50 FACTS ABOUT THE LEANING TOWER OF PISA

50 FACTS ABOUT THE LEANING TOWER OF PISA

1. Construction of Tower began in 1173 under supervision of architect Bonanno Pisano.

2. Bell tower was built as manifestation of city’s pride and was meant to reflect rich city of Pisa.

3. Work on Tower ceased in 1178 for reasons unknown; studies have shown that soil on which Tower was built would not have been able to withstand more construction at that time.

4. Construction began again, but ceased in 1278.

5. Had Tower been completed at this time, would have collapsed because of the stress on soil.

6. During actual construction of Tower in 1100’s, Tower originally leaned north
- Masonry blocks placed on each level to correct lean of axis.

7. By end of its construction, the Tower leaned significantly to the South.

8. Tower was finally completed in 1370; height is 53 m.

9. From early 1990 until December 2001, Tower was closed to public because of safety issues.

10. Italian engineers implemented complex $25 million rescue plan in order to stabilize Tower.

11.  Although Tower looks as if it might collapse at any moment, in reality, it is more stable now than at any time in past few centuries.

12. In 1838, architect Alessendro della Gherardesca constructed a walkway around Tower base .

13. Water filled the walkway area after the excavation extended below water table.

14. Plan increased tilt of Tower by over one quarter of a degree.

15. Gherardesco placed 0.7 meter thick ring of concrete around walkway to help stabilize Tower, but excavation nearly caused its downfall.

16. In 1934, engineers used grout injection to stabilize the foundation of Tower.

17. This process led to a displacement of Tower.

18. The tip of Tower tilted 10 mm more to South.

19. In 1993, 600 Mg of lead weights were added to north side of Tower, attached by a removable concrete ring placed around base of Tower
- Reduced leaning by nearly one minute of an arc
- Reduced moment that pulled on Tower by 10%.

20. Load was increased in 1995 to 900 Mg while engineers attempted to replace lead weights with ground anchors.

21. One unique idea was to drill 10,000 holes in Tower to significantly reduce its weight.

22. Replica was to be placed next to Tower leaning in opposite direction to hold original tower in place.

23. A new restoration idea was presented in the 1990s
- Known as soil extraction, or soil subsidence
- Its goal was to excavate earth from beneath Tower’s foundation on its northern side so that Tower would tilt back toward perpendicular.

24. Idea was put into motion after various tests on Tower itself and on soil underneath its foundation.

25. Temporary cables attached to 3rd level of Tower
- Would support Tower if anything went wrong during soil extraction.

26. Lead weights were attached to ends of cables to ensure that Tower would remain steady.

27. First soil extraction occurred on February 9, 1999
- Extracted by means of corkscrew drills.

28. At first, Tower showed no sign of rotation, but then rotated toward the North.

29. Tower had rotated seven seconds of an arc toward the North by February 23, 1999, but then it rotated back toward the South
- Occurred as a result of strong, cold winds from the North
- Tower soon began to rotate back toward the North after winds had diminished.

30.Soil extraction was stopped after Tower had rotated a total of eighty seconds of an arc by June 1999.

31. Three of the lead weights were removed in July 1999, and this resulted in a discontinuation of rotation.

32. Main soil extraction began in the year 2000, after preliminary extractions had shown vast improvement.

33. Tower had a tendency to rotate to the East throughout the process, so soil also had to be extracted from foundation’s west side.

34. Tower continued to move northward, and slowly the lead was removed from the structure.

35. Restoration process was finished on June 6, 2001.

36. Tower had returned to position it was in before 1838.

37. Restoration process moved Tower 1,830 seconds of an arc.

38. Design process cost the Italian taxpayers $25 million.

39. Design process was complicated by decree made by Italian Government that needed to be approved regularly by Italian Parliament
- Delayed restoration process
- Work was halted for long periods of time.

40. Restoration process was halted when harsh winds caused Tower to rotate toward the South.

41. Throughout restoration process, Tower had to be closed to tourists
- Tourists had been able to pay a fee so they could climb Tower.

42. Stabilization of Leaning Tower provided difficulties of its own
- Tower was originally constructed on weak, compressible soil, which increased .instability of Tower.
- Ground on south side of Tower had to be treated with delicacy because any .disturbance could result in falling of Tower.
- Original design of Tower had to be respected throughout the process to conserve monument’s character.

43. There are 294 stairs to top of Tower.

44. Leaning Tower weighs about 14,700 metric tons.

45. About three million people visit Tower annually.

46. There are seven bells on Tower, largest of which weighs 3.5 tons.

47. Restoration process was very difficult to execute
- Soil on which Tower was built was very unstable
- Tower’s original design had to be maintained.

48. Soil extraction was a successful process that saved Tower from collapse.

49. Speculation on whether restoration process will be beneficial in future
- Professor Burland, who oversaw the restoration process, believes Tower may stay in its current condition
- Professor Burlandspeculates that Tower may begin rotating again, and in 300 years,
Tower will be where it was in 1990s.

50. Leaning Tower was reopened to public on December 15, 2001.

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FUN FACTS ABOUT THE EIFFEL TOWER

FUN FACTS ABOUT THE EIFFEL TOWER

1. From the ground to the second floor: 

5 (one in the East pillar, one in the West pillar, one in the North pillar, one private elevator in the South pillar for the “Jules Verne” restaurant and one goods elevator in the South pillar). From the second floor to the top: two sets of two duo lifts.

It towers over the Paris skyline and is one of the most recognized monuments in the world. The Eiffel Tower has a storied past and has served its city well as a worldwide ambassador. Here are some fun facts to help you learn a little more about the Eiffel Tower.

2. The Eiffel Tower is nicknamed “The Iron Lady”.

The French people have nicknamed the Eiffel Tower “La dame de fer” which translates to“The Lady of Iron.” Most of the structure is made of puddle iron, which is a pure form of iron. Puddled iron is stronger than regular iron and is used for buildings that need a lot of extra strength. Because the tower is so tall, the iron needed to be strong enough to support the weight and to fight the winds that press against the top of the tower.

3. For 41 years the Eiffel tower was the tallest structure in the world.

When it was built in 1889, the Eiffel Tower surpassed the Washington monument as the tallest structure in the world, and it held that title for 41 years. When it was first  built, the tower was 986 feet (300.5 meters) tall. In 1930 the Chrysler Building was built in New York City. The Chrysler Building stands 1057 feet (322.2 meters) tall, including its spire. Later that same year a 77 foot (23.5 meter) tall radio antennae 

was added to the tower to again make it the tallest building in the world, but only for a short time. At 1,063 feet (324 meters) tall, the Eiffel Tower is the height of an 81 story building.

4. There are over 18,000 pieces of iron in the tower.

The tower is actually made up of 18,038 pieces of iron two and a half million rivets. Each of these pieces is held in place with rivets. A rivet is a metal pin that has a head at one end. The other end is hammered into a head with a hole in it, after it has gone through the iron. There are over two and a half million rivets holding together the Eiffel Tower! It took 300 workers over two years to build the tower.

5. The Eiffel Towerwas built as the entrance to aWorld’s Fair.

The tower was meant to serve as the entrance to the World’s Fair, held in Paris from May to October 1889. People would enter the fair by walking under the tower. The World’s Fair was called the Exposition Universelle and it marked the one hundred year anniversary of the French Revolution. During the fair, countries and organizations from all over the world had exhibits at the fair. World’s Fairs can be huge, with many buildings and exhibit halls included. They are still held today, about every two to three years apart.

6. The Eiffel Towerwasn’t finished when it first opened.

The World’s Fair opened on May 6, 1889, but the Eiffel tower wasn’t completely finished yet. The tower workers worked hard all night to finish enough of the tower that people could climb up to the second floor platform safely.  The second floor platform is 377 feet (115 meters) above ground and it provided a wonderful view of the Exposition Park. Only construction workers were allowed to go above the second floor platform.

7. Many people hated the tower when it was first built.

When the tower first went up, a lot of people really didn’t like the way it looked. The newspapers were filled with angry letters that had been written against the tower. Even famous people such as the writer Alexandre Dumas, the composer Charles Gounod, and the painter and sculptor Ernest Meissonier wrote letters against the tower. Some people even called it a “metal asparagus.”

Even though many people hated it, it was too late to change the design of the tower. It needed to be in place for the opening of the World’s Fair, so the tower was finished. Over the years, many people have changed their mind about the tower. It is now considered to be not only a great piece of architecture, but a great work of art.

8. The Eiffel Towerwas meant to be taken apart and destroyed.

When the tower was originally built, it was only supposed to stand for 20 years. In fact, the original rules for the contest for the entrance tower said that it must be easy to demolish! At the end of the twenty years, in 1909, the City of Paris became the owner of the tower. Instead of demolishing it, the city decided that it would make a great radio tower. The tower served as a radio tower during the First World War. It was used to jam the radio signals of the German army that was approaching Paris. It was also used in September 1914 to send taxi cabs carrying over 6,000 French soldiers to battle the Germans in a place called Marne.

9. The Eiffel Tower is actually painted three different colors.

When you look at the Eiffel Tower, it looks like it is painted one solid color all the way up. It isn’t. If there was one solid color on it, the tower would actually look like it was painted in different colors. This is because your eyes see light and colors a bit differently when they are far away than they do when they are close up. 

Also, the amount of light reflected from the sky in the background is also different.The tower is repainted every seven years, to keep the color bright and to protect the tower from rust. It takes about 55 to 65 tons (50 to 60 tonnes) of paint to paint the entire tower. As of 2011, the tower was painted bronze, however the color will sometimes change. On the first floor of the tower visitors can vote on which color should be used for a future painting.

10. There are 72 men’s names engraved on the Eiffel Tower.

When Gustave Eiffel designed the Eiffel Tower, he included the names of 72 prominent French men. These men were engineers, scientists, and other important people. Gustave Eiffel wanted to recognize the important work they had done, so he had their last names engraved just below the first level in letters that are two feet (60 cm) tall.At some time around 1900 the names were painted over. They were left hidden for about 80 years. Then in 1986 and 1987 they were cleaned off and fixed up. They are now painted in gold. While there are 72 men’s names from several different occupations, there are no women included!

11. The Eiffel Tower bends in the sunlight!

Iron expands when it gets hot. When the sunlight hits the side of the tower for long periods during the day, the iron on that side of the tower heats up. That causes it to expand and grow larger, pushing over onto the cooler, shorter side of the tower.On very hot days, the tower will lean over seven inches (17 cm) from the center due to the heated iron.

12. At one time the Eiffel Towerwas used as a giant billboard!

From 1925 to 1930, three sides of the tower showed huge, lighted advertisements. The billboards advertised a company called Citroen, which is a French auto maker. The Citroen Company has been around since 1919, and they are still building cars today. In 1930 the billboards were removed so the tower could be completely seen again.

13. It is illegal to publish pictures of the Eiffel tower when it is lit.

In 1989 the Eiffel Tower was lit up in lights in honor of its 100th birthday. The organization that runs the tower decided to copyright the lighting display. In June 1990 a French court ruled that the display was an “original visual creation” and could be protected by a copyright. Usually an “original visual creation” refers to a photograph, a drawing or a painting, but in this case the court decided that it applied to the way the tower was lighted. Because of that it is illegal to publish any pictures of the Eiffel Tower showing it with the lights lit, even if you take the pictures yourself!

There is one way to get around this rule, though. If you take a picture of Paris at night and the Eiffel Tower just happens to be in the picture, that is allowed. The tower cannot be the main focus of the picture, though.

14. You cannot climb to the very top of the tower.

There are three level areas on the tower where people can walk around and admire the view. The first level is 187 feet (57 meters) above the ground and sits just above the arches. To reach it you can take one of four elevators, that climb up the legs of the tower. The elevators are actually sets of stacked cars and they go up to the first and second levels. You can also climb up the 347 steps in the legs.

The second platform is about one-third of the way up the tower, or about 381 feet (116 meters) above ground. It can be reached by climbing 674 steps from the ground, or by taking one of the elevators.

The third platform is at 910 feet (277 meters) above the ground and can only be reached by elevator. There is a set of stairs with 1,710 steps that reaches the third platform, but it is closed to the public. This platform is often very windy and very cold. From here you can see all over Paris, but you can’t see very many of the 

buildings since they are so far away.

Even at this level you are over 76 feet (23.2 meters) from the top of the tower and 153 feet (46.6 meters) from the top of the radio antennae.

15. The Eiffel Tower sways in the wind.

It is very windy at the top of the Eiffel Tower. Even on a warm, sunny day there are tremendous winds. The winds are actually strong enough to bend the tower. The top of  the tower will sway back and forth in the winds. It can sway as much as 5 inches (13 cm) back and forth. This may not seem like much, and it isn’t. But when you are standing 910 feet (277 meters) above the ground, you probably wish that what you were 

standing on didn’t move at all!

16. Born on December 15, 1832 in Dijon, Gustave Eiffel was an exceptionally gifted engineer and builder. He graduated from the prestigious Ecole Centrale de Paris. His extraordinary career was marked in 1876 by the construction of the Maria Pia bridge over the River Douro in Portugal, then by that of the Garabit Viaduct in central France in 1884 and Budapest station in Hungary. He was responsible for the metal structures of the Bon Marché department store and the Crédit Lyonnais bank in Paris, the cupola of the Nice observatory, and, above all, the very impressive internal structure of the Statue of Liberty. The construction of the Eiffel Tower in 1889 was his crowning achievement.

17. But the Tower is also affected by heat. When the temperature is high, that portion of the structure exposed to the sun expands more than the portion in the shade. To “get out of the sun”, the Tower can lean as much as 18 centimeters.

18. The Tower hosted the first radiophonic experiments and played a crucial role in the beginnings of French television. Gustave Eiffel greatly encouraged research into radio transmissions by allowing the Tower to be used as a monumental antenna. In 1909, the Tower was saved from demolition thanks to the launch of wireless telegraphy. The top of the Tower was modified over the years, to accommodate an ever-growing number of antennas. Today, it is home to several dozen antennas of all sorts, including a television mast that reaches a height of 324 meters. The first experiments in television broadcasting from the Tower date from 1925 and the first regular broadcasts from 1935.

19. In 1999 a golf tournament is held in Paris for the first time with the first and last hole under the Eiffel Tower.

20. In 2004 the VTT champion, Xavier Casas from Andorra, beats his own record for climbing the steps on a VTT:  1,300 steps! He obtained an entry in the Guinness Book of World Records for this feat.

21. Because of its size and structure, the Eiffel Tower has inspired extremely sophisticated and original lighting innovations. By turns a sparkler, a Parisian beacon, an advertising sign, a torch, a Christmas tree, a beauty bathed in red and a fireworks theatre, the Tower has a history that is closely linked with the history of lighting. Spectaculars, bedazzlements, memories the very night it was inaugurated, ten thousand gaslights enhanced the gown of the Iron Lady!

22. To protect the Iron Lady’s surface, the Eiffel Tower is covered in paint. In fact, the stylish Lady’s attentiveness to color coordination has resulted in the need for three different shades of paint to go with the hues of the Parisian sky darkest at the bottom, lightest at the top.

23. The history behind the Eiffel Tower restaurants is inseparable from the “Great Moments” in history from the monument’s opening to the public in 1889. The Tower offers its visitors breathtaking seating overlooking Paris: a delight for the eyes and the taste buds. Today a range of restaurants cater to the different needs and tastes, from snack shops to gourmet cooking. 

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