Inside the Worlds largest operating diesel locomotive Union Pacific DD40X 6936 Cheyenne, Wyoming.

Take a peek inside Union Pacific DD40X, the Worlds largest operating diesel locomotive. This locomotive typically travels with the Union Pacific 844 steam engine during excursions. Filmed during the annual steam shop open house of 2009 in Cheyenne, Wyoming. For a in depth look at another DD40X locomotive inside and out click this link