The first set of photos are of three Long Island Railroad diesels assembling the consist for travel to New York City where the circus will perform in Madison Square Garden.
The "Red Unit" train is basically the same although there some differences. Both units use coaches (many are old Union Pacific coaches) for the workers which are are divided into small cubicles for some privacy. These are seen in the second set of photos.
The management cars, the ones with fewer windows, are more or less like two seperate living quarters, one on the vestibule end of the car and other on the other end of the car. The performers cars are much the same except some of the higher management and performers may have an entire car to themselves. When Gunther Gebel Williams was on the show he had an entire car.
The bi-level car carries management private vehicles on top and the tiger handling cages below along with whatever else fits.
Utility wagons/trailers are carried on flat cars. They are seen in the third set of photos. In them the show carries rigging, costumes, lighting ring curbs, rubber mats for the floor of the arena and whatever else needed for the show.
The animal cages are white and have windows. When they are off of the train the ends and sides open up to form a habitat where the cats can exercise, and are free to move about.
The wagons with the blue tarps carry special floats. There is even a wagon called the PIE (privileged individuals and employees) wagon, also an ex UP baggage car, which prepares food for the employees at the arena.
The blue open wagon with the tube type fenceing carries the corrals for the horses, camels,zebras, llamas etc.
Thank you to Larry Loper for the above information.There is a web site for the list of all RBBB cars: http://chicago.railfan.net/cgi/photos.pl/?page=RBBX_prior