WeberFan wrote:Every now and again, I get a thought in my head and can't let go of it. This one noodled around for most of the weekend, and I just got around to searching through the various threads until I found the most appropriate one.
For some reason, I was under the mistaken impression that a Diesel
REQUIRED a glow plug to operate.
Not so.
In fact, in watching a Science Channel program this evening, I watched a guy put a small wad of cotton into a clear plexiglass tube, fit a hand-operated piston in the top, and rapidly force the piston downward. The compression he induced was sufficient to heat the air enough to ignite the cotton wad.
Fascinating!
So I did some more digging and learned that a glow plug was only needed when starting the Diesel in cold weather (exactly as other posters on this forum stated). Obviously an electrically-powered glow plug would violate the Proscriptions. But if you put a "jacket" around the cylinder, and if you forced hot steam through the jacket, you'd get the cylinder / piston plenty warm and would eliminate the need for a glow plug. This wouldn't be necessary in a warm engine room aboard ship or when operating in warm climates.
So I envision low-RPM, high-torque diesels being used for maritime operations in place of steam engines, and used to power land vehicles (trains, heavy-wheeled off-road vehicles).
There's nothing inherently bad with steam-powered vessels, but you either need an oil-powered furnace to generate the steam or you need a lot of man to shovel coal around. IIRC we haven't heard anything about oil-powered furnaces yet. Diesel (or any other heavy liquid hydrocarbon) is easier to store and easier to move around. Also, no matter how you cut it, coal being stored in a coal bunker still has a lot of air space between the chunks of coal - wasted volume. Not a factor with oil, which can easily be pumped where it's required.
I'm not sure which engine is more efficient - steam or diesel. Probably depends on a lot of factors and is probably application-specific.
Diesels can probably be started faster than steam engines, so going from a cold start to full operations is going to be faster than it would be with a comparable steam plant.
Just some thoughts added to what is already a mature forum.