EMD GP60B

The EMD GP60B was a cabless booster variant of the GP60 road switcher, produced exclusively for the Atchison, Topeka and Santa Fe Railway in 1991. Only 23 units were constructed, all assigned Santa Fe road numbers 325 through 347, making the GP60B one of the rarer products of Electro-Motive Division's later production years. The cabless configuration was chosen to complement Santa Fe's GP60M fleet, allowing additional tractive effort to be added to consists without requiring a separate operating crew position. The GP60B was part of a broader wave of GP60-series orders that Santa Fe placed with EMD during the late 1980s and early 1990s. The railroad had previously taken delivery of standard-cab GP60s and the distinctive North American Safety Cab GP60M units, and the booster units rounded out its commitment to the four-axle, 3,800-horsepower platform. When the Burlington Northern and Santa Fe merger was completed in 1995, the GP60Bs passed into BNSF ownership, where the majority continued to see active service for a number of years. One unit from the original batch, road number 347, became notable for an unusual rebuilding effort completed in 2010, when a cab salvaged from a Union Pacific SD40-2 was grafted onto the locomotive, effectively converting it into a conventional cabbed unit. This modification stood as a testament to the durability of the GP60 platform even as newer, more powerful six-axle locomotives had come to dominate mainline freight operations across North America. The GP60B, like the broader GP60 family, represented the final chapter of EMD's long line of four-axle Geep locomotives built for Class I railroad service.

The GP60B was powered by the EMD 16-cylinder 710G3B prime mover, producing 3,800 horsepower and driving the locomotive through a conventional DC traction system arranged in a B-B wheel configuration. The four-axle layout placed the GP60B in a lighter weight class than the six-axle units that had become increasingly prevalent in heavy freight service, but the platform offered good tractive effort for helper and secondary road assignments. One distinguishing engineering feature of the cabless design was the repositioning of the dynamic brake equipment, which on the GP60B was moved forward along the carbody and away from the prime mover, a layout change made practical by the absence of a cab at either end and one that allowed for somewhat more flexible internal arrangement of major components. The 710G3B engine at the heart of the locomotive was a member of EMD's third-generation prime mover family and incorporated onboard microprocessor controls that managed engine functions, cooling systems, and other operational parameters, replacing a significant number of relays and discrete wiring circuits found in earlier EMD designs. The GP60 series as a whole shared its frame with the GP59, and the GP60B carried over this structural foundation while adapting the bodywork to the booster configuration. With a total production run of only 23 units, the GP60B remained a specialized and relatively uncommon variant within the broader GP60 production history.