Union Pacific Railroad Company Rolling Stock Photographic Roster
Reporting Marks: UP Cars Numbered 450900 - 450999
AAR Class:
RB: Bunkerless refrigerator car with or without ventilating devices and with or without device for attaching portable heaters. Constructed with insulation in side ends, floor and roof to meet maximum UA factor requirement of 250 BTU/F/Hour for 50 foot cars and 300 BTU/F/Hour for 60 foot cars. Effective for cars ordered new after March 1, 1984.
