Now see, a decent trolley can normally climb a wall giggling.
My guess whould be 8-10% and no telling if it had a traction tire.
You might be able to go from lower level grade to a 2cnd tier elevation with a trolley line (say a 10-12" toal rise)
There is opportunity to explore more prototypical operations here really. I suggest trying the different ways of running for sure. Looping trains are my indoor campfire and makes up most of my run time. But I have done the prototype stuff plenty of times before. From switching to timetables and scale distances, speeds, stops, etc.. Don't assume you do or don't like things; try them first. Some folk like the organization/ timeline challenge more than trains themselves. (look at Tycoon and Farm games)
( I loop while playing a shunting game app sometimes, lol)
Scene: a small switcher pretty much dedicated to the lowlands. Long trains can't pull out ofthe hole, but a switcher likely could with 1-2 cars. So the switcher dominates the lowland shuffles, and takes just one or two cars uphill onto a siding on the highland slowly assembling a train there, and maybe grabbing supplies &/or empties for product during returns to the lowland, or waiting for the upland train to drop its cars, and take the new train, etc.
Those are some great things to consider, and I can definitely see a small switcher being a possibility. This is why I came to this board...the ideas here seem to be infinite!
Thanks for replying!