 The SDP40 and the SDP35 & SDP45 instead have the same appearance as their freight counterparts.This look was contemporary to, and eventually overtaken by cowl units like the GE U30CG and EMD FP45, SDP40F and F40PH.Visually, the locomotive is a hood unit distinguished only by the shape of its rear end behind the radiators, with its flat end having no number boards, shuttered boiler air intake on each side, extra exhaust stacks over the boiler, cantilevered walkway around the flat end, and very steep rear steps.