A welder puts some elbow grease into it as he grinds fresh welds on repairs to the nose of Union Pacific SD40-2 No. 3071 at the Downing B. Jenks Shop in North Little Rock, Arkansas, on May 19, 2015. The locomotive is getting rebuilt into a SD40N, with the “N” in the designation coming from the NEXSYS control system by ZTR Control Systems used by UP in the rebuild to replace the older EMD Dash 2 component cards and system. UP also installs a remanufactured prime mover, along with reconditioned main generator, traction motors, trucks and other major components during the process. The cab is rebuilt, replacing worn out and rusted portions, and adding new doors, air conditioning, PTC capability and rewired electrical cabinets.