The locomotive model designation is interpreted as follows: B (B type truck arrangement, 2 axles per truck) 40 (4000 horsepower) -8 (the generation when it was designed, in this case meaning the late 1980s) W (Widecab).
ATSF was the only railroad to order the B40-8W, and a B unit (cabless booster unit) was almost made with it, but because the price would have been the same for B40-8Ws with cabs or without, they decided to order units with cabs only. [citation needed]
All of ATSF's B40-8Ws were passed on to BNSF Railway, with some later sold to other railroads.