Tuesday, 5 February 2013

Beauvais Cathedral (Part Two).



Text and Illustrations from Wikipedia - the free encyclopaedia,
unless otherwise stated.



File:Picardie Beauvais4 tango7174.jpg


Français : Cathédrale Saint-Pierre de Beauvais, Oise, Picardie, France. Horloge astronomique.
English: Beauvais Cathedral, Oise, Picardie, France. Astronomical clock.
Photo: September 2008.
Source: Own work.
Author: Tango7174
(Wikimedia Commons)


In the race to build the tallest Cathedral in the 13th-Century, the builders of Saint-Pierre de Beauvais pushed the technology to the limits. Even though the structure was to be taller, the buttresses were made thinner in order to pass maximum light into the Cathedral. In 1284, only twelve years after completion, part of the Choir Vault collapsed, along with a few Flying Buttresses. It is now believed that the collapse was caused by resonant vibrations caused by high winds.

The accompanying photograph shows lateral iron supports between the Flying Buttresses; it is not known when these external tie rods were installed. The technology would have been available at the time of the initial construction, but the extra support might not have been considered necessary until after the collapse in 1284, or even later.


File:Picardie Beauvais3 tango7174.jpg


Français : Cathédrale Saint-Pierre de Beauvais, Oise, Picardie, France. 
Horloge à carillon du XIVè siècle.
English: Beauvais Cathedral, Oise, Picardie, France. 
14th-Century chiming clock.
Photo: September 2008.
Source: Own work.
Author: Tango7174
(Wikimedia Commons)


In the 1960s, the tie rods were removed; the thinking was that they were disgraceful and unnecessary. However, the oscillations created by the wind became amplified, and the Choir partially disassociated itself from the Transept. Subsequently, the tie rods were re-installed  but this time with rods made of steel. Since steel is less ductile than iron, the structure became more rigid, possibly causing additional fissures.





Lateral Supports of Flying Buttresses.
Photo: March 2007.
Source: Own work.
Author: Tvbanfield
(Wikimedia Commons)


The floor plan shows that the original design included a Nave that was never built. Thus, the absence of shouldering support, that would have been contributed by the Nave, contributes to the structural weakness of the Cathedral.

With the passage of time, other problems surfaced, some requiring more drastic remedies. The North Transept now has four large wood-and-steel lateral trusses at different heights, installed during the 1990s, to keep the Transept from collapsing. In addition, the main floor of the Transept is interrupted by a much larger brace that rises out of the floor at a 45-degree angle. This brace was installed as an emergency measure to give additional support to the Pillars that, until now, have held up the tallest Vault in the world.


File:Beauv kated vitraze DSCN4397.JPG


English: Beauvais Cathedral. Stained-Glass.
Česky: Katwedrála v Beauvais, vitráže
Photo: August 2010.
Source: Own work.
Author: Sokoljan
(Wikimedia Commons)


These temporary measures will remain in place until more permanent solutions can be determined. Various studies are under way to determine with more assurance what can be done to preserve the structure. Columbia University is performing a study on a three-dimensional model, constructed using laser scans of the building, in an attempt to determine the weaknesses in the building and remedies.

Several of the Chapels contain Mediaeval stained glass windows, made during the 13th- through to the 15th-Centuries. In a Chapel close to the Northern Entrance, there is a Mediaeval clock (14th-15th-Century), probably the oldest fully-preserved and functioning mechanical clock in Europe. In its vicinity, a highly complicated astronomical clock with moving figures was installed in 1866.


THIS CONCLUDES THE ARTICLE ON BEAUVAIS CATHEDRAL.


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