A As if a throwback to the B unit era of the 1940s, ’50s, and ’60s in U.S. railroading, Santa Fe ordered 23 GP60Bs in 1991. Management logic at the time suggested
that both the GP60 and GP60Bs would be strictly assigned to high speed mainline service and the theoretical inconvenience of putting together a string of units for a train would be minimal.
With a group of cabbed units, there didn’t have to be a specific order, with the exception that the lead unit should be facing forward. In addition, B units can be less expensive to purchase, with their lack of cabs, radios, air conditioners, heating and other equipment.
While most of Santa Fe’s GP60Bs are in service, today they are usually assigned to local and secondary freights with other four-axle power. – Bob Miller, longtime railfan, Southern California