Looking at the maps available in the public domain it appears they plan to cut straight through Oldham in some capacity, which is what peaked my interest.
Only problem I can foresee with a tunnel is that we’re famous for mines as well as cotton mills. There’s still a lot of old capped off mines under residential areas in Oldham.
The same problems with disused mine workings will also apply if, as suggested by others, the tunnel portal is at Guide Bridge. The difference is that the area north and east of Guide Bridge not only has disused mine workings but also peat bogs. I admit to not knowing enough about tunnelling to be able to say whether peat bogs create a problem.
I would suggest that the field to the east of Marsden Station containing the Marsden Skate Park would be the best location for the portal it would avoid any complications of the tunnel site.
The railway is on the north side of the valley, well above the level of the centre of the village. A new tunnel from the vicinity of the skate park (actually the old goods yard) would need a very steep gradient to get underneath firstly the canal and then the River Colne from there. I can't see that being realistic.
To be honest I don't see this project happening at all, in any form, the government has crayons bigger than this forum and drawing pictures of projects that don't need funding for another decade or two is good for deceiving the masses. That's why I prefer incremental progress..
When the IRP was published there were those who suggested that the proposed new line to Marsden was included for no other reason than to allow Grant Shapps to say in media interviews that high speed rail was coming to Yorkshire. I thought this was too cynical, until Mr Shapps said precisely that.
I have come round to the conclusion that there is not and was not any intention to build a new high speed line to Marsden. For so much of what this current government does, the media coverage is an end in itself. It got the short term media coverage that the government wanted.
Announcing things that will never happen is just as effective for (as you put it) deceiving the masses, and a whole lot cheaper than actually building stuff.
It's worth pointing out that there has been almost no speculation locally about where this high speed line will emerge and its environmental impact on the upper Colne Valley. That's because almost no-one around here expects it to happen.
