distributed power

[trainbearmedic]

I have noticed that Union Pacific is using D.P. on some of its Intermodal and manifest trains westbound on the old Baird Sub.  These trains leave what used to be Centenial Yard with at least two units on the head end and one on the rear, pushing.  I first "heard" what I thought was D. P., about six weeks ago.  I have since that time witnessed many intermodal/double stack trains with the rear pusher.  These trains usually run aound 6:00 to 8:00 P. M. Anybody out there klnow when this actually started?