SkyTran
Encyclopedia
Personal rapid transit
Personal rapid transit , also called podcar, is a public transportation mode featuring small automated vehicles operating on a network of specially built guide ways...
system first proposed by inventor Douglas Malewicki
Douglas Malewicki
Douglas Malewicki is an American aerospace engineer and inventor. Many of his inventions concern flying vehicles, but the range is quite diverse...
in 1990, and under development by Unimodal Inc. Lightweight two-passenger vehicles suspended from elevated passive magnetic levitation
Magnetic levitation
Magnetic levitation, maglev, or magnetic suspension is a method by which an object is suspended with no support other than magnetic fields...
tracks are expected to achieve the equivalent of over 200 miles per gallon fuel economy at 100 miles per hour or faster. A prototype of the SkyTran vehicle and a section of track have been constructed. Inductrack, the proposed magnetic levitation system for SkyTran, has been tested by General Atomics with a full scale model. UniModal Inc. is now collaborating with NASA to test and develop SkyTran.
System details
To minimize maintenance and make switching on and off the tracks efficient at high speeds, the proposed system would use the InductrackInductrack
Inductrack is a passive, fail-safe electrodynamic magnetic levitation system, using only unpowered loops of wire in the track and permanent magnets on the vehicle to achieve magnetic levitation. The track can be in one of two configurations, a "ladder track" and a "laminated track"...
passive magnetic levitation
Magnetic levitation
Magnetic levitation, maglev, or magnetic suspension is a method by which an object is suspended with no support other than magnetic fields...
system instead of wheels. Passive maglev requires no external power to levitate vehicles. Rather, the magnetic repulsion is produced by the movement of the vehicle over shorted wire coils in the track. The cars would be driven by a Linear motor
Linear motor
A linear motor is an electric motor that has had its stator and rotor "unrolled" so that instead of producing a torque it produces a linear force along its length...
in the track or vehicle. Therefore, the system will have very few moving parts
Moving parts
The moving parts of a machine are those parts of it that move. Machines comprise both moving and fixed parts. The moving parts have controlled and constrained motions....
; primarily just the vehicle itself moving along the track, its parking wheels and door, and fans in heating and air conditioning units; so its promoters refer to the system as "solid state." http://www.aerowebspace.com/AIAA/archives/SkyTran.pdf
The passive maglev coils are enclosed and supported by a light shell called a guideway
Automated guideway transit
Automated guideway transit is a fully automated, driverless, grade-separated transit system in which vehicles are automatically guided along a "guideway". The vehicles are often rubber tired, but other systems including steel wheels, air cushion and maglev systems have also been used in experiments...
that also captures the vehicles mechanically to prevent derailment. Malewicki proposes a 3D grid design that avoids accident-prone intersections by grade separation
Grade separation
Grade separation is the method of aligning a junction of two or more transport axes at different heights so that they will not disrupt the traffic flow on other transit routes when they cross each other. The composition of such transport axes does not have to be uniform; it can consist of a...
, with guideways and their exit and entry ramps crossing above or below each other. Tracks will be supported 20 or 30 feet above the ground by standard metal utility poles. They could also be attached to the sides of buildings.
Cost comparison with other public transit systems
According to the US National Transit Database (record of every public transit system in the US), the average light rail system costs $5.66 per passenger mile ($1.78 for capital cost and $3.55 for operating cost). This compares with $1.41 per mile for driving a car. Skytran infrastructure can be built for 5-10x less cost than light rail by reducing the weight of empty vehicles to under 70 lbs per linear foot, compared with light rail vehicles weighing 990 lbs per linear foot.History
Malewicki conceived the SkyTran idea in 1990, filing a US patent application that year that was granted as US Patent #5108052 in 1992. He published several technical papers on SkyTran in the following years. In 1991, he presented a paper entitled "People Pods - Miniature Magnetic Levitation Vehicles for Personal Non-Stop Transportation" to the Society of Automotive Engineers (SAE) Future Transportation Conference in Portland, Oregon. The paper is a thorough description of the concept, although some important features of the current SkyTran design are only discussed as options, including magnetic levitation rather than wheels and hanging below the guideway instead of riding above it.The paper describes how Malewicki had built and driven a freeway-legal 154-MPG car in 1981, but realized it could never be safe on a street surrounded by vehicles an order of magnitude heavier. Elevated tracks would allow a very light vehicle to be safe. They are also basic to the system's inexpensiveness, because there is no need to acquire a huge right of way and tear down buildings. It presents an aerodynamic analysis (Malewicki is an aerospace engineer) supporting claims of very high energy efficiency (the paper claims 407 miles/gallon for SkyTran's current two-passenger tandem design, though the Unimodal site claims only, "over 200 miles/gallon"). It also described how a very light vehicle that can squeeze both surfaces of a track simultaneously could brake safely to a stop from 100 miles per hour in just 55 feet.
In 1999, Malewicki was invited to present an overview of the future of transportation for the Institute of Electrical and Electronic Engineers (IEEE) Proceedings. His submission, rather than projecting the future, described "a retrospective of solid-state transportation systems" imagining the progress of the SkyTran invention from the perspective of the year 2052.
In the same year, he also gave interviews to the industry magazines Industrial Design and EV World.
Once Malewicki and his partners began making proposals to transit systems, these proposals and their other efforts to publicize the idea began to be described in popular technology magazines and local and national news articles.
The 2008 energy shortages have stimulated interest in many Green vehicle
Green vehicle
A green vehicle or environmentally friendly vehicle is a road motor vehicle that produces less harmful impacts to the environment than comparable conventional internal combustion engine vehicles running on gasoline or diesel, or one that uses alternative fuels...
proposals, including SkyTran. The cover of Popular Science Magazine June, 2008 special issue on "The Future of the Environment", featured a SkyTran like vehicle prominently in an artist's conception of a future energy-efficient city. "Maglev SkyTran" is one of the transportation proposals in the "Green Mega-City" plan, and its online version included animations that present several SkyTran and Personal Rapid Transit
Personal rapid transit
Personal rapid transit , also called podcar, is a public transportation mode featuring small automated vehicles operating on a network of specially built guide ways...
ideas, such as passengers exiting and boarding at off-line elevated "portal" stops while high-speed traffic continues to speed by on its main line.
Unimodal hired an NASA subcontractor to build simulations of the vehicle and dynamics using funding from a US DOT grant. Unimodal has also built a prototype vehicle and guideway at NASA Ames, Moffett field.
Interest from Local Government
Mountain View is considering a PRT system from the downtown train station to the Shoreline area, where young employees from Google and Microsoft are expected to embrace its cutting-edge means of moving people around.Council members say it is premature to call PRT their favorite transportation solution for the Shoreline area, but so far its purported low cost and efficiency looks attractive in comparison to the light rail and shuttle services touted for Shoreline Boulevard over the years. Light rail projects have cost $100 million per mile while SkyTran would cost only $10 million per mile.
See also
- Personal rapid transitPersonal rapid transitPersonal rapid transit , also called podcar, is a public transportation mode featuring small automated vehicles operating on a network of specially built guide ways...
- Maglev train proposalsMaglev train proposals-Denmark:As a part of the suggestion af making a bridge across Kattegat, there has been proposals of a Maglev connection between Copenhagen and Århus.- Germany :...
- InductrackInductrackInductrack is a passive, fail-safe electrodynamic magnetic levitation system, using only unpowered loops of wire in the track and permanent magnets on the vehicle to achieve magnetic levitation. The track can be in one of two configurations, a "ladder track" and a "laminated track"...
- TransportTransportTransport or transportation is the movement of people, cattle, animals and goods from one location to another. Modes of transport include air, rail, road, water, cable, pipeline, and space. The field can be divided into infrastructure, vehicles, and operations...
- Sustainable transportSustainable transportSustainable transport refers to any means of transport with low impact on the environment, and includes walking and cycling, transit oriented development, green vehicles, CarSharing, and building or protecting urban transport systems that are fuel-efficient, space-saving and promote healthy...
- Green vehicleGreen vehicleA green vehicle or environmentally friendly vehicle is a road motor vehicle that produces less harmful impacts to the environment than comparable conventional internal combustion engine vehicles running on gasoline or diesel, or one that uses alternative fuels...
- MISTERMISTERMISTER is a personal rapid transit system developed in Poland...
A Polish PRT system with a similar design, but without the magnetic elevation or streamlined railway. - ShweebShweebShweeb is a proposed personal transit network based on human-powered monorail cars. The project prototype was originally designed and implemented in Rotorua, New Zealand as a leisure attraction....
A human powered PRT project developed and tested as an amusement park attraction, and chosen for funding by Google based on submissions to its 10^100 idea competition.
External links
- US Patent D329028, "Monorail vehicle", filed June 12, 1990 and issued September 1, 1992.
- http://www.unimodal.com
- http://web.archive.org/web/*/http://www.skytran.net/ Archive of old SkyTran.net site
- Are Magnetically Levitating 'Sky Pods' the Future of Travel?
- The International Maglevboard
- Skytran vehicle and guideway at NASA Ames
- NASA Skytran press release
