well, the grades don't let me sleep.
on my new layout i use 13 meters (42') to gain 70 cm (2' 4") of height.
that would be 5.4% (after my mileage)
that was the steepest grade on which my small locos (with additional weight) could draw up trains of 14 aixles.
any steeper trial produced nothing but slipping locos.
so, now i am told, that one can use 1 in 5 grades (for me = 20% grade)
that means i should need only 3.5 meters (11' 4") for that difference in height.
i really would like to know, how i could save that much space.
but my locos don't even move themselves up this grade. (let alone a string of cars)
to visualize about what we are talking, i took a 150cm (5') piece of rail and a 30cm (1') piece.
the resulting one in five (20%) grade looks like this: