Identification
The SW1 appears very similar to its SW and SC predecessors, but has only a single stack instead of two, a significantly shorter hood and a larger rear platform, no small louvres on the front top hood sides, and a large grille instead of lifting vents on top of the hood front. The sandbox in front of the radiator is somewhat smaller on the SW1.
Compared to later EMD switchers, the SW1 has a much shorter hood, large platforms at each end, a single exhaust stack, and a large 'satchel' type sandbox.
Read more about this topic: EMD SW1