http://weldingdesign.com/archive/beginnings-and-development-pressure-hull-welding-united-kingdom-submarines http://weldingdesign.com/archive/beginnings-and-deve

http://weldingdesign.com/archive/beginnings-and-development-pressure-hull-welding-united-kingdom-submarines http://weldingdesign.com/archive/beginnings-and-development-... The quality of the weld is extremely important, enough so to justify the 0% o2 environment.