A submarine (or sub) is a watercraft capable of independent operation underwater. (It differs from a submersible, which has more limited underwater capability.) The term “submarine” is also sometimes used historically or informally to refer to remotely operated vehicles and robots, or to medium-sized or smaller vessels (such as the midget submarine and the wet sub). Submarines are referred to as boats rather than ships regardless of their size.
Although experimental submarines had been built earlier, submarine design took off during the 19th century, and submarines were adopted by several navies. They were first used widely during World War I (1914–1918), and are now used in many navies, large and small. Their military uses include: attacking enemy surface ships (merchant and military) or other submarines; aircraft carrier protection; blockade running; nuclear deterrence; stealth operations in denied areas when gathering intelligence and doing reconnaissance; denying or influencing enemy movements; conventional land attacks (for example, launching a cruise missile); and covert insertion of frogmen or special forces. Their civilian uses include: marine science; salvage; exploration; and facility inspection and maintenance. Submarines can be modified for specialized functions such as search-and-rescue missions and undersea cable repair. They are also used in the tourism industry and in undersea archaeology. Modern deep-diving submarines derive from the bathyscaphe, which evolved from the diving bell. (Full article...)
Image 12A 16th-century minecart, an early example of unpowered rail transport (from Rail transport)
Image 13The Great North Road near High gate on the approach to London before turnpiking. The highway was deeply rutted and spread onto adjoining land. (from Road transport)
Image 22Traffic congestion persists in São Paulo, Brazil, despite the no-drive days based on license numbers.
Image 230-Series Shinkansen, introduced in 1964, triggered the intercity train travel boom. (from Rail transport)
Image 24European rail subsidies in euros per passenger-km for 2008 (from Rail transport)
Image 25An ambulance from World War I (from Transport)
Image 26Customized motorcycle to maximize load capacity. Mobility is important for motorcycles, which are primarily used for transporting light cargo in urban areas. (from Transport)
Image 35A cast iron fishbelly edge rail manufactured by Outram at the Butterley Company for the Cromford and High Peak Railway in 1831; these are smooth edge rails for wheels with flanges. (from Rail transport)
Image 38Bardon Hill box in England (seen here in 2009) is a Midland Railway box dating from 1899, although the original mechanical lever frame has been replaced by electrical switches. (from Rail transport)
Image 39Bronocice pot with the earliest known image of a wheeled vehicle in the world, found in Poland (from Transport)
Image 50German soldiers in a railway car on the way to the front in August 1914. The message on the car reads Von München über Metz nach Paris ("From Munich via Metz to Paris"). (from Rail transport)
Image 51The engineering of this roundabout in Bristol, United Kingdom, attempts to make traffic flow free-moving.
Image 52The Lockheed SR-71 remains unsurpassed in many areas of performance. (from Aviation)
Image 53Interior view of a high-speed bullet train, manufactured in China (from Rail transport)
Image 61According to Eurostat and the European Railway Agency, the fatality risk for passengers and occupants on European railways is 28 times lower when compared with car usage (based on data by EU-27 member nations, 2008–2010). (from Rail transport)
... that a section of Mississippi Highway 489 was designated as the Jason Boyd Memorial Highway to commemorate the MDOT superintendent who was killed while removing debris from the road?