An Encyclopedia of the History of Technology part 51 ppsx

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an Act was obtained in 1885 but the Manchester Ship Canal Company had to
repurchase the old Bridgewater Canal from the railways and they had difficulty
in raising the capital. The target was reached with a month to spare. Work
commenced in 1887 and at times 17,000 men, with a great deal of novel
mechanical equipment, were employed on cutting the canal. Construction
included the entrance locks at Eastham and four other sets of locks. Brindley’s
original aqueduct was replaced by the Barton Swing Aqueduct. At the
Manchester end a dock system was established which became very busy with
cotton and grain traffic. Through sailings started on 1 January 1894 and the
canal was formally opened on 21 May 1894. Additional docks nearer the
Liverpool end were opened in 1922 and 1933 and a new Queen Elizabeth II
dock for oil tankers at Eastham, just below the entrance to the Ship Canal, in
1954. With the decline of the cotton industry and the changing pattern of sea
transport the Manchester Ship Canal also became moribund.
Sir Edward Leader Williams, who before becoming engineer to the
Manchester Ship Canal had been engineer to the Weaver Navigation, had
conceived the idea of constructing a lift between the Weaver and the Trent and
Mersey Canal at Anderton to overcome a difference in levels of 15m (50ft) and
the design by Edwin Clark was the progenitor of several lifts on the Continent.
Completed in 1875, it was built as a hydraulically counterbalancing lift with
two tanks supported on pistons. The cylinders in which the pistons worked
were interconnected and the flow of hydraulic fluid could be started and
stopped by opening and closing a valve in the connecting pipe, so that the
descent of one tank controlled the ascent of the other. In 1882 one cylinder
burst and both cylinders were renewed but by 1905 corrosion was affecting
both cylinders again and it was decided to convert the lift to two independent
tanks, each counterbalanced by a series of weights suspended on cables carried
over 2m diameter pulleys mounted on the summit of the structure.
During the first half of the twentieth century the carriage of bulk materials,

coal, timber and grain, steadily passed to rail and then road transport. For
example, the Lee traffic, which had consisted mainly of these three types of
cargo, fell from over 610,000 tonnes in 1911 to an occasional barge in the
1960s. In 1948 most of the canals in the United Kingdom were nationalized,
coming ultimately under the control of the British Waterways Board.
Commercial traffic soon fell to negligible proportions on the narrow canals,
and was gradually replaced by a thriving leisure industry aided by an energetic
campaign for canal preservation, (see p. 516).
FRANCE
In mediaeval France water carriage was mainly served by the great rivers such
as the Loire, Seine, Rhône, Somme, Saône and Dordogne, and although the
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Romans had suggested a link between the Moselle and the Saône the first
major French canal was not started until the seventeenth century. Even river
navigation was to a much lower standard than would be acceptable later.
Traffic was mainly downstream, either using rafts of timber as on the Sarre,
where they could be floated down to water-powered sawmills on the banks, or
on purpose-constructed boats, as on the Dordogne and elsewhere, which at the
end of a single voyage could be disassembled and their timber sold. The
demand for timber from Holland for naval construction led to a considerable
traffic in rafts down the Sarre, Moselle and Rhine. Even the busiest river in
France, the Loire, was only navigable from All Saints to Pentecost (November
to April) each year.
At the beginning of the sixteenth century the return of Francis I to France
accompanied by Leonardo da Vinci turned ideas to linking rivers to provide a
through route between the Mediterranean and the Atlantic, avoiding the long
haul round the Iberian Peninsula. Two proposals were actively considered,
neither of which came to fruition at the time but which were later to be built as
canals; one linking the Saône and the Loire and the other Garonne and the

Mediterranean.
By the end of the sixteenth century the growing demands of Paris for food,
plentifully available in the Loire valley, stimulated Henry IV and his adviser
the Due de Sully into considering a link between the Seine and the Loire.
Surveys were made and a scheme prepared by Hugues Cosnier was approved
on 11 March 1604 whereby a canal would be built from Briare on the Loire to
Montargis on the Loing. The Loing was navigable and joined the Seine to
reach Paris. Work started in 1605 but was abandoned following the
assassination of the king in 1610. By then 42km (26 miles) had been
constructed together with 35 locks, which included a seven-rise staircase at
Rogny. Recommendation for its completion was made in 1628 but it was not
until 1638 that authorization to resume was granted by Louis XIII to
Guillaume Boutheroue and Jacques Guyon, Sieur du Chesnoy. The canal was
completed in 1642 and became the second summit level canal, and the first
modern one, in Europe. The seven-rise staircase of locks at Rogny, a
remarkable civil engineering development at the time, was superseded in 1887
by six individual locks but the remains of the staircase are still to be seen, a
tribute to the builders. The Canal de Briare is still in use with a recent modern
feature—the longest canal aqueduct in the world across the Loire at Briare.
Completed in 1896 and designed by Gustave Eiffel, it is 662m (2172ft) long
consisting of an iron trough mounted on 15 piers. With facilities for draining it
into the Loire, it links the Canal de Briare with the early nineteenth-century
Canal Lateral à la Loire and obviated a difficult level crossing over the Loire.
In the south of the country the valley between the Massif Central to the
north and the foothills of the Pyrenees to the south suggested the site for a
waterway link between the Mediterranean and the Atlantic and various
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surveys were made. Nicholas Bachelier, instructed by Francis I in the sixteenth
century, proposed a canal from the Garonne at Toulouse to the Aude and into

the Mediterranean and this was the first survey of many. One of the problems
was the supply of water to the summit level. This was solved by the 50-year-
old Pierre Paul Riquet, a native of Beziers, who, with no previous experience
of canal engineering, realized how the waters of the Montagne Noire could be
tapped and used as feeders for the summit level. Ultimately, after further delay
but with the recommendations of the Archbishop of Toulouse and of Colbert,
Minister of Finance, Riquet was granted a patent on 18 November 1666 to
construct the canal in eight years by January 1675: he was then 62. Though
work was pushed forward with great pertinacity—there were at the peak period
12,000 working on construction—many new difficulties, both physical and
financial, conspired to delay completion. Riquet died on 1 October 1680,
prevented by a few weeks from seeing his final triumph, for the official opening
of the Canal du Midi took place in the presence of many dignitaries on 15
May 1681.
Riquet’s solution to the summit-level water supply was to divert water from
the small rivers flowing down from the Montagne Noire into a large reservoir,
the Bassin de St Ferreol, and then down the mountain in a feeder into a
holding basin at Naurouze. The dam for the St Ferreol reservoir was the first
for water for a navigable canal and was the biggest civil engineering
undertaking on the project. This was supplemented in 1791 by a second,
smaller, reservoir, the Bassin de Lampy. From Naurouze water was available to
supply the locks both to the east and the west. That this solution was effective
has been proved by its continued use for 300 years. A second important
contribution made by Riquet was the world’s first canal tunnel, the Malpas
tunnel 165m (541ft) in length. One end is still unlined and the winds of three
centuries have eroded the soft friable rock so that it looks like the entrance to a
cavern. Riquet’s third triumph was the construction of an eight-lock staircase at
Fonserannes on the opposite bank of the Orb from Beziers. This flight was
bypassed in 1985 by a water slope similar to the one constructed on the Canal
Lateral à la Garonne at Montech.

Originally the canal crossed the Orb at Beziers on the level, but in 1856 a
new line leading from the seventh lock on the Fonserannes staircase was
constructed leading to the present aqueduct across the river. This was built
with the architectural grandeur commensurate with Riquet’s original
conception. A further problem on the canal which received a unique solution
was the level crossing of the river Libron, west of Agde. Here the bed of the
canal is actually below sea level, and as the Libron is liable to bring down large
quantities of silt in flash floods which could not be cleared by scouring. Riquet
devised a flat-topped barge which could be sunk in the bed of the canal so that
the flood water passed over its deck without diminishing the flow velocity and
allowing the silt to settle out of suspension into the lower canal bed. This has
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been superseded by a structure diverting the Libron’s flow alternately into one
of two channels separated on the canal by a chamber the length of a barge like
a lock chamber with gates at each end. Each of the channels has a deck which
can be lowered over the canal so that the flood water passes over this. As the
barge passes through the chamber the flood water can be directed first through
one channel and then the second so that its flow is not impeded. This ensures
that the canal can still be used even though the Libron is in flood.
The 240km (149 mile) long Canal du Midi provided half the distance of the
link between the Mediterranean and the Atlantic, but it did not overcome the
difficulties of navigation on the Garonne between Toulouse and Bordeaux.
Bypassing at least part of this section was first proposed by Riquet, but
authorization had to wait until 1838. It was then agreed that a 194km (120.5 mile)
lateral canal should be built, leaving only the 54km (33.5 miles) between Castets-
en-Dorthe and Bordeaux with the navigation in the tidal Garonne. The Canal
Lateral à la Garonne was opened from Toulouse to Agen in 1850 and completed
in 1856. It includes the 539m (1768ft) long masonry aqueduct over the Garonne
near Agen. Between Toulouse and Noissec near the short branch canal to

Montauban are the five locks at Montech which were bypassed in 1974 by the
experimental water slope. This is one of the most significant developments in
inland waterway engineering since the invention of the pound lock.
The water slope, designed by Professor Jean Aubert, Inspecteur-Général des
Ponts et Chaussées, consists of an inclined rectilinear concrete flume linking
the upper and lower pounds of the canal. A wedge of water in which the barge
floats is pushed up the slope by a moveable dam, rather like a giant bulldozer
blade, called a shield. At the top of the slope the wedge of water makes a level
with the surface in the upper pound and the gate which holds back the upper
pound falls under the pressure of the wedge. To propel the shield at Montech
two 1000hp diesel-electric locomotives are used. The controls are linked so that
one unit is a slave to the other manned unit. The units are mounted on rubber
tyres to give better adhesion up and down the slope, but there is also a raised
continuous plinth against which horizontal guide wheels mounted beneath the
unit, run to keep the unit on the set track. The shield has neoprene rollers
mounted on the two sides and the bottom to squeegee against the contour of
the flume, ensuring minimal loss of water from the wedge. The slope of the
flume is three per cent and its effective length of 443m (1453ft) gives a change
in level between the upper and lower pounds of 13.3m (43.6ft) (equivalent to
five locks). In front of the shield there is a cradle with two arms which adapt to
the shape of the bow or stern of the barge. The speed of travel is 4.5kph
(2.8mph). The experiment was a success and a similar slope was constructed
and is in operation at the Fonserannes staircase at Beziers on the Canal du
Midi. The German authorities also carried out a feasibility study with a view
to its use at Scharnebeck on the Elbe Seiten Canal but in the end decided on a
lift instead.
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In the north progress on the Canal du Midi was watched with interest and
immediately after its completion the Due d’Orléans, Louis XIV’s brother,

obtained a concession to build the Canal d’Orléans to link Orleans on the
Loire with Montargis on the Loing. This was completed by 1692, but the
capacity of the Loing between Montargis and the Seine was insufficient to cope
with the traffic generated by this and the Briare canal. Accordingly, in 1724,
the Canal du Loing was completed parallel to the river and passing through
Nemours to join the Seine near Fountainbleau.
The great expansion in the north-west of France came later and was
intimately linked with the Belgian waterway system. An early development
was the opening in April 1734 of the Canal de Picardie, later to become part of
the Canal de St Quentin, linking the Somme and the Oise near Chauny.
Otherwise the position at the beginning of the eighteenth century was that the
Sambre was navigable north-east from Maubeuge and coal was imported from
Liège via the Meuse and the Sambre. The Escaut was only navigable in France
between Valenciennes and Condé by 75 tonne boats, but from Condé into
Belgium 150 tonne boats could pass. The Scarpe was navigable in theory from
Arras, but in practice Douai was the limit. The boatmen of Arras attempted to
organize themselves into a guild in 1704 to obtain privileges; but their boats
were very small and the hauliers had to be in the water. The Deule was
navigable above Lille on the Haute Deule and below on the Basse Deule but
there was no navigable link between them, although in 1693 a link between
the Scarpe at Douai and the Haute Deule at Lille had been opened.
The far-sighted Sebastien de Vauban realized the need for progress in
communications in the area and advocated in 1705 an improved Scarpe
between Mortagne at its junction with the Escaut and Douai; a link between
Valenciennes and Gravelines; a link between Douai and Bouchain by the
Sensée; the completion of navigation through Lille, and of the connections
between the Lys and the Aa. It was over a century before all these waterways
were completed. Of those mentioned the Neuffossée Canal linking the Aa at St
Omer with the Lys at Aire was completed in 1774 with a five-rise staircase lock
at Arques, just south of St Omer.

The traffic steadily grew on the Neuffossée Canal which formed a useful
link with the coast but the staircase lock at Arques, or as it is usually known,
Fontinettes, created a bottleneck. By the 1860s boats could wait for up to a
week to pass through and it became the practice to allow boats to pass up and
down on alternate days, thus permitting the locks to be used more intensively.
Ultimately the authorities decided to install a parallel flight of locks, but this
decision coincided with the opening of the English Anderton lift in 1875 in
Cheshire between the Weaver and the Trent and Mersey Canal. Edwin Clark
was commissioned to design a similar structure on a much larger scale at
Fontinettes, which adequately dealt with the traffic problem. Each of the two
tanks was capable of taking a 300 tonne Freycinet-type péniche. The lift
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worked on the same principle of counterbalancing as at Anderton by putting
extra water in the tank at the upper level and so forcing the piston of the lower
tank to rise, final balancing pressures being obtained by a hydraulic
accumulator. The lift was opened in 1888 and continued in operation into the
1960s. Then the enlargement of the canal to cope with the increased size of
barges raised questions as to the future of the lift. A new large-capacity lift was
considered, but instead a large shaft lock almost on the site of the old five-lock
staircase was constructed and the lift was retained as an industrial monument.
Further south a very old proposal, the Canal du Charollais, now the Canal
du Centre was to link the Loire south of Nevers at Digoin with the Saône to
form part of a north-south link across France. This scheme was revived and
work started in 1782, opening to navigation in 1793. Work also started in 1793
on the Canal de Bourgogne to link the Saône and the Yonne, again to provide
a north-south connection.
The French Revolution put a temporary end to most major works and it
was not until Napoleon, with his vital awareness of the importance of canals,
came to power that projects likely to come to fruition were again considered.

In the west in Brittany, in order to stimulate industry and agriculture, a start
had already been made in 1580 in making the River Vilaine navigable inland
to Rennes, and in 1627 the States of Brittany approved the canalization of the
Aulne between Brest and Carhaix, but the work was not pursued. In 1783 a
network of canals with Rennes as the centre was proposed on the grounds that
they would provide communication which would avoid the English blockade.
Such canals were those linking Brest and Nantes, Pontivy and Lorient, and
Rennes and St Malo. The plans lay dormant until revived by Napoleon in
1810. On 7 September 1811 stonelaying at the first lock on the Nantes-Brest
Canal took place at Chateaulin but work was suspended between 1814 and
1822. It was opened in stages as lengths were finished, but it was not
completed throughout until 1836. Unfortunately it was severed later by the
construction of the great dam and reservoir at Guerledan.
Another canal which was early considered was a link between the Loire
at Decize and the Yonne at Auxerre. This, the Nivernais Canal, was started
in 1784 but again the Revolution temporarily put an end to construction,
delaying its opening until 1834. It is a delightful canal and forms yet
another north-south link on the French canal system. One of its feeders, the
Rigole d’Yonne, crosses the Yonne valley at Montreuillon over a 33m
(109ft) high and 152m (502ft) long aqueduct constructed entirely in
masonry and opened in 1842.
East-west links were still unsatisfactory, so a major waterway, the Marne-
Rhine Canal providing communication between Paris and Strasbourg and
also giving access to the industrial areas of Alsace and Lorraine, was started
in 1846. It passes through difficult country and is unusual in having two
summit levels. The 310km (192 mile) waterway was completed in 1853. At
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the same time a second canal, the Aisne-Marne Canal, connected it with
the industrial areas of north-east France, a connection which improved after

1881 by the construction of the Oise-Aisne Canal. Also linked with the
Marne-Rhine Canal and consequential on the Franco-Prussian war of 1870–
1 was the Canal de l’Est running north on the canalized River Meuse, with
an interesting short tunnel at Revin built to cut off a great loop of the river;
the canal’s southern portion forms a link to Corre at the start of the
navigation down the Saône to Lyons. Another modern development can be
seen on the Marne-Rhine Canal. At Arzviller, a few kilometres east of
Strasbourg, the canal rises through 17 locks up the Zorn valley and at the
top of the flight enters a tunnel where, until recently, electric mules towed
the barges through. There were considerable delays in passing the locks, so
in the 1960s two new lengths of canal were built, one at the level of the
canal below the lowest lock and the other at the level above the highest
lock. Linking the two levels is a steep inclined plane where the barge is
carried up or down transversely in a tank. The difference in level is 44.5m
(146ft) and the slope is 41°. Only one tank is used but provision was made
for the installation of a second should the need arise. The incline was
opened for traffic on 27 January 1969. Further modernization took place on
the western side of this summit in 1964 with the replacement of six locks
with a single deep lock at Rechicourt.
Also branching off the Marne-Rhine Canal is the Canal des Houillères de la
Sarre, or the Sarre Coal Canal, suggested in 1838 when the Marne-Rhine was
still under consideration. The project ran into considerable opposition but was
sanctioned in 1861 when it was to be financed jointly by Prussia and France as
it would benefit both countries. It was constructed between 1862 and 1866
and the first barge from Gondrexange on the Marne-Rhine Canal reached
Sarreguemines on 15 May 1866. Over the years it has been gradually
deepened and modernized. With the work in hand by Germany in canalizing
the Saar (Sarre) to modern standards from the Moselle near Trier to
Saarbrücken, this canal may prove a valuable link between the Moselle and the
Strasbourg area.

In the east and south the construction of the Rhône-Rhine Canal from
Strasbourg via Mulhouse, with a further link to the Rhine at Basle and a short
branch canal to Colmar, continuing via Besançon to the Saône north of
Chalon and thence to the Rhône at Lyons, has over the years completed
another vital link for north-south traffic. The first section from St Symphorien
on the Saône to Dôle on the Doubs was completed in 1802. The remainder of
the section between Strasbourg and the Rhône were opened as completed until
the first vessel to make the full journey passed through the lock at Strasbourg
on 31 December 1832.
The Rhône itself has been largely tamed in this century with the
construction of dams for power stations and the associated deep locks for
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barge traffic, and with the necessary improvements to the Rhône-Rhine Canal
it will soon be possible for the large Rhine barges and pushtows to travel from
Rotterdam to the Mediterranean at Marseilles where a new link, the Liaison
Rhône-Fos, was opened in 1983 taking 4500 tonne pushtows.
The Moselle has been improved with new freight handling facilities at
Thionville allowing 3200 tonne pushtows to run directly to the Rhine at
Koblenz, and the modernization of the Moselle at Liverdun now allows the
Marne-Rhine traffic to use the canalized river instead of crossing by an
aqueduct. Improvements south of Dunkirk now allow the Europa barges to
serve the port and connect with the Escaut to both Belgium and central
France.
Finally, the river navigation of the Seine has been transformed. Although
navigation from the sea to Paris and beyond has existed for centuries, until
the nineteenth century it was difficult and costly partly because of the
current passing bridges and partly because of low water in summer. In
addition many mills had been built, both on the banks and jutting out into
the river, and these caused obstructions. Despite works carried out

elsewhere in France, canalization of the Seine did not begin until after 1840
when five locks and dams were built giving a depth of 1.6m (5.2ft). Twenty
years later this was improved to 2m and three more locks were added.
After 1910 a major reconstruction took place and the number of locks was
reduced to the present total of six. Further improvement was completed
with enlarged locks in 1964. An example of this development can be seen
at Andresy, just below the confluence of the Oise and the Seine, where
there are two small locks built in 1880, a dam and large lock 160m by 12m
(525ft by 39ft) with a depth over sill of 5m (16.4ft) opened in 1959, and a
new lock of 185m by 24m (607ft by 79ft) opened in 1974. This is fitted
with a cylindrical sector horizontally rotating gate at the upstream end of
the lock. The lock is capable of taking a 5000 tonne pushtow. All the locks
below the port of Gennevilliers below Paris have now been enlarged to
these dimensions. This has also allowed the development of inland ports as
at Boneuil and Gennevilliers and more recently, post-1976, at Limay on the
site of a former quarry. Now sea-going coasters of up to 200 tonnes as well
as the usual self-propelled barges of up to 1350 tonnes can operate through
to Paris.
THE LOW COUNTRIES
The generally flat terrain of Belgium and the Netherlands, much of it
reclaimed from the sea, has been particularly favourable to the development of
inland navigation, and in the north it has been considerably influenced by the
extensive and complicated delta of the Rhine.
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Further south, in the area between Amsterdam and Rotterdam, it is true to
say that the rivers and canals determine the Dutch landscape. In Roman times
there were three main channels of the Rhine into the sea. One flowed to the
north and entered the Ijsselmeer (Zuider Zee). The middle one, now known in
its remaining stretches as the Oude Rijn (Old Rhine), entered the sea to the

west of Leiden. The third, the southern branch, is the modern outlet via
Rotterdam and the Hook of Holland. The Romans wished to connect the
middle and southern outlets in a north-south direction and, because of the
difficulty of cutting an effective channel through the inland peat, they
constructed a canal lateral to the coastal sand dunes from the Old Rhine west
of Leiden to the Rhine near Maassluis. This was known as the Vliet. The
southern portion has disappeared, but the part between Leiden and Rijswijk
still survives. Further east a more complicated route from Muiden on the
Ijsselmeer using the Vecht to Utrecht joined the Lek near Gein close to where
the present Merwede Canal enters the Lek. A canal was built through the
centre of Utrecht in 1150 and still survives as the Oude Gracht (Old Canal).
With local city and provincial power politics able to demand and purchase
rights it is not surprising that yet another north-south route was developed
soon after 1200. The Gouwe was constructed from near Alphen a/d Rijn on
the Old Rhine southwards through Gouda to the Hollandse Ijssel and thence
to the Lek. Finally in 1220–6 a lock called a spoje was installed at Spaarndam
and could have been a pound lock. At this time neither Amsterdam nor
Rotterdam existed.
Utrecht responded by allowing its outer moat to be used for navigation,
although commercial interests were against this on account of loss of trade
within the city. New ports were established along the Rhine at Schiedam in
1260 and later at Delfshaven and Rotterdam with their own connections with
the interior. In order to permit larger vessels to pass through without their
masts fouling the superstructures of the locks, mitre gates were installed at a
new lock at Spaarndam in 1567 and at a similar lock at Gouda in 1578.
In the seventeenth century new canals were built specially for passenger
traffic conveyed in horse-drawn boats known as trekschuiten. Between 1630 and
1660 over 650km (404 miles) of these canals were built linking city with city,
though not necessarily to form a continuous waterway. Nevertheless they
constituted the first internal passenger network in the world, with the boats

running to a timetable and providing on many routes a frequent service which
was a boon to travellers. Some routes persisted well into the railway age.
Meanwhile Amsterdam was growing and needed improved transport
connections with the sea. An early route was for vessels to sail east across the
Zuider Zee to Kampen and then up the Ijssel past Zwolle and Deventer to join
the Neder Rijn (Lower Rhine) near Arnhem. An alternative route was to sail
along the coast of the Zuider Zee to Muiden and then up the Vecht to Utrecht
and the Kromme (Crooked) Rijn to Wijk bij Duurstede. In time the Crooked
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Rhine silted up and a new canal was made from Utrecht to Vreeswijk known
as the Vaartse Rijn or Rhine Navigation leading into the Lek by a lock built in
1284. This very early lock was 54.5m (178.8ft) long and 4.75m (15.6ft) wide.
One of the early new canals for trekschuiten was the Weespertrekvaart, a
canal between the Amstel at Amsterdam and the Vecht near Weesp
constructed in 1638, which allowed vessels to reach the Rhine without
traversing the dangerous passage across the Zuider Zee. By the beginning of
the nineteenth century this had become neglected. Between 1815 and 1822
William I restored it and it was then known as the Keulse Vaart (Way to
Cologne). The Lek also was silting by this time, and so a further canal, the
Zederik Canal, was built from Vianen opposite Vreeswijk to Gorinchem on
the Waal (otherwise the Merwede) and completed in 1825. In 1890 this
canal and the Keulse Vaart south of Utrecht were improved to take 2000
tonne craft, and together they became known as the Merwede Canal. The
density of traffic generated posed further problems. In 1921 more than 300
ships passed the lock at Vreeswijk on each of 29 days, and by 1930 waiting
time to pass the lock could be up to twelve days. Because of these delays it
was decided to construct a new Amsterdam-Rhine Canal and this was started
in 1937. It involved upgrading the Merwede Canal from Amsterdam to
Utrecht and then, bypassing Utrecht to the west, it followed a new alignment

to Wijk bij Duurstede where it crossed the Lek on the level and continued to
Tiel on the Waal. A branch, the Lek Canal from south of Utrecht to
Vreeswijk, was completed in 1937 to benefit traffic travelling west to
Rotterdam. The Amsterdam-Rhine Canal was opened in 1953; by the 1970s
it had proved so successful that it was becoming congested and further
enlargement had to be made. This was completed in 1981. The problems of
crossing the Lek with pushtows were the subject of intensive studies at the
Delft Hydraulics Laboratory. At both sides of the river egg-shaped basins
were formed and these created whirlpool eddies keeping the main current in
its bed. In this way the creation of shoals was avoided and very little
dredging is required. The new massive lock structures are dramatic examples
of modern canal architecture.
By the late eighteenth century large ships were finding it difficult to reach
Amsterdam owing to the silting of the Zuider Zee so a proposal to link
Amsterdam with Den Helder, which had permanent deep water, was
approved; construction started on the Noordhollandsche Canal in 1819 and its
82km (51 miles) were completed in 1825. It was not particularly successful and
in 1876 it was superseded by the North Sea Canal giving a more direct route to
the sea at Ijmuiden.
The network of small waterways in north Holland has offered few problems
to its intensive use as an integrated transport system, but with the increased
size of barges against the old dimensions of bridges and locks it was necessary
to improve conditions. In 1935 work started on building a new canal across