Talk:Diesel-electric
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It would be nice if the "Ships" section quantified what it means by 'recent development. There have been diesel-electric/prop ships in the US since at least the 1950s (Puget Sound ferries), and diesel-electric/paddles in the UK since 1934(search for ferry). That doesn't seem all that much more 'recent' than the dates being compared, 1912 and 1920s. (Of course, there's also the problem that ship doesn't mention "diesel-electric" at all.) Seattlenow 08:31, 9 February 2006 (UTC)
Finnish navy also had two coastal cruisers which had diesel electric propulsion. These both ships, Väinämöinen and Ilmarinen, had four Germania diesel engines and two Leonard electric motors. These ships were laid down in 1929, launched in 1931, commissioned in 1932 and 1933 respectively. *Nappula 13:38, 2 March 2006 (UTC)
Yes, but how does diesel electric work exactly
[edit] Concerning the advantages of diesel-electric locomotive or DEMU power
"...direct-drive diesel locomotive would require an impractical number of gears to keep the engine within its powerband; coupling the diesel to a generator eliminates this problem." This should explain how. It should be emphasised that power still needs to be transmitted to the generator or alternator via a simple gearbox but this is advantageous because;
1) Mere cables transmit the power to the axle traction motors, not a complex system of rods
2) Sending power to a generator via a low powerband (i.e. diesel) is analogous to sending power to a propeller, in that one gear ratio is enough, unlike sending power to wheels, where several ratios are necessary. This is because the high friction between wheels and contact surface requires a low gear for takeoff to avoid stalling, and higher gears thereafter, since the output shaft moves relative to vehicle speed and would over-rev the engine if just one gear was available. In a generator or alternator, the force is magnetism, not a high friction surface so a high gear is fine since the magnetism is not great enough to stall the engine. The result is that the diesel-electric system puts the diesel’s low powerband to best use.
I really want an engineer to check the above!
[edit] 'Gulping' Fuel
Under 'Buses' - Is this really the most formal way to word it? What about "Would be running at it's least efficient point?", or similar? - THD TommyD (talk) 13:08, 4 January 2008 (UTC)
