Distribution of Crane Forces in Mill Buildings

The operation of overhead cranes in mill buildings may impose severe dynamic loads on the structure, particularly on single bent structures where transverse (lateral) forces from the travel of heavily loaded crane trolleys may cause undesirable sway of the boats in the immediate vicinity of the crane. The bracing provided between individual bents tends to distribute these forces to adjacent bays with an effectiveness that depends on the relative stiffness of the bents and of the bracing transmitting these forces. When attempting to find the exact distribution of the transmitted forces, the entire structure must be treated as a space frame. This entails prohibitively cumbersome calculations. A method is presented which, based on certain simplifying assumptions, offers a comparatively simple solution of the force distribution among the various bents by applying calculus of finite differences.