Learn about the USS Permit, a Cold War submarine that defied physics at crush depth. Discover the incredible story of this remarkable submarine in this video!USS Permit pushed submarine depth limits beyond test depth in 1963, revealing mysteries of HY-80 steel pressure hulls that led to the SUBSAFE program. After the USS Thresher disaster, Permit-class submarines tested extreme diving depths where physics behaved unexpectedly. Admiral Rickover’s investigation transformed submarine safety.Resources:Norman Polmar & Kenneth J. Moore, “Cold War Submarines: The Design and Construction of U.S. and Soviet Submarines” (Potomac Books, 2004) – Comprehensive technical details on Permit-class submarine construction, HY-80 steel specifications, and SUBSAFE program implementation.James Bryant Conant III, “The Last Dive of the Thresher” – Documentation of the Thresher disaster investigation and subsequent naval reactor safety protocols under Admiral Rickover’s direction.U.S. Navy SUBSAFE Program documentation and Naval Sea Systems Command historical records on submarine depth testing procedures and pressure hull certification standards (declassified materials from 1963-1996).If you are enjoying this investigation into history’s hidden conflicts, please verify your subscription to the channel Cold War Chronicles. We declassify the past to understand the present.#USSPermit #ColdWarSubmarines #SUBSAFE #USSThresher #NavalHistory #SubmarineWarfare #AdmiralRickover #NuclearSubmarines #HY80Steel #DepthTesting #ColdWar #MilitaryHistory #NavalEngineering #SubmarineSafety #PermitClass #1960sNavy #PressureHull #TestDepth #SubmarineDisaster #NavalReactors