A lock is a hydraulic Work of art established in a channel or a River to make it navigable and make it possible the Bateau X to cross unevennesses. The lock includes/understands a hopper in which one can vary the level of water. It is isolated from the levels upstream and downstream by doors provided with valves called “sluice valves”.
In the beginning (the Middle Ages, Rebirth), the word “lock” indicates a simple winnowing (Latin Aqua exclusa: separate water). If it is about a work of navigation, that is then specified “lock of navigation”, i.e. in fact a sluice. It is by gradually bringing closer two sluices framing a basin which will become the hopper which one will evolve to the lock, by the intermediate stage to the Bassin to marine doors. This occurs during. It can be empirical work smart millers seeking a means of saving the water lost with each passage of boat in a marine door (a sluice) simple.
Contrary to a largely spread idea, Léonard de Vinci is not the inventor of the lock, even if he worked much on the question and even designed channels. The principle of the hopper on variable level existed before him, just as probably that of the doors known as “busquées” which form an angle pointed upstream so as to resist the pressure of water according to a principle close to that of the vault, but applied to the horizontal one. One gradually passed from the sluice antiquated, dangerous and very consuming water to the “modern” lock by the intermediate stage of the Bassin to marine doors or “Paléo-lock” which consists of a vast basin being used as hopper, framed upstream and downstream by sluices. Léonard de Vinci probably put the final key at this work by recommending the rectangular form that we generally know to him.
The names of many engineers of the Rebirth, especially Italian, are associated with this progressive invention of the lock: Bertola da Novate, Fiorivanti da Bologna, and of course Léonard de Vinci which, as we have just seen it, if he did not invent the lock with the clean direction, put his final key to him while bringing the last improvements there, as for example a small shutter placed at the bottom of the door which allows a sufficient water flow to balance the pressure on both casements and to facilitate the opening of it, preceding the future “butterfly valves”. The Dutch engineers are not remains about it either, but their names did not reach us.
Thereafter, one will not cease improving the system, but the principle remains the same one. One will employ sometimes, instead of the traditional busquées doors, of the doors with guillotines or the doors known as “sector”, or of the plunging valves.
Until the end of the 19th century, the maximum fall of the locks hardly exceeds 4 m, because the system of valves punts does not function any more under one too strong pressure. It is the invention of the cylindrical valve by the engineer Moraillon at the end of this 19th century which will allow the construction of locks of high fall exceeding 5 m: on a vertical roll, the pressures are cancelled, and there is not any evil to raise such a valve.
Some heights record
In France, with the gauge Freycinet, the locks of higher falls are:
1. Réchicourt, on the Channel of the Marne in the Rhine (in the department of the Moselle), with 15,70 m
2. Crissey, on the Channel of the Center (in the north of Trawl-net/the Saone), with 10,50 m
3. Flandres, on the Channel Saint-Denis (beside the city from the Villette in Paris), with 9,80 m
7. Laroche and Germigny, on the Channel of Burgundy, with 5,50 m each one
10. Several locks of the Channel of the Center, with 5,20 m, and several of the Channel of Briare, with 5 Mr.
11. The lately rehabilitated (September 20th, 2007) lock of descent in the Loire of Orleans, at the end of the Channel of Orleans, with a variable fall according to the level of the Loire, but higher than 5 Mr.
On the Channel of the South, near Béziers, the eightfold lock of Fonséranes allows the crossing of uneven of 21,50 meters out of 300 meters length, but its lower hopper is out-service, and one enters directly its 2nd hopper which is in level high constant (it is only the prolongation of the level of the tubular bridge of Béziers). I.e. that today this work does not catch up with any more that one fall of about 16 Mr.
On the Channel of Briare, the model of Fonséranes, the sevenfold lock of Rogny, caught up with a fall of 24 m on a little more than 220 m length.
In large gauge, the highest locks of France are on the the Rhone, highest being Saint-Pierre (Bollène) with 23 Mr.
Out of gauge lower than Freycinet, one can quote two recent locks on the Lot: Castelmoron (10 m) and Villeneuve (13 m).
Abroad, one will find that of Zaporoje, on the Dniepr, which reaches 37 m, and that of Carapatello, on the Douro, which reaches 34 Mr. the very recent locks of the stopping of the Three Throats, in China, are even higher.
On the other hand, in France, the locks of weaker fall are in the Marais Poitevin where some hardly exceed 20 cm, and on the Canal of Ourcq, where it turn around 50 cm.
In the case of the River S or navigable River S, the locks are established with the right of a Barrage which creates a water level upstream. The unit is called a “locked stopping”. One usually finds some on the the Seine, the Yonne, the Marne, the Oise, the Cher, the Lot, the Tarn, the Mayenne, the the Sarthe, the Seille, etc
The crossing of a lock is an operation of which the duration varies with the design of the work, and not only according to its height or of its volume of water necessary (“bathed”). It is necessary to balance the water level with a level then with the other, by transferring each time a mass from water of the level upstream towards the level downstream, corresponding to the volume of bathed (either right-angled parallelepiped (length of the hopper × width of the hopper × drop height). That supposes a channel in the case of a water supply proportioned with the intensity of navigation. The passable unevenness by a lock is limited to 25 m approximately. Beyond it is necessary to create a series of locks in chain, which still complicates the passage. One knows some however which exceeds the 30 m of fall: Carapatello on the Douro with the Portugal: 34 m, and Zaporoje on the Dniepr: 37 Mr.
One also finds locks at the entry of some port S subjected to the Marée. The lock is used to keep a depth of constant water in the basin even with low tide. The schedules of opening are indicated compared to the schedules of tide in the nautical Instructions. The days of low coefficients, certain small ports do not open the lock of the day because even with high tide, the water level outside is too low to make it function correctly.
Located in the wearing of Antwerp, in Belgium, the lock of Berendrecht is largest of planet: 500 meters length, 68 m broad and 18 m of depth. Before it, the locks of the wearing of Antwerp “Kruiskans”, “Baudouin”, “Zandvliet” were successively largest of the world.
On the other hand, smallest (which is not a model) is perhaps in France, in the Marais Poitevin, with Maillé with the locality the Aqueduct. It measures 7 m on 3, and its fall oscillates between 0 and 30 cm according to the level of the river on which it is, the Jeune Autize.
Evolution in the construction industry
Lock with door with raising (known as “with guillotine”)It is the first lock known to date, i.e. a portion of channel closed by two doors, which has the advantage of requiring that an minor amount of water compared to the sluice. It is in 983, qu' a Chinese engineer of the name of Chhaio Wei-yo built the first hopper equipped with a door with raising at its two ends. The disadvantage was that these doors punts were easily manoeuvrable only for the rather low heights of water because of the pressure exerted on them. In 1438, in Europe, two Italian engineers, Filippo Degli Organi and Fiorivanti di Bologna , create the first lock on the Naviglio Grande in Vierenna, one of the channels of Milan.
This system is always used, in particular for the gates lower of the locks of high fall as on the Rhone, or that of Crissey on the channel of the Center or on the locks of the tilted Plan of Saint-Louis-Arzviller. They are also called “doors with guillotine”.
Lock with busquées doorsTo mitigate the pressure exerted on the doors, then perpendicular to flow, in 1460 one invented the doors known as busquées, i.e. that once closed, the angle which they form opposes to flow water whose pressure ensures closing and the sealing. Does invention what one allot - to wrong or rightly? - with Léonard de Vinci (which is 8 years old in 1460!), as well as the system of operation and of the small shutters with bolt placed at the bottom of the doors which allow the duct drainage of the level the hopper or conversely to balance the pressure on both leaf S or casements, and to facilitate the opening of it. These small shutters will become thereafter the sluice valves, i.e. of the valves sliding vertically. A drawing of the hand of Léonard (museum of Closed Lucé with Amboise) seems to accredit this thesis, but it simply did not improve what existed already front him?.
In 1485, the engineer of the duke of Milan, Bertola da Novate , built the channel of Bereguardo with these first modern locks.
In France, this invention was implemented, for the first time seems it, by an Italian engineer whose name was not preserved (perhaps it is about same Bertola da Novate), on the Yèvre at the beginning of XVIe century. It was taken again and improved since 1605 by Hugues Cosnier , on the Canal of Briare (Hugues Cosnier was also the inventor of the multiple lock ). Hugues Cosnier will also substitute for the sluice valves in the doors a system of aqueducts in masonries, the “drums”, always sealed by valves, which allow a more important water surge and distributed better. On the other hand, that is more expensive construction. Cosnier saw this system applied successfully in Belgium.
The busquées doors are so effective that they are still very current in all the channels of the world, and in particular on the channels of France.
Lock with swivelling doors or “doors sector”This type of door has casements whose curve of the Extrados cancels the pressure of water. It is the same architecture of the leaves of the Barrage S mobiles with vertical axis. This system, which seems to be tested for the first time on the sluice of the small channels of the high Seine at the XVIIIe century, names “doors sector”. It is this principle which governs the doors of the stopping of Maeslantkering in Holland ().
The various shapes of locks
Oval locksTo some of the first locks whose walls are built with stones, one gave an oval form to resist the rock pressure. This provision was recommended and applied in particular by Pierre-Paul Riquet for his Canal of the South, and was taken again for the Lez. Abroad, one finds locks oval in Scandinavia, in England, Spain, Italy…
Rectangular locksThe use of the reinforced concrete allows the construction of parallel locks walls offering better a resistance to pushed ground. The implementation and maintenance are some simplified. But before the use of the concrete, the rectangular form had been adopted for the large majority of the hoppers, and this since Hugues Cosnier on the Canal of Briare, during first half of the XVIIe century.
Lock round AgdeBuilt of 1679 to 1680 and single in the world, this hopper with the characteristic to have three doors and, by a simple rotation, allows the boat to choose between three directions (Herault, the ship canal or the Canal of the South).
In the Seventies, work of setting to the standards modified the aspect of the work.
Lock round the Lorraine onesThis other round lock belongs to the Latéral channel in the Loire. It is located at the origin of the junction of Apremont, which is used as hydrant in Combining it to feed the channel since Guétin until Briare. It was built of 1835 to 1841 and measures 32 m in diameter. In addition to its food role, it was used formerly as entry on the network of the channels with the boats built in Veurdre, a little upstream on Combining it. It preserves nothing any more but its food role nowadays. Its circular form was dictated by the need for directing its entry in river towards the downstream in order to avoid the stranding of it. The boats carried out an almost complete rotation in the hopper, the entry and the exit being almost side by side.
To cross the important unevennesses, other devices were also designed:
- the ship lifts
the tilted plane which were born in England as of the end of the XVIIIe century. The boat can be transported either dry there (Elblag in Poland, Krasnoïarsk in Ukraine), or in a vat full of water (Ronquières in Belgium, tilted Plan of Saint-Louis-Arzviller in France). Most of Krasnoïarsk on the Iénisséi with a fall from approximately 100 Mr.
Locks and environmentWithout denying the many environmental advantages of transport by Barge S, one can admit that the locks contribute to some environmental problems:
- Artificialisation of the rivers (if they increase oxygenation locally, they contribute to give in suspension of the Sédiment S often polluted in the channels)
- to limit the oxidation and the wear of essential parts of lock lockgates, these parts functioned drowned a long time in a bath of mercury (until more than 1 kg of mercury per door), with tiny in normal weather but very important losses in the event of accident. The mercury lost in the channels can be transformed into very toxic Methyl-mercury by the bacteria of the sediments, downstream, and it is strongly bioaccumulable.
- After-effects of war: Certain locks having been the object lasting the recent wars (since 1870) of intensive shootings, their funds and accesses can still contain immersed Munitions or not exploded Munitions, possibly chemical for those of the period 14-18. These ammunition will be likely to pose problems of toxicity for the environment and the personnel when they start to flee following their corrosion. Germany, Belgium and the North of France are concerned.
- They are places where the boats must slow down, stop, then to start and accelerate, certain marines making turn to full their engines. Fuel sometimes not desulphured used by these engines, and oil can be at the origin of an air pollution and grounds increased around the zone of the lock. Let us relativize however: this pollution remains very specific and if one refers to transported tonnage (250 tons for motorized Freycinet of channel, propelled by an engine of 200 approximately cv), it is very largely lower than the total emissions of a semitrailer (450 cv to carry 25 tons), and the boat does not encumber the roads.
- Very enlightened the night, for safety reasons, on the main roads which function 24:00 on 24 (the Rhone, the Seine), they contribute to the phenomenon of luminous Pollution, which could be reduced with a variable lighting according to the need and the weather conditions.
- the Wheel of Falkirk
- Network of the inland waterways
- Lock with fish
- List of the locks of the channel of the South
- List of the locks of the channel of the Garonne
- Locks of Fonséranes
- Écluses of the Channel of the South
- Deltawerken Online Krammer Locks, separates salt water and the fresh water
- interactive Simulation of lock - Discovered operation of a lock (in French, English, Dutch)
- river Lexicon and boatman in the Babel Project: the lock
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