USA: Union Pacific has begun testing four RP20SD 2000 hp genset loconmotives built by Railpower for the Roseville hump yard 30 km northeast of Sacramento.

The locos use the frames and bogies of scrapped six-axle EMD road switchers, and have three gensets onboard with room for a fourth to be installed later. Each loco will work as a pair with an EMD SD38-2.