It is far from a stale debate though. One of the biggest issues with the viability of the Canada Dock branch Line has always been its lack of electrification. In the coming years that will become a moot point. The likelihood of fossil fuel trains continuing in the future are virtually zero.
Given we have left the EU and with the need to combat climate change then the CDBL becomes more viable by the day. Battery hybrid trains powered by clean renewable energy is clearly the future.
The bit I don't understand is your insistence that a Stadium has to somehow fund a passenger line. The economic argument for passengers on the CDBL is likely to become overwhelming.
As for the West Coast Main Line maybe you should have a look at the two Eccleston interchanges. They provide a link to the WCML with no need to head into Lime Street.
I enjoy a natter around playing with trains as much as the next person who enjoys a natter about playing with trains but this is a football forum and a stadium thread inside a football forum, so if it's not about how it would help a stadium, I'd take it elsewhere - plenty of choo-choo forums about.
As it happens, I disagree with you about the future of the CDBL - you have to think about why it was abandoned to freight and what has changed in the interim to consider a re-look. I'm all for greener, public transport but there just isn't the working population to support opening seven or eight stations - with batteries or not. I'd seriously doubt any feasibility study got past this first stumbling block - not enough demand or not enough foreseeable future demand but even if it did...
More to the point and more to the point of stadiums, it doesn't have the connectivity for fans from both near and far and if it could, it would cost five arms and six legs. I can take you through the issues one by one if you like but there's more to it than electrification or batteries. Electrification would help freight sure but there's a lot else to consider for passengers.
I know there's at least one 'connection' at Earlestown but that's single track i think and the route through Huyton has pretty low spare capacity and I don't recall it being suitable for the sort of trains that make a difference from real distance (I believe I went through it once on a super-slow, late night diversion from somewhere south but i might have dreamt that).
Not to mention last time I looked, there's only one line through the tunnel at Olive Mount Chord, because the tunnel wasn't big enough for containers unless the line ran down the centre line (massive, massive cost to change that, ditch the last freight line into the docks altogether or widen a 200m tunnel with a large-ish roundabout on top of it... even as a local commuter line) - hence the focus on WCML via Runcorn towards or into Lime Street. Proper heavy rail with proper trains already scheduled to run on it.
Even that means either a spectacularly expensive and probably geometrically impossible rail flyover directly into the CDBL or crossing commuter rail traffic before Edge Hill (engineering works), re-opening a platform at Edge Hill before the Waterloo tunnel and/ or running further into Lime Street to make the journey attractive to other users and hence viable and 'reversing' back through Edge Hill and onto the CDBL. But what do you do with the trains during the game (because there's nowhere to go at the other end - it being well, a 'branch' line). Back to Lime Street and forward again to Huyton, the North and Manchester or the Midlands and South?
And that connection into town at the dock end? There isn't one (I read there used to be a link
from Alexandra Dock to Southport but I haven’t found it*). The line runs under the Northern line and straight into the docks - so again, very significant if not massive engineering and cost to get up the level and connect with Sandhills etc. A really difficult piece for the viability of it all, even as a local commuter line - let alone for the added bonus of serving a stadium.
Then there's cost of signalling and safety and new stations and whatever else was on that list etc etc...
* ok, Super choo now. This is possibly the potential link/ points from CDBL to Southport line - north of Bank Hall.
