NY Times: Amazing Secrets of the Third Rail

Published by Colin on 31st July 2002.

Several subway train systems in the world use the technique of pumping electricity back into the system when braking, where it is consumed by nearby trains. However, this technique is not very efficient and incurs lots of power loss. New York subway technicians have come up with [a system that uses flywheels](http://www.nytimes.com/2002/07/30/nyregion/30TUNN.html "NY Times: Amazing Secrets of the Third Rail