The other problem it solves is the complex transmission required. Diesel-Hydraulic locomotives were built, but were not successful long term. The most famous is

The other problem it solves is the complex transmission required. Diesel-Hydraulic locomotives were built, but were not successful long term. The most famous is the Krauss-Maffei ML4000, built for the Southern Pacific railroad. https://en.wikipedia.org/wiki/Krauss-Maffei_ML_4000 https://en.wikipedia.org/wiki/Krauss-Maffei_ML_4000