I enquired (both by email and during an end of session discussion) the feasibility of a heavy rail link from Marple into Stockport by creating a spur onto the Reddish line. I was told it had been looked into and dismissed due to the lack of available platform space.
Thanks for this report Steve. I'm not surprised that you were told the scheme is not viable, but I am surprised at the reason you were given.
There were once, long ago, 'bay platforms' at the north and (I think) the south end of platforms 1 and 2, similar to platform 3a which is still in use.
If a route from Marple via Bredbury and the Guide Bridge line were to be built, the northern bay platform (platform 1a) could easily be reopened. Similarly, if the route via the Middlewood Way and Hazel Grove were constructed, a south-facing bay platform (1b) could be opened.
It hard to believe that that is the real reason.