Originally Posted by
TransWorld
We are just going to disagree on that. Remember, a gas is contained by a pressure vessel, not a tank. Pressure vessels are much thicker. As a result, they are more robust and less prone to impacts of flight dynamics. Metal fatigue is tested for periodically, just like structural integrity metal fatigue of the plane.
I would suspect that the more likely source of leaks would be the plumbing not the tanks. But assuming we are talking about liquid H2 it actually doesn't have to be a pressure vessel at all, it could just be a tank that's vented for boil-off pressure relief.
Space launch vehicles tend to use pressure vessels because the pressurized tank is an integral structural component of the rocket. They also use near paper-thin walls, and it only needs to work once (for traditional expendable boosters).
For clarity I've been talking about liquid H2, pressurized gaseous H2 I don't think is practical for large airplanes...
Too little pressure and you can't carry enough. Too much pressure, and the weight of tank becomes impractical. And those points would overlap.