" it is aiming to have three quarters of its planned Arterio schedules introduced by the end of Summer 2026"
Which if comes true and refers to units, could be 68 701s? So 8 701/5 units, either as 10 or 5 car trains?
(Perhaps used at lines via Ash vale, operational spares, rescue or training units?), think 2 701/5s are already training units?
Unless I am misunderstanding this?
This surely refers to services operated, rather than units in service.
The Arterio planned roll out was to replace the 455's, 450's and 458's on the following terminator services - Reading, Windsor, Shepperton, Weybridge (via Staines), Hampton Court, Chessington South, Dorking and Guildford, plus the Hounslow and Kingston rounders.
As they are running a thinned out timetable from 2017 when they were ordered, they don't need to 701/5's to operate any of these services. Assuming a 90-95% availablility the 54-57 701/0's in service each day will be able to manage the services on their own. Any short formed services will be able to be covered by the displaced 450/458's.
The December 2026 timetable change will be when the 701/5's will start to be needed. As this will
likely re-introduce one more Guildford via Epsom per hour, one more Dorking per hour and two more Hounslow rounders per hour. There is unlikely to be enough free paths - between Raynes Park and Waterloo - to add an extra two Chessington's and two extra Hampton Court services per hour.