Four SDs represent four phases of Missabe power at Duluth's Endion Yard. SD9 143 is a Phase 3 SD9 featuring the original SD9 car body with 48 inch roof fans. Behind it engine 128 is a phase 2, same car body, but 4 36 inch roof fans. Engine 169 is a rare phase 4 SD9 that introduced the SD24 type car body for the short hood and cab but kept the SD9 phase 3 long hood. An early repaint to the arrowhead scheme, engine 185 is actually an SD18, similar in appearance to 169 escept the rear radiator is raised several inches like an SD24. Interesting variations on a railroad that at the time appeared to use only one locomotive type. (Not counting SD38ACs delivered in 1971.)
