On July 24th, 2011, as Union Pacific train SWAAN 24 (Special, Walker CA to Anaheim CA), the Ringling Bros. and Barnum & Bailey Circus train, heads south down Anaheim's Olive Street, the train is followed by a pair of 3GS21B switchers, which will assist with the positioning of the circus train cars when they get to South Anaheim, about a mile ahead.
