What is the difference between a C44-9W & an AC4400
The spelling. Just kidding! Could not resist.
AC4400 has Ac traction motors and switch gear the C44 - 9 is DC powered.
Pete
It has been pointed out one is the DC model and one is an AC model. There are differences in the electrical panel on the left side and the location of the air conditioner also.
BNSF 783 is one of the DC models. You can spot the air conditioner system behind the conductors side and notice the solid panels under the cab both sides. Most of the other details are close and the frame length is the same for the Dash 9 and the AC4400 models. Some of the air filters on the long end hood might be different when you compare details.
The AC4400 model has the air conditioner filters under the left side of cab and filters on the right side under the engineer also. The air conditioner was moved from the location behind the conductor to make room for the electrical panel for the AC4400. It is behind the conductor in that raised area where the DC model has the air conditioner. One other difference is the extended dynamics brakes on some AC4400 have three sets of inlets on the right hand side. Not all AC4400 had the three inlets but some railroads had that option.
The number boards are one of the UP units are high and the other unit has low number boards. That was an option and not a spotting feature. All of the UP units when new had the lower number boards, but the SP units had the higher number boards.
