bobga --
The answer to your question is that the Disneyland roller coaster you
have in mind (which is called "California Screamin'") is powered by
"linear induction motors," or "LIMs". According to the Disney
official responsible for the safety of its coasters, these motors use
"propulsion fins" on the underside of the coaster that provide "an
electromagnetic push that sends the train…from 0-55 mph in about 4
seconds."
These fins are pictured at this linked page:
Disney Announces Chief Safety Officer
http://laughingplace.com/News-PID505970-505973.asp
A very informative online source for a layman's description of linear
induction technology as it is applied to roller coasters can be found
at the following link on the University of Texas website. For the
non-engineer, the page includes links to basic definitions (such
"rotor" and "stator"). It also compares linear induction motors to
other propulsion systems used in modern roller coasters. The
conclusion of the author is that LIMs "completely changed the rules"
of roller coaster design:
Mechanical Engineering Dept.: University of Texas at Austin: New
Roller Coaster Technologies
http://www.me.utexas.edu/~uer/roller/tech.html
Another online description of the use of LIMs in roller coaster
construction contains a useful summary of how the power generated by
the motor is transformed into a coaster's motion:
"Typically, the flat metal bars are fins on each side of the train are
mounted between the wheel assembly and the seats. The stator coils are
in anchored motor housing which extends out from the loading platform
along the track. As the train accelerates, the stator coils are
powered consecutively in a time sequence so that as each fin passes
between a pair of stator coils, the train is pulled forward. The
momentum from the launch carries the train up the first hill and then
gravity and momentum do the work on the remainder of the ride just as
they do on more conventional coasters.
Andy Delaney (personal site): Limited Induction Motors
http://www.idsi.net/~delaney/Coasters/lims.htm
Additional Sites:
An introduction to limited induction motors:
Force Engineering
http://www.force.co.uk/page2.html
Another summary of LIM technology:
Productfinder.com: Limited Induction Motor (LIM)
http://www.theproductfinder.com/motors/linind.htm
LIM use in rapid transit systems, such as monorails:
Jetrail.com: Linear Induction Rapid Transit
http://www.jetrail.com/transit.html
LIM use in elevator door systems:
Otis Elevators
http://www.otis.com/innovationdetail/0,1416,CLI1_IID806_RES1,00.html
Google Search Terms:
"california dreamin" disneyland ride
://www.google.com/search?sourceid=navclient&q=%22California+Dreamin%27%22+Disneyland+ride
"california screamin" disneyland ride propulsion OR propelled
://www.google.com/search?sourceid=navclient&q=%22California+Screamin%27%22+Disneyland+ride+propulsion+OR+propelled
"linear induction motor OR motors"
://www.google.com/search?q=%22linear+induction+motor+OR+motors%22&hl=en&lr=&ie=UTF-8&start=10&sa=N
I am confident that I have given you the information you specifically
seek, as well as supplementary information that will lead you to
sources that will satisfy any curiosity you develop about this
interesting technology. If any of this information is unclear, or if
any of the links don't function, please ask for clarification before
rating the answer.
markj-ga |
