Just curious, triggered by the story about the TEE der DDR story. It seems that diesel-hydraulic has never been successful in the U.S. (other than, perhaps, in some industrial situations). Everything here is and, with miniscule (in numbers) exceptions, has been diesel-electric on main lines. Europe, however, has had many diesel-hydraulic locomotives which have been successful even ir relatively heavy-haul and high-speed operations. What's the difference?

Yes, there were some K-M and Alco diesel-hydaulics (again, in the great scheme of things, insignificant numbers and not operationally successful == not duplicated after the Alcos and not sold to anybody but SP and (briefly) D&RG. And yes, there were some diesel-mechanicals outside of industrial plants, mostly passenger cars like RDCs and doodlebugs. Maybe the RDCs would qualify as part-hydraulic since they had fluid couplings or torque converters (not sure which) but final drive was mechanical. Again, in total numbers compared to the rest of the North American diesel-powered fleet, insignificant. What's so different about U.S. and North America generally that makes hydraulics not work here, besides the NIH phenomenon and lack of maintenance familiarity? What's wrong with the concept, in other words?