Please do not confuse this with NREX SD40-2B's. Those are recently bought CP SD40-2's that have had the cab salvaged and B unit decals added, whereas this is the real deal. Back when CP started getting serious about locotrol, they decided to dedicated a batch of SD40-2 engines to the service. It then occured to them that since the engines would no longer ever be leading or be occupied, the cab, windows, ditchlights etc. could be stripped. During the 1990s power shortages most regained their functional cabs, but a few remain like this one. Now that the mid-train locotrol jobs are run by the new more powerfull AC4400CW's, these oddballs are left to wonder the system. The good news is that some of them have been repainted in the new paint scheme, meaning CP isn't retiring them anytime soon. Although it is fair to call them B units, CP doesn't recotnize this fact, treating it as a SD40-2 that is not lead capable. Here CP 6076 is trailing two more SD40-2's through a wall of containers while being wyed in the depot.