Thursday, May 12, 2016

What About an Electric Wind Turbine for Nephi’s Ship? – Part I

One of our readers sent in a question that deserves an extended answer, so these two posts are dedicated to that inquiry.
    Comment #1: “I have been sending your articles to a friend who has objected to some of your pieces, such as: (1) Nephi could've built an electric motor which is similar to a wind turbine...” Adam D. W.
Modern Wind Turbine—more complicated than it appears
    Response: You have to love it when someone says, “Oh, he could have just done this….” Without thinking about what that entailed. Take this person's wind turbine as an example. Something has to collect the wind, hence, usually or typically some type of turning vanes are required. This would mean that the ship would have to have some tall portion where the vanes would be placed; secondly, the vanes system would have to create a force that could be collected; third, the collected force, in some way would have to be converted to a driving force; fourth, the driving force would have to power something that pushed the ship forward. Could it be done. No doubt. Would it work? Perhaps, however, no one has ever bothered to try to make such a vessel driven by a wind turbine which should suggest its impracticability.
    On the other hand, looking further into this, keep in mind that the purpose of a wind turbine is to create electricity or a suction for pumping. How does that occur? Simply stated, a wind turbine works the opposite of a fan. Instead of using electricity to make wind, like a fan, wind turbines use wind to make electricity. The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity. So you would need some type of generator, motor, or alternator to make use of the electricity being developed.
    Then, too, one might suggest a paddlewheel system where the generated power (electricity) turns the paddlewheel. Whether this has ever been accomplished, I am unaware, however, it should be kept in mind that a paddlewheel system was tried on ocean vessels in the past and never with very good results though some crossing of the Atlantic were achieved—paddlewheels and deep oceans don’t make for good sailing. As an example, the 280-foot sidewheel steamer S.S. Central America (S.S. George Law), and known as the “Ship of Gold,” because it carried 30,000 pounds of gold (over $50-million in today’s value), went down off the coast of the Carolinas in a Category 2 hurricane (a major hurricane is Category 3 and above). Called “an appalling loss of life,” 420 of the passenger and crew of 578, were lost in a disaster that “had no parallel” among American navigation disasters.
In a wind turbine, the terms “wind energy” or “wind power” describe the process by which the wind is used to generate mechanical power or electricity. Wind turbines convert the kinetic energy in the wind into mechanical power, which can then be used for specific tasks (such as grinding grain or pumping water) or a generator can convert this mechanical power into electricity, which can be used to drive some type of shaft or propeller in a ship. To use such a turbine, the two or three blades must be “upwind” with the blades facing into the wind at all times.
    Utility-scale turbines of today range in size from 100 kilowatts (pumping water) to as large as 2 or 3 megawatts. Larger wind turbines are more cost effective and are grouped together into wind farms to create sufficient electrical power, which then provide bulk power to the electrical grid. In recent years, there has been an increase in large offshore wind installations in order to harness the huge potential that wind energy offers off the coasts; however, it should be kept in mind that wind has to be constant for such a turbine to have any ongoing value or effect such as in driving a ship, unless there was some type of electrical “grid” in which electricity or energy could be stored.
    It should also be kept in mind that a wind turbine is not a simple matter, though they operate on a simple principle. The energy in the wind turns two or three propeller-like blades around a rotor. The rotor is connected to the main shaft, which spins a generator to create electricity. This means that Nephi would have been required to build something that has close tolerances of variable size in order to turn one another.
Some of the simple mechanisms used in the old wind mill turbines that used wind power to drive ranch and farm equipment
    One of the questions one might want to ask, is why would the Lord go to all this trouble, introducing a system that would be 2600 years before its time, requiring Nephi to have metallurgy capability far beyond that of forging tools or clasps or nails, when a much simpler and easily accomplished method and using the winds and currents the Lord already developed was open to them?
    Consider, that the most advanced wind turbine of today requires some type of gear box that connects a low speed shaft to a high speed shaft and increases the rotational speeds from 30-60 rpm to 1000 to 1800 rpms, which is the speed required to produce electricity by most generators. The gear box is heavy and requires exactness beyond anything Nephi would have ever achieved to that point—in fact, not even modern man has been able to devise a direct drive generator that operates at lower rotational speeds and does not need gear boxes. Also, some type of generator is required to produce 60-cycle AC electricity (which is pretty much an off-the-shelf induction generator of today).
    In addition, to avoid damage to the blades and machinery, wind turbines cannot operate above about 55-mph winds, so there would need some type of controller (or person) to shut off the turbine and turn it on up above. Today’s turbines also have some type of yaw motor to power the yaw drive so when the wind shifts, the mechanism can shift the direction of the blades to keep them into the wind—an absolute must in a moving turbine.
    In addition, the optimum number of blades for a wind turbine depends on the job the turbine has to do—for generating electricity a turbine needs to operate at high speeds, but do not need much turning force, thus they need only two or three blades. On the other hand, wind pumps need turning force but not much speed and therefore have many blades , so they turn slowly with considerable torque in low winds and need to be regulated in high winds. For Nephi’s use, these blades would have to be some type of lattice work over which a type of fabric could be interwoven or stretched. Solid blades, like made of wood panels, probably would not have stood up to the constant pounding of air gusts. It also might be mentioned that without gyroscopes, there would be no way to keep the blades pointing level into the wind as the ship moved up and down the swells and across the fetches. These “tower” turbines would also need gearbox and crankshaft to convert the rotary motion into reciprocating strokes carried downward through a rod to the pump cylinder below or to another gear box to turn a shaft.
In addition, gears would be needed to turn the rim which drives the horizontal gearwheel called a wallower on top of the vertical upright shaft. In most cases, depending on the final configuration, there would need to be other gear wheels along the course of the tower and at the base.
(See the next post, “What About an Electric Wind Turbine for Nephi’s ’Ship? – Part I)

3 comments:

  1. You've got to be kidding. Someone actually suggested this absurd plan? I'm sure for the only purpose of catapulting the Nephites into North America.

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  2. You would be surprised the comments, questions and arguments we get from people with very strong views, though seldom well thought out.

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