Clock towers are a specific type of structure that house a turret clock and have one or more clock faces on the upper exterior walls. Many clock towers are freestanding structures but they can also adjoin or be located on top of another building. Some other buildings also have clock faces on their exterior but these structures serve other main functions.
36-680: The Rajabai Tower is a clock tower in Mumbai India. It is in the confines of the Fort campus of the University of Mumbai . It stands at a height of 85 m (280 ft or 25 storeys). The tower is part of The Victorian and Art Deco Ensemble of Mumbai , which was added to the list of World Heritage Sites in 2018. The Rajabai Clock Tower was designed by Sir George Gilbert Scott , an English architect. He modeled it on Big Ben in London. The foundation stone
72-463: A church or municipal building such as a town hall . Not all clocks on buildings therefore make the building into a clock tower. The mechanism inside the tower is known as a turret clock . It often marks the hour (and sometimes segments of an hour) by sounding large bells or chimes , sometimes playing simple musical phrases or tunes. Some clock towers were previously built as Bell towers and then had clocks added to them. As these structures fulfil
108-474: A mannequin , every hour. It was possible to re-program the length of day and night daily in order to account for the changing lengths of day and night throughout the year, and it also featured five robotic musicians who automatically play music when moved by levers operated by a hidden camshaft attached to a water wheel . Line (mains) synchronous tower clocks were introduced in the United States in
144-635: A clock added in 2002, has a roof height of 240 m (790 ft), and an antenna height of 272 m (892 ft). The Abraj Al Bait , a hotel complex in Mecca constructed in 2012, has the largest and highest clock face on a building in the world, with its Makkah Royal Clock Tower having an occupied height of 494.4 m (1,622 ft), and a tip height of 601 m (1,972 ft). The tower has four clock faces, two of which are 43 m (141 ft) in diameter, at about 400 m (1,300 ft) high. Turret clock A turret clock or tower clock
180-753: A clock was put up in a clock tower, the medieval precursor to Big Ben , at Westminster , in 1288; and in 1292 a clock was put up in Canterbury Cathedral . The oldest surviving turret clock formerly part of a clock tower in Europe is the Salisbury Cathedral clock , completed in 130. A clock put up at St. Albans , in 1326, 'showed various astronomical phenomena'. Al-Jazari of the Artuqid dynasty in Upper Mesopotamia constructed an elaborate clock called
216-455: A few cases, possibly mercury . During the fourteenth century, the emergence of the foliot replaced the high-maintenance water clocks. It is not known when that happened exactly and which of the early 14th century clocks were water clocks and which ones use a foliot. The Heinrich von Wieck clock in Paris dating from 1362 is the first clock of which it is known with certainty that it had a foliot and
252-422: A square form up to the gallery at the top of the first level which is at a height of 68 feet (21 m) from the ground. The form changes from a square to an octagon and the height from this gallery to the top of the tower is 118 feet (36 m) and the third stage to the top of the finial is 94 feet (29 m), thus making a total height of 280 feet (85 m). During its time, it was the tallest structure in
288-669: A verge escapement. The fact that there is a sudden increase in the number of recorded turret clock installations points to the fact that these new clocks use verge & foliot. This happens in the years 1350 and onwards. qui etait a present moult demolis et venus k ruyne et en peril de keir (tomber) de jour en jour et en obtenir l'autorisation d'y placer une orloge pour memore des heures de jour et de nuit sicomme il est en pluseurs autres lieux et bonnes villes du paus environ". It becomes apparent that even small towns can afford to put up public striking clocks. Turret clocks are now common throughout Europe. No surviving clock mechanisms (apart from
324-517: Is a clock designed to be mounted high in the wall of a building, usually in a clock tower , in public buildings such as churches , university buildings, and town halls . As a public amenity to enable the community to tell the time, it has a large face visible from far away, and often a striking mechanism which rings bells upon the hours. The turret clock is one of the earliest types of clock. Beginning in 12th century Europe, towns and monasteries built clocks in high towers to strike bells to call
360-517: The Council on Tall Buildings and Urban Habitat a structure is defined as a building if at least fifty percent of its height is made up of floor plates containing habitable floor area. Structures that do not meet this criterion, are defined as towers . A clock tower historically fits this definition of a tower and therefore can be defined as any tower specifically built with one or more (often four) clock faces and that can be either freestanding or part of
396-745: The Parliament of Canada in Ottawa , and the Zytglogge clock tower in the Old City of Bern , Switzerland . The tallest freestanding clock tower in the world is the Joseph Chamberlain Memorial Clock Tower (Old Joe) at the University of Birmingham in Birmingham , United Kingdom. The tower stands at 100 metres (330 feet) tall and was completed in 1908. The clock tower of Philadelphia City Hall
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#1732855839553432-414: The canonical hours for the purpose of calling the community to prayer. Installed in clock towers in cathedrals , monasteries and town squares so they could be heard at long distances, these were the first turret clocks. By the 13th century towns in Europe competed with each other to build the most elaborate, beautiful clocks. Water clocks kept time by the rate of water flowing through an orifice. Since
468-437: The "castle clock" and described it in his Book of Knowledge of Ingenious Mechanical Devices in 1206. It was about 3.3 metres (11 feet) high, and had multiple functions alongside timekeeping . It included a display of the zodiac and the solar and lunar paths, and a pointer in the shape of the crescent moon that travelled across the top of a gateway , moved by a hidden cart and causing automatic doors to open, each revealing
504-931: The 1920s. Some clock towers have become famous landmarks. Prominent examples include Elizabeth Tower built in 1859, which houses the Great Bell (generally known as Big Ben ) in London , the tower of Philadelphia City Hall , the Rajabai Tower in Mumbai , the Spasskaya Tower of the Moscow Kremlin , the Torre dell'Orologio in the Piazza San Marco in Venice , Italy , the Peace Tower of
540-780: The Library and the Rajabai Clock Tower received the UNESCO Asia-Pacific Award for Cultural Heritage Conservation. Clock tower Clock towers are a common sight in many parts of the world with some being iconic buildings. One example is the Elizabeth Tower in London (usually called " Big Ben ", although strictly this name belongs only to the bell inside the tower). There are many structures that may have clocks or clock faces attached to them and some structures have had clocks added to an existing structure. According to
576-589: The authenticity of those that do survive is disputed. What little is known of their mechanisms is mostly gleaned from manuscript sources. The "country" column refers to the present (2012) international boundaries. For example, Colmar was in Germany in 1370, but is now in France. The verge and foliot escapement is thought to have been introduced sometime at the end of the thirteenth century, so very few if any of these clocks had foliot mechanisms; most were water clocks or in
612-637: The city of Mumbai. During the 19th century it played the tunes of " Home! Sweet Home! " and " A Handel Symphony ", out of a total of sixteen tunes, which changed four times a day. It currently chimes only one tune every 15 minutes. From October 2013 to 11 May 2015, the tower underwent restoration work under the observation of Anita Garware (Heritage Society), Rajan Welukar (Vice-Chancellor; University of Mumbai) and N Chandrasekar (CEO, Tata Consultancy Services). It reopened in March 2015 after renovation. The restoration efforts were recognised by UNESCO in 2018 when
648-410: The community to prayer. Public clocks played an important timekeeping role in daily life until the 20th century, when accurate watches became cheap enough for ordinary people to afford. Today the time-disseminating functions of turret clocks are not much needed, and they are mainly built and preserved for traditional, decorative, and artistic reasons. To turn the large hands and run the striking train,
684-416: The definition of a tower they can be considered to be clock towers. Although clock towers are today mostly admired for their aesthetics, they once served an important purpose. Before the middle of the twentieth century, most people did not have watches, and prior to the 18th century even home clocks were rare. The first clocks did not have faces, but were solely striking clocks , which sounded bells to call
720-479: The force of the wheel train. The error in the first mechanical clocks may have been several hours per day. Therefore, the clock had to be frequently reset by the passage of the sun or stars overhead. The pendulum clock was invented and patented in 1657 by Dutch scientist Christiaan Huygens , inspired by the superior timekeeping properties of the pendulum discovered beginning in 1602 by Italian scientist Galileo Galilei . Pendulum clocks were much more accurate than
756-455: The late 13th century kept time with a verge escapement and foliot (also known as crown and balance wheels). In the second half of the 14th century, over 500 striking turret clocks were installed in public buildings all over Europe. The new mechanical clocks were easier to maintain than water clocks, as the power to run the clock was provided by turning a crank to raise a weight on a cord, and they also did not freeze during winter, so they became
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#1732855839553792-411: The late 19th century. Some mechanical turret clocks are wound by electric motor. These still are considered mechanical clocks. This table shows some of the turret clocks which were installed throughout Europe. It is not complete and mainly serves to illustrate the rate of adoption. There are hardly any surviving turret clock mechanisms that date before 1400, and because of extensive rebuilding of clocks
828-410: The locally available buff coloured Kurla stone. The tower has one of the best stained glass windows in the city. The ground floor has two side rooms, each measuring 56 ft × 27.5 ft (17.1 m × 8.4 m). The tower forms a carriage porch 2.4 m (26 sq ft), and a spiral staircase vestibule of 2.6 m (28 sq ft). The Tower, over the carriage porch, has
864-497: The mechanism of turret clocks must be more powerful than that of ordinary clocks. Traditional turret clocks are large pendulum clocks run by hanging weights, but modern ones are often run by electricity. Water clocks are reported as early as the 16th century B.C. and were used in the ancient world, but these were domestic clocks. Beginning in the Middle Ages around 1000 A.D. striking water clocks were invented, which rang bells on
900-549: The most common type, called gravity escapements , instead of applying the force of the gear train to push the pendulum directly, the escape wheel instead lifted a weighted lever, which was then released and its weight gave the pendulum a push during its downward swing. This isolated the pendulum from variations in the drive force. One of the most widely used types was the three-legged gravity escapement invented in 1854 by Edmund Beckett (Lord Grimsthorpe). Electric turret clocks and hybrid mechanical/electric clocks were introduced in
936-485: The pendulum clock was increased by the invention of the anchor escapement in 1657 by Robert Hooke , which quickly replaced the primitive verge escapement in pendulum clocks. The first tower clock with the new escapement was the Wadham College Clock , built at Wadham College, Oxford , UK, in 1670, probably by clockmaker Joseph Knibb . The anchor escapement reduced the pendulum's width of swing from 80 to 100° in
972-417: The previous foliot clocks, improving timekeeping accuracy of the best precision clocks from 15 minutes per day to perhaps 10 seconds a day. Within a few decades most tower clocks throughout Europe were rebuilt to convert the previous verge and foliot escapement to pendulums. Almost no examples of the original verge and foliot mechanisms of these early clocks have survived to the present day. The accuracy of
1008-436: The rate of flow varies with pressure which is proportional to the height of water in the source container, and viscosity which varies with temperature during the day, water clocks had limited accuracy. Other disadvantages were that they required water to be manually hauled in a bucket from a well or river to fill the clock reservoir every day, and froze solid in winter. The first all-mechanical clocks which emerged in Europe in
1044-488: The standard mechanism used in the turret clocks being installed in bell towers in churches, cathedrals, monasteries and town halls all over Europe. The verge and foliot timekeeping mechanism in these early mechanical clocks was very inaccurate, as the primitive foliot balance wheel did not have a balance spring to provide a restoring force , so the balance wheel was not a harmonic oscillator with an inherent resonant frequency or "beat"; its rate varied with variations in
1080-477: The surrounding community to work or to prayer. They were therefore placed in towers so the bells would be audible for a long distance. Clock towers were placed near the centres of towns and were often the tallest structures there. As clock towers became more common, the designers realized that a dial on the outside of the tower would allow the townspeople to read the time whenever they wanted. The use of clock towers dates back to antiquity . The earliest clock tower
1116-405: The varying torque on the wheel train caused by the weight of the huge external clock hands as they turned, which was made worse by seasonal snow, ice and wind loads on the hands. The variations in force, applied to the pendulum by the escape wheel, caused the period of the pendulum to vary. During the 19th century specialized escapements were invented for tower clocks to mitigate this problem. In
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1152-413: The verge clock to 3-6°. This greatly reduced the energy consumed by the pendulum, and allowed longer pendulums to be used. While domestic pendulum clocks usually use a seconds pendulum 1.0 meter (39 in) long, tower clocks often use a 1.5 second pendulum, 2.25 m (7.4 ft) long, or a two-second pendulum, 4 m (13 ft) long. Tower clocks had a source of error not found in other clocks:
1188-399: Was blind and as a staunch follower of Jain religion, she was supposed to consume her dinner before the evening. Legend says that the evening bell of the tower helped her to know the time without anyone's help. The tower was closed to the public after it became a frequent spot for those attempting suicide. The tower was built in a fusion of Venetian and Gothic styles. It is built out of
1224-523: Was laid on 1 March 1869 and construction was completed in November 1878. The total cost of construction came to ₹550,000, a large amount of money for the time period. A portion of the total cost of construction was donated by Premchand Roychand Jain , a wealthy broker who founded the Bombay Stock Exchange on the condition that the tower be named after his mother Rajabai. Premchand Roychand 's mother
1260-608: Was part of the tallest building in the world from 1894, when the tower was topped out and the building partially occupied, until 1908. Taller buildings have had clock faces added to their existing structure such as the Palace of Culture and Science in Warsaw , with a clock added in 2000. The building has a roof height of 187.68 m (615.7 ft), and an antenna height of 237 m (778 ft). The NTT Docomo Yoyogi Building in Tokyo , with
1296-632: Was the Tower of the Winds in Athens , which featured eight sundials and was created in the 1st century BC during the period of Roman Greece . In its interior, there was also a water clock (or clepsydra), driven by water coming down from the Acropolis . In Song dynasty China , an astronomical clock tower was designed by Su Song and erected at Kaifeng in 1088, featuring a liquid escapement mechanism. In England,
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