RBS Express railroad trains were 3 mobile United States Air Force radar stations for 1CEVG Radar Bomb Scoring (RBS) of Strategic Air Command bomber crews beginning in March 1961. Electronic equipment included the "MSQ-39, TLQ-11, MPS-9, and the IFF/SIF for the MSQ-39" along with support railcars ("work train"), and the trains were temporarily used at various rail sites (e.g., sidings) with the radar antennas emplaced using hoists built onto flatcars. Pulled by a "contracted locomotive" that left the train at the site (e.g., for 45 days), and a North American B-25 Mitchell was used for calibration of the radar station.