Long time O modeler moving up to G my question is i have a retaining wall in my backyard that is about 14" tall I would like to climb above it to the terrice level What is the rise to run ratio to achieve this? Also being in California going with a mining logging theme what would be a good engine? I'm sure being new to this scale many more questions to follow.
Welcome to the wacky world of G scale!
Grades for outdoors are really no different than they are for indoors. A practical maximum is 4%, which is 4" rise for every 100" run. So, if you want to hop a 14" retaining wall, you're going to need 350" (almost 30') of track to do so. Obviously, if you can get away with less of a grade, all the better. But 4% has historically proven to be a good practical maximum grade where you can still run reasonable length trains without slipping, etc.
As for locomotives, if logging/mining is your theme, then any of the Bachmann geared or logging locos would fit the bill nicely. The Shay, Climax, or Heisler are all good runners. The 2-6-6-2 is another good choice for a logging theme, though thematically, a bit more Pacific Northwest than California. I've got the Heisler, and it's a very reliable, smooth running loco. It's logged countless hours during open houses where I need something that just runs and runs and runs without paying any attention to it.
Later,
K
Welcome to the wonderful world of G Scale
I use a Bachmann 38 ton Shay. I have it on an Auto reverse back and forth section of track and it is always on whenever I am running the layout. It to is a great runner and goes and goes. I pull 4 log cars and a caboose. The greade is 4&1/2 %. It runs from my log loader to the sawmill. It has been a nice way to provide action without paying attention to it while I run other trains.
As for questions, Ask away!! This is a very friendly board with lots of great guys who are always glad to help folks get started!