Belfries, bell frame constructions performing both static and dynamic functions

In simplified layman’s terms, a bell weighing 1,000 kg burdens the clock tower by a weight of 1,000 kg. However, if the bell swings, dynamic propulsive thrust is also created which can add up to three times the weight of the bell itself, in this example as much as 3,000 kg. Thus, with each swing a lateral force effect of up to 3,000 kg results, e.g. in the case of a straight headstock vertical pressure on the plating of Vmax 3.1 KN; horizontal pressure on the bearing of Hmax 1.6 KN; in connection with Hmax: Vmax of 1.6 KN.


For this reason, a belfry is much more than just housing or scaffolding carrying the bell and making its swing technically possible. Since the belfry acts like a ‘tower inside the tower’, the dynamic propulsive force of the swinging bell is not inside the bell, but far deeper down, at the foundations of the belfry, where it is transferred to the bell tower in reduced force.