The Making Of Cologne Cathedral: Materials And Mastery

The Cologne Cathedral is a Gothic masterpiece that was constructed over seven centuries. The cathedral is made of different types of rock, including trachyte, sandstone, and limestone. The cathedral's distinctive black patina is the result of weathering, soot, and biofouling. Over 300,000 tonnes of stones were used in its construction. The cathedral features two large spires that stand at 515 feet (157 meters) tall, making it the tallest twin-spired church in the world.

Sandstone and trachyte

The Cologne Cathedral is made of several different types of stone, including sandstone and trachyte. The cathedral is a testament to the endurance of European Christianity and is the largest Gothic church in northern Europe. Construction began in 1248 and was completed in 1880, with several long breaks in between.

The cathedral is made of different types of rock, each weathering differently due to their characteristics. Sandstone, for example, is more susceptible to the elements and is constantly being renewed. Trachyte, on the other hand, is considered very weather-resistant. The cathedral is also made of basalt lava, which is grey in colour, and limestone, which is used for many sculptures and canopies.

The varying types of stone used in the construction of the cathedral have resulted in a black patina that has characterised the building for centuries. This is due to weathering, soot, and biofouling. The cathedral is constantly in need of repair and renovation to preserve its structure.

The Cologne Cathedral is a masterpiece of Gothic architecture, with its immense twin towers standing at 515 feet (157 meters) tall. The building is a renowned monument of German Catholicism and was declared a World Heritage Site in 1996. It is Germany's most visited landmark, attracting an average of 6 million people a year.

Iron roof girders

The completion of the Cologne Cathedral in 1880 was a testament to the enduring strength of European Christianity. The construction of this Gothic masterpiece spanned several centuries and was marked by various challenges and setbacks. When work resumed in 1842, architects remained faithful to the original medieval plans and drawings, employing more modern construction techniques, including the use of iron roof girders.

The iron roof girders played a crucial role in the structural integrity of the cathedral. Unlike traditional wooden rafters, these iron trusses provided exceptional strength and stability to the roof, allowing it to support the heavy lead roof. In fact, the iron truss was the largest steel structure in the world in 1860, three decades before the completion of the Eiffel Tower. This innovative use of iron contributed to the overall grandeur and resilience of the cathedral.

The decision to use iron for the roof girders was not only a matter of structural integrity but also had practical considerations. Iron, being stronger and more durable than wood, reduced the need for frequent repairs and maintenance. This was especially important given the lengthy construction history of the cathedral and the desire to ensure its longevity.

The use of iron roof girders also had aesthetic implications. By choosing iron, the architects were able to create a more open and spacious interior, as iron girders could span longer distances without the need for additional support. This contributed to the overall grandeur and airiness of the cathedral's interior, enhancing its visual appeal.

Additionally, the iron roof girders played a pivotal role in preserving the cathedral during World War II. While the building suffered damage from Allied air raids, the use of iron girders helped prevent more severe structural damage. The iron truss, being stronger and more fire-resistant than wooden rafters, likely contributed to the cathedral's resilience during the bombings.

In conclusion, the iron roof girders of the Cologne Cathedral are a testament to the ingenuity and innovation of its architects and builders. By employing this modern construction technique, they not only ensured the structural integrity of the building but also contributed to its aesthetic appeal and longevity. The iron girders continue to play a vital role in preserving this masterpiece of Gothic architecture for future generations to admire and appreciate.

Stained glass windows

The Cologne Cathedral features a variety of stained glass windows, ranging from the 14th to the 21st century. The earliest of these are the clerestory windows in the choir, which were completed in 1311 and contain 95% original glass. These are the largest series of stained glass windows from the 14th century still in existence in Europe. The windows feature geometric patterns and are made up of 10,170 sq. ft. of glass surface.

The St. Peter and the Tree of Jesse Window, created in 1509, depicts St. Peter, the patron saint of the cathedral, and the Tree of Jesse, which shows Christ's royal ancestry. The left panel shows Jesus summoning St. Peter, one of the Twelve Apostles, who was a Galilean fisherman. The right panel shows the Jesse Tree, with Jesse, the father of King David, on the right side. The upper left figure is St. Peter, usually depicted with the keys to heaven.

The Nativity Window, created in 1507, shows the shepherds at left, the Annunciation in the centre, and Mary Immaculate on the right.

The Coronation Window, also from 1509, depicts the Trinity and Mary in heaven, and Michael the Archangel or St. George slaying Satan.

The 19th century saw the addition of several stained glass windows to the cathedral, including the St. Stephen Window (1848), the Pentecost Window (1848), the Lamentation Window (1847), and the Adoration of the Magi Window (1846), all of which were donated by King Ludwig I of Bavaria. The Bayernfenster, a set of five windows on the south side, are highly representative of the painterly German style of the 19th century.

The most recent addition to the cathedral's stained glass collection is the abstract window in the south transept, designed by German artist Gerhard Richter and inaugurated in August 2007. The window is composed of 11,263 to 11,500 squares of coloured glass, arranged in a random pattern by a computer program. The colours were chosen from a palette of 800, with 72 colours ultimately selected, including those used in the cathedral's medieval and 19th-century windows. The window measures 106 sq. m. and was funded by around 1,200 donors, with Richter himself working without a fee.

Flying buttresses

The flying buttresses of Cologne Cathedral are an integral part of its Gothic architectural style. Externally, the outward thrust of the vault is supported by these flying buttresses, which are designed in the French manner.

The buttresses at Cologne Cathedral are constructed from stone, with the filigree buttresses and arches exposed to the elements. Over time, these stone structures have been susceptible to weathering, with the sulphur content of the air and bird droppings contributing to their deterioration. Conservation efforts are ongoing to preserve these intricate architectural features.

The flying buttresses, along with the pinnacles, form an intricate network of supports that enable the cathedral's immense height while maintaining structural stability. They are an essential element of the Gothic style, which emphasises verticality and strives for closeness to God through light-filled, soaring interiors.

The buttresses also contribute to the overall aesthetic of the cathedral, adding a sense of elegance and complexity to the exterior. Their design and placement showcase the ingenuity of the medieval builders, who created a system that distributes weight and stress effectively, ensuring the structural integrity of the cathedral for centuries.

Medieval crane

The construction of Cologne Cathedral was a long and challenging process that spanned centuries, with work beginning in 1248 and finally concluding in 1880. During this period, the site was often left idle due to various interruptions, including wars and financial difficulties. One such interruption occurred when the project lost funding around 1560, leaving the south tower topped with a huge crane that remained a part of the Cologne skyline for 400 years.

This medieval crane, standing 184 feet (56 metres) above the ground, was a testament to the ambition and scale of the construction project. With the resumption of work in the 19th century, the crane was finally removed, and the cathedral was completed to its original medieval plan.

The crane's presence for such an extended period highlights the challenges faced by the builders of Cologne Cathedral. The project required significant resources, including approximately 300,000 tonnes of stone, and the expertise of many craftsmen, including stonemasons and stone sculptors. The use of different types of rock in the construction, such as Schlaitdorf sandstone, also presented ongoing maintenance challenges due to varying weathering rates.

The completion of the cathedral in 1880 was a significant milestone, and it stood as the tallest building in the world for four years until the completion of the Washington Monument. The perseverance and dedication that characterised the construction of Cologne Cathedral have made it a renowned monument of German Catholicism and Gothic architecture.

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