I am planning my garden railway and plan to use the top of my 120' retaining wall for parallel tracks. I will exit the wall with R5 at each end but the rest is straight. It is currently topped with 8" bricks which is great for a single track but too narrow for parallel tracks. I was told you...

I've been lurking here for awhile now gathering information and certainly have gathered a lot of good information from the many posts. Thank you everyone, many questions were answered just by reading old posts. I'm in Southern Nevada, about 110 degrees outside as we speak. Attached is my track...