paddle steamer

paddle steamer, a vessel with paddle wheels usually driven by the earliest forms of steam propulsion. The type which has two, one on either side mounted amidships, was known as a side-wheeler; the other, where a single paddle wheel is mounted at the stern, was known as a stern-wheeler. They were powered by reciprocating engines, though in the USA they often had a walking beam engine.

Various forms of man-operated paddle-wheel boats were in use long before the introduction of any kind of power, both in China and later in Europe. With the development of steam propulsion in the latter half of the 18th century various experiments were made in Europe to apply it to paddle wheels. The first to make a practical success of powering a boat in this way was a French engineer, the Marquis de Jouffroy d'Abbans (1751–1832). His 1776 experiment with a 13-metre (43-ft) boat on the Doubs River failed, but in 1783 his paddle steamer Pyroscaphe, with a displacement of 182 tons, was propelled against the current on the river Saône for fifteen minutes before it disintegrated. Another pioneer, the American John Fitch (1743–98), after a successful trial of a 14-metre (45-ft) paddle steamer in 1787, built a larger one the next year which ran regularly between Philadelphia and Burlington, NJ, though it was not large enough to be economically viable. The same year, in England, Patrick Miller also launched a steamboat. This was powered by an engine made by William Symington which drove a paddle between two hulls, and in 1802 William Symington produced the Charlotte Dundas. The first paddle steamer in Europe to run a regular commercial service for passengers was the 13-metre (43-ft 6-in.) Comet which, from 1812, plied between Glasgow and Greenock. Other early paddle steamers such as the Clermont, Savannah, Enterprize, Great Western, and Sirius, all contributed to the slow transition from sail to steam.

The earliest powered paddle wheels carried six or more fixed floats, and some, like those fitted to the Savannah, could be dismantled and carried on deck when not in use. By about 1840 most paddle wheels were fitted with a feathering device in which radial rods mounted on an eccentric moved the floats in turn so that as they entered the water and left it they remained nearly upright, thereby gaining more propulsive power and causing less wash. In the early days of the 19th century there were also many experiments in the arrangement and shape of the floats, from single paddles to multiple shutters, all aimed at increasing the wheel's efficiency and reducing the shocks as the floats struck the water. Many variations of these ideas in model form can be seen in the Science Museum, South Kensington, London. Up to the end of the paddle steamer era, however, the traditional wheel with feathering floats was almost universal.

For the first fifty years of steam propulsion at sea the paddle steamer had few rivals. But shipowners were well aware of some of its disadvantages. One was the danger of broken paddle shafts and damaged engines when the ship rolled heavily in bad weather. Another was the varying effect in speed and coal consumption between a deeply laden cargo vessel, whose wheels would be well immersed, and one which was in ballast, when the wheels would have little grip of the water. For warships, too, paddle wheels proved far too vulnerable to enemy gunfire or collision, which hastened the introduction of the propeller.

However, passengers using the ocean liners of the day were reluctant to trust themselves to the early screw-driven steamers. Brunel, for one, recognized this reluctance and when his huge Great Eastern was launched in 1858, she had, in addition to a single 7.3-metre (24-ft) propeller, the largest pair of paddle wheels ever fitted to a steamship. The Cunard Line, too, was slow to abandon the paddle steamer, and continued to build them for its North Atlantic service until 1861. The last one, the 3,850-ton Scotia, was the most handsome—and powerful—ship on the Atlantic at that time and the ultimate in ocean-going paddle steamers. Her side lever engines, built by Robert Napier, had cylinders 254 centimetres (100 in.) in diameter with a 3.6-metre (12-ft) stroke which developed 4,600 horsepower to give a service speed of 16 knots. As late as 1874 she was still able to make the year's second fastest crossing by a Cunard liner, in a time of 8 days, 16 hours.

With the introduction within the next ten years of high pressures in marine boilers, together with the introduction of the propeller and the compound engine, with its greatly increased economy in coal and water consumption, the paddle wheel was gradually abandoned. But for passenger services on rivers and lakes, and in inshore waters, they held their own until well into the 20th century. Unlike the propeller, paddle wheels exert virtually as much power going astern as ahead, and a paddle steamer is far more manoeuvrable than a similar-sized screw steamer. This agility made the paddle steamers popular and well adapted for excursion services all over the world.

For the same reason paddle tugs were built for all kinds of service except ocean work. As they carried no passengers, they were legally permitted to disconnect the shaft and to work each wheel independently of the other. By varying the speed of the wheels, or by going ahead on one wheel and astern on the other, a paddle tug could turn in almost its own length. The British Admiralty thought so highly of them that even after the Second World War (1939–45) naval tugs were being built with paddle wheels operated with a diesel-electric drive.

Even when propellers became the normal means of propulsion, stern-wheelers, flat-bottomed craft with a single paddle wheel at the stern, were retained to work in very shallow waters. The wheel, in this case usually of a simple type with fixed floats, was driven direct by two cylinders of long stroke placed on deck on a level with the paddle shaft and fed from a boiler, or boilers, mounted on the same deck right forward near the bows. Stern-wheelers were used extensively for police work in the Chinese rivers, in the form of river gunboats, and for freight and passenger services on rivers in India, Iraq, and Australia.

However, in North America, although roughly half the river steamboats were stern wheelers, the larger and faster passenger riverboats were almost all side-wheelers. Some Mississippi and Ohio steamboats, powered by 12-metre (40-ft) paddle wheels turned by walking beam engines, were built as large as 5,000 tons gross with five or six decks rising above a flat hull shaped like a pointed tea tray. In the great steamboat races of the 1870s, speeds of 18 and 19 knots were claimed between Natchez and New Orleans. Larger numbers of stern-wheelers plied the rivers and lakes of British Columbia, Canada, than were employed on the Mississippi River. Modern versions of this type continue to be built, but only three of the original ones survive today and only one, the Samson V, is preserved afloat.

Bibliography

Spratt, H. Philip , The Birth of the Steamboat (1953).