A steady stream of people Tuesday toured the “Experience the Union Pacific” rail car and viewed the “Big Boy” No. 4014 steam engine on the U.P. side rail near Front and Chestnut streets. The Experience Car is a multimedia walk-through exhibit that tells the story of the transcontinental railroad, shows the evolution of locomotives and demonstrates modern rail technology. The Big Boy will pull out of North Platte this morning en route to Cheyenne. On its way, it will stop in Ogallala, Chappell and Sidney today.