Extending Hull Life
Here's a quick discussion over at DoD Buzz about the Pentagon finally admitting what everyone has known for years -- the size of the U.S. submarine fleet is going to drop below the minimum required to support its missions by 2030. Of most interest to me is the consideration of keeping some boats in commission longer. Excerpt:
But that may be difficult, cautioned a top naval analyst. Shipbuilding expert Ron O’Rourke of the Congressional Research Service, appearing after Blake before a panel of the House Armed Services Committee, warned lawmakers that it may be hard to extend the service of the Navy’s fast-attack subs because of limitations on the lives of their pressure hulls. The Navy keeps its nuclear submarines in excellent condition, but the ships were built to meet exact tolerances and specifications, and it may be more expensive than it’s worth — or even impossible — to keep submarines sailing for much longer than their planned lives.That's really the whole problem with extending submarine lives -- unless they come up with a method of annealing the entire pressure hull, they're going to have to reduce some of the engineering margins built into the design. We all know that American submarines are incredibly over-engineered, but at some point you're going to have that catastrophic failure as you try to push the limits, and a submarine crew will pay with their lives.
What do you think? Are there reasonable methods of extending submarine hull life without unduly risking the crew? (If you bring up some sort of depth limitation, please remember not to mention any numbers below 800 feet.)