I started in HO trains at age 4 back in Jersey. Then I got started again in 8th grade. Then yet again as a very young father. All the starts were because of my father being the the Army and then me and the required moves. I haven't done anything with model trains in years, 1983 in fact when I build 3 N scale layouts for my sons. Well I've been retired from the Army for 10 years now and have 6 grand children who love trains aged 1 to 7. I have limited space in the old farm house here so I'm looking for advice on a layout that will be simple enough for a 3 yo to run the throttle or allow the 7 yo some fun with switching and so on. I can put in a 4'x8' layout without causing problems. Any advice or guidance would be helpful. Thanks