Canals

views updated Jun 27 2018

CANALS

CANALS. Even before the Revolutionary War gave New impetus to American expansionism, the colonial political and economic elites were deeply interested in the improvement of inland transportation. Vessels that plied offshore waters, small boats and rafts on the streams down to tidewater, and local roads and turnpikes served the immediate commercial needs of farmers and townspeople in the Atlantic coastal area. But the loftier dreams of planters, merchants, and political leaders—as well as of the common farmers who constituted by far most of the free population in British America—looked beyond the "fall line" that separated the rivers flowing to the coast from those that ran to the Ohio-Mississippi basin. A vast area for settlement and productivity—and riches—lay in the interior, and by the early 1790s demands for diffusion of New transport technologies and for investment in internal improvements were voiced frequently in both state and national political forums.

It was widely recognized that unless bulk agricultural commodities, which were the staples of a commercialized and expanding farm economy, could be carried cheaply

and over long distances, settlement and economic growth would be badly hampered in the region beyond the Appalachian Mountains. Then, too, there were opportunities for construction of short lines on the Atlantic seaboard to link already developed areas (coal mines, farming and lumber regions, and rising industrial sites), with the promise of immediate traffic and revenues. The latter were "exploitative" projects, tapping existing trade routes and resources; but the major east-west projects were "developmental," promoted with the goal of opening Newly or sparsely settled areas to economic opportunities. There was also a nationalistic or patriotic goal of canal promotion: to bind together far-flung sections of the young nation and to prove the efficacy of republican government.

And yet total canal construction in the United States up to 1816 totaled only 100 miles—the longest canal project being the Middlesex, which linked Boston's harbor with the farm region to the north. Other lines of some importance linked Norfolk, Virginia, to Albemarle Sound and connected the Santee River area to Charleston, South Carolina. Although many other canal projects were proposed up and down the Atlantic coast, progress was difficult because of shortages of capital and skepticism with regard to engineering feasibility projects. Moreover, regional or local jealousies notoriously worked against successful mobilization of governmental support in both the U.S. Congress and the state legislatures.

In the period from the mid-1820s to the Civil War, however, the United States underwent a vast expansion of canal construction, becoming the world's leading nation in both mileage of canals and the volume of tonnage carried on them. The canal lines were of crucial importance in the integration of a national economy, and they played a key role in the so-called "Transportation Revolution" that expedited both westward expansion and a robust industrialization process in the North and West.

Advantages, Disadvantages, and Construction Challenges

Canal technology proved especially attractive for several reasons. Since the 1760s, successful large-scale canal projects had been built in both Great Britain and France, and these canals had brought enormous economic advantages to the regions they served. The engineering advances pioneered in Europe gave American promoters confidence that they could build canals with equal success.

There was a downside to canal technology, too, though it was not always fully recognized in America. Difficult topography or uncertain water supply meant complex and highly expensive construction design. Canal building before the 1850s was mainly done with hand tools, augmented only by some primitive animal-powered machinery. A canal line had to be furnished with locks, permitting boats to pass through from one water level to another. The segments of line between the locks were of very gradual grade to permit controlled flow. At each lock, a gate at its higher level would be opened while the gate on the lower end was kept closed; once a boat entered the lock's chamber from the higher level, the upper gate was closed (holding the water flow back) while the lower gate was opened. As water ran out, the boat was carried down to the lower level, then passed through the open gate. For "upstream" movement, from the lower level to the higher, the process was reversed. The lock would be drained to the lower level, the boat would enter through the bottom gate, which was then closed, and water would then be admitted from the upper gate, lifting the boat up to the higher level. In steep areas, "flights" of locks, closely spaced, were necessary and often involved complex engineering; for transit of the boats, these series of locks meant a slow stretch and usually long waiting periods.

Locks varied in size. Lifts ranged from two to thirty feet, and there were great differences in the distances between gates as well as in the construction materials used. Masonry locks and metal or metal-trimmed gates were far more expensive—and more durable—than wooden gates and timber-supported rubble for the walls as found on some of the lines. The total rise and fall over an entire line was measured as "lockage," and served as an index of the difficulty of construction. For example, New York's Erie Canal route measured lockage of 655 feet, by contrast with Pennsylvania's lockage of 3,358 feet between Philadelphia and the Ohio River.

The size of the boats that could be accommodated, as well as the volume of water needed, were functions of the dimensions of the canal bed, or its "prism," as well as of the size of lock chambers. Prisms on American canals varied greatly, most of them ranging from forty to sixty feet in width at the top, with sloping sidewalls leading to a bottom of twenty-five to forty-five feet across. The Pennsylvania system was the most complex in engineering using inclined planes and steam-powered winches to drag boats out of the water and over some of the steepest hills.

To supply the line with flowing water, engineering plans had to include river connections, dams and reservoirs with feeder lines to the canals, and often massive culverts and aqueducts. Building the sidewalls to minimize loss of water through seepage was another challenging and expensive aspect of design. On many of the larger canals, such as the Ohio lines, engineers took advantage of fast-flowing feeder streams to design water-mill sites into the line.

Once a canal was in operation, moreover, maintaining navigation was a continuous challenge. Winter ice, droughts, floods, and breaches in the water-supply system would frequently cause navigational closings. Even in the best of circumstances, it was difficult to maintain regular schedules on the lines because of traffic bottlenecks at the locks and the continuous maintenance needed to keep water flowing.

Although steam-powered propeller craft were used on a few canal lines, this form of transport placed dangerous pressure on the canal walls. Hence, the use of horses or mules to haul canal boats was nearly universal, with the animals walking along the "towpath" alongside the line. Freight boats typically of 50-to 125-ton capacity operated at speeds of one to three miles per hour. On most lines they were owned by individuals or private companies, the line being a common carrier under the law.

In the short run, all the disadvantages of canal technology were more than offset by the cost savings for long-distance hauling, especially of bulk goods and produce. In the long run, however, innovations in steam technology and railroad engineering were destined to render many canals the losers in a New competitive age in transport that took shape in the late 1840s and the 1850s.

The Erie Canal

The great breakthrough came in 1817 with New York State's commitment to building the Erie Canal to connect the Hudson River at Albany with Buffalo on Lake Erie, a


project far greater than any previously attempted in America. The Erie was important to subsequent canal development in several ways, most notably because it provided a model of public enterprise through its financing, administration, and implementation. The state raised capital through bond issues both in New York and in Europe, and supplemented these funds with tax revenues. Actual construction was overseen by a board of commissioners, some of whom were personally involved in the fieldwork, but the project became a celebrated "school for engineers," with most of the junior personnel learning their skills on the job under the tutelage of Benjamin Wright and James Geddes, two of less than twenty men who then constituted the profession in America. Many of the Erie engineers went on to direct canal surveys in other states.

The canal was divided into sections for purpose of construction, with private contractors taking on the work under the state engineers' supervision—a scheme that was emulated by nearly all the major canals subsequently built. It was an immediate commercial success once opened to its full length in 1825, leading the New York legislature to authorize a series of additional canals as well as the improvement and enlargement of the original line.

No nonmilitary enterprise in the United States had ever involved such expenditures as did the Erie, whose initial construction cost $6 million. The number of laborers employed was also unprecedented in any economic enterprise of the day. The state's construction expenditures energized local economies, giving part-time employment to farmers and creating sudden demand for stone, timber, mules, and oxen, and provisions for workers. Like canals and other public works throughout the country, moreover, the Erie attracted immigrant workers (mainly Irish and German) who were employed to do much of the most dangerous work.

The Erie's commercial impact on the rural countryside and on New York City's role as a center for trade with the interior and for exports to Europe—together with the rich stream of revenues from the tolls—heightened expectations everywhere in the country that other canals could produce equally spectacular fiscal and developmental results.

The Post-1825 Boom in Canal Building

Emulation of New York followed quickly. In 1825 Pennsylvania authorized a $10 million project, combining canal technology with the use of inclined planes. It was completed in 1834, tapping the Ohio Valley's farm country at Pittsburgh and giving Philadelphia trade advantages similar to those that its rival New York City had obtained from the Erie. The first of the western states to build a major line was Ohio, which authorized construction in 1825. Although still small in population and financial resources, Ohio, too, resorted to creation of a state enterprise and borrowed heavily both in the East and in Europe. Erie Canal engineers were brought in at first, but Alfred Kelley of Cleveland and Micajah Williams of Cincinnati,


local entrepreneurs with no prior engineering experience, took principal charge of overseeing construction once the technical plans were adopted. Although administrative incompetence and corruption plagued the Pennsylvania project, Ohio's record was widely admired for its efficiency and strength of design. One line, the Ohio Canal, was completed in 1834 and extended from Cleveland on Lake Erie to Portsmouth on the Ohio River—the first water link between the Great Lakes and the great Mississippi-Ohio basin. A second line, completed in the mid-1840s, linked Cincinnati with Toledo to the north.

Other important lines begun or fully built prior to 1840 included the Delaware and Hudson Canal, a successful private line in the Pennsylvania coal country; the Delaware and Raritan Canal, also private, linking Philadelphia and New York; and the Chesapeake and Delaware Ohio Canal, which with substantial state support built a line, surveyed by the engineer William Strickland, through Maryland to link Baltimore with the Philadelphia port.

In the period 1815–1834, $60 million was invested in 2,088 miles of canals, with 70 percent of the funds coming from governmental sources, mainly the states. Most of the funds were borrowed at home and abroad. Also, Congress authorized the Army Engineers to conduct surveys for the states and federal companies; made some direct federal investments; and gave several million acres of public lands to Ohio, Indiana, and Illinois to subsidize their canal projects during this period.

In the decade following, 1834–1844, the "canal enthusiasm" continued to animate state governments and private promoters. Rivalries among states and competition among cities were intense, feeding the spirit of optimism. A new wave of canal construction followed, with the projects again heavily financed by loans from Europe and the eastern cities. Almost 1,300 miles of canal were built during this ten-year period. They cost $72 million, of which 79 percent represented public funds. In addition to major New state canal systems begun in Illinois and in Indiana (where the Wabash and Erie line would open another link for direct trade between the Ohio River and Lake Erie), and in Illinois, three of the pioneering state projects—the Erie, Ohio's two main canals, and the Pennsylvania system—were further expanded to satisfy sections of their states that had been left out of the original system designs. As the New canals were generally of larger dimensions than the first ones to be built, the carrying capacity for canal traffic doubled between 1834 and 1844. Until 1839, conditions of prosperity and expansion sustained the canal-building movement, and expenditures for the New canals stimulated overall economic growth.

Financial Problems and Railroad Competition

The 1837 financial panic and the 1839–1843 depression created enormous fiscal problems for many canal states, leading to defaults on state debts in Pennsylvania and Indiana. Because many of the expansion projects and new lines produced toll revenues far below expectations, moreover, there was widespread disillusionment with state enterprise; and this became a factor favoring railroads as an alternative to canals, especially given the much greater reliability of rail transport. In the Ohio-Indiana-Illinois area, by 1848 the proliferation of canal lines also produced intensified competition between the various Great Lakes and Mississippi River routes, now also served by steamboat lines on these connecting waters. The east-west and local railroads of the 1850s made matters worse. The result was heavy downward pressure on canal rates, consequently reduced revenues, and, soon, a scenario of operating deficits that placed an unwelcome burden on taxpayers.

Transport competition drove down rates so much that the period from the mid-1840s to the Civil War formed a distinctive "second phase" of the Transportation Revolution. By 1850–1852, for example, western canal tolls were less than a third the level of the 1830s, creating still further fiscal problems for the canal states and companies. Where private investment had been invited on a matching basis for "mixed" canal enterprises, the costs fell hard on the capitalists as well. But while revenues fell, ton-miles of canal transportation continued to expand on all the major lines throughout the 1850s.

During the period 1844–1860, a last major cycle of canal construction produced 894 miles of line at a cost of $57 million. Here again, governmental activism was crucial, with public funds accounting for two-thirds of the total expended. Much of this increase constituted the completion or improvement of lines built earlier; in addition, the still-successful Erie system in New York was further enlarged and upgraded. A large expenditure was made, too, on the Sault Ste. Marie Ship Canal, a short but massive deepwater project that connected Lake Huron with Lake Superior.

Although much of the canal system experienced operating deficits in the 1850s, the impetus these New facilities had given the economy had clearly warranted most of the capital invested. Commercialization of agriculture in the western states and other interior had been made possible, while eastern manufacturers and importers were afforded economical access to interior markets. Coal-mining and iron centers were linked, and consumer prices fell where the transport facilities had proliferated. In sum, the areas served by canals were enabled to build on comparative economic advantage; and, at least in the northern states, processing of primary products carried by the canals served as the origin of manufacturing growth that augmented urban commercial activity.

Railroad competition led to many closings of once-important canals; indeed, more than 300 miles of line were abandoned by 1860. A few of the canals did continue to carry heavy traffic after the Civil War. The most important to commerce in the twentieth century was the Atlantic intra-coastal waterway, which permitted vessels to transit offshore waters safely from New England to Florida. The Erie retained importance as a barge canal, as did some of the shorter coal-carrying lines. Some of the old canal lines became rights-of-way for railroads or modern roads; others were absorbed into the changing landscape as development went forward. In scattered locations, a few segments of the great canal lines are today preserved or restored for enjoyment of citizens seeking a glimpse of the once-glorious era of canal transport in America.

BIBLIOGRAPHY

Fishlow, Albert. "Internal Transportation in the Nineteenth and Early Twentieth Centuries." In The Cambridge Economic History of the United States. Edited by Stanley L. Engerman and Robert E. Gallman. Volume 2. New York: Cambridge University Press, 2000.

Goodrich, Carter. Government Promotion of American Canals and Railroads, 1800–1890. New York: Columbia University Press, 1960. Reprint, Westport, Conn.: Greenwood Press, 1974.

Goodrich, Carter, ed. Canals and American Economic Development. New York: Columbia University Press, 1961.

Gray, Ralph D. The National Waterway: A History of the Chesapeake and Delaware Canal, 1769–1965. 2d ed. Urbana: University of Illinois Press, 1989. The original edition was published in 1967.

Larson, John Lauritz. Internal Improvement: National Public Works and the Promise of Popular Government in the Early United States. Chapel Hill: University of North Carolina Press, 2001.

Scheiber, Harry N. Ohio Canal Era: A Case Study of Government and the Economy, 1820–1861. 2d ed. Athens: Ohio University Press, 1987. The original edition was published in 1969.

Shaw, Ronald E. Canals for a Nation: The Canal Era in the United States, 1790–1860. Lexington: University of Kentucky Press, 1990.

Taylor, George Rogers. The Transportation Revolution, 1815– 1860. New York: Rinehart, 1951. Reprint, Armonk, N.Y.: M. E. Sharpe, 1989.

Harry N.Scheiber

See alsoErie Canal ; Illinois and Michigan Canal ; Nicaraguan Canal Project ; Panama Canal .

Canals

views updated May 08 2018

Canals

Human societies have long worked on changing nature's waterways for their purposes. Canals are artificial waterways constructed for irrigation , drainage, river overflows, water supplies, communications, and navigation, or in connection with power generation from hydroelectric dams. The digging of canals for irrigation probably dates to the beginnings of agriculture, with traces of canals found within ancient Chinese, Egyptian, and Babylonian civilizations. Written evidence shows that the Suez Canal, for instance, was excavated prior to 2000 b.c.e. It was documented to be navigable for small vessels by 600 b.c.e. and remained in operation for fourteen centuries as a convenient trade route between the Mediterranean and Red Seas. One of the world's longest canals, the Grand Canal of China, was constructed primarily during the seventh and thirteenth centuries. The 1,900-kilometer (1,200-mile) canal connected the cities of Beijing and Hangzhou, and is often considered the most notable of the early canals.

Pre-Industrial Canal Era

The regions that built canals during the pre-industrial era were those possessing fairly level landscapes, like Mesopotamia (around Iraq and Iran), Egypt, and China, or where channels were branches of the sea, like in the Netherlands. This pattern occurred because the practice of building locks had not yet been invented. Nevertheless, these waterways were not constructed on one continuous level. Evidence shows that the early Egyptian and Chinese canals were adapted to the differing land contours, often using an inclined plane for transferring boats to successive levels. Even today, China uses similar methods on its extensive canal system.

Locks Era

The introduction of locks throughout Europeprimarily for economic, political, and military gainsbetween the fifteenth and seventeenth centuries spurred rapid canal-building. France was the first to build extensive systems. The greatest work of that period was the Languedoc Canal, connecting the Bay of Biscay with the Mediterranean Sea. The canal, completed in 1681, was an enormous undertaking with its length of 240 kilometers (148 miles), rise of 183 meters (600 feet) above the sea, numerous locks and aqueducts , tunnel of more than 213 meters (700 feet), and capacity for floating gigantic barges.

Industrial Revolution Era

Gangs of laborers (called "navvies" or "navigators") first constructed British canals to provide artificial waterways for more efficient transportation of goods and materials during the Industrial Revolution of the eighteenth century. Canals served to open up countries to the Industrial Revolution, just as the Internet is opening up the world to the Information Revolution. Waterways afforded a cheap means of transportation, one that could bring input materials to production centers and then take finished products away for mass marketing. Thus, canals played a role in aiding the movement of populations to production centers.

British Isles.

Canal building in Ireland, Scotland, and England flourished in the late eighteenth and early nineteenth centuries. Three of the most notable canals were the Grand Canal in Ireland, the Caledonian Canal in Scotland, and the Manchester Ship Canal in England. The Grand Canal was begun in 1756 for trade and passenger transportation, and extended 134 kilometers (83 miles) between Dublin and Shannon Harbor. The Caledonian Canal was completed in 1847 as a 97-kilometer (60-mile) waterway from Inverness to Fort William, to provide a safe route for naval ships during the Napoleonic wars. The Manchester Ship Canal, which was completed in 1894, opened Manchester Port to oceangoing vessels, and contributed to the thriving industrial English economy.

European Mainland.

Belgium, France, Holland, and Germany became the first countries in Europe to develop inland waterway systems by using canals to connect water bodies. For example, the German Kiel Canal was completed in 1895 as the shortest link between the North Sea and the Baltic. Today these countries possess an integrated waterway network such as the Midland Canal, a series of German canals that facilitates eastwest transportation of raw materials and manufactured goods.

North America.

In 1730, a small excavation was cut across a narrow piece of land in a bend of the Mohawk River near present-day Utica, New York. It is commonly believed that this canal was the first artificial waterway to be created in the United States, and today it symbolizes the beginning of the U.S. canal era.

The first U.S. navigation canal was built in 1793 around the rapids of the Connecticut River at South Hadley, Massachusetts. Two levels that were connected by a water-filled incline transported boats by dragging them with cables operated by waterpower. The construction of the Erie Canal, started in 1817, was largely responsible for opening the American Midwest to settlement. More than 7,250 kilometers (4,500 miles) of water routes, mostly in the middle Atlantic and central states, were created from the seaboard to the inland lakes to help expand a fledging country.

Navigation Canals

Large canals are primarily built for navigation. Navigation canals were developed after irrigation canals, and for a long time were level, shallow depressions, or had inclined planes in which vessels were hauled between levels. Over the years, such canals have been expanded in width and depth in order to accommodate larger boats, and they have, in some cases, been constructed to form bridges or to pass through tunnels to overcome mountains. Canals were built larger and larger so that water transport could better compete with railway transportation.

Navigation canals usually are classified as either ship canals, which are deep enough to accommodate oceangoing ships, or barge canals, which are shallow and for use mainly by barges.

Barge Canals.

On most large, shallow canals, barges are pushed or pulled by tugboats and towboats. Modern barges are designed to carry specific types of cargo: (1) open-hopper barges carry gravel, coal, and large equipment;(2) covered dry-cargo barges carry dry chemicals, grain, and other commodities that must be kept dry; and (3) tank barges carry liquid and petroleum chemicals.

Ship Canals.

Some ship canals, such as the Suez and Panama Canals, provide navigational shortcuts by connecting large water bodies. The 64-kilometer (40-mile) long Panama Canal, which goes across the Isthmus of Panama in Central America, allows vessels to travel between the Pacific and Atlantic oceans, avoiding the long voyage around South America. At the time it was constructed, it was estimated that this trip around took approximately 5 to 6 months; the canal reduced the length of the trip to as many weeks.

Other ship canals, such as the Houston Ship Channel (in Texas) and the Manchester Ship Canal (in northwestern England), connect an inland harbor to the ocean. These canals play an important role in the nation's waterborne transportation system.

Construction

Major canals are usually constructed as open-cut excavations with the use of construction tools and machinery. The cuts are often built with masonry to prevent bank erosion. Unlike roads and railways, canals cannot be made to conform to terrain irregularities, but must consist of one or more level stretches. Where different levels meet, vessels are transferred from one stretch to the next by locks. When a boat enters a lock and all gates are secured, the downstream gates open and water flows in. When the level is equal on either side of the downstream gate, water stops flowing, the downstream gate then opens, and the boat continues onto the new water level.

Canalization of Rivers.

In the early years of canal building, when important rivers were found to be not navigable at certain points, side canals running parallel to the river were built so that vessels could bypass that section and reenter it at a more suitable point. With the invention of power machinery, this practice has generally been discarded in favor of canalization of the river itself; that is, a river is dredged at shallow regions and provided with dams and locks that control the river's level.

In the United States, for example, construction of 40 locks and dams on the Ohio River was completed in 1929; and later modernized with 18 highlift locks in 1981. Canalization of the upper Mississippi River from Minneapolis, Minnesota to Alton, Illinois (just above St. Louis, Missouri), was completed in 1940.

In 1954, the U.S. Congress authorized the federal government to join with Canada in the construction of the St. Lawrence Seaway. The United States built two canals, three locks, and various other improvements along the St. Lawrence River from Montreal, Quebec to Ogdensburg, New York.

The Canadian canal system includes the St. Lawrence River canals, the Ottawa River canals, the Chambly Canal, the Rideau Canal, and the Trent Canal (part of the TrentSevern Waterway). Of these, the St. Lawrence system has long been the most important, because it provides a waterway 4.3 meters (14 feet) deep from the head of Lake Superior to the Gulf of St. Lawrence. As part of the project, completed in 1959, the waterway was deepened to 8.2 meters (27 feet) to permit large oceangoing vessels to sail from the Atlantic Ocean to such ports as Chicago, Illinois, and Duluth, Minnesota. The 3,700-kilometer (2,340-mile) Great LakesSt. Lawrence Seaway system is the world's longest deep-draft inland waterway, extending from the Atlantic Ocean to Duluth, Minnesota on Lake Superior.

see also Army Corps of Engineers, U.S.; Leonardo Da Vinci; Navigation at Sea, History of; Transportation.

William Arthur Atkins

Bibliography

Hadfield, Charles, ed. World Canals. Newton Abbot, U.K.: David & Charles, 1986.

Shaw, Ronald E. Canals for a Nation. Lexington: University of Kentucky Press, 1990.

Internet Resources

Make the Dirt Fly! The Building of the Panama Canal. Smithsonian Institution Libraries Online Exhibit. <http://www.sil.si.edu/Exhibitions/Make-the-Dirt-Fly>.

WHO OWNS THE PANAMA CANAL?

The Panama Canal, which crosses the central part of Panama in Central America, was built by the United States from 1904 to 1914. Under a 1903 treaty, the United States controlled as a U.S. territory both the waterway and a 16kilometer (10-mile) swath across the isthmus known as the Panama Canal Zone.

During most of the twentieth century, the Panamanians resented this arrangement, arguing that their country was unjustly denied canal benefits. Eventually, riots and global pressures led the United States in 1979, under then-president Jimmy Carter, to recognize Panama's eventual ownership of the canal and all the surrounding lands.

Former president Carter and Panamanian president Mireya Moscoso signed documents in December 14, 1999, giving Panama full control of the Panama Canal. The actual transfer to Panama occurred on December 31, along with complete control of canal operations and full possession of the Panama Canal Zone.

Canal

views updated May 17 2018

Canal

History

Construction and operation

Resources

A canal is a human-made waterway or channel that is built for navigation, irrigation, drainage, or water supply.

There are two major types of transportation canals. One is an inland waterway, or water route, that either follows the lay of the land or has locks, for example the long-abandoned Erie Canal in the eastern United States. The other is a canal that is built to shorten a sea route, for example the Suez Canal, which connects the Mediterranean and Red Seas, and the Panama Canal, which connects the Atlantic and Pacific Oceans across the Isthmus of Panama.

Canals can be among the most complicated engineering projects of their times. A canal across the Isthmus of Panama, for example, was first envisioned by Spanish explorers in 1513. The French began construction of a canal across the isthmus in 1880, but abandoned work in 1889. Excavation of the canal was resumed by the United States in 1904, and the Panama Canal finally opened in 1914. As many as 40,000 workers were employed at different times during the construction of the Panama Canal, which required the construction of towns to house workers, railroads to move supplies and large amounts of excavated soil and rock, and the invention of new kinds of construction equipment. Perhaps the most prominent engineering accomplishment during construction of the Panama Canal was the Culebra Cut, a 8.75-mi (14 km) excavation across the continental divide that was plagued by landslides. The total amount of soil and rock excavated along the Culebra Cut was estimated to have been about 100,000,000 cubic yards (76,500,000 cubic meters), or the equivalent of more than 8 million large dump truck loads. Monitoring of persistent landslides along the Culebra Cut persists to this day.

Many long-abandoned inland canals in the United States, British Isles, and Europe are currently the focus of restoration projects. This work, often undertaken by volunteer groups, is being undertaken to repair the effects of neglect, educate the public about the historical significance of canals, and provide new recreational opportunities.

History

The earliest canals were built by Middle Eastern civilizations primarily to provide water for drinking and for irrigation. In 510 BC Darius I, King of Persia, ordered the building of a canal that linked the Nile River to the Red Sea; this canal was a forerunner of the modern Suez Canal. The Chinese were perhaps the greatest canal builders of the ancient world, having linked their major rivers with a series of canals dating back to the third century BC. Their most impressive project was the Grand Canal, the first section of which opened around AD 610. With a total length of 1,114 mi (1,795 km), it is the longest canal in the world. Canals were used by the Romans, but were neglected for the centuries after the fall of the Roman Empire. The commercial expansion of the twelfth century spurred the revival of canals, and it is estimated that as much as 85% of the transport in medieval Europe was by canal.

Many early canals were called contour canals because they followed the lay of the land and simply went around anything in their way. Major changes in ground and water levels have always presented canal builders with their greatest engineering challenge. At first, boats were towed or dragged over slipways to the next level. The invention of the modern lock in China solved this problem and allowed more ambitious canal building projects. The modern two-gate lock evolved from the slow and unsafe Chinese flash lock, which that had only one gate. The flash lock eventually made its way to Renaissance Europe, where it was modified with a second gate. The development of the lock heralded a period of extensive canal construction across Europe, and it is not surprising that each nation responded in its own particular way. The Naviglio Grande Canale in Italy (11791209) and the Stecknitz Canal in Germany (13911398) are two that made important contributions to waterway technology. Also in China, a 684 mi (1,100 km) branch of the Grand Canal was finished in 1293. Over the next few centuries, France built the pioneering Briare Canal (completed in 1642) and the famous Canal du Midi (1681), which joined the Mediterranean and the Atlantic and would serve the world as an example of complex civil engineering at its best. This remarkable French canal stimulated an era of British canal construction that began with the completion of the Bridgewater Canal (1761). In Germany, the Friedrich Wilhelm Summit Canal was completed in 1669, and in other nations, extensive waterway systems were developed. With industrial production steadily growing in the nineteenth century, transport by canal became essential to the movement of raw materials and goods throughout Europe. The need to predict the kinds of rocks encountered during canal construction led the British engineer William Smith to create the worlds first geologic map.

The United States has a shorter tradition of canal building. Its first major canal was the Erie Canal, constructed during the beginning of the nineteenth century. Completed in 1824, the 364 mi (586 km) canal provided a water route that brought grain from the Great Lakes region to New York and the markets of the East. With the construction of railroads in the

KEY TERMS

Contour canal Usually early canals that followed the meandering natural contours of the land.

Flash lock A simple wooden gate that was placed across a moving body of water to hold it back until it had become deep; the sudden withdrawal of the gate would cause a flash of water that would carry a boat downstream and over the shallows below.

Inland waterway An artificial waterway or channel that is cut through land to carry water and is used for transportation.

Lock A compartment in a canal separated from the main stream by watertight gates at each end; as water fills or drains it, boats are raised or lowered from one water level to another.

Slipway An inclined path or road leading into a body of water over which, in ancient times, boats were dragged or rolled from one body of water to another.

1830s, the United States quickly abandoned its canals in the belief that rail would be the best method for every transport task. The Europeans did not react the same way to railroads, maintaining their canal systems as a complementary system not in competition with railroads. Today, inland waterways or canals play a major transportation role in the United States and the rest of the world, for it has been realized that canals are perfectly suited for carrying low-value and high-bulk cargoes over long distances.

Sea canals, the great canals that shorten sea routes, are glamorous and highly visible engineering achievements. Three well-known examples are the Kiel Canal connecting the North and Baltic Seas (1895), the Suez Canal linking the Mediterranean and Red Seas (1869), and the Panama Canal between the Atlantic and Pacific Oceans (1914). Sea-to-sea ship canals face the problem of obsolescence: some new ships are too large for old canals. Both the Kiel and the Suez canals have been enlarged, but the Panama Canal is not large enough to accommodate the worlds largest ships.

Construction and operation

Engineers designing a canal must take several things into consideration. They must formulate the dimensions of the canal to accommodate the numbers and sizes of ships that are predicted to use the waterway. Natural obstacles in the path of the canal, such as bedrock outcrops, must also be modified, removed, or avoided. There must be adequate vertical clearance above the canal and the clearance afforded by preexisting bridges must be able to accommodate the vessels that will use the canal. Finally, engineers must decide the scale and location of associated structures, such as bridges, tunnels, and locks.

The paths of most canals are affected by variations in the levels of terrain. Engineers compensate for these variations with either locks or inclined planes. A lock is a segment of the waterway that is closed off by gates at either end. When a vessel enters the lock, the front gate is already closed. The back gate is then closed behind the vessel, and the water level within the lock is raised or lowered to the level of the water on the outside of the front gate. Valves on the gates control the level of the water. Whereas locks are the most common means of compensating for elevation changes, the procedure is slow and uses a large amount of water. Inclined planes can be used to elevate and lower smaller vessels; they use no water and often allow more rapid passage of vessels. When vessels reach certain stations along the waterway, they are pulled out of the water and moved on trucks up or down the plane.

Canal operators must monitor the canals supply of water. If the natural supply of water at the upper end of the canal is deficient, it must be supplemented by water pumped into the reservoirs. If nature supplies the reservoir with excess amounts of water, some of the water must be diverted from the canal. Otherwise, excess water may strengthen the current and disrupt canal operations.

Resources

BOOKS

McCullough, David. The Path Between the Seas: The Creation of the Panama Canal 1870-1914. New York: Simon & Schuster, 2004.

Bernstein, Peter L. Wedding of the Waters: The Erie Canal and the Making of a Great Nation. New York: W.W. Norton, 2006.

Leonard C. Bruno

Canal

views updated May 09 2018

Canal

A canal is a man-made waterway or channel that is built for navigation, irrigation , drainage, or water supply. When the word is used today however, it is usually in the context of transport or navigation by boats. Canal transport should not be confused with navigating on a river, because a canal is entirely artificial (although canals are in many cases connected with a natural body of water).

There are two major types of transport canals. One is an inland waterway, or water route, that either follows the lay of the land or has locks. The other is a canal that is built to shorten a sea route. Examples of the latter are the Suez Canal, which connects the Mediterranean and the Red Sea, and the Panama Canal, which shortens the voyage from Europe to America's west coast by 3,000 m (4,800 km). From the earliest times, canals were built because they were the simplest and cheapest way of moving heavy goods.

Canals can be among the most complicated engineering projects of their times. A canal across the Isthmus of Panama, for example, was first envisioned by Spanish explorers in 1513. The French began construction of a canal across the isthmus in 1880, but abandoned work in 1889. Excavation of the canal was resumed by the United States in 1904 and the Panama Canal finally opened in 1914. As many as 40,000 workers were employed at various times during the construction of the Panama Canal, which required the construction of towns to house workers, railroads to move supplies and enormous amounts of excavated soil and rock, and the invention of new kinds of construction equipment. Perhaps the most prominent engineering accomplishment during construction of the Panama Canal was the Culebra Cut, a 8.75-mi (14-km) excavation across the continental divide that was plagued by landslides. The total amount of soil and rock excavated along the Culebra Cut was estimated to have been about 100,000,000 cubic yards (76,500,000 cubic meters), or the equivalent of more than 8 million large dump truck loads. Monitoring of landslides along the Culebra Cut persists to this day.

Many long-abandoned inland canals in the United States, British Isles, and Europe are currently the focus of restoration projects. This work, often undertaken by volunteer groups, is being done to repair the effects of decades of neglect, educate the public about the historical significance of canals, and provide new recreational opportunities.


History

The earliest canals were built by Middle Eastern civilizations primarily to provide water for drinking and for irrigating crops . In 510 b.c. Darius I, King of Persia, ordered the building of a canal that linked the Nile River to the Red Sea; this canal was a forerunner of the modern Suez Canal. The Chinese were perhaps the greatest canal builders of the ancient world, having linked their major rivers with a series of canals dating back to the third century b.c. Their most impressive project was the famous Grand Canal, the first section of which opened around a.d. 610. With a total length of 1,114 ft (1,795 km), it is the longest canal in the world. Canals were employed by the highly practical Romans, but were neglected for the centuries after the fall of the Roman Empire. The commercial expansion of the twelfth century spurred the revival of canals, and it is estimated that as much as 85% of the transport in medieval Europe was by canal.

Many early canals were called contour canals because they followed the lay of the land and simply went around anything in their way. Major changes in ground and water levels have always presented canal builders with their greatest engineering problem; at first, boats were simply towed or dragged over slipways to the next level. The invention of the modern lock in China solved this problem at once, causing the full development of canals. The modern two-gate lock evolved from the slow and unsafe Chinese "flash lock" that had only one gate; the "flash lock" eventually made its way to Renaissance Europe, where it was modified with a second gate. The development of the lock heralded a period of extensive canal construction across Europe, and it is not surprising that each nation responded in its own particular way. The Naviglio Grande Canale in Italy (1179–1209) and the Stecknitz Canal in Germany (1391–1398) are two that made important contributions to waterway technology. Also in China, a 684 mi (1,100 km) branch of the Grand Canal was finished in 1293. Over the next few centuries, France built the pioneering Briare Canal (completed in 1642) and the famous Canal du Midi (1681), which joined the Mediterranean and the Atlantic and would serve the world as an example of complex civil engineering at its best. This remarkable French canal stimulated the era of British canal construction that began with the completion of the Bridgewater Canal (1761). In Germany, the Friedrich Wilhelm Summit Canal was completed in 1669, and in other nations, extensive waterway systems were developed. With industrial production steadily growing in the nineteenth century, transport by canal became essential to the movement of raw materials and goods throughout Europe.

The United States has a shorter tradition of canal building. Its first major canal was the Erie Canal, constructed during the beginning of the nineteenth century. Completed in 1824, the 364-mi (586 km) canal provided a water route that brought grain from the Great Lakes region to New York and the markets of the East. With the construction of railroads in the 1830s, the U.S. quickly abandoned its canals in the belief that rail would be the best method for every transport task. The Europeans did not react the same way to railroads, maintaining their canal systems as a complementary system not in competition with railroads. Today, inland waterways or canals play a major transportation role in the United States and the rest of the world, for it has been realized that canals are perfectly suited for carrying low-value and high-bulk cargoes over long distances.

Sea canals, the great canals that shorten sea routes, are glamorous and highly visible engineering achievements. Three well-known examples are the Kiel Canal connecting the North and Baltic Seas (1895), the Suez Canal linking the Mediterranean and Red Seas (1869), and the Panama Canal between the Atlantic and Pacific Oceans (1914). Sea-to-sea ship canals face the problem of obsolescence: some new ships are too large for old canals. Both the Kiel and the Suez canals have been enlarged, but the Panama canal is not large enough to accommodate the world's largest ships.


Construction and operation

Engineers who are designing a canal must take several things into consideration. They must formulate the dimensions of the canal to accommodate the numbers and sizes of ships that are predicted to use the waterway. Natural obstacles in the path of the canal, such as rock formations, must also be modified, removed, or avoided. There must be adequate vertical clearance above the canal and the clearance afforded by pre-existing bridges must be able to accommodate the vessels that will use the canal. Finally, engineers must decide the scale and location of associated structures, such as bridges, tunnels, and locks.

The paths of most canals are affected by variations in the levels of terrain. Engineers compensate for these variations with either locks or inclined planes. A lock is a segment of the waterway that is closed off by gates at either end. When a vessel enters the lock, the front gate is already closed. The back gate is then closed behind the vessel, and the water level within the lock is raised or lowered to the level of the water on the outside of the front gate. Valves on the gates control the level of the water. Whereas locks are the most common means of compensating for elevation changes, the procedure is slow and uses a large amount of water. Inclined planes can be used to elevate and lower smaller vessels; they use no water and often allow more rapid passage of vessels. When vessels reach certain stations along the waterway, they are pulled out of the water and moved on trucks up or down the plane .

Canal operators must monitor the canal's supply of water. If the natural supply of water at the upper end of the canal is deficient, it must be supplemented by water pumped into the reservoirs. If nature supplies the reservoir with excess amounts of water, some of the water must be diverted from the canal. Otherwise, excess water may strengthen the current and disrupt canal operations.

Although canals are among the oldest civil works, they play a major role in commerce because they are by far the least expensive form of inland transportation yet devised.


Resources

books

Hadfield, Charles. World Canals: Inland Navigation Past andPresent. New York: Facts On File, 1986.

Payne, P. S. Robert. The Canal Builders: The Story of Canal Engineers Through the Ages. New York: Macmillan Co., 1959.

Spangenburg, Ray, and Diane K. Moser. The Story of America's Canals. New York: Facts On File, 1992.


other

Panama Canal Authority. The Panama Canal. (October 17, 2002). <www.pancanal.com/eng/index.html>.

Leonard C. Bruno

KEY TERMS

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contour canal

—Usually early canals that followed the meandering natural contours of the earth.

Flash lock

—A simple wooden gate that was placed across a moving body of water to hold it back until it had become deep; the sudden withdrawal of the gate would cause a "flash" of water that would carry a boat downstream and over the shallows below.

Inland waterway

—An artificial waterway or channel that is cut through land to carry water and is used for transportation.

Lock

—A compartment in a canal separated from the main stream by watertight gates at each end; as water fills or drains it, boats are raised or lowered from one water level to another.

Slipway

—An inclined path or road leading into a body of water over which, in ancient times, boats were dragged or rolled from one body of water to another.

Canals

views updated Jun 27 2018

Canals

Sources

Canal Fever. Even before its completion in 1825 the Erie Canal was making money for its owner, the state of New York. This made state governments all over the nation take notice. Excitement over the Erie prompted several Eastern states to start canal projects in the 1820s, but it was in the new states between the Appalachians and the Mississippi that canal fever took particularly virulent form. Between 1810 and 1840 canal mileage in the United States increased from 100 to over 3, 300 miles, a building boom paralleled only by the rapidity of railroad construction in the following decades and the building of the interstate highway system in the 1950s and 1960s.

Need. Before the canals some Western farmers and storekeepers made annual trips to the Eastern cities to sell their produce and cattle or to stock up on dry goods for the coming year. Traveling in caravans over the mountains along the National Road bound for Baltimore and Philadelphia, their transportation costs ate up a large percentage of their revenue. By the 1830s flatboats and steamboats had alleviated some of these problems by carrying an ever-widening stream of grain and meat from cities such as Cincinnati downriver to New Orleans and beyond. Still, legislators in the Old Northwest concluded that a significant profit might be made if riverborne commerce could be supplemented by a network of canals linking every area of the region with Lake Erie and the Erie Canal. Moreover, canals would help speed the immigration of new settlers into the still lightly populated Northern prairie areas of Ohio, Indiana, and Illinois. Thus, in 1825 the Ohio legislature authorized a canal construction program, and by 1833 a 308-mile canal did indeed join the Lake Erie port of Cleveland with Portsmouth on the Ohio while feeder channels with connections to navigable rivers touched almost every major region of the state. Like the Erie Canal, the Ohio system was initially a great success. Ohios experience was so favorable that it prompted Indiana and Illinois to launch their own state building programs, with nearly disastrous results.

Wabash and Erie Canal. Canals seemed like a good idea to Hoosiers who looked at the success of the Erie Canal and the Ohio system. In 1836, in the midst of economic boom times, the Indiana legislature enthusiastically adopted the Mammoth Internal Improvement Bill authorizing loans and state bonds to finance an ambitious program of canals, railroads, and turnpikes. Unfortunately, a year later the nation plunged into a deep economic depression, and by 1841 Indiana was near bankruptcy with a state debt of over $13 million, mostly attributable to the investment in internal improvements (by comparison, the state debt in 1827 had amounted to only $18, 700). Incompetence and corruption in canal finance and construction soured the state on the continued expense of internal improvements, and much of the ambitious 1836 plan was abandoned. Still, construction on the Wabash and Erie Canal continued slowly, reaching Terre Haute in 1849 and ending at Evansville on the Ohio in 1853. Upon completion the Wabash and Erie,

with its 450-mile network, became the longest canal in the United States, but within two decades railroad competition made the system obsolete. The Wabash and Erie helped promote settlement in northern Indiana, but its total receipts of $5.5 million never even matched its cost, which exceeded $8 million.

Traveling. Canals were built primarily for the shipment of commodities and dry goods, but somewhat to their owners surprise they quickly became popular passenger routes as well, prompting canal companies to build new accommodations for the traveling public. Canal passenger service came in two classes: the cheaper regular or line boats (which carried freight as well) and the more-elegant luxury or packet boats. Packets were brightly decorated and averaged about three and one-half miles per hour (forty to fifty miles a day) as opposed to the two or two and one-half common in the line boats. Both were pulled by horses, mules, or oxen walking along the towpath by the side of the canal. The standard passenger canal boat was fifty to sixty feet long (short enough to fit into the locks along the way) and was divided into four or five cabins: a small forward space for the six crew members, a ladies cabin and room also forward, the cooks quarters, and a larger middle or rear cabin that served as a sleeping parlor for the men and a dining room for all. Passengers slept on bunks or narrow shelves fitted to the walls. When the boats were overcrowded, which was often, passengers slept on the floors, tables, and anywhere else they could find room. Such accommodations were not always secure, as one Swedish traveler found in the 1830s when another craft coming too close to ours, scraped his canal boat and precipitated about a dozen sleeping individuals from the second and third tier onto the unfortunate beings who were lying on the floor. Traveling on these placid watercourses bored many passengers and led as well to attacks by mosquitoes, as one young woman en route across Indiana in 1851 found out when her hot and stuffy little room filled one evening with all the mosquitos ever hatched in the mud puddles of Indiana. When canal passenger service gave way to the greater speed and excitement of steamboat and railroad service, few mourned its passing.

Decline. Canals were expensive. The average turnpike in early national America cost $5, 000 to $10, 000 per mile to build, whereas canal construction averaged about $20, 000 to $30, 000 per mile. They proved equally expensive to repair. Floods were a constant threat to canals, washing out retaining walls and filling in channels. Furthermore, canals were most successful when used near capacity (maximizing toll revenues per mile) and when they could accommodate bulky and heavy loads that other carriers could not profitably handle, such as coal or lumber. But light usage in isolated areas, frequent locks, narrow channels, and of course winter freezes reduced the efficiency and profitability of canals. The reckless legislative authorization of large sums of public money for canal construction often led to cost overruns, political favoritism in the granting of contracts, and outright theft and mismanagement. All of these problems aside, it was the advent of the railroad that sounded the death knell for canals. Railroads were almost as expensive as canals to construct, but they were cheaper to repair and did not require huge supplies of water. Moreover, unlike canals, railroads could provide dependable all-weather transport for a full range of dry goods, not to mention people. Nonetheless, many canals did continue to compete successfully with railroads in the shipment of bulky commodities, even after the Civil War.

Sources

Harry N. Scheiber, Ohio Canal Era: A Case Study of Government and the Economy, 18201861 (Athens: Ohio University Press, 1969);

Ronald E. Shaw, Canals for a Nation: The Canal Era in the United States, 17901860 (Lexington: University Press of Kentucky, 1990);

George Rogers Taylor, The Transportation Revolution: 18151860, Economic History of the United States, volume 4 (New York: Holt, 1951).

Canal

views updated May 17 2018

Canal

A canal is a human-made waterway or channel that is built for transportation, irrigation, drainage, or water supply. Although canals are among the oldest works of civil engineering, they continue to play a major role in commerce, as they are the cheapest form of inland transportation yet devised.

The earliest canals were built by Middle Eastern civilizations primarily to provide water for drinking and for irrigating crops. The Nahrwan Canal, 185 miles (300 kilometers) long, was built around 2400 b.c. between the Tigris and Euphrates Rivers (in present-day Iraq). Egypt's ancient pharaohs linked the Mediterranean and Red Seas with a canal that the Romans later restored and used for shipping.

The Chinese were perhaps the greatest canal builders of the ancient world, having linked their major rivers with a series of canals dating back to the third century b.c. Their most impressive project was the famous Grand Canal, begun in the sixth century b.c. and completed in the thirteen century. Stretching for a total length of 1,000 miles (1,600 kilometers), the Grand Canal is the longest canal in the world.

Transportation

Canal systems for transportation were not widespread in Europe until the seventeenth and eighteenth centuries. The famous Canal du Midi in southern France allowed oceangoing ships to travel 150 miles (240 kilometers) from the Atlantic Ocean to the Mediterranean Sea. The completion of this canal in 1681 spurred the construction of transportation canals in England, Germany, and other European countries. With the onset of the Industrial Revolution in Europe in the eighteenth century, transport by canal soon became essential to the movement of raw materials and manufactured goods throughout Europe.

The first major canal in the United States was the Erie Canal. Completed in 1824, the 364-mile (586-kilometer) canal provided a water route that brought grain from the Great Lakes region to New York and the markets of the East. With the coming of the railroads in the 1830s, the United States quickly abandoned its canals, believing that rail was then the best method for shipping and transportation. Today, however, inland canals play a major transportation role in the United States and the rest of the world, since they are perfectly suited for carrying low-value, high-bulk cargoes over long distances.

Words to Know

Contour canal: Usually early canals that followed the meandering natural contours of the landscape.

Inland canal: An artificial waterway or channel that is cut through land to carry water and is used for transportation.

Lock: A compartment in a canal separated from the main stream by watertight gates at each end; as water fills or drains it, boats are raised or lowered from one water level to another.

Construction and operation

The paths of most canals are affected by variations in the landscape through which they pass. Very early canals followed the lay of the land, simply going around anything in their way. Because of this, they were called contour canals. These canals could not, however, connect two bodies of water that were at different heights. The invention of the lock system in China in the tenth century solved this engineering problem, opening the way for the full development of canals.

In the modern lock system, a segment of a canal is closed off by gates at either end. When a boat enters the lock, the front gate is already closed. The back gate is then closed behind the boat, and the water level

within the lock is raised or lowered to the level of the water on the outside of the front gate. Valves on the gates control the level of the water.

Sea canals, the great canals that shorten sea routes, are engineering achievements. Three outstanding examples are the Suez Canal linking the Mediterranean Sea and the Gulf of Suez (1869), the Kiel Canal connecting the North and Baltic Seas (1895), and the Panama Canal linking the Atlantic and Pacific Oceans (1914).

[See also Lock ]

canal

views updated Jun 11 2018

canal.
1. Channel, gutter, or pipe to convey any liquid, usually water.

2. Long, narrow, artificially created water-course for the ornamentation of a park, or for inland navigation.

3. Flute in the shaft of a column or pilaster.

4. Spiral channel (canalis) flanked by small convex mouldings from the eye following the revolutions of the volute, and carrying over to the other volute between the abacus and echinus of the Ionic capital.

Canals

views updated May 18 2018

CANALS

Artificial channels for the conveyance of water, used for navigation, transportation, drainage, or irrigation of land.

As a general rule, states supervise the construction and operation of canals by private canal companies. The site of the canal is selected by the state. State law determines the manner of acquiring property used for construction or maintenance of canals. Condemnation or appropriation and contract or grant are the usual methods of acquisition. Additional methods include accretion—the gradual accumulation of land by natural causes—and dedication—the gift of land to the government by its owner for public use.

The state has authority to supervise the construction of bridges over public canals. A city may build bridges over canals within its limits, but it cannot interfere with one constructed and managed by the state on its own property.

State law can confer the power to charge tolls for use of a canal. Rates can be neither discriminatory nor in excess of the amount authorized by law.

canal

views updated May 14 2018

ca·nal / kəˈnal/ • n. an artificial waterway constructed to allow the passage of boats or ships inland or to convey water for irrigation. ∎  a tubular duct in a plant or animal, serving to convey or contain food, liquid, or air: the ear canal. ∎  Astron. any of a number of linear markings formerly reported as seen by telescope on the planet Mars.

canal

views updated May 18 2018

canal Artificial waterway for irrigation, drainage, navigation or in conjunction with hydroelectric dams. Canals were built 4000 years ago in ancient Mesopotamia. Today, the longest canal able to accommodate large ships connects the Baltic and White Seas in n Europe and is 227km (141mi) long. The heyday of canal building in England was in the late 18th–early 19th century.