Submarines: Crack Of Doom

Archives

July 29, 2009: A one inch, hairline crack, was found on the pressure hull of the 14 year old USS Toledo (a Los Angeles class SSN, or nuclear attack submarine). The crack was in the metal plate, not a weld. After carefully examining the crack, the plate will be replaced. Above the crack, there was a 21 inch hairline crack in the outer (non pressurized) hull, which was under the sail. The USS Toledo had just undergone a three year refit, costing $179 million. The sub will be sent to a nearby (to New London, Connecticut) shipyard, for the repairs.

Such a crack in the pressure hull is a serious problem, because it makes it more likely that the pressure hull would fail, and flood the boat, at less than the "test depth" (about two thirds the "design depth," which is the maximum depth the sub can operate at). Going a little deeper gets you to the collapse (or "crush") depth, at which the pressure hull is crushed and implodes. The deepest diving U.S. subs, the Seawolf class, are believed to have a test depth of 490 meters (1,600 feet) and a collapse depth of 730 meters (2,400 feet). During World War II, collapse depths were never more than a thousand feet. Since then, larger boats, built of stronger metals, have greatly increased the depth subs can operate at. But that only works if the crew knows the limits of their boats, and cracks in the pressure hull reduce those limits.

 

 

X

ad

Help Keep Us From Drying Up

We need your help! Our subscription base has slowly been dwindling.

Each month we count on your contributions. You can support us in the following ways:

  1. Make sure you spread the word about us. Two ways to do that are to like us on Facebook and follow us on Twitter.
  2. Subscribe to our daily newsletter. We’ll send the news to your email box, and you don’t have to come to the site unless you want to read columns or see photos.
  3. You can contribute to the health of StrategyPage.
Subscribe   Contribute   Close