Northern will need way more than 26 319s, potentially. I tried to review this in the following thread, which does need updating now.
http://www.railforums.co.uk/showthread.php?t=89934
14 319s due by mid 2015, as we know, more required when Preston-Blackpool goes live, then Something like 40 to 45 319s by Dec 2016 by when Manchester to Blackpool/Wigan will have all been wired, I've suggested that Northern could loose its 323s to LM with an equivalent number of 319s to Northern bringing the total up to around 60 by Dec 2017 then when the Trans Pennine wiring from Manchester to Leeds and York is done by Dec 2018, that requirement could be up to around 80 units, especially if the chance to replace the 321/322s is taken, meaning that Northern is close to having a requirement for all 86 units.
Fair enough, I didn't have any solid numbers to base my theory on, so your detailed posting in that other thread is very useful.
Looking solely at the North West electrification sections of that post, I suspect however that in reality the total number of 319s eventually operated by Northern might be rather more conservative than your estimations (Though still more than my suggested 26 units):
May 2014; North West Electrification
Event; Manchester-WCML link wired, 10x class 350/4s introduced on Manchester-Edinburgh & Glasgow.
Effect ; 7x class 185s released for additional Newcastle to Liverpool services. No cascade to other TOCs.
Issues; None Noted.
Dec 2014; North West Electrification
Event; Liverpool LS to Manchester Airport, Liverpool LS to Wigan NW & Liverpool LS to Warrington BQ plus Liverpool LS to (Ordsall Lane) & Manchester Victoria routes wired.
Effect; At least 12x DMU released (3, 4, 2 & 3 diagrams respectively), although likely to be more (up to 16) as some diagrams are currently pairs. Current Liverpool LS to Stalybridge hourly services, replaced by half-hourly to Manchester Victoria (5 diagrams?) and/or Liverpool LS to Manchester Airport frequency doubled to half-hourly. Potential for Liverpool LS-Blackpool services to be cut back to Preston, allowing EMU operation (extra 4 diagrams required).
Issues; Availability of EMUs not confirmed, assumed 6x class 319s ex-Thameslink available, but potentially more (unconfirmed) units required. Service pattern changes not confirmed.
May 2016; North West Electrification
Event; Blackpool North to Preston
Effect; At least 4x DMU released (likely to be more as some diagrams are currently pairs) if service pattern of Liverpool LS-Blackpool direct not revised when Liverpool LS-Wigan wired in Dec 2014.
Issues; Availability of EMUs not confirmed, assumed batch of 29 class 319s ex-Thameslink, displaced by TSGN class 387s by December 2015, whilst service pattern changes not confirmed.
Dec 2016; North West Electrification
Event; Oxenholme to Windermere
Effect; At least 1x class 185 released. Possible transfer to Northern franchise and operated by class 319s.
Issues; Availability of replacement EMUs not confirmed, assumed 2 extra class 319s ex-Thameslink. Service pattern changes including possible franchise/operator alterations not confirmed.
Dec 2016; North West Electrification
Event; Preston-Manchester Victoria-Stalybridge & Guide Bridge-Stalybridge routes wired.
Effect on Northern; Blackpool North to Manchester Victoria & Preston to Hazel Grove services converted to EMU operations, with at least 4 diagrams respectively on each route above, with up to 10x DMUs displaced, but likely to be more as some diagrams are currently pairs, plus peak time extras.
Effect on TPX; Manchester Airport to Blackpool North services (4 diagrams) able to be operated by EMUs. Possible transfer to Northern franchise and operated by class 319s.
Issues; Availability of EMUs not confirmed, assumed additional class 319s ex-Thameslink, of which up to 44x units are expected to be displaced by class 700s between Dec 2015 and Dec 2016. Service pattern changes not confirmed. Northern class 319 fleet potentially up to around 45 units.
Keeping a running total of 319 diagrams as we go, a more conservative tally might offer:
May 2014; North West Electrification – 0 x 319 diagrams
Event; Manchester-WCML link wired, 10x class 350/4s introduced on Manchester-Edinburgh & Glasgow.
Effect ; 7x class 185s released for additional Newcastle to Liverpool services. No cascade to other TOCs.
Dec 2014; North West Electrification – 12 x 319 diagrams (Plus others unconfirmed)
Liverpool LS to Manchester Airport – 3 diagrams
Liverpool LS to Wigan NW - 4 diagrams
Liverpool LS to Warrington BQ – 2 diagrams
Liverpool LS to (Ordsall Lane) & Manchester Victoria – 3 diagrams
Current Liverpool LS to Stalybridge hourly services, replaced by half-hourly to Manchester Victoria (5 diagrams?) and/or Liverpool LS to Manchester Airport frequency doubled to half-hourly. Potential for Liverpool LS-Blackpool services to be cut back to Preston, allowing EMU operation (extra 4 diagrams required).
May 2016; North West Electrification – 16 x 319 diagrams
Event; Blackpool North to Preston – 4 diagrams
Dec 2016; North West Electrification – 18 x 319 diagrams
Oxenholme to Windermere – 2 diagrams
Effect; At least 1x class 185 released. Possible transfer to Northern franchise and operated by class 319s.
Dec 2016; North West Electrification – 30 x 319 diagrams
Preston-Manchester Victoria-Stalybridge & Guide Bridge-Stalybridge routes wired.
Blackpool North to Manchester Victoria – 4 diagrams
Preston to Hazel Grove services – 4 diagrams
Manchester Airport to Blackpool North services – 4 diagrams
So 30 diagrams, plus admittedly the "others unconfirmed" bit under the December 2014 requirement which could bring the total closer to 40. Hopefully, at this stage somebody within Northern Rail has a reasonable idea of how many EMUs the company will actually require by December 2016, but I have not heard any plans mooted recently to replace the 321s and 322s around Leeds, or the 323s around Manchester.
