PaulB wrote:What are they being replaced with?
It's a complex cascade... but in summary:
Longer distance routes are getting 101 brand new trains built by CAF:
https://www.bbc.co.uk/news/uk-england-48770078. 10 of these are already in daily use on routes between Doncaster and Leeds, and Manchester/Liverpool to Cumbria.
This allows a cascade of existing stock to urban and inter-urban routes.
Plus:
16 "Turbostar" fully refurbished 3-car multiple units cascaded (mostly from ScotRail) - these used to run Scotland's intercity routes.
12 class 319 4-car units, of which 8 are being converted to bi-mode (electric/diesel)
Various cascaded Sprinter/15x series stock.
All non-new stock has either had, or will get, a full refurbishment (whole new interior, including USB/power sockets and wifi.