Locks on the Canal du Midi
Encyclopedia
There are 91 working locks on the Canal du Midi along its 240 kilometres (149.1 mi) course from the Bassin du Thau
on the Mediterranean
coast to the junction with the Canal lateral a la Garonne in Toulouse
. There are a further 13 locks on the 37 kilometres (23 mi) La Nouvelle branch
which runs through Narbonne
to the Mediterranean at Port-la-Nouvelle
. The locks are all under the management of the French
navigation authority
, Voies navigables de France
.
was built between 1666 and 1681 by Pierre-Paul Riquet
to provide an inland water route through Southern France
between the Atlantic
at Bordeaux
and the Mediterranean at Sète
via the Garonne
. The first design for the locks on the canal was a rectangular shape however due to a collapse of a side-wall early in the building program (exactly which lock is not recorded), Riquet modified his plans and rebuilt both existing and new locks with an ovoid
chamber. They were typically 11m wide at the mid-point and 6m at the gates with an overall length of 30.5m. Riquet also restricted the maximum rise to 2.9m so whereas previously he would have built one deep lock he instead used intermediate gates creating double, triple and sometimes quadruple chambers. During the Canal du Midi modernisation program of the 1970s several of these multiple chambers were converted into single "deep" locks with concrete side walls.
The lock gates were originally made of oak in the traditional mitre pattern with balance beams and each gate had a single large wooden sluice
drawn up by a vertical screw. The introduction of electric
and hydraulic
systems for both the lifting of the sluices and the opening of the gates has seen the removal of the balance beams and modern gates are of metal construction.
At each lock there is a double-fronted two-storey lock keeper
's house upon which is fixed either a cast iron
or a masonry
sign showing the name of the lock and the name and distance to the adjacent locks in each direction. The locks are still operated by lock keepers and passage is only possible when they are in attendance however on La Nouvelle branch operation by boaters is allowed. The locks are open every day except 1 January, 11 November and 25 December, from 08:00 until 17:30 out of season and 08:00 until 19:00 in the summer peak; all locks are closed 12:30 – 13:30 for lunch.
and Mediterranee Lock west of Castelnaudary
before dropping down to sea level
at Sète
.
The graph shows the profile of the Canal du Midi from Toulouse
(1), through the summit of the canal at Seuil de Naurouze
(2), Castelnaudary
(3), then Carcassonne
(4) and Trèbes
(5). The channel continues to Béziers
just after Fonsérannes Lock (6), and then on to Agde
(7) before flowing in to the Bassin de Thau
at Sète (8).
At 193 metres (633.2 ft), Naurouze is the highest point of the canal with a drop of 57.18 metres (187.6 ft) between the summit and Toulouse and 189.43 metres (621.5 ft) between the summit and Sète. The longest pound is 53.49 kilometres (33.2 mi) between Argens Lock
(Aude) and the Fonsérannes Lock (Hérault) while the shortest reach is 250 metres (820.2 ft) between two locks at Fresquel..
from the Canal lateral a la Garonne in the west to the Bassin du Thau in the east. Staircase locks are counted as a single entity but the number of individual chambers in the flight is noted. Travelling west - east from Toulouse to Sète the locks numbered 1–18 are ascending and 19–86 are descending.
Étang de Thau
Étang de Thau or Bassin de Thau is the largest of a string of étangs that stretch along the Languedoc-Roussillon, French coast from the Rhône River to the foothills of the Pyrenees which form the border to Spain. It is the second largest lake in France.-Description:It is about 21 km long...
on the Mediterranean
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean surrounded by the Mediterranean region and almost completely enclosed by land: on the north by Anatolia and Europe, on the south by North Africa, and on the east by the Levant...
coast to the junction with the Canal lateral a la Garonne in Toulouse
Toulouse
Toulouse is a city in the Haute-Garonne department in southwestern FranceIt lies on the banks of the River Garonne, 590 km away from Paris and half-way between the Atlantic Ocean and the Mediterranean Sea...
. There are a further 13 locks on the 37 kilometres (23 mi) La Nouvelle branch
La Nouvelle branch
The La Nouvelle branch It is also sometimes referred to as or . is a lateral branch of the Canal du Midi in Aude, south-central France which runs from the Canal du Midi through Narbonne and on to the Mediterranean...
which runs through Narbonne
Narbonne
Narbonne is a commune in southern France in the Languedoc-Roussillon region. It lies from Paris in the Aude department, of which it is a sub-prefecture. Once a prosperous port, it is now located about from the shores of the Mediterranean Sea...
to the Mediterranean at Port-la-Nouvelle
Port-la-Nouvelle
Port-la-Nouvelle is a commune in the Aude department in southern France.-External links:** Navigation, mooring and the canal....
. The locks are all under the management of the French
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
navigation authority
Navigation authority
A navigation authority is a company or statutory body which is concerned with the management of a navigable canal or river.-Rights of a navigation authority:...
, Voies navigables de France
Voies navigables de France
is the French navigation authority responsible for the management of the majority of France's inland waterways network and the associated facilities—towpaths, commercial and leisure ports, lock-keeper's houses and other structures. VNF was established in 1991 and took over the responsibility for...
.
Construction
The Canal du MidiCanal du Midi
The is a long canal in Southern France . The canal connects the Garonne River to the on the Mediterranean and along with the Canal de Garonne forms the Canal des Deux Mers joining the Atlantic to the Mediterranean. The canal runs from the city of Toulouse down to the Étang de Thau...
was built between 1666 and 1681 by Pierre-Paul Riquet
Pierre-Paul Riquet
Pierre-Paul Riquet was the engineer and canal-builder responsible for the construction of the Canal du Midi.-Background:...
to provide an inland water route through Southern France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
between the Atlantic
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
at Bordeaux
Bordeaux
Bordeaux is a port city on the Garonne River in the Gironde department in southwestern France.The Bordeaux-Arcachon-Libourne metropolitan area, has a population of 1,010,000 and constitutes the sixth-largest urban area in France. It is the capital of the Aquitaine region, as well as the prefecture...
and the Mediterranean at Sète
Sète
Sète is a commune in the Hérault department in Languedoc-Roussillon in southern France. Its inhabitants are called Sétois....
via the Garonne
Garonne
The Garonne is a river in southwest France and northern Spain, with a length of .-Source:The Garonne's headwaters are to be found in the Aran Valley in the Pyrenees, though three different locations have been proposed as the true source: the Uelh deth Garona at Plan de Beret , the Ratera-Saboredo...
. The first design for the locks on the canal was a rectangular shape however due to a collapse of a side-wall early in the building program (exactly which lock is not recorded), Riquet modified his plans and rebuilt both existing and new locks with an ovoid
Oval
An oval is any curve resembling an egg or an ellipse, such as a Cassini oval. The term does not have a precise mathematical definition except in one area oval , but it may also refer to:* A sporting arena of oval shape** a cricket field...
chamber. They were typically 11m wide at the mid-point and 6m at the gates with an overall length of 30.5m. Riquet also restricted the maximum rise to 2.9m so whereas previously he would have built one deep lock he instead used intermediate gates creating double, triple and sometimes quadruple chambers. During the Canal du Midi modernisation program of the 1970s several of these multiple chambers were converted into single "deep" locks with concrete side walls.
The lock gates were originally made of oak in the traditional mitre pattern with balance beams and each gate had a single large wooden sluice
Sluice
A sluice is a water channel that is controlled at its head by a gate . For example, a millrace is a sluice that channels water toward a water mill...
drawn up by a vertical screw. The introduction of electric
Electricity
Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...
and hydraulic
Hydraulics
Hydraulics is a topic in applied science and engineering dealing with the mechanical properties of liquids. Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on the engineering uses of fluid properties. In fluid power, hydraulics is used for the generation, control,...
systems for both the lifting of the sluices and the opening of the gates has seen the removal of the balance beams and modern gates are of metal construction.
At each lock there is a double-fronted two-storey lock keeper
Lock keeper
A Lock keeper, or lock operator looks after a canal or river lock, operating it and if necessary maintaining it or organizing its maintenance. Traditionally, the lock keeper lived on-site, often in a small purpose-built cottage. The occupation is dying out...
's house upon which is fixed either a cast iron
Cast iron
Cast iron is derived from pig iron, and while it usually refers to gray iron, it also identifies a large group of ferrous alloys which solidify with a eutectic. The color of a fractured surface can be used to identify an alloy. White cast iron is named after its white surface when fractured, due...
or a masonry
Masonry
Masonry is the building of structures from individual units laid in and bound together by mortar; the term masonry can also refer to the units themselves. The common materials of masonry construction are brick, stone, marble, granite, travertine, limestone; concrete block, glass block, stucco, and...
sign showing the name of the lock and the name and distance to the adjacent locks in each direction. The locks are still operated by lock keepers and passage is only possible when they are in attendance however on La Nouvelle branch operation by boaters is allowed. The locks are open every day except 1 January, 11 November and 25 December, from 08:00 until 17:30 out of season and 08:00 until 19:00 in the summer peak; all locks are closed 12:30 – 13:30 for lunch.
Profile
At its western end, Toulouse, the canal is at an altitude of 132 metres (433.1 ft) and climbs to 193 metres (633.2 ft) at its summit level between Ocean LockOcéan Lock
Océan Lock is a single chamber lock on the Canal du Midi. The adjacent locks are Mediterranee Lock 5190 metres to the east and Emborrel Lock 4157 metres to the west. Ocean Lock marks the start of the summit section of the canal when travelling west to east....
and Mediterranee Lock west of Castelnaudary
Castelnaudary
Castelnaudary is a commune in the Aude department in the Languedoc-Roussillon region in south France. It is in the former province of the Lauragais and famous for cassoulet of which it claims to be the world capital, and of which it is a major producer....
before dropping down to sea level
Sea level
Mean sea level is a measure of the average height of the ocean's surface ; used as a standard in reckoning land elevation...
at Sète
Sète
Sète is a commune in the Hérault department in Languedoc-Roussillon in southern France. Its inhabitants are called Sétois....
.
The graph shows the profile of the Canal du Midi from Toulouse
Toulouse
Toulouse is a city in the Haute-Garonne department in southwestern FranceIt lies on the banks of the River Garonne, 590 km away from Paris and half-way between the Atlantic Ocean and the Mediterranean Sea...
(1), through the summit of the canal at Seuil de Naurouze
Seuil de Naurouze
The Seuil de Naurouze, aka Col de Naurouze, is a mountain pass in southern France. It is the watershed point identified by Pierre-Paul Riquet when he designed and built the Canal du Midi. Water falling on the western side of this point flows to the Atlantic Ocean and on the eastern side to the...
(2), Castelnaudary
Castelnaudary
Castelnaudary is a commune in the Aude department in the Languedoc-Roussillon region in south France. It is in the former province of the Lauragais and famous for cassoulet of which it claims to be the world capital, and of which it is a major producer....
(3), then Carcassonne
Carcassonne
Carcassonne is a fortified French town in the Aude department, of which it is the prefecture, in the former province of Languedoc.It is divided into the fortified Cité de Carcassonne and the more expansive lower city, the ville basse. Carcassone was founded by the Visigoths in the fifth century,...
(4) and Trèbes
Trèbes
Trèbes is a commune in the Aude department in southern France.-Population:-External links:*...
(5). The channel continues to Béziers
Béziers
Béziers is a town in Languedoc in southern France. It is a sub-prefecture of the Hérault department. Béziers hosts the famous Feria de Béziers, centred around bullfighting, every August. A million visitors are attracted to the five-day event...
just after Fonsérannes Lock (6), and then on to Agde
Agde
Agde is a commune in the Hérault department in southern France. It is the Mediterranean port of the Canal du Midi.-Location:Agde is located on the river Hérault, 4 km from the Mediterranean Sea, and 750 km from Paris...
(7) before flowing in to the Bassin de Thau
Étang de Thau
Étang de Thau or Bassin de Thau is the largest of a string of étangs that stretch along the Languedoc-Roussillon, French coast from the Rhône River to the foothills of the Pyrenees which form the border to Spain. It is the second largest lake in France.-Description:It is about 21 km long...
at Sète (8).
At 193 metres (633.2 ft), Naurouze is the highest point of the canal with a drop of 57.18 metres (187.6 ft) between the summit and Toulouse and 189.43 metres (621.5 ft) between the summit and Sète. The longest pound is 53.49 kilometres (33.2 mi) between Argens Lock
Argens Lock
Argens Lock is a single chamber lock on the Canal du Midi. It lies east of the small town of Argens in the Aude region of Languedoc, France. The adjacent locks are Fonserannes Lock 53,868 metres to the east and Pechlaurier Lock 2485 metres to the west....
(Aude) and the Fonsérannes Lock (Hérault) while the shortest reach is 250 metres (820.2 ft) between two locks at Fresquel..
List of locks
The following list numbers the locksLock (water transport)
A lock is a device for raising and lowering boats between stretches of water of different levels on river and canal waterways. The distinguishing feature of a lock is a fixed chamber in which the water level can be varied; whereas in a caisson lock, a boat lift, or on a canal inclined plane, it is...
from the Canal lateral a la Garonne in the west to the Bassin du Thau in the east. Staircase locks are counted as a single entity but the number of individual chambers in the flight is noted. Travelling west - east from Toulouse to Sète the locks numbered 1–18 are ascending and 19–86 are descending.
See also
- Aqueducts on the Canal du MidiAqueducts on the Canal du MidiAqueducts on the Canal du Midi allow the canal to intersect and cross over natural streams. There are two exceptions, the first is the Herbettes Aqueduct where it crosses a four lane highway in Toulouse...
- Canal du MidiCanal du MidiThe is a long canal in Southern France . The canal connects the Garonne River to the on the Mediterranean and along with the Canal de Garonne forms the Canal des Deux Mers joining the Atlantic to the Mediterranean. The canal runs from the city of Toulouse down to the Étang de Thau...
- Water features on the Canal du MidiWater features on the Canal du MidiThe balancing of incoming and outgoing water allows the Canal du Midi to operate as it does. Each time a lock operates, large quantities of water are either required to fill it or dump from it into the lower level pound. There must be a constant source of water in order to fill and the excess...