802's were mostly to get rid of HST's on the Devon and Cornwall services, as such for those services they could have mostly retained HST's and not impacted on the Mark 3's that are not currently planned to be doing anything.
So in order to relieve short, low-capacity dmus that aren't suitable for long-distance services, you propose using more short, low-capacity dmus that aren't suitable for long-distance services, and would eat up yet more track capacity, rather than making better use of the existing express passenger paths between Reading, Oxford and Birmingham by running longer, higher-capacity trains in them.
I am suggesting using short DMU's to provide extra capacity on services that are unlikely to used by most of their passengers for very long trips, the longest is likely to be Slough to Birmingham, but most would be centred around the Banbury Oxford section. As most of the passengers between London and Oxford would be the same as currently use the service.
XC units aren't confined to specific bits of the network, are they? You can't just get from Oxford to Manchester direct, you can get to Leeds and Newcastle too and more capacity is needed everywhere on that network, end of story.
There are already several XC services that only run in pairs over sections of the total length of the service. As such there could be more of those as a first step. If these were focused on the core they would bring the most benefit. Given you can't provide more capacity everywhere all at once without having trains not in service, then incrementally increasing key sections is the best way.
Nor will Turbos with a 90mph top speed be welcome on the main line east of Reading from the end of next year, nor would their presence make pathing services north of Banbury any easier.
Many passengers on the Cotswold Line, where services are a jumble of HSTs, 180s and Turbos at present, actively avoid Turbos when they can - a trip or two in a crowded 165 between Reading and Birmingham might make people reconsider their dislike of Voyagers.
If the 16x's are that crowded then the service is clearly needed and will be profitable enough to look at other rolling stock during the lifetime of the franchise. It would mean that those who suggested a service to Birmingham where proved right.
In reality, and it was why I talked about 150 passengers sitting in 2+1 configuration on 3+2 seats, the trains are likely to be comfortably loaded and therefore likely to benefit those who stay on the XC services.
However, again whatever is true of the Birmingham services is also true of the Stratford services. As such what rolling stock would be used for that and where are you getting it from?
Much of the current glut of new-build trains is due for delivery in 2019 or early 2020 - so there will be a lot of production lines looking for things to do around the time new franchises should be let, with the likelihood lead-in time would be much shorter than you suggest. If 769s are being produced in small batches, on s stop-and-go basis when an order comes in, they aren't going to arrive in too much of a hurry.
Based on the franchise timetable there's three full month's between the GWR announcement and the franchise starting (assuming announced 31 December and start of 1 April) with no additional reporting period extensions possible, that means any new stock will be a little way off. However it would be possible for supply chains to be preparing for a potential order (i.e. funding out who could supply what and when) so that they were able to move fairly fast once an order was placed.
The thing that is worth noting is that there's a potential additional 11 reporting periods which the SofS could extend the XC franchise into. Potentially pushing new XC trains since time down the line.
The other possibility is that XC it's for the 222's which means waiting for them to finish at the East Midlands franchise before they can be refreshed and then brought into service.
Of course it could even be possible that XC are told to get on with what they've got as it will only be a few years before HS2 drastically changes their market. Likewise HS2 could kill the Stratford tourist market from Paddington.
In that rather than it take 2:10 for a direct service from Paddington that runs every 2 hours it takes up to 2:10 (if you assume a 30 minutes change time from HS2 to Moor Street) from Euston for a service that runs half hourly, and so people opt for the more frequent service so that they can just turn up and go rather than plan when to go.
Of course GWR could opt for a new bimodal or new DMU which is not an Intercity style train, maybe with a 110mph capability. In doing so they could be at the front of a production line.
However all of that is a long way down the line in terms of should there be a Stratford or Birmingham service from Paddington. I think that there should be (both) and that although there could be some people who travelled from London to Birmingham on a Birmingham service it would be a lot less than those who would do so to Stratford. However there would still be enough people making shorter journeys that it would be worth doing, even once HS2 starts to operate.