I’m not an expert on the trains but have followed the discussions on Skyscrapercity and Railforums about what’s happening around Manchester for a few years. I assume that a lot of those people have studied the issues and some will work or have worked in the industry so know the problems faced. Nothing is 100% impossible but there appear to be issues about…
No spare terminating capacity at either Victoria or Piccadilly. This means trains have to wait outside stations until a platform becomes available or they just leave longer gaps in the schedules. They are planning to add new sidings so trains at Victoria can run through and then come back but that just partly helps fix the current situation, it doesn’t necessarily mean new services can be added.
When a new path is suggested, it needs to run a route that involves as little use of points as possible as it means other trains have to wait until it has crossed over when they switch tracks. A route from Newton Heath would need to switch tracks quite a bit so I doubt it would get signed off.
Changing direction at a station also causes problems as the dwell time blocks the line or platform longer than a train simply calling as it passes through.
This is why reopening Park is the most likely scenario, however no-one has ever mentioned it AFAIK on any of these forums so I am guessing there’s not much of a business case for it. That idea may not even be possible now, I’ve never asked, but if it is it would be a station on an existing service so doesn’t add to the issues above, except it still affects the scheduling of current trains, even that might be a show stopper.
