About fifteen years ago a friend showed me a rather tatty photocopy of a “Proposed Grand Commercial Canal” linking Peak Forest and Sheffield canals. I have recently, with invaluable (and bloody fast) help from Sheffield Library, found a much more interesting document of which that was only part. (I have no Idea about copyright law but, as this document is dated 1824, I suspect I’m OK)
Even at this size (about one quarter of the original) a lot of the detail can be seen (click the picture and then click with the magnifying glass).
Thus far the path is almost the same as the rail line to Sheffield,however the proposed canal tunnel is slightly to the south of the rail, emerging at Smeecliffe[sic] Wood to the west of Millthorp[sic]:
The Sheffield branch also has alternatives: down Norton Leys[sic] through Heeley to the present canal basin or along the ridge through Manor and down to Attercliffe.
There is considerable fall from Norton to Sheffield canal and it was apparently the intention, if the Manor→Attercliffe route were taken, to use a Railway and Inclined Plane over the latter part of the route. The number of locks required on the Norton→Heeley route boggles the mind somewhat.