A
pound lock is type of
lockA 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 whose water level can be varied; whereas in a caisson lock, a boat lift, or on a canal inclined plane, it is the...
that is used almost exclusively nowadays on
canalCanals are artificial channels for water. There are two types of canal: aqueduct canals are used for the conveyance and delivery of water, and waterway canals are navigable transportation canals used for passage of goods and people, often connected to existing lakes, rivers, or oceans.The word...
s and
riverA river is a natural watercourse, usually freshwater, flowing toward an ocean, a lake, a sea or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water...
s. A pound lock has a chamber (the
poundA canal pound is the stretch of level water impounded between two canal locks. Canal pounds can vary in length from the non-existent, where two or more immediately adjacent locks form a lock staircase, to many miles.-History:...
) with
gatesFloodgates are adjustable gates used to control water flow in reservoir, river, stream, or levee systems. They may be designed to set spillway crest heights in dams, to adjust flow rates in sluices and canals, or they may be designed to stop water flow entirely as part of a levee or storm surge...
at both ends that control the level of water in the pound. In contrast, an earlier design with a single gate was known as a
flash lockEarly locks were designed with a single gate, known as a flash lock. The earliest European references to what were clearly flash locks were in Roman times....
.
Indirect evidence suggests that pound locks may have been used in antiquity by the
Ptolemaic GreeksPtolemaic Egypt began when Ptolemy I Soter declared himself Pharaoh of Egypt in 305 BC and ended with the death of queen Cleopatra of Egypt and the Roman conquest in 30 BC. The Ptolemaic Kingdom was a powerful Hellenistic state, extending from southern Syria in the east, to Cyrene to the west, and...
and the
RomanThe Roman Empire was the post-Republican phase of the ancient Roman civilization, characterised by an autocratic form of government and large territorial holdings in Europe and around the Mediterranean. The term is used to describe the Roman state during and after the time of the first emperor,...
s.
Pound locks were created in ancient
ChinaChina is a cultural region, an ancient civilization, and, depending on perspective, a national or multinational entity extending over a large area in East Asia....
during the
Han DynastyThe Han Dynasty was the second imperial dynasty of China, preceded by the Qin Dynasty and succeeded by the Three Kingdoms . It was founded by the peasant rebel leader Liu Bang, known posthumously as Emperor Gaozu of Han. It was briefly interrupted by the Xin Dynasty of the former regent Wang Mang...
,
Song DynastyThe Song Dynasty was a ruling dynasty in China between 960 and 1279; it succeeded the Five Dynasties and Ten Kingdoms Period, and was followed by the Yuan Dynasty. It was the first government in world history to issue banknotes or paper money, and the first Chinese government to establish a...
(960–1279 AD), pioneered by the government official and engineer
Qiao WeiyoThe Song Dynasty provided some of the most significant technological advances in Chinese history, many of which came from talented statesmen drafted by the government through imperial examinations....
in 984, mentioned by the Chinese polymath scientist
Shen KuoShen Kuo or Shen Gua , style name Cunzhong and pseudonym Mengqi Weng , was a polymathic Chinese scientist and statesman of the Song Dynasty...
(1031–1095) in his book
Dream Pool EssaysThe Dream Pool Essays was an extensive book written by the polymath Chinese scientist and statesman Shen Kuo by 1088 AD, during the Song Dynasty of China...
(published in 1088), and fully described in the
Chinese historical textThe Twenty-Four Histories is a collection of Chinese historical books covering a period of protohistory and history from 3000 BC to the Ming Dynasty in the 17th century. The whole set contains 3213 volumes and about 40 million words...
Song Shi (compiled in 1345).
In medieval
EuropeEurope is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally divided from Asia to its east by the water divide of the Ural Mountains, the Ural River, the Caspian Sea, the Caucasus Mountains , and the Black Sea to the southeast...
a type of pound lock was first built in 1373 at
VreeswijkVreeswijk is a former village and municipality in the Dutch province of Utrecht. The municipality merged with Jutphaas in 1971, and is now the southern half of the town of Nieuwegein....
, the Netherlands.
A
pound lock is type of
lockA 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 whose water level can be varied; whereas in a caisson lock, a boat lift, or on a canal inclined plane, it is the...
that is used almost exclusively nowadays on
canalCanals are artificial channels for water. There are two types of canal: aqueduct canals are used for the conveyance and delivery of water, and waterway canals are navigable transportation canals used for passage of goods and people, often connected to existing lakes, rivers, or oceans.The word...
s and
riverA river is a natural watercourse, usually freshwater, flowing toward an ocean, a lake, a sea or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water...
s. A pound lock has a chamber (the
poundA canal pound is the stretch of level water impounded between two canal locks. Canal pounds can vary in length from the non-existent, where two or more immediately adjacent locks form a lock staircase, to many miles.-History:...
) with
gatesFloodgates are adjustable gates used to control water flow in reservoir, river, stream, or levee systems. They may be designed to set spillway crest heights in dams, to adjust flow rates in sluices and canals, or they may be designed to stop water flow entirely as part of a levee or storm surge...
at both ends that control the level of water in the pound. In contrast, an earlier design with a single gate was known as a
flash lockEarly locks were designed with a single gate, known as a flash lock. The earliest European references to what were clearly flash locks were in Roman times....
.
History
Indirect evidence suggests that pound locks may have been used in antiquity by the
Ptolemaic GreeksPtolemaic Egypt began when Ptolemy I Soter declared himself Pharaoh of Egypt in 305 BC and ended with the death of queen Cleopatra of Egypt and the Roman conquest in 30 BC. The Ptolemaic Kingdom was a powerful Hellenistic state, extending from southern Syria in the east, to Cyrene to the west, and...
and the
RomanThe Roman Empire was the post-Republican phase of the ancient Roman civilization, characterised by an autocratic form of government and large territorial holdings in Europe and around the Mediterranean. The term is used to describe the Roman state during and after the time of the first emperor,...
s.
Pound locks were created in ancient
ChinaChina is a cultural region, an ancient civilization, and, depending on perspective, a national or multinational entity extending over a large area in East Asia....
during the
Han DynastyThe Han Dynasty was the second imperial dynasty of China, preceded by the Qin Dynasty and succeeded by the Three Kingdoms . It was founded by the peasant rebel leader Liu Bang, known posthumously as Emperor Gaozu of Han. It was briefly interrupted by the Xin Dynasty of the former regent Wang Mang...
,
Song DynastyThe Song Dynasty was a ruling dynasty in China between 960 and 1279; it succeeded the Five Dynasties and Ten Kingdoms Period, and was followed by the Yuan Dynasty. It was the first government in world history to issue banknotes or paper money, and the first Chinese government to establish a...
(960–1279 AD), pioneered by the government official and engineer
Qiao WeiyoThe Song Dynasty provided some of the most significant technological advances in Chinese history, many of which came from talented statesmen drafted by the government through imperial examinations....
in 984, mentioned by the Chinese polymath scientist
Shen KuoShen Kuo or Shen Gua , style name Cunzhong and pseudonym Mengqi Weng , was a polymathic Chinese scientist and statesman of the Song Dynasty...
(1031–1095) in his book
Dream Pool EssaysThe Dream Pool Essays was an extensive book written by the polymath Chinese scientist and statesman Shen Kuo by 1088 AD, during the Song Dynasty of China...
(published in 1088), and fully described in the
Chinese historical textThe Twenty-Four Histories is a collection of Chinese historical books covering a period of protohistory and history from 3000 BC to the Ming Dynasty in the 17th century. The whole set contains 3213 volumes and about 40 million words...
Song Shi (compiled in 1345).
In medieval
EuropeEurope is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally divided from Asia to its east by the water divide of the Ural Mountains, the Ural River, the Caspian Sea, the Caucasus Mountains , and the Black Sea to the southeast...
a type of pound lock was first built in 1373 at
VreeswijkVreeswijk is a former village and municipality in the Dutch province of Utrecht. The municipality merged with Jutphaas in 1971, and is now the southern half of the town of Nieuwegein....
, the Netherlands. This pound lock serviced many ships at once in a large
basin- Natural forms :* Depression - landform lower than the surrounding area, such as the Kalahari Basin* Drainage basin - in geography and hydrology, a hydrological basin or catchment basin, a region of land where water drains downhill into a specified body of water* Endorheic basin - in geography...
, yet the true pound lock (i.e. one for a small basin) came in 1396 with the one built at
DammeDamme is a municipality located in the Belgian province of West Flanders, six kilometres northeast of Brugge . The municipality comprises the city of Damme proper and the towns of Hoeke, Lapscheure, Moerkerke, Oostkerke, Sijsele, Vivenkapelle, and Sint-Rita. On 1 January 2006, the municipality had...
near
BrugesBruges is the capital and largest city of the province of West Flanders in the Flemish Region of Belgium. It is located in the northwest of the country....
. A famous civil engineer of pound locks in Europe was the
ItalianItaly , officially the Italian Republic , is a country located on the Italian Peninsula in Southern Europe and on the two largest islands in the Mediterranean Sea, Sicily and Sardinia. Italy shares its northern, Alpine boundary with France, Switzerland, Austria and Slovenia...
Bertola da Novate (c. 1410-1475), who constructed 18 of them on the Naviglio di Bereguardo (part of the
MilanMilan in Italy, is the capital of the region of Lombardia and of the province of Milan. The city proper has a population of about 1.3 million, while the urban area is the fifth largest in the E.U. with an estimated population of 4.3 million...
canal system sponsored by Francesco Sforza) between the years 1452 and 1458.
External links