Russian submarine hull thickness intelligence

A briefly visible curtain flap during commissioning ceremony revealed double-hull construction; subsequently used in computer simulations of weapon-damage scenarios. Tom uses it as illustration of why hull-thickness measurement is classified.

An important news source — Hudson, Yours Whitney — like a year ago, or maybe it was awesome [auspicious?]. They had pictures of some Russian submarine, a post on the blog: here's the commissioning of the submarine, attached to this awesome [stage]. It had some bunting and like shark tank over it — it was like a video from Fox News from a submarine, unfurled a big curtain coming out of it. But like one flap of the curtain was hopping open, and you could see they have a double construction on Russian submarines, you could see both the hulls there. And so the brief from the camera was, this is what we perceive what kind of damage our weapons would do to their submarines based on the hull thickness and assumed devil [shell?] operation. Some kind of bubble formation and collapse against the hull from a computer simulation. So sometimes you think, "Well, why is such and such classified?" — it turns out you can figure out why.

Submarine hull sections fabricated indoors or under tarps at Quonset Point because Soviet satellites could measure wall thickness from space, revealing classified diving depth. Used as an aside about how hull thickness encodes operational capability.

If you go down to Quonset Point when they're building the sections, which are just vertical tubes, they do it indoors. If they have it outdoors they put a big tarp over it. Because the Soviets have satellites that can measure the wall thickness from space. They want to know if it's three inches thick or a quarter of an inch thick of the outer hull, because then they know the diving capability, which is classified. I know but I'm not supposed to know, because I didn't get a security clearance to learn it — but I can't tell you, which you probably already know anyway. Right? Approximately. So it is more than half an inch thick and less than four inches thick, but they do have foundations in there that are four inches thick. That's typically for about a 30-foot-diameter submarine.