Interesting explanation for what is needed - but no details as to what Northern has actually got or can deliver. Are you saying that Northern can't muster the units, or the staff, or reliability just mucks it all up so often, or ... ?
None of the above!
I haven't been out that way for a while. It would be useful to know how many units/carriages are allocated to provide the various services ie single 153, doubled up 153, doubled up 156 or whatever.
Part of the apparent 'inefficient' resource allocation is the need to allocate capacity at certain times of the day ie holding units back for certain departures and also having one of the loco hauled sets at Barrow during the daytime.
What I was suggesting is that a regular interval timetable is perfectly achievable, utilising existing 'standard hourly paths' out of the WCML at Lancaster and Carlisle. That such a service would require 8 rather than 13 diagrams (so a clear saving). That units would cross at convenient points. That several minutes can be allowed at St Bees for trains to cross. That several minutes can be allowed at Barrow for recovery/crew change/attach & detach. And even after that plenty of time is available at Lancaster and Carlisle for turnround/recovery. Additional peak time extras can be added from the 5 diagram 'saving'.
Why the current and previous timetables are such a dogs breakfast only Northern/Network Rail insiders know!
A regular interval timetable is far easier for the public to understand and remember. What time is the train Fred? 0617 and every hour. Coming back 0738 and every hour. Only two numbers to remember - 17 and 38.
As an aside, all of the Lancaster - Preston trips, all of the current trips through to Manchester Airport and the interworking with the Windermere service can be achieved with the same 13 diagrams plus one for Windermere ie 14 total.