"Frankenloco" BNSF 4729. 12 min of GE diesels idling. 

BNSF 4729 was trailing 4th in a consist of a six on a Provo to Stockton manifest. They were stopped west of Colfax to wait on a couple UP eastbounds, so I sent up and let the camera roll to catch these monsters idling, air compressors kicking in as well as pop off valves releasing.