An Encyclopedia of the History of Technology part 53 pdf

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An Encyclopedia of the History of Technology part 53 pdf

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PART THREE: TRANSPORT 502 by King Charles XII to build a canal from Gothenburg to the Baltic. Unfortunately the king was killed in battle with the Norwegians in the same year and the project languished. A further start on making locks at Trollhätten was made in 1755 but following a landslide that work, too, was abandoned. However, in 1793 a new company took over the construction and on 14 August 1800 the route, requiring eight locks at Trollhätten, was completed to Lake Vänern. In 1832 the canal was completed from Lake Vänern through Lake Vättern to Söderkoping and the Baltic. The Trollhätten flight was then the restrictive factor on the size of vessels which could traverse the full length of the canal and so a new flight was started there in 1838 and completed in 1844. The 1800 and 1844 flights, although on a different alignment, were used concurrently until 1916. By the beginning of the twentieth century it was again necessary to provide larger locks. In 1905 the government assumed control of the canal and in 1910 work on a third different alignment was begun. Completed in 1916, it has locks 87m (285.4ft) by 12.5m (41ft) with 4m (13ft) draught, later increased to 4.6m (15ft). There are three locks in a staircase, then a short pound, and finally a single lock to raise vessels to the upper level. In the 1970s considerable improvements were made to the fairways on the river and the Göta Canal today carries a steady freight traffic as well as providing a regular passenger service. Also from Lake Vänern leading towards the Norwegian border is Sweden’s most beautiful waterway, the Dalsland Canal. Constructed between 1865 and 1869, it has 25 locks in its 255km (158.4 miles) length: only about 8km are artificial cuts, the remainder of the route using natural lakes. At Häverud (where there is a canal museum) the canal climbs one side of the valley down which a stream cascades. Half-way up the valley the canal crosses the gorge in an iron trough and passes along a ledge cut in the rock face before leading to the next lake. Once used by the iron working industry, it now carries little if any commercial traffic. Another early canal is the Strömsholms Canal from the western end of Lake Mälaren north-west of Stockholm. It was built between 1775 and 1795 and its 108km (67.1 miles) were used for the transport of iron ore. It bypasses the K61-back river and has 26 locks between Lake Barken and Malaren. It is now used entirely by pleasure craft. THE SOVIET UNION The Soviet Union includes in its extensive geographical area several river systems which are among the largest in the world, and many have long navigable stretches. Several of the rivers are more than 1600km (1000 miles) long and many have extensive tributaries, in three cases giving drainage areas of over 25 million km 2 each. But the Soviet Union faces the same problem as Canada, the fact that the INLAND WATERWAYS 503 rivers are frozen over for five to seven months of the year. Most rivers run from a central watershed either north to the White Sea or the Baltic or south to the Caspian or the Black Sea and as their headwaters are reasonably close, and there are tributaries flowing east or west to the main rivers, reasonable links could be made. One of the earliest was inspired by Peter the Great and work started on a Neva (Lake Ladoga) —Volga link in 1703 with a short canal near Vyshniy- Volochok, roughly half-way between Moscow and St Petersburg. An improved line followed which became successful. In the south also at the beginning of the eighteenth century, a start was made on linking the Volga and the Don so that traffic could go to either the Black Sea or the Caspian Sea. At the end of the eighteenth century new schemes were being proposed including an improved Neva-Volga link much further north, the Mariinski route via Lakes Onega and Ladoga which was opened in 1810. Another route linking the Black Sea and the Baltic was constructed using the Dnieper, the Berezina river and the western Dvina to join the Baltic at Riga. This involved the construction in 1804 of a short canal near Lepel about half-way between Minsk and Vitebsk. Two other canals completed this phase of canal building. The Tikhvine Canal, opened in 1811, is the link between the waterway system to the west from Dereva on a tributary of the Syas river, via the Syas itself and Lake Ladoga, and to the east via the upper reaches of the Mologa river which ultimately flows into the Volga at Nijni-Novgorod (Gorki) and thence to the Caspian Sea. The second, opened in 1828, links the Sheksna river with Lake Kubinskoe and thence by a roundabout river route to Archangel on the White Sea. Later in the nineteenth century the Moskva was canalized for 160km (99 miles) from Moscow to the Oha, giving improved communication between the city and the Caspian. By the mid-nineteenth century there were more than 80,500km (50,000 miles) of navigable rivers and canals in Russia. Further improvements in the north-west came in 1885 with the opening of a dredged and embanked channel down the River Neva from St Petersburg to Kronstadt. After the establishment of the Soviet regime in the Soviet Union several waterway routes were developed, but the most important new construction was the Volga-Don Canal. First conceived in the nineteenth century, it was started in 1938 but because of the war was not completed until 1952. It links Volgograd (previously Tsaritsyn and then Stalingrad) with the Don at Kalach, a distance of 101km (62.8 miles). Since the Second World War the Dneiper has been improved for 3000 tonne vessels and the six locks provided include those bypassing Dneiperpetrovsk (previously Ekaterinoslav). Developments are also taking place in Siberia, mainly in association with the provision of hydro-electric power: the outstanding example is the Krasnoyarsk dam on the Yenisei river. There a double inclined plane has been constructed to lift boats over the dam, one inclined plane leading from the upper level above the power station on to the crest of the dam and a second plane lowering the boats into the tail water PART THREE: TRANSPORT 504 below the station. The two planes are not in a direct line, so the caisson or tank, travelling on rails, is turned through 142° on a turntable before the second plane can be traversed. Opened in 1976, it carried smaller vessels and passenger boats until the first 1500 tonne petrol barge crossed it in 1983. EASTERN EUROPE Like the Rhine, the Danube has been one of the main arteries of trade through Europe and improvements have been made intermittently since Roman times when a towpath was cut in the Carpathian gorges to assist the passage of boats through the very difficult sections and small lateral canals were constructed. A proposal by Charlemagne to link the Danube and the Rhine in 793 came to nothing although some digging was done. A thousand years later the construction of the Rhine-Main-Danube Canal is bringing the idea to fruition (see p. 499). In what is now Yugoslavia a link between the river Theiss (Tisa) and the Danube near Bezdan was begun in 1795 and completed in 1802; it was extended in 1856 when a lock said to be the first built in concrete in Europe was included in the extension. From this, the Franzen, or King Peter I, Canal, a branch, the Franz Joseph or Mali Canal, was built between 1855 and 1872. In 1829 the Danube Steam Navigation Company was formed and operated eventually over the whole length of the river. Difficulties arose at the outfall into the Black Sea as Russia controlled that part of the river and proposals were made in 1837 to build a canal between Cernavodi and Constanta, a distance of 64km (39.8 miles). Water could not be guaranteed at the summit level and the project was abandoned. The concept was revived in 1949 and work began on the link. It stopped in 1953, but was restarted in 1975 under the control of Romania. The canal, taking 5000 tonne vessels and 3000 tonne pushtows and having two locks, was formally opened in 1984. The Romanian government proposes to build a 74km (46 miles) canal from the Danube to Bucharest. The problem of the Iron Gates gorge has been solved by the construction of a hydro-electric scheme with a bypass canal and this has enabled the river flow to be controlled. With the Danube capable of handling a greater volume of traffic in greater units, proposals are under consideration for a link with the Oder and the Elbe to the north, while to the south the Yugoslavian authorities are actively considering a canal connecting the Danube and the Adriatic which would involve the construction of several inclined planes and tunnels. In Poland the Elblaski Canal, part of which is river navigation, joins the Vistula at Torun. Built during the period 1844–60, it is 163km (101 miles) long and includes four inclined planes, at Buczyniec, Katy, Olesnica and Jelenie, over which barges are carried dry in cradles. The power to initiate movement is derived from a waterwheel on each plane. Between 1881 and 1885 five of the original seven locks on the canal were replaced by a fifth INLAND WATERWAYS 505 inclined plane at Calvny. The five planes are still working and are maintained as a tourist attraction. In the south the Oder navigation is extended into the Silesian coalfield by the Gliwice Canal, originally built between 1788 and 1806 as the Klodnitz Canal and improved in 1930–8, when it was known as the Adolf Hitler Canal, it was given its more appropriate name after the war. Gliwice is an important inland port and handles a large tonnage, some of which goes south to Czechoslovakia and more goes north along the Oder for export. Further north the Bydgoszcz Canal (Bromberg Canal) forms a link together with river navigations between the Oder and the Vistula. The Vistula and the Oder are being improved to take 3500 tonne pushtows and in the mid-1980s a new canal, the Slaski Canal (Silesian Canal) was started. Poland will also receive great benefit from the proposed link between the Danube and the Oder. SPAIN AND PORTUGAL In northern Spain the Imperial Canal in Aragon was built as an irrigation canal parallel with the Ebro between Tudela and Saragossa in 1528, but between 1770 and 1790 it was enlarged, the first six barges arriving at Saragossa in 1784. The Castile Canal was intended to link the Douro and the Castilian plain with the coast at Santander, but its navigation was limited to a main line and a branch in the plain. Although started in 1753 it was delayed owing to wars and the first barge did not reach Valladolid until 1835 and Medina de Rioseco until 1849, where a plaque in the church of St Mary commemorates the event. In Portugal major improvement works on the Douro have taken place, including lock construction. THE SUEZ CANAL For long the idea of a waterway from the eastern end of the Mediterranean to the Gulf of Suez at the head of the Red Sea had been a mirage, but it became a reality when Ferdinand de Lesseps, who had been French consul in Cairo in the 1830s and had visualized the success that could be achieved by its completion, found nearly 25 years later that Prince Said, whom he had known had unexpectedly become King of Egypt. From him de Lesseps received authority to build a 164km (102 mile) canal linking the two seas. Because of his devotion to railways and the fear that the Suez Canal might be detrimental to the Egyptian Railway engineered by himself, Robert Stephenson vehemently opposed the scheme and his influence led to the virtual British boycott of the proposal. It therefore became a prestigious French undertaking, opened on 17 November 1869 by the Empress Eugènie of France. Britain’s attitude changed PART THREE: TRANSPORT 506 when the vital importance of the canal to the sea route to India was realized and in 1874 the British government purchased King Said’s share in the Canal. Freedom of navigation to all vessels was granted in 1888. After his triumph in creating the Suez Canal de Lesseps went on to plan the Panama Canal (see p. 514). In 1956 the Egyptian Government under President Nasser nationalized the canal but navigation continued. In 1967, as a consequence of the war between Israel and Egypt, the canal was closed. After clearance of minefields, wrecks and other obstructions it was reopened in 1975 and Egypt engaged on a massive reconstruction scheme which was completed in 1980. On average, 55 ships a day pass through the canal. JAPAN An interesting canal was built in Japan between 1885 and 1890 to link the navigable lake of Biwa via the Yodo river to Osaka Bay. The Biwako Canal (Biwa River Canal) in its 21 km (13 miles) had three tunnels and two inclined planes. The boats were carried on cradles and at each plane there were parallel tracks. The lower incline at Fushima was operated by water power but the upper one near Kyoto was electrically powered by means of Pelton waterwheels (see p. 244). The canal ceased to operate about 1914 but the upper incline is still in existence. CANADA For the exploration and early exploitation of trade in Canada the rivers were invaluable as guidelines through the otherwise trackless plains and forests, but as the country became settled and defence contingencies were added to the trading pattern it was clear that improvements to the waterways would ultimately have to take place. Progress along the St Lawrence was hampered by rapids and falls as well as by floods. In 1779 an army captain, William Twiss RE, was instructed to build a canal past some rapids at Côteau du Lac between Cornwall and Montreal. By the end of the navigation season in 1780 a canal 275km (171 miles) long and 2m (7ft) wide had been completed for traffic, although it was still in an unfinished state. Three locks were built, making the Côteau du Lac Canal the first locked canal in the New World, and it was finally completed in 1783. Two other short canals were also built. The original Côteau Canal was superseded by a single lock canal in 1817 and that survived until 1845. Just above Montreal the Lachine rapids on the St Lawrence formed a barrier to through traffic. In 1680 there had been a proposal to provide a bypass canal, but this suggestion was not considered to be of overriding importance as there was a good portage road between Montreal and Lachine and loads were not INLAND WATERWAYS 507 heavy. But the war of 1812 and the subsequent opening of the Erie Canal (see p. 511) fuelled the Montreal merchants’ anxieties to remove impediments to through waterway traffic. In 1819 they formed a company for building a canal to ensure their control over the trade. Eventually the Lachine Canal was opened to traffic in 1824 with seven locks. This was the first modern canal in Canada. Between 1843 and 1848 the number of locks was reduced to five and their size increased. It was further improved in the 1880s but the construction in the 1950s of the St Lambert and Côte Ste Catherine locks on the St Lawrence Seaway spelled the end of the Lachine Canal; it was closed to traffic in 1970 but maintained for its leisure use and historical significance. The 1812 war with the United States had also highlighted the problem of finding an alternative military route between Montreal and Lake Ontario which would not be exposed to attack from across the international boundary of the St Lawrence river. The solution lay in using the Ottawa river and building a canal across from that river to Lake Ontario, but the Ottawa had rapids which required bypassing and three canals were projected for this purpose. Despite military considerations the canals, the Carillon, the Chute à Blondeau and the Grenville were not officially opened until 1834. Meanwhile a canal had been authorized from Hull on the Ottawa to Kingston, the military base on Lake Ontario and in 1826 Colonel John By, who had worked on the Côteau Canal in 1802, arrived in Quebec to be responsible for building the Rideau Canal. His task was to build a 210km (130 mile) navigation through virgin forest via rivers and lakes virtually unknown, and to do it as quickly as possible. Its construction included the magnificent flight of eight locks rising from the Ottawa river in what is now Ottawa, but which was originally called Bytown in the Colonel’s honour. His other achievement was the Jones Fall dam, 18m (60ft) high and 106.5m (350ft) long at its crest. This change in level in the canal is accommodated by three locks. Opened in May 1832, the Rideau Canal is one of the very attractive waterways of the world. Always the obvious direct route between the sea and the Great Lakes, the St Lawrence dominated the Canadian waterway scene, but between Lakes Ontario and Erie rose the natural barrier of Niagara Falls. From the earliest days it was recognized that a canal with locks would be necessary to pass the Niagara escarpment of loom (3 2 7ft). Although a report at the end of the seventeenth century to Louis XIV suggested a canal, it was realized that the expense would be vast. The question was posed again in 1793, but it was left to William Hamilton Merritt to make the first proper survey in 1818 of a possible route and the impetus was given by the construction of the Erie Canal in the United States (see p. 510) which could have an injurious effect on the Canadian carrying trade. In 1823 an Act was passed and after considerable difficulties the first Welland Canal was opened on 20 November 1829. There were 40 locks, 30m by 6.7m (100 by 22ft) with 2m (7ft) of water over the lock sills. The waterway used part of the Welland river as its route. It was reconstructed in 1845 with the number PART THREE: TRANSPORT 508 of locks reduced to twenty-seven but increased in size to 45.5m by 7.5m (150ft by 24ft 6in). Between 1883 and 1885 it was again reconstructed as the third Welland Canal with locks 85m by 14m (280ft by 46ft) and with 4.2m (14ft) of water over the sills. Only one of the locks was eliminated in this reconstruction. At the beginning of the twentieth century it was decided to build a completely new canal to much larger dimensions. Although the earlier route from Port Colborne on Lake Erie was retained above the escarpment, a new line through the lower ground was planned to terminate at a new entrance on Lake Ontario 8km (5 miles) to the east of Port Dalhousie, the old entrance to the canal. The number of locks was reduced from twenty-six to seven with a special eighth guard lock at Port Colborne. The locks are 262m by 24m (859ft by 80ft) with 9m (soft) of water over the sills. This gave a usable length of 233m (765ft) but the Port Colborne lock was 365m (1200ft). Three of the locks formed a massive staircase. Work started in 1913 but because of the First World War was not completed until 1931. Formal opening was on 6 August 1932. Throughout construction the old canal was fully maintained. In 1967 work started on a 13.4km (8.3 miles) channel to move the canal 2.4km (1.5 miles) east of Welland city centre where the canal divided the city in half. Providing a much easier flow for the canal traffic, it was opened on 28 March 1973. Further west the narrow 112km (70 miles) long St Mary’s river links Lake Superior with Lake Huron and there is a variable fall of about 6m (20ft) between the levels of the two lakes. Where the fall occurs stand the twin cities of Sault Ste Marie, generally known as ‘Soo’. A canal, though only for canoes, was built here in 1797–8 by the North-west Fur Company with a lock 11.6m (38ft) long. It was destroyed during the 1812 war but later rebuilt. As the river is the international boundary there were difficulties in obtaining authorization for the construction of locks, but eventually this was granted in 1852. The first vessel used the locks in 1855. Although built by the United States they were also used by Canada. Improvements were made in 1871 and 1881. In 1887 Canada undertook its own lock on the north side within its own territory but it was not completed until 1895. Since then the United States has reconstructed its locks and there are now five parallel locks, the largest of which is 42m by 24m (138ft by 80ft). The Trent-Severn waterway was suggested as far back as 1833 and was based on an old Indian trail. It consists of a number of lakes and rivers linked by short lengths of canal to provide a route between Trenton on Lake Ontario and Port Severn in Georgian Bay on Lake Huron. It was built in stages mainly to serve local needs, but ultimately with the idea of providing a through route for grain traffic. The first boat did not traverse the whole length until July 1920 and by that time it was evident that the canal was not a viable through route for commercial traffic. It does, however, include three interesting features. At Peterborough there is one of two hydraulic lifts of similar design to those at La Fontinettes and La Louvière in Europe (see pp. 487, 493); the other is on the other side of the summit level at Kirkfield. Peterborough has the maximum INLAND WATERWAYS 509 rise of any lift of this type in the world, with a difference in level of 19.8m (65ft) and was completed in 1904. Kirkfield, with a rise of 15.2m (50ft) was completed in 1907. Peterborough is in masonry and concrete, whereas Kirkfield is a steel girder structure. The third feature is an inclined plane or marine railway installed at Big Chute where the land falls 17.6m (58ft) in about 183m (600ft). This was constructed for small craft when it was realized that there would be no commercial traffic using the through route. It was opened in 1919 and reconstructed to a larger capacity, and also to carry boats horizontally, in 1978. There was a second marine railway at Swift Rapids, but that has been replaced by a lock. Like the Rideau, the Trent-Severn now carries a great volume of pleasure traffic. At the Lake Ontario end at Trenton it connects with a short canal, the Murray, across the Isthmus of Murray designed to make open lake navigation round the isthmus unnecessary. In the east the Shubenacadie Canal in Nova Scotia is of interest in that Thomas Telford advised on its construction. It crosses from the Bay of Fundy via the Shubenacadie river to Halifax Harbour, 70km (44 miles) with 15 locks. It was started in 1826 and opened in 1861. Also in Nova Scotia a Baie Verte Canal was proposed and later the proposal was changed to that of a ship railway—the Chignecto Marine Transport Railway—but although much of the track was laid across the isthmus and part of the ship lift was built, finances ran out and the project was abandoned. The greatest Canadian waterway development was the St Lawrence Seaway carried out jointly with the United States. Although agitation for improvements to the river came from the USA after the First World War, and an agreement had been reached in 1932 whereby the two countries would jointly construct the works, the idea was rejected by the USA. A further agreement in 1941 was again rejected by Congress. In 1952, Canada announced that it would undertake the work alone, but on 15 July 1953 the US Federal Power Commission issued a licence to develop the USA share of the project. This was challenged right through to the Supreme Court, which finally rejected the appeal against the licence in 1954. At the same time the President approved legislation to create a St Lawrence Seaway Development Corporation. Work then started to extend deep-sea facilities into the heart of North America. The major work was completed by April 1959, and now only seven large locks (two in the USA), instead of 22, are required to take sea-going vessels inland to Lake Ontario and thus they are able to travel the whole distance of 3768km (2342 miles) inland to Duluth on Lake Superior. The Seaway was formally opened at a joint ceremony on 26 June 1959 by Queen Elizabeth II and President Eisenhower. THE UNITED STATES As more and more settlements became established in North America the need for extended communications became evident, and as early as 1661 Augustine PART THREE: TRANSPORT 510 Herman proposed a canal linking Chesapeake and Delaware Bays to save the long distances and dangers involved in making the Atlantic sea passage between them. A more serious proposal came from Thomas Gilpin in 1764, but construction had to wait until after Independence. Even though the Chesapeake and Delaware Company was incorporated in 1799, work did not begin until 1802, only to be abandoned in 1805 and not resumed until 1824. Completed in 1829 and still important, the canal was the first stage of the long intracoastal waterway that was to develop in the next 150 years. It was enlarged in 1935 to a channel 76m (250ft) wide and 8m (27ft) deep and again in 1954 to 137m (450ft) wide and 1 1–5m (38ft) deep. George Washington had seen the need for canal communication to the interior and he had advocated a link between the eastern seaboard and the Ohio. After Independence, in 1784 he supported a canal connecting Lake Champlain and the Hudson river; the canalization of the Potomac, again towards a link with the Ohio; and what was to become the Schuylkill and Susquehanna in Pennsylvania. In 1785 the James River Navigation was begun in Richmond, Virginia, to improve the river as far inland as Buchanan. By 1789 part of the navigation had been opened, including probably the first locks in the USA, and by 1816 the 322km (200 miles) navigation was completely open. It was later to be bypassed by the James River and Kanawha Canal, which received its charter in 1835 and reached Buchanan in 1851. It was intended to cross the Allegheny Mountains by a series of locks and a 14.5km (9 miles) tunnel to join the Kanawha river, a tributary of the Ohio, but the mountain section never materialized. A third early canal was the Dismal Swamp Canal running southward from Chesapeake Bay to Albemarle Sound. This is another link in the intracoastal waterway, completed in 1805 and subsequently, as with the other early canals, improved. Another canal opened on the coastal route, the Chesapeake and Raritan, was completed in 1834 but does not now form part of the intracoastal waterway as it closed in 1932. On the other hand, the Cape Cod Canal, opened much later, still remains. In 1817 a rather remote vision took practical form and was to influence canal thinking in the whole of North America. This was the decision of New York State to go ahead with the building of the Erie Canal. As early as 1792 the New York State Legislature had authorized the Western Inland Lock Navigation Company to establish a route from the Hudson to Lake Ontario by improving the Mohawk river and linking it to Lake Oneida and the Oneida river. At the same time the Northern Inland Navigation Company was authorized to improve the Hudson to Lake Champlain. In 1796 the Western Company constructed a one-mile canal at Little Falls on the Mohawk but no further progress was made. It was recognized that public funds would be required, but the legislature was not yet convinced. Congress would not support it, but in 1817 New York State had a new Governor, DeWitt Clinton, INLAND WATERWAYS 511 elected on the programme of building the new canal; on 4 July the first sod was cut at Rome on the Mohawk. The canal was to be 580km (363 miles) long, 12m (406) wide and 1.2m (4ft) deep, and the schedule was tight, for it was to be completed in eight years. By 1820 the middle section was complete and it was navigable from Utica to Montezuma. There was disagreement between Buffalo on Lake Erie and Black Rock on the Niagara river as to which should be the western terminus; Buffalo won, with Albany on the Hudson as the eastern terminus. By October 1825, within the stipulated time, the canal was navigable throughout. In that time 83 locks, including five double locks at Lockport on the Niagara escarpment, together with 18 aqueducts across rivers and large streams, had been built. By 1833 an average of one boat every 17 minutes was traversing the canal and transport costs between Buffalo and New York had fallen from $100 to $40 a ton. The Erie Canal’s success soon meant that it was too small for the amount of traffic it generated, so from 1835 to 1862 work proceeded on doubling the width and depth. It had been intended that this work would be completed in five years, but funds were suddenly stopped and it was not until 1854 that money again became available. In 1884 the locks were lengthened to 67m (220ft) and it was proposed that the depth should again be increased, but this last proposal was dropped. At the beginning of the twentieth century, after rejecting the idea of a ship canal, it was decided to build a barge canal to replace the existing waterway. This was constructed parallel to the old canal between 1905 and 1918 and opened on 15 May 1918. The Oswego Canal, 38km (24 miles) long, joins the Erie Canal to Lake Ontario from Syracuse. The Erie Barge Canal, 560km (348 miles) long, has 35 locks and is the main line of the New York State Barge Canal System. This includes a number of branch canals completed between 1823 and 1857 totalling another 190km (117 miles). It is noteworthy that although the Federal government has financed many harbour and river systems within the USA, not one dollar of public money has been spent on the Erie complex and yet this has been of tremendous economic value to the government. Although freight traffic has fallen off, pleasure use has increased and proposals are being examined to provide year-round availability. Further south, in the Pennsylvania region, there had been developments expanding the Schuylkill and Susquehanna and building new canals to carry coal from Pennsylvania to New York and other eastern seaboard communities. In 1823 a new waterway was surveyed and in 1829 the Delaware and Hudson was complete over its 173km (108 miles) from Homesdale across the Delaware river to Kingston on the Hudson. It had 108 locks taking 20 tonne boats, and was deepened in 1842–4 and rebuilt ten years later for 130 tonne boats. The level crossings of the Delaware and Lackawaxen rivers were handicaps, so these crossings were replaced by aqueducts almost at the same time the Orb crossing on the Canal du Midi was replaced (see p. 00). Also carrying coal to . works on the Douro have taken place, including lock construction. THE SUEZ CANAL For long the idea of a waterway from the eastern end of the Mediterranean to the Gulf of Suez at the head of the Red. although much of the track was laid across the isthmus and part of the ship lift was built, finances ran out and the project was abandoned. The greatest Canadian waterway development was the St Lawrence. plane leading from the upper level above the power station on to the crest of the dam and a second plane lowering the boats into the tail water PART THREE: TRANSPORT 504 below the station. The

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