Tight curves—short tunnel—long locomotive Having just negotiated one of the sharpest curves on the Moffat Tunnel Subdivision at 12 degrees, a westbound Union Pacific (Bill Wimmer) passenger special for the engineering department exits short 78-foot Tunnel 29 east of Pinecliffe, Colorado, on April 12, 1999. The 9-car train is pulled by the world’s largest diesel locomotive, EMD DDA40X “Centennial” No. 6936. At 98 feet, 5 inches, the locomotive is over 20 feet longer than Tunnel 29, and it is equally impressive that it can negotiate these curves!
