N Scale Model Railroad that Grows... by Kalmbach. Are the grades acceptable???

[Anonymous]

I am still in the very early stages of my layout and have spent countless hours with graph paper and the RTS software trying to make everything fit into the spae I have available. I am doing N scale with a mining and lumber based theme on 36" x 72" Main section and I have a 24" - 34" (tapered) x 54" shelf for a yard...
Anyway, I have spent so much time trying to accomplish an elevated area on one end and stay within recommended guidelines for grades, etc. As you know a 3% grade rising approx 3" - 4" takes like 8 feet or so. So I think I've got it all figured out and then STUPID ME! I pick up this book while browsing at my LHS. This thing accomplishes most of what I want - within reason - on a 40" x 60" layout. It has a raised, hilly, area in the middle and accomplishes its rise and decent on about 1/2 of the layout... Is this really feasible? What are those grades?
I would be curious to hear from anyone who has seen or built the layout. I think it would be great to put a lumber/logging operation or something up in the hills, expanded on what they show in the book and have a mine coming out of the other side on the main level track or something but I'm just trying to figure out how they accompli***hat in such a small area. I couldn't really tell from the pics what the actual height of the upper level was?
Anyway, sorry for rambling.. just curious...
Also, I didn't have that much time to look at it and I wanted to get some input before I dropped the $15.00 on the book and not use it so if anyone has a copy or picture of it they could show me I would like to look at it more closely...
Thanks,
John