CUSTOM USS HARTFORD (SSN 768) WatchHISTORY USS Hartford (SSN 768) is a Los Angeles class attack submarine. The Los Angeles class, sometimes called the LA class or the 688 class, is a class of nuclear powered fast attack submarines that forms the backbone of the U. S. Navy's submarine force. Sixty two submarines of this class have been completed, 41 are still in active service. The Los Angeles class contains more nuclear submarines than any other class in the world. The class was