Canals, or navigations, are human-made channels, or artificial waterways, for water conveyance, or to service water transport vehicles. In most cases, the engineered works will have a series of dams and locks that create reservoirs of low speed current flow; these reservoirs are referred to as slack water levels just called levels. A canal is known as a navigation when it parallels a river and shares part of its waters and drainage basin, leverages its resources by building dams and locks to increase and lengthen its stretches of slack water levels while staying in its valley. In contrast, a canal cuts across a drainage divide atop a ridge requiring an external water source above the highest elevation. Many canals have been built at elevations towering over valleys and other water ways crossing far below. Canals with sources of water at a higher level can deliver water to a destination such as a city where water is needed; the Roman Empire's aqueducts were such water supply canals. A navigation is a series of channels that run parallel to the valley and stream bed of an unimproved river.
A navigation always shares the drainage basin of the river. A vessel uses the calm parts of the river itself as well as improvements, traversing the same changes in height. A true canal is a channel that cuts across a drainage divide, making a navigable channel connecting two different drainage basins. Most commercially important canals of the first half of the 19th century were a little of each, using rivers in long stretches, divide crossing canals in others; this is true for many canals still in use. Both navigations and canals use engineered structures to improve navigation: weirs and dams to raise river water levels to usable depths. Since they cut across drainage divides, canals are more difficult to construct and need additional improvements, like viaducts and aqueducts to bridge waters over streams and roads, ways to keep water in the channel. There are two broad types of canal: Waterways: canals and navigations used for carrying vessels transporting goods and people; these can be subdivided into two kinds:Those connecting existing lakes, other canals or seas and oceans.
Those connected in a city network: such as the Canal Grande and others of Venice Italy. Aqueducts: water supply canals that are used for the conveyance and delivery of potable water for human consumption, municipal uses, hydro power canals and agriculture irrigation. Canals were of immense importance to commerce and the development and vitality of a civilization. In 1855 the Lehigh Canal carried over 1.2 million tons of anthracite coal. The few canals still in operation in our modern age are a fraction of the numbers that once fueled and enabled economic growth, indeed were a prerequisite to further urbanization and industrialization – for the movement of bulk raw materials such as coal and ores are difficult and marginally affordable without water transport; such raw materials fueled the industrial developments and new metallurgy resulting of the spiral of increasing mechanization during 17th–20th century, leading to new research disciplines, new industries and economies of scale, raising the standard of living for any industrialized society.
The surviving canals, including most ship canals, today service bulk cargo and large ship transportation industries, whereas the once critical smaller inland waterways conceived and engineered as boat and barge canals have been supplanted and filled in, abandoned and left to deteriorate, or kept in service and staffed by state employees, where dams and locks are maintained for flood control or pleasure boating. Their replacement was gradual, beginning first in the United States in the mid-1850s where canal shipping was first augmented by began being replaced by using much faster, less geographically constrained & limited, cheaper to maintain railways. By the early 1880s, canals which had little ability to economically compete with rail transport, were off the map. In the next couple of decades, coal was diminished as the heating fuel of choice by oil, growth of coal shipments leveled off. After World War I when motor-trucks came into their own, the last small U. S. barge canals saw a steady decline in cargo ton-miles alongside many railways, the flexibility and steep slope climbing capability of lorries taking over cargo hauling as road networks were improved, which had the freedom to make deliveries well away from rail lined road beds or ditches in the dirt which couldn't operate in the winter.
Canals are built in one of three ways, or a combination of the three, depending on available water and available path: Human made streamsA canal can be created where no stream presently exists. Either the body of the canal is dug or the sides of the canal are created by making dykes or levees by piling dirt, concrete or other building materials; the finished shape of the canal as seen in cross section is known as the canal prism. The water for the canal must be provided like streams or reservoirs. Where the new waterway must change elevation engineering works like locks, lifts or elevators are constructed to raise and lower vessels. Examples include canals that connect valleys over a higher body of land, like Canal du Midi, Canal de Briare and the Panama Canal. A canal can be constructed by dredging a channel in the bottom of an existing lake; when the channel is complete, the lake is drained and the channel becom
The Briare Aqueduct carries the Canal latéral à la Loire over the River Loire on its journey to the River Seine in France. It replaced a river-level crossing from the canal to meet the Briare Canal, hazardous in times of flood. Between 1896 and 2003 it was the longest navigable aqueduct in the World until the opening of the Magdeburg Water Bridge, it is part of the Canal latéral à la Loire, not, as is believed, the Briare Canal. The Briare aqueduct near Châtillon-sur-Loire was, for a long time, the longest steel canal aqueduct in the world; the aqueduct is 662 metres long and lost its title of longest aqueduct to the Magdeburg Water Bridge which crosses the Elbe and is 918 metres long. The aqueduct was designed by the engineers Léonce-Abel Charles Sigault; the masonry abutments and piers were completed between 1890 and 1896 by Gustave Eiffel and the steel channel was completed by Daydé & Pillé of Creil. The aqueduct was inaugurated on 16 September 1896 with the crossing of the boat Aristide, belonging to Ernest Guingamp.
It allowed the development of transport to the Freycinet gauge between the Loire and Seine, is a registered historic monument in France. The aqueduct is built on fourteen piers; these piers support a single steel beam in turn supporting a steel channel which contains more than 13,000 tonnes of water, 2.2 meters deep and 6 metres wide allowing boats with a 1.8m draught to cross. The width of the aqueduct, towpaths included, is 11.5 meters and its length is 662.7 meters. There is a line of standard lamps on each side of aqueduct; each end is marked by two ornamental columns in imitation of the Pont Alexandre III in Paris. Eight sluices make it possible to empty the aqueduct in the event of severe freezing. Hadfield, Charles. World Canals. David & Charles. ISBN 0-7153-8555-0. McKnight, Hugh. Cruising French Waterways. Adlard Coles Nautical. ISBN 0-7136-6638-2; the French article from which this article was translated Coeur-de-france.com, in French Construction of the Briare Canal and the aqueduct, in French Briare Aqueduct/ Briare at Structurae Le canal Latéral à la Loire, in French
Huddersfield Narrow Canal
The Huddersfield Narrow Canal is an inland waterway in northern England. It runs just under 20 miles from Lock 1E at the rear of the University of Huddersfield campus, near Aspley Basin in Huddersfield, to the junction with the Ashton Canal at Whitelands Basin in Ashton-under-Lyne, it crosses the Pennines by means of the Standedge Tunnel. The canal was first proposed in 1793 at a meeting in the George Huddersfield, its engineer was Benjamin Outram on the recommendation of William Jessop. His plan was to start from the Huddersfield Broad Canal and follow the River Colne with a climb of 438 feet to its summit where it would pass through a tunnel at Standedge before descending through Saddleworth and the Tame valley to the Ashton Canal near Ashton-under-Lyne. There were many woollen and cotton mills along its route which promised ample trade. However, there was the possible problem of the loss of their water supplies and so Outram proposed to build a number of reservoirs. Construction began in 1794 with the marking out of the route.
The practice was to set up a line of pegs or stakes about 50 yards apart so that their tops would indicate the intended water level. It would be possible to construct the appropriate embankments and cuttings; as engineer, Outram provided an oversight of the work but he was occupied by other projects. Day-to-day management was carried out by contractors employed and organised by the canal company committee. Progress was erratic, it was unfortunate that Outram was ill for long periods between 1795 and 1797. The company was short of money because the costs had been underestimated but because shareholders were not honouring their pledges. In 1799, severe floods damaged earthworks along various reservoirs. In particular, overflow of the Tunnelend Reservoir devastated the village of Marsden. Two aqueducts were destroyed, diverting the company's already-stretched funds; the Stakes Aqueduct was in use and had to be replaced immediately. Outram had built it of stone and, due to its low height, it had needed to be constructed in four short spans.
The narrow openings had impeded the unprecedented overflow and Outram replaced it with a single span cast iron structure, similar to the Holmes Aqueduct on the Derby Canal. Outram set out to overcome the problems with the Holmes Aqueduct by making the walls thicker where they joined the baseplates which were thicker; however a major stress was the compressive force along the top of the wall plates where they bow outwards or inwards. In 1875 cross bracings were added to reinforce it; the Stakes Aqueduct is the oldest surviving aqueduct of its type, still in use for its original purpose. Although the canal uses 74 locks to climb and descend the Pennines, there would have had to be many more without the digging of a long tunnel through the Tame/Colne watershed; the canal tunnel is 5,700 yards long making it the longest canal tunnel in the United Kingdom. It is brick lined but in some places the tunnel has been left with a natural rock surface. In 1810, the Diggle Moss Reservoir gave way and Marsden was again flooded along with much of the Colne Valley.
Houses and factories were wrecked and five people lost their lives. The force of the water was such. Despite multiple problems, the building of the Huddersfield Narrow Canal showed that the technique of quantity surveying had advanced greatly. Thomas Telford's report during the construction of the Standedge Tunnel covered every expenditure to the last bucket; the canal operated for 140 years. Although it was moderately successful for a while, its width, the large number of locks and the long Standedge Tunnel made it much less profitable than its main rival the Rochdale Canal which had a similar number of locks but was twice as wide with no long tunnel. Standedge Tunnel proved to be a bottleneck having been constructed without a towpath. Narrowboats had to be'legged' through by professionally employed leggers. A company employee would chain the tunnel entrance behind a convoy of boats and walk over Boat Lane, accompanied by boat boys and girls leading the boat horses, to unchain the opposite end of the tunnel before the boat convoy arrived.
This journey was made at least twice per day for over twenty years. The construction of a double railway tunnel parallel to Standedge canal tunnel adversely affected canal revenues and the canal was abandoned in 1944. After 27 years of campaigning and restoration by the Huddersfield Canal Society, the canal was re-opened to navigation in 2001 when it again became one of three Pennine crossings, the others being the Rochdale and the Leeds and Liverpool; the canal is now used by leisure boaters. During the period of time when the canal was closed, several lengths were culverted and infilled and in some cases built over. Over the course of the restoration project, the vast majority of the obliterated line became available to be opened out again and the canal remains on a identical alignment with some minor alterations; the Huddersfield Narrow Canal connects with the Huddersfield Broad Canal at the eastern end of Lock 1E. Lock 1E is to the west of the A629 Wakefield Road and the canal had been filled in beneath the road.
A new bridge was built in 1985 but the width was only sufficient for narrowboats and so the 300 yards
Magdeburg Water Bridge
The Magdeburg Water Bridge is a large navigable aqueduct in central Germany, located near Magdeburg. The largest canal underbridge in Europe, it spans the river Elbe and directly connects the Mittellandkanal to the west and Elbe-Havel Canal to the east of the river, allowing large commercial ships to pass between the Rhineland and Berlin without having to descend into and climb out of the Elbe itself. Planning for the canal crossing dates back to at least the beginning of the 20th century. Work on the Mittellandkanal began in 1905, while work on the overall project continued until 1942, when all construction was brought to a halt because of World War II. After the war, the government of East Germany did not resume work on the project because east-west trade was no longer important in the context of the Cold War. After the reunification of Germany, the reestablishment of major water transport routes made the water bridge a priority again. Work started with construction taking six years and costing € 501 million.
The water bridge now connects Berlin’s inland harbour network with the ports along the Rhine River. The aqueduct's tough structure incorporates 24,000 tons of steel and 68,000 cubic meters of concrete; the bridge is featured in the motion picture Hanna, at 75 minutes into the film. It is featured in the film "Vitou the Kong" In addition to the bridge, a double lock was constructed to allow vessels to descend from the level of the bridge and Mittelland Canal to that of the Elbe-Havel Canal. Karl Jüngel, Das Wasserstraßenkreuz bei Magdeburg, Undated, ca. 2003 dw-world.de News Article Snopes Photo Gallery Google Maps view of bridge Magdeburg Canal Bridge at Structurae
The Agen Aqueduct is an aqueduct which carries the canal de Garonne across the Garonne. It is located in the Aquitaine region of France; the aqueduct is a dressed stone masonry structure consisting of 23 arches, each of 20m span, which at the time of its completion was the longest navigable aqueduct in France. It has a width of 12.48 m and a canal width of 8.82 m. The width of the channel is insufficient to allow boats to pass each other whilst on the aqueduct. Boats must wait for oncoming traffic to clear the aqueduct before crossing. There is a lock and a canal basin downstream, a canal basin upstream, of the aqueduct; the aqueduct was built of stone blocks from Quercy, under the direction of the engineer Jean-Baptiste de Baudre. On 25 August 1839 Ferdinand Philippe, Duke of Orléans laid the first stone. In 1841 the building of the Bordeaux to Toulouse railway interrupted work on the canal and the aqueduct was rented to farmers for use as a short cut avoiding the Bridge of Agen; the tolls however, were too high to make this idea work.
On 5 May 1846 the work was ordered to resume by a vote in favour of a government act. The aqueduct came into service in 1849. Montech water slope Canal de Garonne Agen The French article from which this article was translated Pont-canal d'Agen Agen Aqueduct at Structurae Pont-canal d'Agen, in French
Cesse Aqueduct is one of several aqueducts, or water bridge, created for the Canal du Midi. The canal crossed the Cesse on the level. Pierre-Paul Riquet, the original architect of the canal, had placed a curved dam 205 metres long and 9.10 metres high across the Cesse in order to collect water to make the crossing possible. The Cesse Aqueduct was designed in 1686 by Marshal Sebastien Vauban and completed in 1690 by Antoine Niquet. Master mason was John Gaudot, it has the middle being 18.3 metres and the side being 14.6 metres each. It is located in Mirepeisset, Languedoc-Roussillon, about one mile from the port town of Le Somail. In 1967, a scene from "Le Petit Baigneur" directed by Robert Dhéry, with Louis de Funès, was filmed a Cesse Aqueduct. Locks on the Canal du Midi Eastern Approach
A waterway is any navigable body of water. Broad distinctions are useful to avoid ambiguity, disambiguation will be of varying importance depending on the nuance of the equivalent word in other languages. A first distinction is necessary between maritime shipping routes and waterways used by inland water craft. Maritime shipping routes cross oceans and seas, some lakes, where navigability is assumed, no engineering is required, except to provide the draft for deep-sea shipping to approach seaports, or to provide a short cut across an isthmus. Dredged channels in the sea are not described as waterways. There is an exception to this initial distinction for legal purposes, see under international waters. Where seaports are located inland, they are approached through a waterway that could be termed "inland" but in practice is referred to as a "maritime waterway"; the term "inland waterway" refers to navigable rivers and canals designed to be used by inland waterway craft only, implicitly of much smaller dimensions than seagoing ships.
In order for a waterway to be navigable, it must meet several criteria: it must be deep enough to accommodate vessels loading to the design draft. Vessels using waterways vary from small animal-drawn barges to immense ocean tankers and ocean liners, such as cruise ships; the European Conference of Ministers of Transport established in 1953 a classification of waterways, expanded to take into account the development of push-towing. Europe is a continent with a great variety of waterway characteristics, which makes this classification valuable to appreciate the different classes of waterway. There is a remarkable variety of waterway characteristics in many countries of Asia, but there has not been any equivalent international drive for uniformity; this classification is provided by the UN Economic Commission for Europe, Inland Transport Committee, Working Party on Inland Water Transport. A low resolution version of that map is shown here. Media related to Waterways at Wikimedia Commons Blue Book on European inland waterways - access to the Blue Book database.
The objective of the “Blue Book” is to establish an inventory of existing and envisaged standards and parameters of "E-waterways" and ports in Europe and to show, on an internationally comparable basis, the current inland navigation infrastructure parameters prescribed on the Agreement on Main Inland Waterways of International Importance Waterscape - Britain's official guide to canals and lakes