Main Bell

The Great Bell in Ptuj is of the Major Seventh bell with lowered prime type. Its strike tone is c’+6/16. Its tonal structure is:

Hum tone: Des°+8/16

Prime: B°+7/16

Tierce: es’+6/16

Quint: a’-4/16

Nominal: c”+6/16

The existing clapper was likely made together with the bell itself when it was cast at the Konrad Schneider foundry. In old times, to ensure reliable operation and ringing that resonated as far as possible, they made clappers that were too heavy for the bells. Today we know that an overweight clapper strikes the bell with excessive force, which can damage the bell. Despite the clapper being of similar age to the bell, the bell itself is extremely precious, so we must protect it as best we can. Therefore, the bell will need to receive a new, much lighter clapper that will strike with much smaller forces, thereby protecting the bell so it is preserved for future generations.

How often should a bell be turned so the clapper doesn’t always strike the same spot?

In some European countries, there is a directive requiring bells to be turned every 25 years. In Slovenia, this is not yet regulated, so it happens that we turn bells sometimes as early as after 15 years (if they had critically heavy clappers that wore them down significantly), while elsewhere they haven’t turned them even after 100 years. It is certainly healthy to perform a precise inspection of the condition and wear caused by the clappers at least every ten years. At that time, experts are consulted on whether the bell needs to be turned. Even when a bell is worn at all possible points to the extent that it is no longer safe to ring, there is a restoration procedure where bronze, structurally identical to the bell’s, is newly applied to the worn spots under special temperature conditions.

The shape of the bell itself has changed significantly throughout history. At first, bells were similar to vessels that had practically no sensible tonal structure.

The shape was perfected through historical periods until, at the end of the 19th century, it settled on the “octave minor” type. This type of bell has tones arranged in a minor chord and therefore sounds very pure. The arrangement of partial tones is conditioned by the shape of the “rib”. Through a precise sequence of thicknesses, curves, and diameters, this determines the frequency at which a certain part of the bell will vibrate.