Past Programs
Engineering - 2008
2008 | 2006 | 2005 | 2004 | 2003
Twin Towers toppled by weakened steel columns
20/09/2008
At high temperature, the strength of steel is controlled by magnetic properties. It is a quantum effect, and explains why the Twin Towers in New York collapsed in 2001. The thermal insulation panels on the columns were knocked off by the impact from the aircraft, exposing the steel to the high temperatures of the fire. The solution is applying the insulation in a different way, or using new steels with additives, allowing them to maintain strength at high temperatures.
BMW's Hydrogen 7
29/03/2008
BMW is developing a hydrogen-powered car. Dave Bean describes its virtues to Robyn Williams.
