The way I used to make sense of it was by reading books by people like James I C Boyd,and others mentioned in previous replies-although the railways are frequently the main subject,you can (with a little patience) interpret alot of the info about locomotives,inclines etc, and where they worked into a sort of rough understanding of the areas of the quarry.
For example when Boyd (and carrington) talk of locos moving from one gallery to another,sometimes having to dismantle them in the process-Holy War being moved by ariel ropeway as an example.By tying the written info to a map as in Carringtons book,or p86 in Boyds Narrow Guage Railways in North Caernarvonshire,a picture of sorts emerges.If theres a good detailed map out there somewhere it would save alot of time though!