How does a Belfry Tower Work
Found throughout the world, belfries are complex structures whose bells have served many uses over the centuries.
Belfries are common features on both religious and civic buildings alike worldwide. Their purpose is to elevate one or more bells to a height at which they can be rung with most effect – ie where there is little obstacle to the passage of their produced sound.
Mounting bells within a belfry is a complex operation, not least due to their extreme weight, and as such, they are typically placed in a space-saving mechanical array (read ‘Anatomy of a bell mechanism’ down). The array allows both multiple bells to be mounted within an enclosed environment and also for their operation to be handled in another room or compartment further down the bell tower.
Bells in a belfry are rung traditionally by bell ringers, who draw down an individual bell’s wheel rope. This has the effect of rotating the wheel and drawing the connected bell upwards, which when released, allows it to swing through a high-degree rotation, forcing its clapper to connect with the inside walls and produce that familiar ringing sound. Today, however, many mechanical systems are also in operation within belfries, either in the form of a carillon (a type of musical instrument in which a selection of smaller bells are rung by an automated keyboard), or by electronic amplification of chimed metal rods through loudspeakers.
Historically, belfries evolved out of early watchtowers, which were common throughout antiquity. Here, rather than calling worshipers to prayer or announcing the time of day, they were used to spot incoming enemies and then broadcast the threat to local soldiers and civilians.
Anatomy of a bell mechanism
Wheel – The wheel is secured to the headstock and holds the end of the bell rope. When the rope is pulled, the wheel spins, and so moves the bell.
Stay – The stay extends from the headstock and allows the bell to be rested on the slider when it is rung in an upright position.
Headstock – Typically a block of wood from which the bell is hung via cannons (metal loops formed at the top of the bell).
Bell – The bell is connected to the headstock via the cannons. Bells are typically made of bell metal, a hard alloy and form of bronze famed for its resistance to oxidation.
Slider – In partnership with the stay, this moving wooden bar allows the bell to be rested when rung in the upright position.
Clapper – The sound produced by the bell is done so by the clapper, which strikes the inside of the bell on either side in opposition to its motion.
A MAINTENANCE CHECKLIST AND RESEARCH ARCHIVE FOR TOWER BELLS