Below are photos for some children's train quilts. One of them identified where they got their pattern. Hope it helps!
http://www.quiltingboard.com/t-6081-1.htm
http://www.quiltingboard.com/t-3548-1.htm
http://www.quiltingboard.com/t-4468-1.htm
The pattern was in the November 2007 issue of Quick Quilts, I don't have an electronic version of the pattern. You can order the magazine at quickquilts.com if you want it.