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The largest swinging bell in the world was cast in Poland

In Poland, the world’s largest swinging bell “Vox Patris” was cast for a special order of the Basilica of the Eternal Father in Trindade, Brazil. This year, it’s unique voice will welcome not only pilgrims from South America, but also from around the world.

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“Vox Patris” was created by Jan Felczyński Church Bell Manufactory from Przemyśl, Rduch Bells & Clocks from Czernica and Metalodlew from Kracow. Over 100 people worked to make this incredible project come true. The journalists were the first to see the outcome in Krakow.

The bell made of bronze (78% copper and 22% tin) weighs 55-tones, is over 4 meters high and has a diameter of 4,5 meters. To make it swing, four linear motors are needed, also the largest ones in the world made so far.

"The weight of „Vox Patris” is equal to 10 African elephants and its height is as big as a giraffe itself. We used 9000 bricks to build its core. With the same amount of bricks we would be able to build at least three detached houses. The mould was made of clay mixed with horse dung. At the time of pouring, the metal floated to it at a speed of 150 kg per second. At the climax it reached 1070 °C," recalled Piotr Olszewski, owner of Jan Felczyński Church Bells Manufactory.

The moment of pouring the alloy into the mould was one of the most important stage in the whole process of creating the bell. "It lasted about 12 minutes and was emotionally intense for us. It was crucial that the mould withstands the pressure and weight of the liquid bronze. After a short while, it was clear that the metal did not escape from the mould and that fact was the crowning achievement of our hard work," said Waldemar Olszewski, the master of bell making.

In the 200-year history of Jan Felczyński Church Bells Manufactory in Przemyśl dozens of bells have been made, and among them very large ones, like “Blessed Wladyslaw” of 10 tones for a church in Ursynów district in Warsaw. However, the biggest challenge for the bell makers from Przemyśl, Silesian specialists and casters from Lesser Poland was creating the “Vox Patris”. Initial talks on the project started in 2013 and were supported by scientific and technical consultations conducted by researchers of Silesian University of Technology in Gliwice and of Metalodlew from Krakow. The first attempt to cast the bell in November 2016 failed due to a mini-crack in the mould, during the second one in the summer of 2017 there were no more surprises. "The failure brought us many precious and useful information and after deep analysis we used different materials to seal and protect the mould," said a scientist from Gliwice, dr hab. inż. Dariusz Bartocha.

Never before had such a large bell been casted, therefore very strict rules were introduced during the work.

"The metal could not have a temperature lower than 1000 °C and higher than 1200 °C. We melted four portions, which were then poured together into a 60-ton vat. We have done tests before, every 10 minutes checking how quickly it cools down. It turned out that we have 3 hours to melt the metal needed to fill the mould. Doing it in such a short time was a real challenge," said the project manager and president of the board of Art-Kolor in Metalodlew group, Jacek Winiarczyk.

The ornamentation of the bell illustrates the history and present day of the Sanctuary in Trindade and shows characteristic motifs of Brazilian flora and fauna. The adornments were made using the lost wax method. The amount of wax used equals an average amount of two years of normal production in the bell foundry in Przemyśl. In order to cast the bell, a foundry pit reaching below the foundations of the factory hall was made.

"The 2-tone clapper for the bell was also designed. After being forged, with mounting, it will be 6 meters long. Its yoke will weigh 10 tons," Grzegorz Klyszcz - the owner of the Rduch Bells & Clocks talks about the unusual sound of "Vox Patris". "It is already known that it is going to have a very low sound, heard within a few kilometers from the Sanctuary. The assumed key note is Fis 00 with the frequency of 92 Hz. The lower octave exceeds 40 Hz. So before we hear the sound of the bell, we will feel it with our whole body. And the shivers passing on the back will be the first sensation of the sound."

“Vox Patris” will be hug on the over 100-meter bell tower. The scientists have to calculate all the forces generated by the bell during its work to evaluate an impact on the construction.

It will sail to Brazil, and will be transported to the harbour on a special car platform. Polish bell makers together with Silesian specialists will create also 68 smaller bells for the Basilica of the Eternal Father in Trindade. The Sanctuary, located in central-western Brazil, is one of the  largest centers of religious worship in this country.

So far the largest swinging bell in Europe, Saint Peter’s bell (Dicker Pitter – 24 tones), hangs in the belfry in Cologne Cathedral. Polish Sigismund Bell weighs 9,6 tones. Until now, the largest swinging bell in the world, weighing over 36 tones and cast in the Netherlands, is located in the Japanese health resort of Gotenba, on the slope of Mount Fuji.

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