ii	Ironbridge Gorge, Shropshire (UK).
Grading: 1. **; 2. ***; 3. ***; 4. *. Total: 9
	This is an ironmaking and collieries landscape centred on the navigable river Severn and its connecting horse-drawn railways and small-boat canals. The latter includes the Hay inclined plane and the Tar Tunnel, which was intended to be an underground mining canal. The Ironbridge Gorge is already a World Heritage site.

iii	Blaenavon, Gwent, Wales (UK).
Grading: 1. *; 2. **; 3. ***; 4. *: Total: 7
	The area of the Heads of the Valleys in South Wales had the largest ironworks in the world in the early 19th century, and Blaenavon retains the substantial remains of works complexes and surrounding settlements, as well as a publicly accessible conserved coalmine. Around this is an ironmaking and collieries landscape which includes the formation of many horse-drawn railways and what was in the early 19th century the longest railway tunnel in the world. The oldest existing railway/canal interchange warehouses (1810-20) survive on the Brecknock and Abergavenny Canal that forms the eastern boundary of the area. This area has been recommended by TICCIH as one of the 28 most important international industrial sites not on the World Heritage List.

iv	Ancoats, Manchester (UK).
Grading: 1. *; 2. ***; 3. ***; 4. **. Total: 9
	The first steam-powered textile mills were in Ancoats.99 When the Rochdale Canal opened, arms of the canal were built to serve these mills, which are on the banks of the canal, only a road separating them. Although the first mill opened before the canal, subsequent developments were encouraged by the canal. The whole area shows how important good transport was to the development of industrial England. Cotton textiles were the most important factor in the economic success of Britain in the 19th century, and this site can be said to symbolize the importance of all these factors. More of the original canalside factory development has disappeared in Birmingham: both Manchester and Birmingham were manufacturing areas at the centre of the Industrial Revolution, where the accessibility of cheap canal transport was crucial to the development of some of the earliest large factory complexes in the world.

In addition to these industrial areas, the designation of any historic city will almost inevitably include the canals or waterways that served these urban centres and their attendant industries. Significant examples of this are Venice (Italy) and the 18th-century City of Bath (UK), both on the World Heritage List. The 19th-century infrastructure and architecture of the City of Glasgow (Scotland, UK) also survives as a substantially intact mercantile and manufacturing centre of the former British Empire, with one of the most impressive intact 19th-century wharfages on the early Forth & Clyde ship canal at Port Dundas.

In many cases involving canal monuments it is most sensible to consider a related group of waterway structures or the whole, or part of, a canal line. Often such a designation made for conservation purposes will include a buffer zone flanking the waterway to safeguard the visible cultural landscape beyond the actual boundaries of the waterway. These designations of a waterway will include a grouping of the types of features whose significance has been considered above. In the following section the various types of waterway line are considered.

This "corridor" designation is especially popular in North America as one aspect of the concept of cultural landscapes. A valuable Information Document on Heritage Canals was drawn up in consultation with canal experts by the Department of Canadian Heritage in 1994 and has been forwarded to the World Heritage Committee for consideration. Whether a particular waterway is designated as a line of canal and associated engineering works, or whether its significance merits the designation of a wider corridor, ought perhaps to relate to how much the canal has influenced the development of the economic development of the corridor through which it runs. A problem in this concept is in densely developed "integrated industrial landscapes" (see above), where successive arterial transport routes intersect one another and relate to a landscape area as a whole and not a definable corridor.

 

A         River navigations

Improvements to bypass natural obstacles along the line of both major and minor rivers have probably been constructed since very early times. It has already been noted how the ancient Egyptians built a canal around the First Cataract on the Nile; they also built a slipway around the Second Cataract at Aswan.

The Fossa Mariana was built in southern Gaul by Caius Marius in about 101 BC and bypassed the difficult Rhône delta via a cut from Arles to the Mediterranean, the course of which was later followed by the now disused Canal d'Arles at Fos. Before the time of the Emperor Trajan the Romans had taken steps to improve the navigation of the Danube. In part of the Carpathian gorges they had made a towing path, in one stretch cut out from the cliff and elsewhere supported on wooden beams in holes drilled into the rock. When Trajan was preparing his conquest of Dacia across the river he strengthened this path and cut one or more canals near Sip at the Iron Gates, up which boats could be towed by teams of oxen. This enabled the two Roman Danube fleets, the Classis Moesica based near the river mouth and the Classis Pannonica, to make contact. The raising of levels at the Iron Gates locks has drowned these remains.

Figure 11 Transformation of the Milan (Italy) water- supply and irrigation canal of 1179-1209 into the lateral Naviglio Grande in 1269 lies at the beginning of the development of the modern canal

 

B         Lateral canals

These are "simple" navigations running parallel to existing rivers. They usually raise no complex problems of water supply or civil engineering and therefore lack the general significance of other types of waterway.

S I T E S

i	Naviglio Grande, Milan (Italy), 1179-1209 & 1269. [Figure 11]
Grading: 1. **; 2. ***; 3. ***; 4. **. Total: 10
	This is a particularly significant and important example dating from the beginning of the development of the modern canal. The origin of this canal lies in an irrigation channel and water supply for Milan which runs from the river Ticino near its outlet from Lake Maggiore south to Abbiategrasso and then east to the southern suburbs of Milan. It was built between 1179 and 1209 from an intake near Casa della Camera for 50km with a fall of 33.5m. In 1269 it was enlarged into a navigation and named the Naviglio Grande.100

 

C         Contour canals

A simple navigation between two valleys could be established by a canal leaving one river and circumventing the adjoining spur on the level, so avoiding the need for an elevated summit level with its water-supply problems.

S I T E S

i	Magic Transport Canal (China), c 219 BC.
Grading: 1. ***; 2. ***; 3. ***; 4. **. Total: 11
	The Ling Chhii (Magic Canal) was constructed for reasons of military transport and supply through the high watershed connecting rivers flowing north and south between the Hsiang and Li rivers. It is the first known contour transport canal. The part of the Ling Chhii which justifies this designation was called the Nan Chhii and branched off from the Hsiang River to run along a suitable level or slightly falling contour for some 3 miles until it met the upper waters of the Li. Additionally to the summit cut, the small Li was canalized using lateral canals for 28km and the larger Hsiang for 2.5km (first mentioned during a rebuilding in AD 825). The locks were transformed from flash to pound locks, possibly in 1059, during general repairs to the canal. There is a large intake dam to the waterway on the Hsiang river; locks were sited at either end of the waterway. The canal formed part of a 1250 mile waterway by 200 BC. It continues in heavy use.101

ii	Karlsgraben (Fossa Carolina), Treuchtlingen, Bavaria (Germany), AD 793.
Grading: 1. ***; 2. *; 3. *; 4. *. Total: 6
	This was the first attempt to cross the greatest of the European watersheds, and was begun by the Emperor Charlemagne in 793. The canal was to link the rivers Altmühl and Schwäbische Rezat, thus joining the Danube to the Rhine. Around 7000 workmen were engaged on the project, but it is uncertain if the canal was ever used. Today it is still possible to see the excavations, part of which are in water.102

iii	Bridgewater Canal, Manchester (UK).
For Grading see below.
	A particularly influential waterway built at the beginning of the Industrial Revolution (see "Technologically significant canals").

 

D         Summit-level canals

Canals could only become an effective means of long-distance communication when the abilities of contemporary engineering were such that they could pass from one valley to the next. These most closely involved two or three technologies. The waterway would have to rise to the top or summit level over a watershed from each side. The huge amounts of water needed to supply the extensive lockage on each side of the summit would need to be supplied via a system of water-feeder channels and reservoirs.

i	Grand Canal (China).
For Grading see below.
	See "Technologically significant canals" and "Reservoirs" for details.

ii	Stecknitz Canal (Germany). [Figure 12]
Grading: 1. ***; 2. ***; 3. **; 4. *. Total: 9
	This was built to transport salt from Lüneburg to the river Trave and Lübeck, whence the salt was exported to Russia and Scandinavia, mainly for salting herring. The Duke of Saxony and Lübeck agreed to make the Delvenau and Stecknitz rivers navigable via the Mölln lake and thus provide a navigation between the Elbe and Trave rivers in 1390. Fifteen staunches were constructed and a 13km summit level. The summit level had little water and millers only opened the flash locks on alternate days. The journey of 100km could take several weeks. The first boat traversed the system in July 1398 and the 12.5-tonne capacity boats were 19m x 3.25m. The first two pound locks were built on the canal in 1480 and the system was improved and carried on in use until replaced by the Elbe-Trave Canal in 1900.103 See "Locks" for details of the substantial remains at the Dückerschleuse, Stecknitz, and the Palm Schleuse in Lauenburg. Several churches along the route of the canal have items given by the Stecknitz boatmen, some dating back to the 16th century. In Lübeck there are two salt warehouses, dating from 1579 and 1745 respectively, which were used to store the salt brought from Lüneburg by the canal boats. There are also warehouses in Lüneburg with a treadmill crane to serve boats.

iii	Canal de Briare (France), 1605-42.
Grading: 1. **; 2. ***; 3. ***; 4. *. Total: 9
	This very influential 55km waterway joins the Loire and Loing rivers. It is the first modern summit level canal in Europe and arguably the ancestor of all the large summit-level waterways of the modern age. Leonardo da Vinci discussed the possibility of two summit-level canals with the French king Francis I: waterways between the Saône and the Loire and between the Garonne and the Aude (the Canal du Midi project). A start was made on a simpler project - a canal between the Loire and the Seine which could supply food to Paris. Hugues Cosnier was appointed engineer-contractor in 1604. The summit level had a 5.25km feeder leading into the Étang de la Gazonne, which acted as a reservoir for the canal, as did the deepening of 2.8km of the 6km of the summit level with one lock that could be taken out of service as the level fell. There were to be 41 masonry locks. There was a 7-rise lock at the northern end of the summit level and 2, 3, and 4 rises elsewhere. The construction was completed in 1638-42 with a second feeder from the Loing to the summit level. A modernized version of the canal is still operating.104

Figure 12 The Palmschleuse (1724) and part of the line of the Stecknitz Canal (Germany), the first summit- level canal in Europe (1398)

iv	Canal du Midi (France), 1667-71.
For Grading see below.
	See the entry for this canal in "Technologically significant canals."

 

E         Technologically significant canals

Listed here are canals that were significant in their overall concept and construction. These are the most influential waterways in this document. All are landmarks in the world history of canals.

i	Grand Canal (China), 4th century BC and AD 581-617 onwards.
Grading: 1. ***; 2. ***; 3. ***; 4. **. Total: 11
	In spite of its great age this remains in use and is still the longest canal in the world. The earliest use of canals in China was for the transport and provisioning of troops and for the transport of grain taxes. The main purpose of the Grand Canal was the collection of the latter. It grew out of the Pien (Bian) Canal in Henan, built in about the 4th century BC. This left a grain-growing area around the Yellow River near Xinyang and ran almost level to the Huaihe and Hongze Lake. The first of many extensions and rebuildings to form the Grand Canal began in the Sui Dynasty (AD 581-617). It left Hangzhou, ran north across the Yangtse and Yellow Rivers, and eventually ended near Beijing. Parts were lateral canals and part was the first summit-level canal known (see "Reservoirs"). The first recorded pound lock was built on the canal in the 10th century (see "Locks"). A text of 1072 mentions the first recorded staircase lock. However, the development of technology in China switched to sea transport in the 13th century and the grain taxes were moved by large sailing ships. Consequently the lesser canal traffic could use double slipways (see "Inclined planes") and simple single-gate locks.105

ii	Canal du Midi (France), 1665-81.
Grading: 1. ***; 2. ***; 3. ***; 4. **. Total: 11
	This was the first heavily engineered summit canal of the modern period and was enormously influential in the conception of canal schemes. It was the greatest civil- engineering project of 17th-century Europe and possibly the world. The idea sprang from an engineering project envisaged by Leonardo da Vinci during the last three years of his life (1516-19), but not executed until 1665-81. It was supported by Louis XIV's chief minister, Colbert, and carried through by Pierre-Paul Riquet, an engineer of great talent and dedication. The canal, which is still fully operational, is 240km long, rises 62.8m from the Garonne at Toulouse to the summit, and then falls 190m to the Étang de Thau. There are a hundred locks, three large aqueduct bridges, a tunnel and numerous weirs, road-bridges, control works and a large and complex water-supply system.106

iii	Bridgewater Canal, Manchester (UK), 1759-61.
Grading: 1. *; 2. ***; 3. **; 4. ***. Total: 9
	This canal in many ways was the harbinger of the Industrial Revolution that started in Britain but spread across the world. The application of advanced civil engineering to solve the problems of economic bulk transport was inspired by the completion of the Canal du Midi in 1681, which the Duke of Bridgewater visited on his continental European travels. The engineers John Gilbert and James Brindley built a 11.7km long canal from tunnels inside the coal mine at Worsley (eventually 42 miles of canal underground on four different levels); on an aqueduct 11.9m above the navigable River Irwell on a 183m long aqueduct to unloading tunnels with shafts to wharves in the town of Manchester above.107 The building of the Bridgewater Canal in England in the 1760s inspired nine decades of canal building in Britain where 6500km (4000 miles) of canals had been built in England and Wales by 1850. It also in turn inspired the construction of many canals in continental Europe and in North America.108 The canal is still open, although a swing aqueduct over the Manchester Ship Canal has replaced Brindley's original aqueduct. The twin entrances to the Worsley underground mining canals are a protected ancient monument and the remaining features and warehouses (see "Warehouses") at the Manchester end are being conserved.

iv	Ellesmere Canal, Clwyd and Shropshire, Wales & England (UK), original mainline, 1793-1805.
Grading: 1. **; 2. ***; 3. ***. Total: 8
	On the Ellesmere Canal the chief engineer of one generation of British canal engineering, William Jessop, oversaw the development of the outstanding canal engineer of the next generation, Thomas Telford, and the genesis of the team that were to develop new structures and canals. The spur that produced these advances was the fusion of lowland English canal technology with the challenges of an upland Welsh landscape. Two deep valleys had to be crossed by the projected mainline of the canal and Jessop also planned tunnels on a grand scale: 4215m at Ruabon, 1131m at Chirk, and 436m at Weston. In the end only 28.6km of this mainline was completed, but its engineering was publicized in Telford's Atlas and by engravings and became very well known and influential internationally. Pont-y-Cafnau, Telford's Longdon-upon-Tern, and Jessop's partner's Derby Holmes iron aqueducts provided the context for Jessop to propose cast-iron aqueducts for Chirk and Pontcysyllte in 1795. Telford acted as resident engineer and Chirk Aqueduct was opened in 1801 as a constructional hybrid. Instead of the unstable mass of puddled clay that characterized the waterproofing of most British aqueducts, the sides of the water channel were sealed in the hydraulic lime used in both earlier continental canal and Roman water-supply aqueducts. Where it was revolutionary was in the use of cast iron for part of the trough of such a large structure, the bottom of the water channel being formed of cast-iron plates. Adjacent to the north was the Chirk Tunnel (1377 ft). With its opening coal could be taken south to branch canals at Frankton leading to Llanymynech limestone quarries and used in limekilns en route. The huge 307m long and 38.4m high Pontcysyllte Aqueduct with its cast-iron deck cast in the specially built Plas Kynaston Foundry nearby was the highest canal aqueduct ever built. The huge approach embankment on its western side would itself stand as a remarkable civil-engineering structure even if the aqueduct did not exist. The abandonment of the proposed canal mainline up to the intended summit level north of the aqueduct meant that an alternative water supply had to be sought. A (navigable) feeder to the river Dee was completed in 1808 with an elegant weir called the Horseshoe Falls. Upstream the large Bala Lake in the Welsh mountains was heightened by a dam (now replaced) in order to serve as a reservoir. The Trevor canal basin to the north of the Pontcysyllte Aqueduct has two original (1805) overbridges which are composite structures of iron and ashlar masonry, having shallow segmental masonry arches supported on curved cast-iron ribs. The basin also served as a transshipment point for the twin-track horse-drawn railway that brought coal down to the canal from the collieries further north. This replaced the proposed flight of locks, which was presumably where the important experimental canal lift, using floats, of Edward Rowland and Exuperius Pickering was built in 1796.109 The ironfounder William Hazeldine, a key member of Telford's contracting team, then used his Plas Kynaston Foundry to cast other bridges and aqueducts on projects engineered by Telford, such as the Caledonian Canal in Scotland and his new Birmingham mainline. There are three great aqueducts that are direct successors of those at Chirk and Pontcysyllte and were built on the 31.5 mile long Edinburgh & Glasgow Union Canal in 1817-22 to take boats 12.5 ft wide, twice the width of those crossing the earlier aqueducts. Telford advised the engineer Hugh Baird on their design but, although they superficially resemble Chirk, they have all-iron troughs and Avon is the second biggest aqueduct in Britain. The aqueducts are 7.24m wide: Slateford is 23m high and 153m long over eight arches, Almond is 23m high and 128m long over five arches, and the Avon is 26m high and 247m long with each of its twelve arches spanning 15.25m (50ft). Telford described one of these as "superior perhaps to any aqueduct in the Kingdom."110

Figure 13 In 1826-38 Thomas Telford pioneered the use of huge earthworks and straight formations on waterways such as the Birmingham Canal Mainline at Smethwick, England (UK). This 22m deep cutting replaced two earlier and higher canals, one of which is seen to the right

v	Birmingham Canal Mainline/Liverpool and Birmingham Canal (UK).
Grading: 1. *; 2. *; 3. ***; 4. *. Total: 6
	Building on the heavy engineering techniques pioneered on the Ellesmere Canal, these improvement works necessitated by traffic congestion pioneered the use of huge earthworks and straight formations in 1826-38 on a scale not seen before. Telford drew up the original report in 1824. In 1827-29, Brindley's (1768-69) and Smeaton's (1790) summit levels on the Birmingham Canal were bypassed by a new 22m deep cutting at Smethwick with double towing-path and Telford's magnificent cast-iron Galton Bridge, an overbridge spanning the 45.75m (150ft) wide cutting in a graceful arch. An earlier branch canal was taken over the new mainline by the elegant cast-iron Engine Branch Aqueduct. Brindley's main line had been shortened from 37km to 26km as work progressed in 1837-38. A new 330m Coseley Tunnel was authorized in 1835 with a double towing-path. The new Birmingham and Liverpool Junction Canal carried this scale of engineering northwards for another 64km in 1826-35. The Tyrley and Grub Street cuttings and the Nantwich, Shebdon, and Shelmore embankments were on a huge scale: Tyrley is 1.6km long and 27m deep, with a soaring masonry bridge on its length; Grub Street is 80 ft deep and 3.2km long, with another high bridge with intermediate strut across the waterway; Shelmore Embankment is 1.6km long and 18m high. Telford lay dying as it slipped and settled continuously: the alternating friable rock and clay at Tyrley also caused continual rock falls during construction. William Cubitt, Telford's assistant on the Birmingham and Liverpool Junction, later went on to do similar work during the straightening of the Oxford Canal.111

vi	The Erie Canal (USA), 1817-25.
Grading: 1. **; 2. ***; 3. **; 4. **. Total: 9
	This canal was significant for being the product of the intercontinental transfer of technology (see "Technology transfer"). Over and above this it pioneered the use of an indigenous culture of low-cost renewable engineering that was vital to the rise of the USA as the world's most powerful nation. The Rideau Canal in Canada, surveyed at the same time, also demonstrates the intercontinental transfer of technology and the adaptation of advanced, highly financed engineering to the circumstances of a developing country. Indeed, the differing states of preservation of the waterways may well mean that the Rideau, rather than the original Erie Canal, is selected as an illustration of this process of intercontinental transfer and development. However, at the time it was the Erie that was far more economically significant. Its engineering works were considerable. One aqueduct over the Mohawk was 228m long, the other was 362m long, and a third over the Genesee at Rochester was 245m long. There were twin five-lock staircases cut into rock at Lockport, near Buffalo, and a deep cutting to the west. There was a great embankment over the Cayuga Marsh, 3.2km long and up to 21m high. Such was the huge success of the waterway that it led to a great "canal mania" opening up much of the USA. The first rebuilding of the Erie Canal took place in 1835, but substantial sections of the canal escaped the successive rebuildings.

vii	Rideau Canal, Ontario (Canada).
Grading: 1. **; 2. **; 3. ***; 4. **. Total: 9
	This was one of the first canals designed specifically for steam-powered ships. It was built in 1826-32 as a military supply route by the British Corps of Royal Engineers and so it is an important example of intercontinental technology transfer. It runs over 202km from Kingston to Ottawa. There are 47 large masonry locks and 52 dams and embankments. A series of stone-arch dams, including the large one at Jones Falls (the first large stone-arch dam in North America), created the series of lakes used to form the waterway. Now a National Park and a popular recreational waterway, it is particularly important in international terms because it is the only canal dating from the great North American canal-building era of the early 19th century that remains operational along its original line with most of its original structures intact.112

 

F         Ship Canals

Under this heading are considered waterways of significance that linked oceans or were large enough to accommodate contemporary sea-going craft.

The first of this type was that built some 4000 years ago by the Pharaoh Sesosteris I, who is recorded as having linked the Nile (which empties into the Mediterranean) with the Red Sea. This important waterway had a very long and significant history (see "Sites" below) interrupted by blockages from lack of maintenance, sandstorms, and silting from the Nile and its floods. The Red Sea was also difficult to navigate with its multiple reefs and shallows and prevailing northerly winds.113

The earliest recorded direct sea-to-sea canal was that built by Xerxes, King of Persia, in 480 BC through the 4km neck of the Mount Athos peninsula as his invasion force closed on Greece.114 The concept of large ship canals was obviously current in the western world even if the technological resources were not generally equal to the task. Periander (600 BC), Demetrius Poliorcetes (4th century BC), Julius Caesar (1st century BC), Caligula, Nero (1st century AD), and Herodes Atticus (2nd century AD) all considered making a canal across the comparatively narrow isthmus of Corinth. Nero actually attempted to build the deep 4- mile canal across the isthmus in AD 67 and, had he survived, it might have been completed. Nero's workers moved half a million cubic metres, out of the necessary 13.5 million, in the three or four months that they were at work. Their engineering works, up to 30m deep and 50m wide for 2km at the western end and 1.5km at the eastern, were visible until the modern canal was completed on the same alignment.115

Over a period of time the size of what were considered to be standard ocean-going vessels changed dramatically. In the modern period many of the European maritime states saw the possibility of extending their surrounding sea-borne trade by large canals extending inland or cut-through appropriate through appropriate necks of land. This process was very widespread and it is difficult to identify any one waterway as being outstandingly significant in this process of evolution.

The Forth and Clyde Canal may have been the first very large totally artificial water channel in the modern period that was completed to carry sea-going ships from sea to sea. Early experiments in steam navigation were held on the canal. The opening of the Kiel Canal as an international waterway in 1785 was also an event of significance.

The Crinan Canal was 9 miles long through the Mull of Kintyre peninsula in Scotland (UK) and was opened in 1809 to aid the development of the western Highlands and Islands. Steamer services used it from 1819 when Henry Bell's pioneering steamship Comet began running between Glasgow and Fort William by way of the canal.116 The Rideau Canal has some significance as the first canal specifically designed for steamships (see "Sites" below). S I T E S

i	Nile (and Mediterranean) to Red Sea (Egypt).
Grading: 1. ***; 2. *; 3. ***; 4. **. Total: 9
	This canal was 97 km long from near the later site of Cairo to the northern part of the Bitter Lakes and thence to the Red Sea. First built 4000 years ago by the Pharaoh Sesosteris I, it was used five centuries later when Queen Hatshepsut employed it to transport myrrh trees from the land of Punt (Eritrea) to decorate the terrace of a temple she had built to Amon-Ra; the story of the trade is related on the walls of this temple at Der el-Bahari in Thebes (1520 BC).117 The canal features again in a wall painting of the time of Seti I (c 1380 BC), but it was gradually overwhelmed by sandstorms and fell into disuse through lack of adequate maintenance.118 Rameses II is said to have rebuilt it in the 12th century BC.119 Around 600 BC the Pharaoh Necho had it partially re-excavated, but killed 100,000 workers in the process, according to Herodotus. However, he did not complete the work as he was "admonished by an oracle that all his labour would turn to the advantage of a barbarian."120 Archaeologists present at the cutting of the modern Suez Ship Canal in 1866 confirmed that King Darius of Persia, who occupied Egypt in 521 BC, completed Necho's canal. The fragments were found of a red granite tablet in the Persian, Median, Assyrian, and Egyptian languages describing the opening of the canal.121 Diodorus Siculus wrote of a later restoration by Ptolemy II that "...Ptolemy Philadelphus ... in the most suitable spot constructed an ingenious kind of lock. This he opened, whenever he wished to pass through, and quickly closed again, a contrivance who usage proved to be highly successful." In fact the canal was often rebuilt - a total of four times between c 600 BC and the 2nd century AD. It was rebuilt again by the Arab 'Amr ibn-al-'As in 641-42. The usability of the canal, at least in that period, seems to have depended on the varying flood or high-water in the Nile itself. In 710 the Arab governor of Egypt wrote a letter to the administrator of Aphrodito up the Nile asking him to send supplies across to Suez: "If you fail to send any of the said materials and provisions and the water has subsided, you will have to carry them by road as far as Suez, paying the expense of porterage out of your private substance. " The surviving remains of the canal suggest that it was about 97km long, 46m wide, and 5m deep.122

ii	Mount Athos Canal (Greece), 480 BC.
Grading: 1. ***; 2. **; 3. **; 4. **. Total: 9
	Xerxes, King of Persia, was taking his army to attack Greece. The first major engineering work en route was a bridge of boats over the Hellespont and the second was a canal so that his ships could avoid the 48km passage round the Mount Athos peninsula. This 4km waterway was given breakwaters at each end to prevent silting. Herodotus described how the Phoenicians showed the other labourers how to excavate a canal cutting by constructing sloping rather than vertical walls. Remains of the canal are still visible.123

Figure 14 The Rideau Canal, Ontario (Canada), was one of the first canals specifically designed with locks large enough for steam-powered ships

iii	Rideau Canal, Ontario (Canada). [Figure 14]
	See "Technologically significant canals."

iv	Suez Canal (Egypt), 1854-69.
Grading: 1. ***; 2. ***; 3. *; 4. **. Total: 9
	The influence of the scale and constructional methods of this waterway profoundly affected all canals built afterwards, and not just ship canals. There was a time in the mid-19th century when it might have been thought that the new railway age would supersede all the relatively small canals built before this period. The 1350-tonne standard barge was a long time in the future. Robert Stephenson, whose Alexandria to Suez Railway was opened in 1856-59, pronounced the Suez Canal impracticable. The French ex-diplomat Ferdinand de Lesseps was a superb organizer and created the first great isthmian canal between two oceans with modern steam-powered dredgers and 20,000 workmen. The 164km lockless canal had a depth of 8m and a bottom width of 22m. Ship canals proliferated all over the world, inspired by the example of Suez. In the Netherlands waterways to the sea from Amsterdam and Rotterdam were constructed in 1862-76 and 1863-72 respectively. A canal was constructed between St Petersburg and Kronstat (Russia) in 1875-84. De Lesseps began work on the Panama Canal in 1884 and a French-promoted company on the Corinth Canal in 1882. In England the Manchester Ship Canal was built to the same depth as the Suez Canal in 1887-94. The Kiel Canal linked the Baltic and North Seas across the Jutland Peninsula in 1887-95.124 This canal is of profound significance but has been repeatedly rebuilt and enlarged.

 

G         Multi-purpose canal systems

As has already been discussed, waterways are unique in being a bulk-cargo transport way utilizing as its transport medium a natural resource. They constitute a resource that can itself be used for a variety of purposes. The extent of this multi-purpose use in some areas can be gauged from the following data: in India out of 11,000km of navigable waterways, 25% were constructed primarily as irrigation canals, 60% were navigable rivers, and 15% were primarily made as navigation canals and are mostly tidal.125

The huge and complex irrigation system of the island of Sri Lanka was built in the 5th century BC and in its complexity it has no parallel, even in contemporary India.126 Much of this system has had an extensive secondary use as a navigation. Details of it are given in the "Sites" section below. In the African state of Mali, canals that were extensively used for irrigation were also used for transport and extended to the old Royal Capital of Tombouctou (Timbuktu).

Many of the early European waterways primarily built for navigation also had a secondary use (often neglected by historians) for powering mills and industrial works.127 Navigable water was also widely used for such purposes in Canada and the rest of North America.

The canals built by the British in mid-19th century India were similarly multi-purpose in type and incorporated some huge aqueduct structures. The primary function of these canals was as irrigation watercourses, but their gradient profile and hence water flow was decided by a determination to allow navigation by the building of frequent locks.

Intercontinental technology transfer of a different type was illustrated by the building of the multipurpose Biwako Canal. The Japanese engineering student Sakuro Tanabe visited the USA to study contemporary canal-building and hydro-electric practice, and on his return built the Biwako Canal in the years 1885-90: this included one of the first hydro-electric power-stations ever built. S I T E S

i	Irrigation/transportation canals system (Sri Lanka), 5th century BC.
Grading: 1. ***; 2. **; 3. ***; 4. **. Total: 10
	A colossal and complex system of inter-related dams, canals, and lakes (tanks and reservoirs) linking to the rivers radiating from the island's central highlands. Aryan settlers of the 5th century BC who practised an agrarian system of agriculture almost immediately started the construction of tanks and irrigation canals in the dry zones of the north, east, and south of the island. Rivers were dammed to feed tanks that had an ingenious technique of locking and letting-out water through a system of valves within cisterns. Channel gradients were very low. The Jaya Ganga (Victorious River) Canal ran down from the Kalaveva reservoir to the Tissavapi reservoir in the ancient capital Anuradhapura, 54 miles (87km) away at a gradient of 6in to the mile. Water from these large reservoirs flooded the paddy-fields and also supported a large secondary trade in rice and timber.128

ii	The Ganges Canal, Roorkee, Uttar Pradesh (India), 1842-54.
Grading: 1. **; 2. *; 3. ***; 4. **. Total: 7
	Over 300 miles long, this is India's most notable canal, built during India's "Golden Age" of irrigation when, between 1817 and 1901, 5483km of main channel and 29,282km of distributaries were built in upper India alone, with many of the main channels also being made navigable.129 The Ganges Canal is still considered to be one of the great irrigation works of the world. The then Governor-General of India, Lord Ellenborough, only agreed to the work being begun provided that it should be first a navigation and only fulfil a irrigation purpose as a secondary role. The Ganges Canal was both the longest navigation and the longest irrigation canal in the world,with 827km of dual-purpose waterway from the Ganges to Nanoon, including its two branches, one to Kanpur, the other to Farrukhabad, and a further 740km of irrigation-only branches. The most spectacular section is the 27km downstream from the Haridwar intake to Roorkee, situated in the foothills of the Himalaya, 160km north-east of Delhi. The canal drops through four 2.7m (9ft) falls, each with a former navigation lock. Two large aqueducts carry the Ranipur and Pathri rivers over the canal whilst the Ratmau River is crossed on the level with an attendant spillway which is opened out during the monsoon. The Solani river is crossed on a magnificent 15-arch aqueduct ornamented with lions and with approach embankments over 2 miles long.130 The canal's engineer, Sir Proby Cautley, founded the University of Roorkee as a training ground for canal engineers. This is now India's famed engineering school, and internationally its origins parallel the central engineering workshops of the Göta Canal at Motala Verkstad, Sweden (1822), which produced many of that country's brilliant early engineers.

 

References and Notes

98      Correspondence from W Hinsch, Verein zur Förderung des Lauenburger Elbeschiffahrtsmuseum, CV.
99      M Williams, Textile Mills of Greater Manchester: Manchester, 1990.
100      C Hadfield, op.cit., 1986, 33.
101      J Needham, op.cit., 299-306.
102      L Schnabel and W Keller, Vom Main zur Donau: Bamberg, 1985.
103      C Hadfield, op.cit., 1986, 33.
104      Ibid., 39-42.
105      Ibid., 22-23.
106      N Smith, op.cit., 160-61.
107      C Hadfield, British Canals: An Illustrated History, 4th ed, 31: Newton Abbot, 1973.
108      B Trinder (ed), op.cit., 132-33.
109      E W Paget-Tomlinson, op.cit., 122-23; C Hadfield, op.cit., 1976, 28, 42.
110      Ibid.
111      Ibid., 94-97, 21 & 29.
112      D Newell, op.cit., 19-45.
113      R E B Duff, op.cit., 9; C Hadfield, op.cit., 1986, 16-17.
114      C Hadfield, op.cit., 1986, 18.
115      Ibid.
116      C Hadfield, op.cit., 1976), 40.
117      R E B Duff, op.cit., 9; B Fletcher, op.cit., 20.
118      R E B Duff, op.cit.
119      C Hadfield, op.cit., 1986, 16.
120      T F Hahn et al., op.cit., 3; R E B Duff, op.cit., 9.
121      Ibid.
122      C Hadfield, op.cit., 1986, 17; T F Hahn, et al., op.cit., 3.
123      C Hadfield, op.cit., 1986, 18.
124      Ibis., 112-18.
125      Personal communication, Dr A S Chawla, Indian delegate to the International Heritage Transportation Canal Corridors Conference, Smiths Falls, Ontario, Canada, 1994.
126      L Prematilleke, Heritage Transportation Canal Corridors of Sri Lanka: paper presented to the Smiths Falls Heritage Canals Conference, 1994.
127      S R Hughes, The Swansea Canal: Navigation and Power Supplier, Industrial Archaeology Review, 4.1, Winter 1979-80, 51-69.
128      Ibid.
129      C Hadfield, op.cit., 1986, 95.
130      W E Trout III, A Canal-Wallah in India (Parts 1 & 2), American Canals: The Bulletin of the American Canal Society, 49, May 1984; 50, August 1984, 6/6.

Acknowledgements

The preparation of this list has been co-ordinated by Stephen Hughes (Royal Commission on the Ancient and Historical Monuments of Wales), the United Kingdom representative to TICCIH, with considerable help from Michael Clarke (Milepost Research), Dr William E Trout (ex-President, American Canal Society), and Dr Christina Cameron and Robert Passfield (Parks Canada). A general consultation has taken place of over 40 experts and organizations from some twenty countries with a significant waterways heritage. The process has been considerably helped by two conferences with substantial international participation: The International Canals Conference of Experts held at Chaffeys Lock, Ontario (Canada) in September 1994, where the introductory definitions were determined, and the Canals Consultation organized by the Institute of Advanced Architectural Studies, University of York (UK) in May 1995, where the system of on-going consultation used in this study was examined.

Several of the illustrations of European waterways in this study have kindly been supplied by Michael Clarke of Milepost Research.

 

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