Union Pacific is currently using 3D printing to add more safety and efficiency to their locomotive production. Several years ago they used 3D printing to create a handheld device meant to work with tracking rail equipment. Now, 3D printing has become quite central for their new Machine Vision imaging system which can examine 22 components from a train that is passing. They have been using 3D printing also to experiment with devices meant for remote control, as well as for preventing the buildup of debris under trains. Read more at 3DPrint.com: http://3dprint.com/177563/union-pacific-3d-printing/