Not What It Seems! At first glance this appears to be just another among hundreds of Union Pacific ES44AC diesels ... But it is not. Train MDOWC-22 (Merchandise; Dolores Yard [Carson CA] to West Colton Yard [Bloomington CA]) is led by a General Electric demonstrator without a normal model designation – The builder's plate (actually a sticker) lists this as an "AC V12 Tier II Prototype". This is a preproduction precursor to the ES44AC, and the UP owned five of them, numbered 5695-5699 (BNSF also received a batch of these, and NS rosters the DC-variant). These were built in January and February 2003, and were used to field test the new Tier II emission systems. The train is seen at the UP's Dolores Yard on July 22nd, 2003. (Thanks to Greg McDonnell for the background information on these, and confirmation of the model.)