While an engineer with Jeffery Mining and Manufacturing Company of Columbus, Ohio, Dierdorff developed insulation that could be packed around electric motor housings to suppress sparking found on early electrical motors. This technology allowed the first safe electric seam cutting tool in underground mining. This tool was capable of cutting anthracite coal and was known as the the Congo Coal Cutter after its success for the Congo Mining Company, of Corning, Ohio.
Dierdorff also worked on developing reliable power systems to deliver electricity to miners underground.
At 15 I Was Crawling below Tons of Earth to Mend a Broken Coal Cutter . . . That's Why I'm Tough; How Life in the Pits Taught Bobby Robson about Survival and Gave Him the Inner Strength to Fight on When Family and Doctors Asked Him to Retire
Aug 26, 2000; Byline: BRYAN COONEY IT IS difficult to imagine that the gentleman crawling somewhat frantically along the floor in front of me...