The locomotives are my design.  The grey one has opening doors that reveal a complete 
engine/generator in the hood.  There is no engine/generator under the red hood since 
there were no opening doors in that color.

The red boxcar is HEAVILY inspired by durbano's Checkerboard Boxcar
http://shop.lego.com/Product/?p=LFH002&mid=1af58fbc-ced0-4d6b-ad11-a40313768508
which is itself inspired by cjmasi's 1900's era Boxcar
http://shop.lego.com/Product/?p=LFH002&mid=897d456f-7f36-4b2a-b792-cd3acaa4270b

Mine is 7-studs wide, durbano's is 6-studs wide and cjmasi's is 8-studs wide.

My red boxcar is the starting point for the other boxcars and the reefers.

The banana design on one of the reefers is from a picture on brickshelf posted by mister-j.
The Coca-Cola reefer was inspired by a picture posted by Caracho (1000steine-Land event in Berlin Germany 2003) 
but the construction is quite different.

The centre-beam flatcars were inspired by Tom ?'s site (lgauge.com) except that mine are 7-studs

The tankcar is my design.  It is based on a technique for making spheres 6,8 studs by Bruce Lowell
(http://bruce.kus-numa.net/lego/miscellaneous/sphere68.html).

Hoppers and gondolas are my designs.