GE Dash 8-39B

The GE Dash 8-39B, designated by GE Transportation Systems as the B39-8, was part of the broader Dash 8 family of freight locomotives that General Electric developed during the 1980s as the company worked to assert its dominance in the North American diesel locomotive market. The type entered production in 1984 and remained in production through 1988, with a total of 47 units constructed. The Atchison, Topeka and Santa Fe Railway was the launch customer, receiving the first three units built to the original design. These early examples served as proving ground locomotives for the platform, and GE engineers used operational experience gained from them to refine both the mechanical systems and the electrical components of the locomotive. Following delivery of those initial Santa Fe units, General Electric introduced a revised carbody design along with various mechanical and electrical improvements for the remaining production locomotives. These later examples are sometimes informally distinguished from the first three by the suffix designation B39-8E, though this was not an official GE model designation. The relatively modest total production run of 47 units reflects the competitive and specialized nature of the four-axle, high-horsepower locomotive market during this period, as many railroads were simultaneously evaluating six-axle designs for heavy freight service. Despite its limited production numbers, the B39-8 occupied an important place in the evolution of the Dash 8 series, demonstrating the viability of GE's new microprocessor-based control systems in a four-axle configuration. The type contributed to GE's growing reputation for reliability and fuel efficiency during a period when the company was actively displacing Electro-Motive Division as the leading supplier of new road locomotives in North America.

The B39-8 was built around GE's FDL16 prime mover, a sixteen-cylinder version of the FDL engine family that had been a cornerstone of GE locomotive design for decades. This engine produced 3,900 horsepower, making the B39-8 among the more powerful four-axle road switchers of its era. The locomotive rode on a B-B wheel arrangement, meaning two two-axle trucks, and employed a conventional DC traction system with direct-current traction motors receiving power from the main alternator and rectifier assembly. The overall configuration made the type well suited to intermodal and manifest freight service where track conditions and consist weights did not necessarily demand the additional tractive effort of a six-axle platform. A hallmark of all Dash 8 series locomotives was the incorporation of GE's advanced wheel slip control and microprocessor management systems, which represented a significant step forward from earlier analog control arrangements. These systems allowed the locomotive to more efficiently manage adhesion and power delivery across varying rail conditions, contributing to improved fuel economy and reduced wheel wear. The carbody revision introduced after the first three Santa Fe units addressed both aesthetic and functional concerns, and the updated design became the template for the production locomotives that followed through the end of the model's run in 1988.

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