On Jul 22, 2008, at 11:53 PM, Srini Ramakrishnan wrote:
My first impressions from looking at the picture gallery - it looks like an enclosed golf cart with a fancy paint job, and those huge tanks look scary. OTOH it is supposed to have a top speed of 150km/h and the gas tanks are tested to be "safe".
High-pressure tanks that are likely to be in situations where failure is probable is a solved problem. When I worked with lightweight 6,000 psi tanks about 10-15 years ago, they were wrapped in aramid fiber or something equivalent. When tank failures occurred, and they did with the abuse they were exposed to, the fibers would catch all the tank fragments and the pressure would bleed out between the fibers. Offhand, I cannot think of a case where anyone was significantly injured by explosive tank failure. It was a very effective and very inexpensive countermeasure, since the fiber wrap did not have to be pretty or resilient, just good enough to catch all the fragments from a single failure so that no one was hurt.
I would guess that it is highly probable that the tanks in this car will be wrapped in a polymer bag designed to catch the fragments should explosive decompression occur, unless the tank pressure is sufficiently low that this is not deemed a concern; lower pressure tanks tend to fail more gracefully -- different materials with different properties. Safe, high-pressure systems is very familiar engineering territory, even if it is not something commonly considered in automotive systems in this context.
Cheers, J. Andrew Rogers
