A motorized pulley, which will let military, paramedics and firefighters climb up 30-storey buildings in 30 seconds, has become a reality thanks to the Powered Rope Ascender. Developed initially for military use, the Ascender is now being touted as a valuable device for the emergency services. The Ascender has been awarded the Lemelson-MIT Student prize for U.S. inventions. Graphic shows Power Rope Ascender and its applications, and explains how it works.