The dynamics of the bell tower of St. Stephen's Church, Willington, Co. Durham

The dynamic response of the masonry bell tower of St. Stephen's Church, Willington, Co. Durham has been measured under the action of forces arising from bell ringing. Natural frequencies,mode shapes and damping factors have been determined for the fundamental sway-type modes in the N-S and E-W directions. Two finite element models of the tower have been developed, one using Timoshenko beam elements and the other using three-dimensional brick elements, in which the masonry properties have been factored so that the computed response matches that measured. The factors applied were within the range of values determined from studies of other bell towers.