SkyTran BrainFAQ
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Most of these
Frequently Asked Questions are referenced in the other sections of our site.
(This section is crude at the moment and just partially complete. Lots
of work remains.)
GeneralWhat is a SkyTran pod?A SkyTran pod is a lightweight, low-cost, two-passenger streamlined vehicle that is magnetically and frictionlessly suspended from a low-cost monorail guideway. Do I need to drive when I'm in a SkyTran pod?No. Each SkyTran
pod has multiple
computers acting to ensure your safety. Onboard computers continually
check on other nearby SkyTran vehicles, monitor the vehicle’s electrical
and mechanical health, and check that the current route to your
destination remains uncongested ahead. Most importantly, the computers
never get distracted. SkyTran commuters relax listening to the stereo, watching TV or surfing the web while traveling back and forth to work or recreation at highway speeds. What is Inductrack passive maglev?Maglev is the ability to magnetically raise an object above a track and propel it without the use of wheels or bearings. After years of national research and billions of dollars in defense spending, SkyTran is the first public application for passive MagLev technology. Through a licensing agreement with Lawrence Livermore National Laboratories, SkyTran will use "Inductrack" technology to propel vehicles at a cost efficiency previously unheard of. Inductrack is a unique hybrid system that, according to a feasibility study conducted by Booz-Allen & Hamilton, "Costs much less than other MagLevs and has operation and maintenance expenses significantly lower than conventional rail." When combined with advancements in computers, control devices and sensing technology, SkyTran is poised to revolutionize transportation for the daily commuter. Unlike other MagLev technology, Inductrack is passive magnetic. That means no high powered magnets or expensive super-cooling is required. SkyTran glides along a magnetic cushion of air levitated by magnets alone. In addition to being extremely efficient, MagLev eliminates the maintenance costs that go with wheels, tires and bearings. The very best tires must still be replaced every 60,000 miles from the constant wear caused by acceleration, cornering and braking. A SkyTran MagLev car, on the other hand, never even contacts its guideway while accelerating, traveling at 100 mph, exiting/merging or braking to a stop. All power transfer to the SkyTran propulsion system is located inside the SkyTran hollow guideway as is the linear drive system itself. This means people (and even birds that land on the SkyTran track) cannot be hurt by touching the guideway. The outside of the guideway carries no current whatsoever. How energy efficient is SkyTran?SkyTran claims an equivalent of 200 MPG while traveling at 100 mph. How can you even talk an "equivalent MPG" when you are using electricity not gasoline? A. What you should care about is how much you spend to buy the energy required to travel back and forth to work. You can find what a kilowatt-hour costs you from your electric utility bill and you can see what a gallon of gasoline costs you by looking at the pump display when you fill your car. The energy cost "equivalent" we talk about depends on the actual costs of gasoline and electricity in your locale. Currently (March 11, 2003) in Southern California, regular gasoline is averaging $2.06 per gallon and electricity costs $.13 per kilowatt-hour. The math question becomes how far will SkyTran travel on $2.06 of purchased "electrical" energy instead of the same amount of purchased "liquid" gasoline energy? A SkyTran vehicle at its full gross weight (carrying two 250 pound passengers) will consume 4.4 kilowatts continuously while traveling 100 mph. Thus, traveling 100 miles costs: (4.4 kilowatts for one hour) times ($.13/kilowatt-hour) = $.572 of energy. This means with $2.06 (the amount that purchases one gallon of gasoline) that we would instead travel: ($2.06/$.572) times (100 miles) = 360 miles. Thus, 360 MPG is the "equivalent MPG" figure we talk about. Note that 360 MPG is 18 times more efficient than a 20 mile per gallon automobile and 12 times more efficient than a 30 mile per gallon automobile! Don't forget Skytran is taking you to your destination through city traffic and congestion at a non-stop 100 mph, not just 65 mph or less!
We tout a 200 MPG figure to be conservative and because a lot of people have a tough time even believing that 200 MPG efficiency is possible. As stated earlier, that equivalent figure varies depending on where you live. In Jerry Fass's hometown of Milwaukee, Wisconsin electricity currently costs $.08 per kilowatt-hour, while regular gasoline costs $1.70 per gallon (March 2003). Using the same math we would see that a SkyTran system in his town would be obtaining an even better equivalent while traveling at a steady 100 mph because of the relatively low cost of electrical energy compared to liquid gasoline energy in Milwaukee. One last comment: All the above is calculated
for a SkyTran vehicle at gross weight with two 250 pound maximum weight
passengers. If you consider gross weight is with TWO passengers, that
means the people in Arizona would be obtaining 1,002 mpg equivalent PER
passenger! A bus that gets 3.5 mpg would have to carry 286 people
to match that! (only 143 to match the per passenger efficiency of a
SkyTran being ridden solo). B. Detailed Comparison Based on Heat Analysis OK, in order to satisfy the academics in the crowd who insist on questioning the validity of my simple cost comparison here comes the thermodynamic heat value equations! As calculated below, SkyTran using the same amount of heat energy as a car uses (as it consumes one gallon of gasoline) will travel 272 miles. The difficulty of calculating a MPG energy equivalence is that SkyTran doesn't use gasoline, it uses electricity. Almost all the electricity in the US power grid comes from heat, including energy generated in fossil fuel, biomass, and nuclear power plants. The automobile uses the heat energy of gasoline to produce power. Therefore heat energy is the common energy source to use for comparison. A gallon of gasoline releases approximately 128,000 BTUs when burned. The average conversion of heat energy to electricity is 31.9% (Anderson). This means that 11.97 kilowatt-hours (kWhr) of electric energy should be generated from the energy in a gallon of gasoline. SkyTran needs four kilowatts to maintain a speed of 100 mph. Assuming a loss of 10% in the power lines and conversion to mechanical energy, SkyTran uses only 0.044 kWhr per mile. Therefore SkyTran gets 272 miles per 128,000 BTU of heat energy (or gallon of gasoline) while cruising at 100 mph. Lets compare SkyTran energy consumption to other forms of transportation. To do this we must look at energy consumed in a trip, not just while cruising. To accelerate the vehicle and one passenger to 100 mpg takes a significant amount of energy. However, unlike automobiles, buses, or light rail, SkyTran has non stop service. This reduces the number of times the vehicle must speed up. Lets assume an average travel distance of 10 miles per acceleration. The energy to accelerate the 400 pounds (a 200 pound person in a 200 pound vehicle) to 100 mph is 0.0557 kWhr. This makes the total trip use 0.0496 kWhr per passenger mile (kWhr/pass-mi), or 0.155 kWhr of heat energy per passenger mile. The below chart compares this energy use to other transportation systems (Anderson)
Much of the energy consumption data of other transit systems comes from: J E Anderson "What Determines Transit Energy Use", Journal of Advanced Transportation, Vol. 22 No. 2, 1988 pp 108-133 Calculations: 1) 128,000 BTU/gal * 0.319 electricity/heat / 3412 BTU/kWhr = 11.97 kWhr of electricity per gallon of gasoline 2) 4 kW * 1.1 (conversion losses to mechanical energy) * 1 hour / 100 miles = 0.044 kWhr/mile 3) 11.97 kWhr/gal / 0.044 kWhr/mile = 272 mile/gal 4) 100 mile/hr * 5280 ft/mile / 3600 sec/hr = 146.7 ft/sec
5) (0.557kWhr + 0.044kWhr/mi * 10 mi) / 10 mi / 0.319 (electricity to heat energy) = 0.155 kWhr/mi Wasn't that fun? All it tells you is that we are currently producing electrical energy in this country for less than we can produce equivalent amount of liquid gasoline energy. How does SkyTran benefit the environment?Scientists have measured the external cost of autos to society. Generally, the figures range from $500 B. per year to $1,500 B. per year just in the US. This comes to about $2,500. per car each year. This fact is troubling when one considers that in the US alone:
On a global scale:
There are currently 500 million cars used by 2 billion people worldwide.Potential auto growth if the US sets the pace - 3 billion cars.The SkyTran system is environmentally friendly. The all electric drive and efficiency of the system helps reduce local pollution and total pollution (CO2, NOx, and noise pollution). As the efficiency and waste reduction related to electrical generation improves, SkyTran will be an even cleaner form of transportation. SkyTran stands to provide a vast improvement to the overall quality of life. EstheticsCapacitySpeedSafetyHow can SkyTran withstand earthquakes?Standard tapered steel light poles support both the guideway and the small additional weight of SkyTran cars with plenty of structural safety to satisfy ASCE earthquake and wind requirements. These poles are so strong and cost effective that windmill manufacturing companies can use them. CostWhy is SkyTran so inexpensive to build?A mile of SkyTran consists of the following elements:
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