FDLseries

The FDL series refers to a line of diesel-electric locomotives manufactured by Fairbanks-Morse, later FMC Corporation. These locomotives were primarily designed for heavy freight service and were known for their distinctive prime movers. The most well-known models within the FDL series include the H10-44, H12-44, H16-44, and H24-66, commonly referred to as the "Train Master."

A key characteristic of the FDL series was its use of the opposed-piston diesel engine. This engine design, developed by Fairbanks-Morse, featured cylinders arranged horizontally and firing towards each other. This configuration allowed for a compact and powerful engine, contributing to the locomotives' robust performance. The H16-44, for instance, was a highly successful model, widely adopted by many North American railroads.

The "Train Master" (H24-66) was the highest horsepower model in the FDL series, designed for demanding mainline freight operations. While innovative, the opposed-piston engines required specialized maintenance, and the complexity of the design, coupled with changing market demands, eventually led to the discontinuation of FDL series production. Despite their relatively short production run compared to some competitors, the FDL series locomotives left a notable mark on railroad history due to their unique engineering and powerful performance.