Design Factors for Fabricated Steel Below-the-Hook Lifting Devices

Abstract

The American Society of Mechanical Engineers has published a new standard for the design of below-the-hook lifting devices. This standard defines design requirements for lifting devices used in conjunction with cranes, derricks, and other types of hoisting equipment. Chapter 2 of the standard defines two design categories that establish the design factor used to calculate allowable stresses for the design of the structural elements of the lifting device. This paper provides an extended discussion of the method by which variations in expected structural strength and applied loads relate to reliability and design factors.