I was thinking that they might be kinda thought provoking, but not sure if anybody would take issue as they are from a copyrighted book long out of print called "Kirkman's Science of Railways". This is actually a series of books that I think went to about 17 volumes. I have a few that interested me that I bought off of Barnes and Nobles used book site. I'll see which volume has the questions. I have seen copies of the individual books in poor but readable condition from $15 up to a lot for real good copies. I usually go for the cheap ones that are falling apart because I want to read them and not worry if I get grease on them or something. I bought a couple volumes on air brakes which include a lot of K brake info that were printed as late as the 20's and I have found the info quite useful over at SVRy.