Design Category and Service Class Selection for Below-the-Hook Lifting Devices

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 construction and general industry in conjunction with cranes, derricks, and other types of hoisting equipment. The standard establishes two design categories and five service classes that define certain requirements for the design of lifting devices. The design category relates to the expected usage of the lifter and the service class guides the design with respect to fatigue life assessment. Successful use of this design standard requires that designers, manufacturers, purchasers, and users of lifting devices all understand the meanings of these design categories and service classes and apply that understanding to the proper specification of lifter design requirements. This paper provides an extended discussion of the design category and service class definitions and provides guidance to purchasers and users of below-the-hook lifting devices in specifying the correct design category and service class.