While in Dublin I got to ride on one of the new DART trains. These run a commuter route to Malahide (among other places). The amazing thing about these newer trains, unlike the majority of older, German trains in the DART system is that they are not powered by overhead electrical cables like most european rail lines, and they aren't powered by a locomotive like in the states. For each pair of cars, one of the cars has a massive diesel engine with a 3 speed transmission in it. What this means is that when the train takes off from a station, it sounds like an 18-wheeler starting out in first gear. The difference is that an 18-wheeler has a bajillion gears to go through to get up to top speed. This train has 3 speeds. As the train starts you can see for every two cars big plumes of smoke come out of the integrated engines. The train gets up to about 20mph and then you hear the whole drive train disengage as the driver at the front changes all of the pairs (usually 3 or 4) of cars from first gear to second, and then reengagage the drive train. Same thing happens from second to third gear which occurs at about 45mph. Once in third gear at a pre-determined point, the driver throws it into neutral and coasts the following mile or two in neutral, something yo could never do in a car because you'd never have a surface as completely smooth and level as rails, and you'd never have enough inirtia (the kind when you've got the weight of a train rolling along at 60mph). Sometimes they use the engine to do
compression braking if they've miscalculated when to start coasting.