Not sure if this is off topic for this thread, but I’m wondering what people think what the end result of the upgrade will look like for us in places like Marsden, Slaithwaite, Deighton etc in terms of frequency of services? Is the work enabling higher speed inter city services to the detriment of local services, ie May 2018 all over again?
With Deighton there will be complete segregation of express and stopping service, which at least in theory should facilitate a more frequent stopping service, though with the four track section feeding back into a busy two track mixed traffic route between Ravensthorpe and Leeds it's unclear how much additional capacity can be realised. Maybe someone with more knowledge than me could comment.
So far as Marsden and Slaithwaite are concerned, the plan is for three-tracking, which must increase capacity but doesn't completely segregate expresses from freight and stopping services. On a four track section it's fairly easy to see how it works in practice to increase capacity, with three-tracking it's less obvious to see how it works. As I understand it, the Springwood tunnels will still be two tracks only, and from Marsden to Stalybridge will still be two tracks. [I've ignored the NPR tunnel to Marsden as being (1) not in my lifetime (2) probably never happening anyway.]
Is it not more likely that the stopping frequency will also be increased?
One would hope so. Around here we have learned not to take promises from train companies and governments for granted. We were told the 2018 timetable would be an improvement on what went before, and that turned out badly.
How is an infrastructure project to improve speed and capacity May 2018 all over again?
It's not so much about what was/is proposed but about the PR spin that accompanies it. May 2018 consisted of big promises of improvement followed by a much worse service. It was largely overlooked in the media with all the focus being on GTR and Northern, but by far the two worst stations on the entire network for punctuality and reliability (as per ontimetrains) during the 2018 timetable were Slaithwaite & Mossley mostly operated by TPE. When that happens, the next set of big promises of improvement tend now to be met with a certain amount of scepticism.
So Marsden, Slaithwaite etc. will gain a more frequent service to Manchester, albeit to Victoria not Piccadilly, but will lose direct services to Leeds.
Going to Victoria might be quite well-received. Unlike the good folk of Southport who were so opposed to the prospect of going to Victoria rather than Piccadilly, there were long-established commuting patterns from the Huddersfield line stations to Victoria (though probably more significant from Greenfield & Mossley than from Slaithwaite & Marsden). That may have changed since 2018, but one advantage of the stopping trains going to Victoria with connections at Stalybridge for Piccadilly is that it would allow cross-platform or same platform interchange. The bay platforms at Victoria may be the only bit of central Manchester rail infrastructure which is underused.
It is a service to Leeds that is the most important of all of them though isn’t it?
It's certainly useful and would be missed if it ended, but in terms of passenger numbers it's probably not that much greater than to Manchester.