`Seawolf submarine hydrogen cracking`

When they had the problem with the Seawolf submarine, these guys had to go into enclosed containers where the steel had to be at 400 degrees Fahrenheit to prevent the hydrogen cracking. They had to wear blue jelly suits. They were only allowed to be in there for like twenty minutes at a time. So they'd have a little cart like a mechanic's creeper to go underneath a car, and they'd roll them in there, and they'd have to have someone outside because this was a confined space. They called them blue jelly suits — they had to wear this suit that had this blue liquid in it that would cool them down, because they were going into a 400 degree oven to do their welding. And they had respirators so they could breathe cooler air so they wouldn't burn up their lungs. They'd go in for like twenty minutes and then have to come out and have a rest, and another guy would go in there. It got a little expensive to build that submarine. But it's because they had too high strength and didn't have good enough hydrogen control.