What Makes a Bell Ring?
A bell is like a metal cup with a clapper hanging inside. When the clapper strikes the bell, the bell vibrates rapidly. (If you gently put your fingers on a ringing bell you can feel the vibrations.)
As the bell vibrates, it causes the surrounding air to move in many little waves, something like the ripples that are made in a pond when you drop a stone in the water.
These waves in the air are called sound waves. The sound waves travel outward in all directions from the bell. When they reach your ears, you hear the ringing sound made by the bell.
Bells are made from an alloy of copper and tin and are arranged in the tower down the musical scale from the smallest (called the ‘treble’) to the biggest (‘tenor’) which is the lowest note. The average tenor weight is 510kg, although they can weigh up to 4,200kg.
Bells are hung within a wooden or steel frame and attached to a wheel. They rotate around the centre of the wheel, with the ‘clapper’ in the centre striking the inside of the bell to sound.
The special feature of bells is that they have a ‘stay’ which allows them to pause in an up-right position. This means the ringer can control when they strike by pulling them from this ‘set’ position to swing at the correct time
Within the frame, the bells pivot on the gudgeon as it swings, while the clapper strikes the inside of the bell to make the noise. Although not shown in the video model, the rope wraps around the wheel as it is what the ringer below uses to control the bell’s swing.