Paddle steamer
From Free net encyclopedia
A paddle steamer, paddleboat, or paddlewheeler is a ship or boat propelled by one or more paddle wheels driven by a steam engine. Boats with paddle wheels on the sides are also called sidewheelers, while those with a single wheel on the stern are known as sternwheelers. The paddle steamer is obsolete technology and few if any have been built since the 1940s.
The paddle wheel is a large wheel, generally built of a steel framework, upon the outer edge of which are fitted numerous paddle blades (called floats or bunkets). In the water, the bottom quarter or so of the wheel is underwater. Rotation of the paddle wheel produces thrust, forward or backward as required. More advanced paddle wheel designs have featured feathering methods that keep each paddle blade oriented closer to vertical while it's in the water; this increases efficiency.
Early Developments
The first paddle steamer was the Pyroscaphe built by Marquis Claude de Jouffroy of Lyons in France, in 1783. It had a horizontal double-acting steam engine driving two 13.1 ft (4 m) paddle wheels on the sides of the craft. On July 15, 1783 it steamed successfully up the Saône for fifteen minutes before the engine failed. Political events interrupted further development.
The next attempt at a paddle-driven steam ship was by the Scottish engineer William Symington. Experimental boats built in 1788 and 1789 worked successfully; in 1802, Symington built a barge-hauler, Charlotte Dundas, for the Forth and Clyde Canal Company. It successfully hauled two 70-ton barges almost 20 miles (30 km) in 6 hours against a strong headwind on test in 1802. There was much enthusiasm, but some directors of the company were concerned about the banks of the canal being damaged by the wash from a powered vessel, and no more were ordered.
While Charlotte Dundas was the first commercial paddle-steamer and steamboat, the first commercial success was possibly Robert Fulton's North River Steam Boat in New York, which went into commercial service in 1807 between New York City and Albany. Many other paddle-equipped river boats followed all round the world.
Seagoing paddle steamers
Image:PS Waverley off Greenock 1994.jpg The first sea-going trip of a paddle steamer was that of the Albany in 1808, which steamed from the Hudson River along the coast to the Delaware River. This was purely for the purpose of moving a river-boat to a new market, but the use of paddle-steamers for short coastal trips began soon after that.
The first paddle-steamer to make a long ocean voyage was the Savannah, built in 1819 expressly for this service. Savannah set out for Liverpool on May 22, 1819, sighting Ireland after 23 days at sea. This was the first powered crossing of the Atlantic, although Savannah also carried a full rig of sail to assist the engines when winds were favorable.
The Sirius in 1838, a fairly small steam packet built for the Cork to London route, became the first vessel to cross the Atlantic under sustained steam power, beating Isambard Kingdom Brunel's much larger Great Western by a day. Great Western, however, was actually built for the transatlantic trade, and its crossing began the regular sailing of powered vessels across the Atlantic. The Beaver was the first coastal steamship to operate in the Pacific Northwest of North America.
The largest paddle-steamer ever built was Brunel's Great Eastern, but it also had an additional screw propulsion and sail rigging. She was 692 feet (211 m) long and weighed 32,000 tons, its paddle-wheels being 56 ft (17 m) in diameter.
In oceangoing service, the paddle steamer became obsolete rather quickly with the invention of the screw propeller, but they remained in use in coastal service, thanks to their shallow draught and good maneuverability.
Types of paddle steamer
Image:MusicCityQueen.jpgThere are two basic ways to mount paddle wheels on a ship; a single wheel on the rear, known as a stern-wheeler, and a paddle wheel on each side, known as a side-wheeler.
Stern-wheelers have generally been used as riverboats, especially in the United States, where they still operate for tourist use, primarily on the Mississippi River. On a river, the narrowness of a stern-wheeler is preferable.
Side-wheelers, meanwhile, have also been used as riverboats, but also commonly as coastal craft. While wider than a stern-wheeler, thanks to the extra width of the paddle wheels and their enclosing pontoons, the side-wheeler has extra maneuverability thanks to the common ability to direct power to one wheel at a time.
Paddle steamers today
Image:PS Waverley leaving Dunoon 1989.jpg Being a long-obsolete technology, the few paddle steamers still operating are deliberate anachronisms, preserved for tourists or as museums. Some paddle steamers still operate on the Mississippi River, as do a couple in the United Kingdom. The paddle steamer Waverley, built in 1947, is the last sea-going paddle steamer in the world. This ship sails a full season of cruises every year from places around Britain, and has sailed across the English Channel for a visit to commemorate the sinking of her predecessor of 1899 at the Battle of Dunkirk.
PS Skibladner is the oldest steamship still in regular operation. Built in 1856, it still operates on lake Mjøsa in Norway.
The Elbe river White Fleet in Dresden, Germany, is said to be the oldest and biggest of the world.
Switzerland too has a large paddle steamer fleet, most of them by the "Salon-Steamer-type" built by Sulzer in Winterthur or Escher-Wyss in Zürich. There are five active and one inactive on Lake Lucerne, Lake Zürich has two, Lake Brienz and Lake Thun one each, Lake Constance also one. Lake Geneva has three converted to diesel electric power in the 1960s and five real paddle steamers. One of them, the "Montreux" has been reconverted in the year 2000 from diesel-electric to steam with an all-new steam engine. It is the worlds first electronically remote controlled steam engine, thus featuring similar low operation costs like state of the art diesel engines, while producing up to 90 percent less air pollution.
See also Steamboat.
de:Raddampfer nl:Raderstoomboot pl:Napęd kołowy statku ru:Пароход