Northern clearly do have a big sprinter problem by the time the current contracts end in 2025 (assuming those contracts still apply) the 150s will be an average of 39 years old, 155/6s 37 and 158s 34. Currently these classes account for 384 of Nothern’s DMU carriages out of a total of 599 64% of self propelled stock.
For context the previous oldest DMU in the area was the class 101 at 47 years and current oldest stock in the 507 at 43 years old. I would stay that 45 years is the longest we can expect any of the 15x stock to last before it becomes uneconomical to maintain so 2030 for the 150s and 2035 for the 158s.
I also believe that stock is being replaced on a more or less total length basis case in point the original 195 order total length was 3343.25m to replace 3316.038m of pacer stock. The only units likely to be available and worth taking are the 50 158s to be released by TfW and EMR and, the 175s from TfW. 170 carriages total length 3969.82m which is about enough to cover the loss of the 150s, 153s and 155s, total length 3992.376m.
Even then Northern in 2025 are still going to be left with 308 carriages that need replacing over the next ten years. 769s are a factor but they’re not well proven and based a platform that’s a minimum also going to be 35 years by this time. Electrification from York to Huddersfield won’t release many units 2 to 4 185s and maybe 2 to 4 Northern units.
Any new electrification based on the previous north west scheme will take 6 to 10 years to be available after commitment to doing it has been established and there aren’t really any easy win lines to do;
- Warrington Central is has quite a few units on local services but expresses that won’t benefit maybe more in the future, needs re-signalling, most likely will have geological issues and has political issues as what kind of line it’ll be the future i.e. tram-train.
- Southport has the issues around Wigan Wallgate.
- Calder Valley is the most ready in terms of route upgrades but the sheer number of tunnels and over bridges is going to push the price tag way up.
- South Leeds commuter routes needs to go all the way Sheffield via Barnsley to be useful.
- Sheffield north to Doncaster and Wakefield seems the most doable but doesn’t free very many DMUs.
- Tram-train south east Manchester could remove 5 hourly diagrams probably saving 10 units.
Some unit saving could be made by pushing some routes around Sheffield on to EMR but that would almost certainly come with the requirement that the Northern 170s also move to EMR so a net neutral move at best.
Best case scenario York/Hull-Manchester, Leeds/Doncaster Sheffield fully wired and Manchester tram-train completed by 2035 around 150 DMU cars required to replace life expired DMUs so equivalent to the complete 195 e.g. 33x3 + 25x2 or just 50x3.
Worst case all the 156s and 158s need replacing in a short space of time that 308 carriages or 7131.76m of train which would require 100 3 car 195s to replace them. (102 based on carriage numbers)
The previous investment was £500 million for 281 carriages so assuming a pure DMU order would be more expensive around £325million for 150 or £650 million for 300 carriages? Although this is all academic while the government maintains its anti diesel stance.
Also of note is that GWR will have 43 158 carriages and SWR 110 158/9 carriages to replace on a similar time scale.