They will run as 5x2 10 car units from Paddington to plymouth, and then split with 5 cars running to Penzance during the low season, and during the higher season, I believe the 9 car 802s will replace them so passengers can walk all the way through.
Whilst that sounds logical and sensible, I remain doubtful as to how well it will work in practice.
Use of a 5+5 train that divides at Plymouth should indeed be fine in the low season, and substituting a full length 802 to run the whole route sounds sensible in the high season, This begs the question "what happens to the 802s during the off season".
Noting the great cost of these new trains, I cant foresee them being left idle, or utilised only sparingly during the off season.
I consider it more probable that the timetable will be planned so as to fully use these very expensive trains, with very little margin for peak flows.
5+5 to Plymouth and 5 only West of Plymouth may work fine most of the time, but I predict that if only 5 vehicles is the norm to Penzance, then that is exactly what you will get, no matter how busy. "We cant obtain extra trains just for the odd bank holiday"
Most of the time 5 cars should be enough for Plymouth to Penzance, Id imagine during holiday periods it would change to 9 car
IET▸ 's right through, with the 5 car units, then going to Oxford, Cotswold Line, Cheltenham and Paignton to displace the 9 car units being used on strengthened Cornwall bound services.
Using 5+5 car units on the Cotswold lines may be problematic. A
GWR▸ train planner, 'Clarence Yard', posting on the RailUk Forum had this to say:
On the 10 car issue, their operation on the North and South Cots is problematic as they are too long for key locations. They lock up track circuits or are too long for some bits of key infrastructure. That is why those services will be 9 car, with few exceptions. The problem is that “the Great Cartographer” thought he needed only 5 cars from Swindon/Oxford but when I looked at the actual passenger figures they told a different story and the late Roger Watkins and I got to work. Morale of the story - don’t use the industry MOIRA revenue prediction system for predicting passenger load by train. Go to actuals and then look at MOIRA.
The full post may be found at <https://www.railforums.co.uk/threads/should-there-be-a-follow-on-order-for-gwr-to-extend-their-80xs.165727/page-5#post-3529647>
I assume the 'Great Cartographer' is Stuart Baker - he of the railway atlas - who was (maybe still is) a civil servant in the
DfT» very closely associated with the Intercity Express programme. A 'gifted amateur' with no experience of running trains.
