The Manchester city central railways issue needs far deeper thinking than 15/16. I say deeper because we're scratching around on the surface where space is severely limited and always will be.
Rail in the future must make much greater use of all the ground below our feet, and quite deep too. We're still transfixed with tagging bits here and there onto Victorian surface infrastructure, and trying to revive more of the same that has long been out of use.
In principle construction of a brand new HS2 route is on the right lines, although the actual route with so much on the surface is another issue. I've previously suggested what might be called a Cross Pennine tube, 100% underground straight and level from Sheffield to Manchester, 32 miles, journey time of 20 minutes compared with today's best of 50 minutes and unlikely to be reduced below 45 minutes anytime soon. OK, file that with the Scotland-Northern Ireland Bridge. Far too far ahead of its time.
But we have Crossrail and Thameslink below London - with Crossrail 2 in the offing. In the 1970s the Mersey Railway was extended with a loop below Liverpool to link city centre stations. By the 1980s the old North Tyneside suburban loop became the Metro with a crossing of two lines at Monument below Newcastle city centre. Tunnels were built below sea level beneath the Mersey and Thames and linked high across the Tyne to run under Gateshead. I haven't forgotten Glasgow underground below the Clyde.
My other favourite example is Oslo where the second busiest station in the country,
Nationaltheatret, is below ground. The rail line to the airport is underground below the city and also through a range of hills en route. The major road across Oslo is underground beneath the harbour and city centre.
It's time to build the Manchester ring with a major terminal for long distance routes below ground. By going below ground we can avoid flat crossovers with subterranean flyovers and unders. The canals and Irwell above shouldn't be an insurmountable issue, see above.
Where's our ambition? If long distance routes can come straight into the centre on dedicated fast track from, say, 5 miles out instead of getting snarled up with stopping services both would benefit. Some freed up surface mileage might be made available for light rail and cycle ways.
I leave it to Mancunians to start a new thread for this idea, suggesting where existing lines might start burrowing down towards the centre, where the circle below the city might go, and where a central interchange might be - or possibly with stops beneath both Piccadilly and Victoria.
If the average long distance service couldn't save at least 5 minutes on every journey it woudn't have been done right.
Yes, it would/will be expensive. But won't it be expensive to continue with the present pain with all the unpredictable delays we have now? It will certainly be expensive to update, replan and construct another patch on to the Victorian infrastructure with 15/16.
Think big. Get it done.