Check out this fascinating behind-the-scenes look at the manufacturing process of what will soon be the world’s heaviest free-swinging bell, from DW Documentary.

It weighs more than 25 tons and is larger than any bell that has come before. In spite of advanced technology, it’s a project that will still require a lot of manual labor and take months to complete. This bell will ring out in the Romanian capital for the next few centuries. It will be the world’s largest free-swinging bell to date. Work on this scale is no everyday matter for a foundry. This bell foundry, which is owned by the Grassmayr family, has been in business continuously since 1599, and yet this project is the biggest challenge in the company’s history. Although modern computer systems can now calculate the bell’s structural integrity, walls and its volume, the manufacturing process in many ways remains an archaic, laborious process. It takes several months and countless steps before – as Friedrich Schiller’s Song of the Bell put it – the bell will sing the praises of its casting master. The filmmakers have accompanied the challenging manufacturing process from the very start.