In the realm of very real rocket science, I was present when a junior level manager came bouncing into the engineering office at "Little B Airplane" company gleefully announcing that "we passed the proof test."

The test article was a hollow spherical tank precisely 6 FEET in diameter, with walls 0.010 inches thick, that they had pressurized to "105% of design limit load" with "dry nitrogen," bringing the average stress in the container wall "to or above" 115,000 psi. The test was mainly to "proof" the weld that ran completely around an "equator" of the tank, to join the two hemispheres from which it was made.

Sufficient details are contained above for anyone with a sophomore engineering education to calculate the "compression energy" that would have been released had any failure occured. Hint: "more than 1,000 lb of TNT?."

They had performed the test during the main day-shift in an occupied building where approximately 300 people were busy building airplanes.

Had there been a failure, that building would have been gone, and the building I was working in some 80 yards away quite likely would have been "damaged beyond safe use."

I think it was remarkable, in fact nearly miraculous, that the the "manager" escaped without bodily harm - from MY OFFICE.

I'm quite sure that my remarks were not officially recorded in the Apollo Liquid Hydrogen Storage Tank Development Archives (Lunar Orbiter subsection).

John