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HISTORY OF CANALS
To the 18th century
The great canal of Darius I: 6th century BC
The cutting of canals for irrigation has been an essential part of the civilization of Mesopotamia, controlling the water of the Euphrates and the Tigris. Several canals link the two rivers, and small boats use these waterways. But the world's first canal created purely for water transport is an incomparably more ambitious affair.
Between about 520 and 510 BC the Persian emperor, Darius i, invests heavily in the economy of his newly conquered province of Egypt. He builds a canal linking the Nile and the Red Sea. Its access to the sea is close to modern Ismailia, which much later becomes the terminus of another great waterway, the Suez canal.
Between about 520 and 510 BC the Persian emperor, Darius i, invests heavily in the economy of his newly conquered province of Egypt. He builds a canal linking the Nile and the Red Sea. Its access to the sea is close to modern Ismailia, which much later becomes the terminus of another great waterway, the Suez canal.
The Grand Canal: 3rd century BC - 13th century AD
The Chinese (the greatest early builders of canals) undertake several major projects from the 3rd century BC onwards. These waterways combine the functions of irrigation and transport.
Over the centuries more and more such canals are constructed. Finally, in the Sui dynasty (7th century AD), vast armies of labourers are marshalled for the task of joining many existing waterways into the famous Grand Canal. Barges can now travel all the way from the Yangtze to the Yellow River, and then on up the Wei to the western capital at Xi'an.
Over the centuries more and more such canals are constructed. Finally, in the Sui dynasty (7th century AD), vast armies of labourers are marshalled for the task of joining many existing waterways into the famous Grand Canal. Barges can now travel all the way from the Yangtze to the Yellow River, and then on up the Wei to the western capital at Xi'an.
Along this great Chinese thoroughfare the rice harvest of the Yangtze is conveyed to the centres of political power in the north.
From the 13th century there is a new northern capital. Kublai Khan establishes himself at Beijing, which becomes the capital of the Mongol or Yüan dynasty. The Mongols extend the Grand Canal all the way north to join Beijing's river at T'ien-ching.
From the 13th century there is a new northern capital. Kublai Khan establishes himself at Beijing, which becomes the capital of the Mongol or Yüan dynasty. The Mongols extend the Grand Canal all the way north to join Beijing's river at T'ien-ching.
Flash locks and pound locks: 10th - 15th century AD
From the very first construction of canals, some method is necessary to cope with differences in water level. The simplest solution is a weir, to hold up the water on the higher side, with a gap in the middle which can be opened to let a boat through. The removal of the barrier, however achieved, is inevitably followed by a sudden rush of water - carrying the vessel easily through in one direction, but making passage very difficult in the other. A primitive lock of this kind is known, for obvious reasons, as a flash lock.
The development of the more sophisiticated pound lock is traditionally credited to an engineer, Chiao Wei-yo, working on the great Chinese canal system in the 10th century AD.
The development of the more sophisiticated pound lock is traditionally credited to an engineer, Chiao Wei-yo, working on the great Chinese canal system in the 10th century AD.
It is said that Chiao is required to construct two flash locks on the Grand canal only about 200 yards apart. He realizes that he has created a pool which will be at the upper or lower level of the canal depending on which of the two barriers is open. Moreover the barrier separating patches of level water can be opened without the obstruction of water pressure.
The result is the pound lock, standard on all modern canals. The first in Europe is believed to have been built in the Netherlands in 1373 at Vreeswijk, where a canal from Utrecht joins the river Lek.
The result is the pound lock, standard on all modern canals. The first in Europe is believed to have been built in the Netherlands in 1373 at Vreeswijk, where a canal from Utrecht joins the river Lek.
At this stage the barrier is a simple sluicegate which has to be raised and lowered like a guillotine. The process is laborious, and the water pressure against the flat surface requires a very strong construction to hold it.
The last missing piece in the design of the modern lock is the mitred lock gate. On this system each end of the lock is closed by a pair of wooden gates slightly too large to close in a normal flush position. They meet with mitred edges pointing in the direction of the higher water level. Water pressure holds them tightly together, until the level is the same on either side - at which point the gates can be easily pushed open.
The last missing piece in the design of the modern lock is the mitred lock gate. On this system each end of the lock is closed by a pair of wooden gates slightly too large to close in a normal flush position. They meet with mitred edges pointing in the direction of the higher water level. Water pressure holds them tightly together, until the level is the same on either side - at which point the gates can be easily pushed open.
The first lock with mitred gates is probably the one built in Milan in about 1500 to join two Canals of differing levels. Known as the San Marco lock, it is likely that its design is by Leonardo da Vinci. As his notebooks reveal, Leonardo is interested in all aspects of hydraulic engineering; and he is employed at this time by the duke of Milan.
From the 12th century Europeans have been busy constructing Canals, even with the primitive device of the flash lock. The mitre lock makes possible increasingly ambitious projects.
From the 12th century Europeans have been busy constructing Canals, even with the primitive device of the flash lock. The mitre lock makes possible increasingly ambitious projects.
European canals: 12th - 17th century AD
In one area of Europe, the Netherlands, canal building is an integral part of economic development. The primary purpose is drainage; an efficient transport network is a welcome bonus. But in Italy, in the late 12th century, an ambitious canal is constructed without any subsidiary motive of drainage or even irrigation.
It is the Naviglio Grande, built between 1179 and 1209 to bring marble from near Lake Maggiore for the construction of the cathedral in Milan. The barges float down the river Ticino before diverting into the canal, which has a fall of 110 feet in its length of 31 miles. The next comparable project, a century later, is a canal with a different purpose - to improve trade.
It is the Naviglio Grande, built between 1179 and 1209 to bring marble from near Lake Maggiore for the construction of the cathedral in Milan. The barges float down the river Ticino before diverting into the canal, which has a fall of 110 feet in its length of 31 miles. The next comparable project, a century later, is a canal with a different purpose - to improve trade.
From 1391 the Stecknitz canal is constructed southwards from the city of Lübeck. Its destination is the Elbe, which is reached early in the 15th century. The new waterway joins the Baltic to the North Sea.
This canal rises some 40 feet from Lübeck to the region of Möllner and then falls the same amount again to reach the Elbe, all in a distance of 36 miles. This must be about the limit which can be safely achieved with Flash locks. With Mitre locks, from the 16th century, anything is possible. And the most ambitious projects are undertaken in France.
This canal rises some 40 feet from Lübeck to the region of Möllner and then falls the same amount again to reach the Elbe, all in a distance of 36 miles. This must be about the limit which can be safely achieved with Flash locks. With Mitre locks, from the 16th century, anything is possible. And the most ambitious projects are undertaken in France.
The Briare canal, completed in 1642, joins the Seine to the Loire; at one point it has a staircase of six consecutive locks to cope with a descent of 65 feet over a short distance. Even more remarkable is the Canal du Midi, completed in 1681, which joins the Mediterranean to the Atlantic by means of 150 miles of man-made waterway linking the Aude and Garonne rivers. At one point this canal descends 206 feet in 32 miles; three aqueducts are constructed to carry it over rivers; a tunnel 180 yards long pierces through one patch of high ground.
The potential of canals is self-evident. It falls to Britain, in the next century, to construct the first integrated system of waterborne traffic.
The potential of canals is self-evident. It falls to Britain, in the next century, to construct the first integrated system of waterborne traffic.
Bridgewater Canal: AD 1759-1761
In 1759 a young self-taught engineer, James Brindley, is invited to visit the duke of Bridgewater. The duke is interested in improving the market for the coal from a local mine which he owns. He believes his coal will find customers if he can get it more cheaply into Manchester. He wants Brindley to build him a canal with a series of locks to get barges down to the river Irwell, about three miles from the mine.
Brindley proposes a much bolder scheme, declared by some to be impossible but accepted by the duke. He will construct a more level canal, with less need for time-wasting locks. He will carry it on an aqudeuct over the Irwell on a straight line to the heart of Manchester, ten miles away.
Brindley proposes a much bolder scheme, declared by some to be impossible but accepted by the duke. He will construct a more level canal, with less need for time-wasting locks. He will carry it on an aqudeuct over the Irwell on a straight line to the heart of Manchester, ten miles away.
On 17 July 1761 the first bargeload of coal is pulled along the completed canal. Brindley's aqueduct (replaced in 1894 by the present swing aqueduct) crosses the Irwell at Barton. The strange sight of a barge floating in a gutter high up in the air becomes one of the first great tourist attractions of the Industrial Revolution. The investment in this private canal rapidly pays off. The price of the duke's coal is halved in the Manchester market.
The Bridgewater canal is the first in Britain to run its entire length independently of any river. It is the start of the country's inland waterway systerm, for which Brindley himself will construct another 300 miles of canals.
The Bridgewater canal is the first in Britain to run its entire length independently of any river. It is the start of the country's inland waterway systerm, for which Brindley himself will construct another 300 miles of canals.
19th century and beyond
Pont Cysyllte: AD 1795-1805
In 1795 Thomas Telford applies cast-iron technology in a bold new context. In 1793 he has been appointed engineer and architect to the Shropshire Union canal, which is to link the Mersey with the Severn. Near Llangollen the proposed route crosses the Dee valley, which is more than 300 yards wide and drops down about 120 feet to the river level below.
The number of locks needed to get a barge down and up again would represent a costly delay for the bargees. Yet an aqueduct of this height and length is a daunting project. The valley is much wider and deeper than the one spanned by Brindley in his heavily buttressed aqueduct at Barton. But Telford accepts the challenge.
The number of locks needed to get a barge down and up again would represent a costly delay for the bargees. Yet an aqueduct of this height and length is a daunting project. The valley is much wider and deeper than the one spanned by Brindley in his heavily buttressed aqueduct at Barton. But Telford accepts the challenge.
Telford constructs at Pont Cysyllte what is in effect an enormous cast-iron gutter. Cast to the correct curves and then welded together, Telford's plates combine to form a channel which is nearly 12 feet wide, with a path alongside for the carthorse. The metal is much lighter than the thick layer of pounded clay and sand used by Brindley to contain the water of the Bridgewater canal. So Telford's aqueduct can be a slender structure of nineteen tall stone arches.
Pont Cysyyllte is ready for the first barge to make the journey across the valley in 1805. Walter Scott describes it as 'the most impressive work of art' which he has ever seen.
Pont Cysyyllte is ready for the first barge to make the journey across the valley in 1805. Walter Scott describes it as 'the most impressive work of art' which he has ever seen.
The Suez Canal: AD 1859-1869
A glance at the map suggests the possibility of a canal linking the Mediterranean and the Red Sea. On the direct route south to Suez half the work is already done by nature, in the form of Lake Timsah and the two Bitter Lakes.
With the increasing importance of India to the European powers in the late 18th century (as the main scene of rivalry between France and Britain) there is a strong military and economic motive to undertake the great task. During the French occupation of Egypt in 1798, Napoleon himself spends several days surveying the region with a party of officers and scientists.
With the increasing importance of India to the European powers in the late 18th century (as the main scene of rivalry between France and Britain) there is a strong military and economic motive to undertake the great task. During the French occupation of Egypt in 1798, Napoleon himself spends several days surveying the region with a party of officers and scientists.
During the early part of the 19th century several plans for a canal are drawn up without success. The breakthrough comes with the accession to the Egyptian throne of Said in 1854. He is a friend of a French diplomat, Ferdinand de Lesseps, who has long had the ambition of achieving a Suez canal. By November 1854 Lesseps has been granted a concession to undertake the project. Eighteen months later he is ready to float the Suez Canal Company.
Half the money is subscribed in France, where Napoleon III has been very supportive of the scheme. None comes from Britain. Indeed the British government does all it can to prevent a development which looks alarmingly like providing the French with a back door to India.
Half the money is subscribed in France, where Napoleon III has been very supportive of the scheme. None comes from Britain. Indeed the British government does all it can to prevent a development which looks alarmingly like providing the French with a back door to India.
Said Pasha himself rescues the scheme by subscribing 60 million francs. On 25 April 1859 Lesseps swings the first pickaxe at the northern end of the route, the site of a new harbour to be named Port Said. He is the first in a labour force soon numbering tens of thousands, who between them excavate over the next ten years 97 million cubic yards (more than two cubic miles) of earth and rock.
For the opening ceremony, in November 1869, thousands of distinguished guests assemble from all over Europe and the Middle East. The procession of ships through the canal is led by the French imperial yacht with the empress Eugénie on board. The journey time to and from India is slashed. East and west are linked as never before.
For the opening ceremony, in November 1869, thousands of distinguished guests assemble from all over Europe and the Middle East. The procession of ships through the canal is led by the French imperial yacht with the empress Eugénie on board. The journey time to and from India is slashed. East and west are linked as never before.
Plans for a canal: AD 1879-1903
In Paris in 1879 there is a high-level gathering of 135 delegates to consider the important topic of a canal linking the Atlantic and the Pacific. The president of the International Congress for Consideration of an Interoceanic Canal is the 74-year-old Ferdinand de Lesseps, hero of the successful completion of the Suez canal just ten years earlier.
De Lesseps is entrusted with the new undertaking, to be achieved through Panama rather than Nicaragua. Unfortunately the ageing engineer, rejecting expert advice, decides on the almost impossible task of a sea-level canal. The intention is to cut through the continental divide which runs the length of the isthmus.
De Lesseps is entrusted with the new undertaking, to be achieved through Panama rather than Nicaragua. Unfortunately the ageing engineer, rejecting expert advice, decides on the almost impossible task of a sea-level canal. The intention is to cut through the continental divide which runs the length of the isthmus.
This error, combined with financial incompetence and the ravages of equatorial disease, forces the French Panama Canal company into liquidation in 1889. The scandal escalates when members of the French government are suspected of taking bribes from the company. De Lesseps is tried in 1893 and is sentenced to five years in prison (he has served none of his sentence by the time the verdict is quashed a few months later).
The collapse of this French effort leaves the field to the Americans, who have been considering a rival venture through Nicaragua. Urgency is added to the issue in 1898 when a much needed US battleship, the oregon, takes two months to steam from the Pacific to the Atlantic round South America.
The collapse of this French effort leaves the field to the Americans, who have been considering a rival venture through Nicaragua. Urgency is added to the issue in 1898 when a much needed US battleship, the oregon, takes two months to steam from the Pacific to the Atlantic round South America.
In 1902 a deal is agreed for the US to purchase the uncompleted work of the French company in Panama, putting this route way ahead of the competition in Nicaragua. During the later months of this same year an agreement is negotiated between the Colombian chargé d'affaires in Washington and the US government for the creation and maintenance of a canal zone. It is generally held that the treaty grants favourable terms to Colombia.
The agreement is ratified in Washington in 1903 as the Hay-Herrán treaty. But three months later it is rejected by the Colombian government - in a reckless act which leads directly to the independence of Panama.
The agreement is ratified in Washington in 1903 as the Hay-Herrán treaty. But three months later it is rejected by the Colombian government - in a reckless act which leads directly to the independence of Panama.
Provincial leaders in Panama fear that this setback may cause the US to select the rival canal route through Nicaragua. An envoy is sent to Washington with details of a planned Panamian revolution. No direct help is promised, but the US warship Nashville steams towards the region. She appears off the coast near Colón on 2 November 1903.
The expected uprising occurs on the very next day, followed by the proclamation of the independent republic of Panama. The Nashville plays no active part, but her presence deters Colombian troops from moving west along the isthmus in time to suppress the revolution. The new republic is immediately recognized by the United States.
The expected uprising occurs on the very next day, followed by the proclamation of the independent republic of Panama. The Nashville plays no active part, but her presence deters Colombian troops from moving west along the isthmus in time to suppress the revolution. The new republic is immediately recognized by the United States.
Building the Panama Canal: AD 1903-1914
One of the first acts of the Panamanian government is the signing of a treaty with Washington for the creation of the proposed canal. In the Hay-Bunau-Varilla Treaty of November 1903 the USA is given in perpetuity exclusive control of a zone (about ten miles wide) through the centre of Panama, in return for $10 million and an annual rent.
With this agreed, there is nothing to delay the construction of the canal except the practicalities of one of the world's most ambitious engineering projects. Debate continues on the relative merits of a sea-level canal or a high-level one (with locks from both Atlantic and Pacific raising ships to a dammed Gatun Lake as the long central section of the waterway).
With this agreed, there is nothing to delay the construction of the canal except the practicalities of one of the world's most ambitious engineering projects. Debate continues on the relative merits of a sea-level canal or a high-level one (with locks from both Atlantic and Pacific raising ships to a dammed Gatun Lake as the long central section of the waterway).
The latter and more practical scheme eventually prevails, under the influence of the chief engineer appointed to the scheme, John F. Stevens (from 1907 he is succeeded in the role by George W. Goethals).
The canal opens to shipping on 15 August 1914. Far away in Europe, just two weeks earlier, the First World War has broken out - confronting the new canal with the first challenge to its proclaimed neutrality. This status has been safely maintained ever since (though if the USA itself is at war the situation becomes academic - an enemy ship, if allowed safely through the canal, will be fair game soon after leaving it).
The canal opens to shipping on 15 August 1914. Far away in Europe, just two weeks earlier, the First World War has broken out - confronting the new canal with the first challenge to its proclaimed neutrality. This status has been safely maintained ever since (though if the USA itself is at war the situation becomes academic - an enemy ship, if allowed safely through the canal, will be fair game soon after leaving it).
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