The safety chain dog system in roller coasters
Animation of the safety chain dog, a version of which was patented by American designer John Miller in 1910. By locking into the grooves of the ratchet rail, it prevents roller coasters from rolling backward should the lift chain break.
Encyclopædia Britannica, Inc.
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Encyclopædia Britannica, Inc.Dairy farming in Denmark.
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Encyclopædia Britannica, Inc.Johannes Gutenberg invented one of the first printing presses using movable type.Media Editor: Miranda Chabot
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Contunico © ZDF Studios GmbH, MainzHow do the waxy coating on some fruits helps them survive different climates?
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© Civil War Trust (A Britannica Publishing Partner)Both Union and Confederate forces needed trains to move and supply troops during the American Civil War, which meant that railroads determined the outcomes of some battles.
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Encyclopædia Britannica, Inc.Animation of a linear synchronous motor (LSM) and a linear induction motor (LIM), which use electromagnets to make roller coasters achieve rapid rates of acceleration.
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Contunico © ZDF Studios GmbH, MainzCommuters in the Tokyo area depend on rail transportation, and most pass through Shinjuku station.
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Contunico © ZDF Studios GmbH, Mainz; Thumbnail © Blanscape/Dreamstime.comLearn about the technology used in Tokyo's railway system.
News •
Higher, Faster, Gnarlier: Have Roller Coasters Become Too Extreme?
• Oct. 22, 2026, 5:05 AM ET (New York Times)
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