| |
| | Submarine - Biocrawler (Site not responding. Last check: 2007-11-02) |
 | | Royal Navy submarines classes, including ballistic missile submarines, are letter-based; thus, all boats of the Swiftsure class begin with the letter S and the Trafalgars, the letter T. Though this has been the way with all Royal Navy submarines, they were originally designated alphanumerically, such as HMS A1 of the A-class of 1903. |
 | | The first military submarine was the Turtle, a hand-powered spherical contraption designed by the American David Bushnell that was designed to accommodate a single man. It was the first verified submarine, capable of independent underwater operation and movement, and the first to use screws for propulsion. |
 | | There were two Russian submarine incidents, and in both cases the submarines in question were lost, along with three United States submarine incidents, one Chinese incident, and one Canadian incident. |
| www.biocrawler.com /encyclopedia/Submarine (5100 words) |
|