Wet winding carbon fiber around a round core is a best practice approach in aerospace to create stiff, strong and lightweight fuselages, such as in the Boeing 787 Dreamliner.
Rush claimed to have a partnership with Boeing, which Boeing denied after the disaster. The relationship may have consisted of no more than buying carbon fiber from the aircraft manufacturer “at a big discount” “because it was past its shelf life for use in airplanes,” according to Arnie Wiseman, travel editor of the Travel Weekly, who recalled a conversation with Rush for the Washington Post.
The main structural difference between a pressure vessel, such as an aircraft fuselage, and a submersible is external versus internal pressure. Internal pressure makes its gas container want to expand. Think of a balloon. The tightly wound carbon fibers around a fuselage are great at resisting expansion. The tensile strength of carbon fiber (as much as 7.06 Gpa) is 4 times better than steel wire (1.77 Gpa). Carbon fiber in tension also offers satisfying simplicity. Like a string being pulled, it keeps its shape in tension. Put carbon fiber in compression, however, and all bets are off.
