> The older cars (the subs) had no AC and required steam for heat. In the summer, lack of steam for heat was not a problem for the subs.

In the latter years, during the winter, the trains were connected to plant steam heat. Then shortly before departure, the plant head was disconnected, but the train boilers in the locomotives weren't used. Don't recall whether the gallery cars used steam heat, but they did have steam lines. Power for car lighting and AC was self-contained.