The concrete cylinders broken in July 2023 were cast in 1923. According to online calculations - depending on the exact date the casting took place – this comes to roughly 36,500 days.

The concrete cylinders are cast onsite and brought to a third-party laboratory, where the curing temperature is set at 23 ± 2°C (73 ± 4°F) and the humidity at a minimum of 95%.