Flywheels are typically made of steel and rotate on conventional bearings; these are generally limited to a revolution rate of a few thousand RPM. Some modern flywheels are made of carbon fiber materials and employ magnetic bearings, enabling them to revolve at speeds up to 60,000 RPM (1 kHz). Carbon-composite flywheel batteries have recently been manufactured and are proving to be viable in real-world tests on mainstream cars.
1925: The Tri-State Tornado. Indiana was one of three Midwest states in the path of the deadliest tornado in American history. On March 18, 1925, the Tri-State Tornado traveled a record 219 miles on the ground from Missouri through Illinois and into Indiana, where it struck Posey, Gibson and Pike counties.
1 Damage $15 million. 2  Maximum precipitation in 24 hours: 10.5 inches recorded in 1905 at Princeton. 3  Maximum snow in 24 hours: 30 inches recorded in December 2004 at southern and east central Indiana 4  . Highest wind gust on record of 111 MPH in Indianapolis occurred on June 29, 1929.