I thought the plan was for the lines to diverge north of the bridge over the A60, so refurbishment of this to allow double track over it will have to come first?
Andy
@Flying Phil may know more about track layout plans than me and whether anything else has been finalised, but here's my tuppence.
I'm not sure on the final plans - that was certainly the plan in the past when the northern section were planning a station with a runaround north of the "gap", but that was based on the original straight alignment rather than the more sinuous route now planned. In the plan below, there will be a gentle left curve with the MML crossing roughly where the tree line on the left of the trackbed is. I'm not sure it would have too much bearing on track laying, but may make a straight points connection at the southern end of the A60 bridge more logical.
There is definitely room along the route for a fairly lengthy "double tracking", mind you - practically the whole route is laid with the "up" trackbed intact as far as 50 Steps Junction. A short double track stretch as far as, say, Stanford Viaduct may be desirable in the short term to allow greater flexibility and to allow heritage running to occur alongside Gypsum flows in the future.
To my knowledge, the layout is yet to be finalised - all we know for sure is that the bridge itself and the viaduct directly south of it as far as the canal will be single track. Apart from that, it's all up for discussion (funding permitting).