The Medicare Coverage Database (MCD) contains all National Coverage Determinations (NCDs) and Local Coverage Determinations (LCDs), local articles, and proposed NCD decisions.
USS Constitution. Launched in Boston in 1797, the oldest commissioned warship afloat earned her nickname Old Ironsides during the War of 1812 when she fought the British frigate HMS Guerriere. During this historic battle, cannonballs fired at USS Constitution appeared to bounce off, causing one of her crew to remark that her sides were made of iron.
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.