U.S. Navy titanium submarine program decision

The cost reasoning: at $100/lb fabricated titanium, an eighteen-billion-dollar fleet buy yields one titanium sub vs. nine steel subs or three stainless steel subs. Combined with the creep-fatigue barrier (§4), the U.S. did not pursue titanium submarines.

If you have to make it out of all stainless steel, now you're talking about a five-billion-dollar hull. Ten times the price. You just ordered nine submarines for eighteen billion. Would you rather purchase three submarines that were non-magnetic? And why don't we build titanium submarines? Because the price of titanium fabricated is probably a hundred dollars a pound. So with eighteen billion dollars you could have purchased one submarine. Now you have to ask, would you rather have a nuclear carrier or a nuclear submarine?

Eagar's first ONR research project at MIT (1977). David Taylor work on whether to match Soviet titanium subs. Cost: ~100× HY-100 hull; ~$3,000/lb vs $25–30/lb.

I said steel is heavy. To give you an idea: [Tom holds up a steel sample.] this is a piece of one-inch steel made about thirty years ago. [Tom holds up a second sample.] This is a piece of two-inch-thick titanium electroslag weld made at our Graduate Center when we were looking at trying to build a titanium submarine. Why have we not built a titanium submarine? A long time ago the Soviets did that. The main source of titanium — it's like aluminum, it's about the fifth most abundant element in the Earth's crust. Titanium is not scarce.

The Navy developed a 100 ksi submarine steel when it wanted to build its own titanium submarine. Pelloux's quip about submarines designed in the fully plastic region so the crew gets squeezed slowly rather than drowning.

Now it turns out the Navy developed a 100 ksi submarine steel at one time, when they wanted to build their own titanium submarine. You can see submarines they build in the fully plastic region. As Professor Pelloux, who's a fracture person here, used to say: they want a submarine so that when you go — if the submarine starts losing power and goes sinking to the bottom of the ocean — you slowly squeeze everyone, rather than fracture, so you don't die by drowning, you get slowly squeezed to death. Anyway, he's right.