411 REFERENCE · Wikibooks
Trainz/Transparent Windows using Blender
Reference material by Wikibooks contributors. This retains its source identity and is not 411 news reporting.
Scenery objects treat transparency differently to rolling stock. Only other scenery objects can be seen through transparent scenery objects.
For Blender settings see Torsten's comments in this thread in the Trainz forum labeled "Transparent and semi- transparent meshes with Blender 2.65":
http://forums.auran.com/trainz/showthread.php?98810-Transparent-and-semi-transparent-meshes-with-Blender-2-65&p=1113319#post1113319
Creating a transparent file in GIMP then painting it with opacity of around 30% seems to work.