15 December 2001

The Leaning Tower of Pisa reopens after 11 years and $27,000,000 spent to stabilize it, without fixing its famous lean.

Leaning Tower of Pisa
Torre pendente di Pisa
The Leaning Tower of Pisa SB.jpeg
Leaning Tower of Pisa in 2013
Religion
AffiliationCatholic Church
Ecclesiastical or organizational statusActive
Location
LocationPisa, Italy
Geographic coordinates43°43′23″N 10°23′47″E / 43.72306°N 10.39639°E / 43.72306; 10.39639Coordinates: 43°43′23″N 10°23′47″E / 43.72306°N 10.39639°E / 43.72306; 10.39639
Architecture
Architect(s)Bonanno Pisano
StyleRomanesque
Groundbreaking1173
Completed1372
Specifications
Height (max)55.86 metres (183.3 ft)
Materials
Website
www.opapisa.it
Part ofPiazza del Duomo, Pisa
CriteriaCultural: i, ii, iv, vi
Reference395
Inscription1987 (11th session)

The Leaning Tower of Pisa (Italian: Torre pendente di Pisa) or simply the Tower of Pisa (Torre di Pisa [ˈtorre di ˈpiːza]) is the campanile, or freestanding bell tower, of the cathedral of the Italian city of Pisa, known worldwide for its nearly four-degree lean, the result of an unstable foundation. The tower is situated behind the Pisa Cathedral and is the third-oldest structure in the city's Cathedral Square (Piazza del Duomo), after the cathedral and the Pisa Baptistry.

The height of the tower is 55.86 metres (183.27 feet) from the ground on the low side and 56.67 metres (185.93 feet) on the high side. The width of the walls at the base is 2.44 m (8 ft 0.06 in). Its weight is estimated at 14,500 metric tons (16,000 short tons).[1] The tower has 296 or 294 steps; the seventh floor has two fewer steps on the north-facing staircase.

The tower began to lean during construction in the 12th century, due to soft ground which could not properly support the structure's weight, and it worsened through the completion of construction in the 14th century. By 1990, the tilt had reached 5.5 degrees.[2][3][4] The structure was stabilized by remedial work between 1993 and 2001, which reduced the tilt to 3.97 degrees.[5]

Architect

There has been controversy about the real identity of the architect of the Leaning Tower of Pisa. For many years, the design was attributed to Guglielmo and Bonanno Pisano,[6] a well-known 12th-century resident artist of Pisa, known for his bronze casting, particularly in the Pisa Duomo. Pisano left Pisa in 1185 for Monreale, Sicily, only to come back and die in his home town. A piece of cast bearing his name was discovered at the foot of the tower in 1820, but this may be related to the bronze door in the façade of the cathedral that was destroyed in 1595. A 2001 study seems to indicate Diotisalvi was the original architect, due to the time of construction and affinity with other Diotisalvi works, notably the bell tower of San Nicola and the Baptistery, both in Pisa.[7][page needed]

Construction

Construction of the tower occurred in three stages over 199 years. On 5 January 1172, Donna Berta di Bernardo, a widow and resident of the house of dell'Opera di Santa Maria, bequeathed sixty soldi to the Opera Campanilis petrarum Sancte Marie. The sum was then used toward the purchase of a few stones which still form the base of the bell tower.[8] On 9 August 1173, the foundations of the tower were laid.[9] Work on the ground floor of the white marble campanile began on 14 August of the same year during a period of military success and prosperity. This ground floor is a blind arcade articulated by engaged columns with classical Corinthian capitals.[citation needed] Nearly four centuries later Giorgio Vasari wrote: "Guglielmo, according to what is being said, in the year 1174, together with sculptor Bonanno, laid the foundations of the bell tower of the cathedral in Pisa".[10]

The tower began to sink after construction had progressed to the second floor in 1178. This was due to a mere three-metre foundation, set in weak, unstable subsoil, a design that was flawed from the beginning. Construction was subsequently halted for almost a century, as the Republic of Pisa was almost continually engaged in battles with Genoa, Lucca, and Florence. This allowed time for the underlying soil to settle. Otherwise, the tower would almost certainly have toppled.[11] On 27 December 1233, the worker Benenato, son of Gerardo Bottici, oversaw the continuation of the tower's construction.[12]

On 23 February 1260, Guido Speziale, son of Giovanni Pisano, was elected to oversee the building of the tower.[13] On 12 April 1264, the master builder , architect of the Camposanto, and 23 workers went to the mountains close to Pisa to cut marble. The cut stones were given to Rainaldo Speziale, worker of St. Francesco.[14] In 1272, construction resumed under Di Simone. In an effort to compensate for the tilt, the engineers built upper floors with one side taller than the other. Because of this, the tower is curved.[15] Construction was halted again in 1284 when the Pisans were defeated by the Genoans in the Battle of Meloria.[9][16]

The seventh floor was completed in 1319.[17] The bell-chamber was finally added in 1372. It was built by , who succeeded in harmonizing the Gothic elements of the belfry with the Romanesque style of the tower.[18][19] There are seven bells, one for each note of the musical major scale. The largest one was installed in 1655.[11]

History following construction

Between 1589 and 1592,[20] Galileo Galilei, who lived in Pisa at the time, is said to have dropped two cannonballs of different masses from the tower to demonstrate that their speed of descent was independent of their mass, in keeping with the law of free fall. The primary source for this is the biography Racconto istorico della vita di Galileo Galilei (Historical Account of the Life of Galileo Galilei), written by Galileo's pupil and secretary Vincenzo Viviani in 1654, but only published in 1717, long after his death.[21][22]

During World War II, the Allies suspected that the Germans were using the tower as an observation post. A U.S. Army sergeant sent to confirm the presence of German troops in the tower was impressed by the beauty of the cathedral and its campanile, and thus refrained from ordering an artillery strike, sparing it from destruction.[23][page needed][24]

Numerous efforts have been made to restore the tower to a vertical orientation or at least keep it from falling over. Most of these efforts failed; some worsened the tilt. On 27 February 1964, the government of Italy requested aid in preventing the tower from toppling. It was, however, considered important to retain the current tilt, due to the role that this element played in promoting the tourism industry of Pisa.[25]

A multinational task force of engineers, mathematicians, and historians gathered on the Azores islands to discuss stabilisation methods.[when?] It was found that the tilt was increasing in combination with the softer foundations on the lower side. Many methods were proposed to stabilise the tower, including the addition of 800 tonnes of lead counterweights to the raised end of the base as a temporary intervention.[26]

The tower and the neighbouring cathedral, baptistery, and cemetery are included in the Piazza del Duomo UNESCO World Heritage Site, which was declared in 1987.[27]

The tower was closed to the public on 7 January 1990,[28] after more than two decades of stabilisation studies and spurred by the abrupt collapse of the Civic Tower of Pavia in 1989.[29][30] The bells were removed to relieve some weight, and cables were cinched around the third level and anchored several hundred meters away. Apartments and houses in the path of a potential fall of the tower were vacated for safety. The selected method for preventing the collapse of the tower was to slightly reduce its tilt to a safer angle by soil removal 38 cubic metres (1,342 cubic feet) from underneath the raised end. The tower's tilt was reduced by 45 centimetres (17.7 inches), returning to its 1838 position. After a decade of corrective reconstruction and stabilization efforts, the tower was reopened to the public on 15 December 2001, and was declared stable for at least another 300 years.[26] In total, 70 metric tons (77 short tons) of soil were removed.[31]

After a phase (1990–2001) of structural strengthening,[32] the tower has been undergoing gradual surface restoration to repair visible damage, mostly corrosion and blackening. These are particularly pronounced due to the tower's age and its exposure to wind and rain.[33] In May 2008, engineers announced that the tower had been stabilized such that it had stopped moving for the first time in its history. They stated that it would be stable for at least 200 years.[31]

Surviving earthquakes

At least four strong earthquakes hit the region since 1280, but the apparently vulnerable Tower survived. The reason was not understood until a research group of 16 engineers investigated. The researchers concluded that the Tower was able to withstand the tremors because of dynamic soil-structure interaction (DSSI): the height and stiffness of the Tower, together with the softness of the foundation soil, influences the vibrational characteristics of the structure in such a way that the Tower does not resonate with earthquake ground motion. The same soft soil that caused the leaning and brought the Tower to the verge of collapse helped it survive.[35]

Technical information

An elevation image of the Leaning Tower of Pisa cut with laser scan data from a University of Ferrara/CyArk research partnership, with source image accurate down to 5 mm (0.2 in).
  • Elevation of Piazza del Duomo: about 2 metres (6 feet, DMS)
  • Height from the ground floor: 55.863 metres (183 ft 3.3 in),[36] 8 stories[37]
  • Height from the foundation floor: 58.36 m (191 ft 5.64 in)[38]
  • Outer diameter of base: 15.484 metres (50 ft 9.6 in)[36]
  • Inner diameter of base: 7.368 metres (24 ft 2.1 in)[36]
  • Angle of slant: 3.97 degrees[39] or 3.9 metres (12 ft 10 in) from the vertical[40]
  • Weight: 14,700 metric tons (16,200 short tons)[41]
  • Thickness of walls at the base: 2.44 metres (8 ft 0 in)
  • Total number of bells: 7, tuned to musical scale,[42] clockwise:[citation needed]
    • 1st bell: L'Assunta, cast in 1654 by , weight 3,620 kg (7,981 lb)
    • 2nd bell: Il Crocifisso, cast in 1572 by , weight 2,462 kg (5,428 lb)
    • 3rd bell: San Ranieri, cast in 1719–1721 by , weight 1,448 kg (3,192 lb)
    • 4th bell: La Terza (1st small one), cast in 1473, weight 300 kg (661 lb)
    • 5th bell: La Pasquereccia or La Giustizia, cast in 1262[43] by , weight 1,014 kg (2,235 lb)
    • 6th bell: Il Vespruccio (2nd small one), cast in the 14th century and again in 1501 by , weight 1,000 kg (2,205 lb)
    • 7th bell: Dal Pozzo, cast in 1606 and again in 2004, weight 652 kg (1,437 lb)[44]
  • Number of steps to the top: 296[45]

About the 5th bell: The name Pasquareccia comes from Easter, because it used to ring on Easter day. However, this bell is older than the bell-chamber itself, and comes from the tower Vergata in Palazzo Pretorio in Pisa, where it was called La Giustizia (The Justice). The bell was tolled to announce executions of criminals and traitors, including Count Ugolino in 1289.[46] A new bell was installed in the bell tower at the end of the 18th century to replace the broken Pasquareccia.[citation needed]

The circular shape and great height of the campanile were unusual for their time, and the crowning belfry is stylistically distinct from the rest of the construction. This belfry incorporates a 14 cm (5.5 in) correction for the inclined axis below. The siting of the campanile within the Piazza del Duomo diverges from the axial alignment of the cathedral and baptistery of the Piazza del Duomo.[citation needed]

Guinness World Records

Two German churches have challenged the tower's status as the world's most lop-sided building: the 15th-century square Leaning Tower of Suurhusen and the 14th-century bell tower in the town of Bad Frankenhausen.[47] Guinness World Records measured the Pisa and Suurhusen towers, finding the former's tilt to be 3.97 degrees.[39] In June 2010, Guinness World Records certified the Capital Gate building in Abu Dhabi, UAE as the "World's Furthest Leaning Man-made Tower";[48] it has an 18-degree slope, almost five times more than the Pisa Tower, but was deliberately engineered to slant. The Leaning Tower of Wanaka in New Zealand, also deliberately built, leans at 53 degrees to the ground.[49]

Gallery

See also

References

  1. ^ "Leaning Tower of Pisa Facts". Leaning Tower of Pisa. Retrieved 5 October 2013.
  2. ^ "Europe | Saving the Leaning Tower". BBC News. 15 December 2001. Retrieved 9 May 2009.
  3. ^ "Tower of Pisa". Archidose.org. 17 June 2001. Archived from the original on 26 June 2009. Retrieved 9 May 2009.
  4. ^ "Leaning Tower of Pisa (tower, Pisa, Italy) – Britannica Online Encyclopedia". Britannica.com. Retrieved 9 May 2009.
  5. ^ "Leaning tower of Pisa loses crooked crown". Irish News. Retrieved 10 June 2020.
  6. ^ "Endex.com". www.endex.com. Archived from the original on 13 August 2007.
  7. ^ Pierotti, Piero. (2001). Deotisalvi – L'architetto pisano del secolo d'oro. Pisa: Pacini Editore
  8. ^ Capitular Record Offices of Pisa, parchment n. 248
  9. ^ a b Potts, David M.; Zdravkovic, Lidija; Zdravković, Lidija (2001). Finite Element Analysis in Geotechnical Engineering: Application. Thomas Telford. p. 254. ISBN 9780727727831.
  10. ^ Vasari, Giorgio (1878). Le opere di Giorgio Vasari: Le vite de' più eccellenti pittori, scultori ed architettori (in Italian). G.C. Sansoni. pp. 274. OCLC 15220635. Guglielmo, secondo che si dice, l'anno 1174, insieme con Bonanno scultore, fondò in Pisa il campanile del Duomo, dove sono alcune parole
  11. ^ a b "Fall of the Leaning Tower – History of Interventions". NOVA Online (PBS). 1999. Retrieved 24 April 2019.
  12. ^ Public Record Offices of Pisa, Opera della Primaziale, 27 December 1234
  13. ^ Public Record Offices of Pisa, Opera della Primaziale, 23 February 1260
  14. ^ Public Record Offices of Pisa, Roncioni, 12 April 1265.
  15. ^ McLain, Bill (1999). Do Fish Drink Water?. New York: William Morrow and Company, Inc. pp. 291–292. ISBN 0-688-16512-5.
  16. ^ Touring club italiano (2005). Authentic Tuscany. Touring Editore. p. 64. ISBN 9788836532971.
  17. ^ Roth, Leland M. (13 March 2018). Understanding Architecture: Its Elements, History, and Meaning. Routledge. p. 98. ISBN 9780429975219.
  18. ^ G. Barsali (1999), Pisa. History and masterpieces, Bonechi, p. 18, ISBN 8872041880
  19. ^ Giorgio Vasari, Jean Paul Richter (1855), Lives of the Most Eminent Painters, Sculptors, and Architects, H. G. Bohn, p. 153
  20. ^ Some contemporary sources speculate about the exact date; e.g. Rachel Hilliam gives 1591 (Galileo Galilei: Father of Modern Science, The Rosen Publishing Group, 2005, p. 101).
  21. ^ "Sci Tech : Science history: setting the record straight". The Hindu. 30 June 2005. Retrieved 5 May 2009.
  22. ^ Vincenzo Viviani on museo galileo
  23. ^ Shrady, Nicholas (2003): Tilt: a skewed history of the Tower of Pisa
  24. ^ "Why I spared the Leaning Tower of Pisa". The Guardian. 12 January 2000. Retrieved 19 July 2012.
  25. ^ "Securing the Lean In Tower of Pisa". The New York Times. 1 November 1987.
  26. ^ a b "Tipping the Balance". TIME Magazine. 25 June 2001. Retrieved 30 May 2020.
  27. ^ "Piazza del Duomo, Pisa". UNESCO World Heritage Centre. Retrieved 8 August 2016.
  28. ^ "BBC on this day: 1990: Leaning Tower of Pisa closed to public". BBC News. Retrieved 29 April 2020.
  29. ^ Hofman, Paul (30 July 1989). "Italy's Endangered Treasures". New York Times. New York. Retrieved 29 April 2020.
  30. ^ Montalbo, William D (18 March 1989). "900-Year-Old Bell Tower Collapses in Italy; Three Killed". Los Angeles Times. Los Angeles. Retrieved 29 April 2020.
  31. ^ a b Duff, Mark (28 May 2008). "Europe | Pisa's leaning tower 'stabilised'". BBC News. Retrieved 5 May 2009.
  32. ^ A profile of an engineer employed to straighten the tower Archived 27 January 2012 at the Wayback Machine Ingenia, March 2005
  33. ^ "Restoration work is mentioned at the official website of the square". Archived from the original on 25 October 2009. Retrieved 14 May 2007.
  34. ^ Tom (6 May 2015). "Leaning Tower of Pisa in the 1890s". Cool Old Photos. Retrieved 5 March 2019.
  35. ^ "500-year-old Leaning Tower of Pisa mystery unveiled by engineers". ScienceDaily. 9 May 2018. Retrieved 22 November 2018.
  36. ^ a b c "2051?". The Michigan Architect and Engineer. 27: 17. 1952.
  37. ^ Burland, J.B. (2008). "Stabilising the Leaning Tower of Pisa: the Evolution of Geotechnical Solutions". Trans. Newcomen Soc. 78 (2): 174. doi:10.1179/175035208X317657. ISSN 0372-0187.
  38. ^ Valdes, Giuliano (1994). Art and History of Pisa. Casa Editrice Bonechi. p. 44. ISBN 9788880290247.
  39. ^ a b "German steeple beats Leaning Tower of Pisa into Guinness book". Trend News Agency. AFP. 9 November 2007. Archived from the original on 4 May 2009.
  40. ^ tan(3.97 degrees) * (55.86m + 56.70m)/2 = 3.9m
  41. ^ Strom, Steven; Nathan, Kurt; Woland, Jake; Lamm, David (28 September 2009). Site Engineering for Landscape Architects. John Wiley and Sons. p. 124. ISBN 9780471695493.
  42. ^ Black, William Harman (1920). The Real Europe Pocket Guide-book: Number 10 of the 'Black's Blue Books'. Brentanos. pp. 360. OCLC 316943604.
  43. ^ Black, Charles Bertram (1898). The Riviera, Or The Coast from Marseilles to Leghorn: Including the Interior Towns of Carrara, Lucca, Pisa and Pistoia. A. & C. Black. pp. 148. OCLC 18806463.
  44. ^ "Leaning Tower of Pisa: 1920s Photo of Dal Pozzo". www.endex.com. Archived from the original on 18 April 2010. Retrieved 9 August 2010.
  45. ^ Davies, Andrew (2005). The Children's Visual World Atlas. Sydney, Australia: The Fog Press. ISBN 1-74089-317-4.
  46. ^ "Torre pendente" (in Italian). Lucca turismo. Retrieved 19 March 2008.
  47. ^ Sunday Telegraph no. 2,406, 22 July 2007
  48. ^ "Not so fast, Pisa! UAE lays claim to world's furthest leaning tower". CNN news. 7 June 2010. Retrieved 6 June 2010.
  49. ^ 'Leaning and tumbling towers' on Puzzling World website, viewed 30 July 2011

External links

15 December 1960

Richard Pavlick is arrested for plotting to assassinate USA President-Elect John F. Kennedy.

In November of 1960, John Fitzgerald Kennedy was elected President of the United States. Three years later, he was assassinated by Lee Harvey Oswald, shot while in a motorcade going through Dallas, Texas.
Had Richard Paul Pavlick gotten his way, Oswald would have never gotten to pull the trigger. Because Pavlick wanted to kill JFK first.

On December 11, 1960, JFK was the President-Elect and Richard Paul Pavlick was a 73 year old retired postal worker. Both were in Palm Beach, Florida. JFK was there on a vacation of sorts, taking a trip to warmer climates as he prepared to assume the office of the President. Pavlick had followed Kennedy down there with the intention of blowing himself up and taking JFK with him. His plan was simple. He lined his car with dynamite — “enough to blow up a small mountain” per CNN — and outfitted it with a detonation switch. Then, he parked outside the Kennedy’s Palm Beach compound and waited for Kennedy to leave his house to go to Sunday Mass. Pavlick’s aim was to ram his car into JFK’s limo as the President-to-be left his home, blowing both assassin and politician to smithereens.

But JFK did not leave his house alone that morning. He made his way to his limo with his wife, Jacqueline, and children, Caroline and John, Jr., with him. While Pavlick was willing to kill their husband and father, he did not want to kill them, so he resigned himself to trying again another day. He would not get a second chance at murderous infamy. On December 15th, he was arrested by a Palm Beach police officer working off a tip from the Secret Service.

Pavlick’s undoing was the result of deranged postcards he sent to Thomas Murphy, then the Postmaster of Pavlick’s home town of Belmont, New Hampshire. Murphy was put off by the strange tone of the postcards and his curiosity led him to do what Postmasters do — look at the postmarks. He noticed a pattern: Pavlick happened to be in the same general area as JFK, dotting the landscape as Kennedy travelled. Murphy called the local police department who in turn called the Secret Service, and from there, Pavlick’s plan unraveled.

The would-be assassin was committed to a mental institution on January 27th of the following year, a week after Kennedy was inaugurated as the 35th President of the United States, pending charges. These charges were eventually dropped as it became increasingly clear that Pavlick acted out of an inability to distinguish between right and wrong, but nevertheless, Pavlick remained in institutions until December 13, 1966, nearly six years after being apprehended. He died in 1975.

Bonus fact: If Pavlick seems old for a would-be Presidential assassin, your instincts are correct. Lee Harvey Oswald was just 24 years old, making him the youngest of all four of the men who assassinated Presidents. John Wilkes Booth was 26 when he killed Abraham Lincoln; Leon Czolgosz was 28 when he assassinated William McKinley, and Charles Guiteau was 39 when he murdered James A. Garfield.

15 December 2001

The Leaning Tower of Pisa reopens renovation.

On this day in 2001, Italy’s Leaning Tower of Pisa reopens after a team of experts spent 11 years and $27 million to fortify the tower without eliminating its famous lean.

In the 12th century, construction began on the bell tower for the cathedral of Pisa, a busy trade center on the Arno River in western Italy, some 50 miles from Florence. While construction was still in progress, the tower’s foundation began to sink into the soft, marshy ground, causing it to lean to one side. Its builders tried to compensate for the lean by making the top stories slightly taller on one side, but the extra masonry required only made the tower sink further. By the time it was completed in 1360, modern-day engineers say it was a miracle it didn’t fall down completely.

Though the cathedral itself and the adjoining baptistery also leaned slightly, it was the Torre Pendente di Pisa, or Leaning Tower of Pisa, that became the city’s most famous tourist attraction. By the 20th century, the 190-foot-high white marble tower leaned a dramatic 15 feet off the perpendicular. In the year before its closing in 1990, 1 million people visited the old tower, climbing its 293 weathered steps to the top and gazing out over the green Campo dei Miracoli outside. Fearing it was about to collapse, officials appointed a group of 14 archeologists, architects and soil experts to figure out how to take some–but not all–of the famous tilt away.

Though an initial attempt in 1994 almost toppled the tower, engineers were eventually able to reduce the lean by between 16 and 17 inches by removing earth from underneath the foundations. When the tower reopened on December 15, 2001, engineers predicted it would take 300 years to return to its 1990 position. Though entrance to the tower is now limited to guided tours, hordes of tourists can still be found outside, striking the classic pose–standing next to the tower pretending to hold it up–as cameras flash.

15 December 2010

A boat of asylum seekers crashes into rocks off the coast of Christmas Island, Australia, killing 48 people.

On 15 December 2010, a boat carrying around 90 asylum seekers, mostly from Iraq and Iran, sank off the coast of Christmas Island, an Australian territory in the Indian Ocean, killing 48 people aboard; 42 survivors were rescued.

At about 6.30 a.m. local time the boat collided with rocks north of Flying Fish Cove close to Rocky Point and was then smashed against the nearby cliffs, complicating rescue attempts. For a period of about one hour, the unpowered boat was washed back and forth as backwash pushed it away from the cliff. Many of those who entered the water grabbed onto the flotsam and jetsam as the boat quickly broke up.Residents tried to help victims by throwing them life jackets and other objects. Some refugees were battered by the debris from the disintegrating boat and some were able to use the life jackets thrown from the shore. Rescue efforts by Australian Customs and Border Protection included allocation of HMAS Pirie and ACV Triton, with at least 42 survivors having been recovered from the ocean. One man was able to scramble ashore himself with a great leap.[10] Poor weather conditions made rescue operations difficult. Two critical care teams from the Royal Flying Doctor Service of Australia left from Perth to provide medical assistance.