How does a diesel locomotive work?
A. Actually, this is a trick question. Locomotives come in diesel-electric, diesel-hydraulic, and as a test a steam-electric engine was built. The first part of the name indicates how the power is generated and the second how it is transmitted to the driving wheels. The diesel engines are huge internal combustion engines (sometimes more than one per locomotive), named after Rudolf Diesel who patented the concept in 1892. In a diesel-electric they are used to power electric generators, and the electricity is used to drive electric motors. These are called traction motors and one is attached by a gear system to each powered axle. I don’t know the details of how diesel-hydraulic engines work, but basically something like an automatic transmission is used to connect the diesel motors to the axles via driveshafts (I’m making this all up!) It turns out to be very difficult to build these to handle the large loads involved, so all modern locomotives [in the United States – see below] are of t
