The Medicare Coverage Database (MCD) contains all National Coverage Determinations (NCDs) and Local Coverage Determinations (LCDs), local articles, and proposed NCD decisions.
USS CONSTITUTION. The Constitution--called Old Ironsides because cannonballs could not penetrate her tough oak sides--was one of the first of the original six frigates that made up the U.S. Navy. A 44-gun frigate built at the Edmond Hartt Shipyard, Boston, MA, in 1797.
When used as a nautical vessel designation, the letters SS stand for steam ship or screw steamer. It was originally used to distinguish a screw steamer from a paddle steamer, which was called a... When used as a nautical vessel designation, the letters SS stand for steam ship or screw steamer. It was originally used to distinguish a screw steamer from a paddle steamer, which was called a PS. After paddle steamers started to decline in popularity, SS became an acronym for steam ship instead of just screw steamer. Screw steamers were developed after paddle steamers. Paddle steamers had performance issues if the ship was lowered due to added weight.