CRANES20.3Figure 20.1 The telescopic boom on this all-terrain cranecarries both a main load fall and an auxiliarytip for a whip line. The carrier, with a separate driving cab, is suited both for highway driving and off-roadtravel. Note that all wheels are turned to maneuver the crane into operating position, demonstrating the crabsteering. This crane carrier has five axles but machines with heavier road weight have as many as nine.(Paul Yuskevich.)member extending forward from the mast to support the lifting trolley, sheaves, hookblock, and load. (3) In Europe, the term is used for a crane boom. Correspondingly, theextension to the main boom is known as a fly jib.Latticed boom. A boom constructed of four longitudinal corner members, called chords,assembled with transverse and/or diagonal members, called lacings, to form a trusswork in two directions. The chords carry the axial boom forces and bending moments,while the lacings resist the shear forces (Fig. 20.2).Lifting capacity. The maximum gross load weight that a crane manufacturer has deter-mined a crane can safely handle under specified conditions as stipulated in the loadchart.Lift crane. A crane configured for lifting, booming, swinging, or traveling with loadsattached to the crane hook block as contrasted to a crane configured for lifting materialwith a bucket or grapple.Load. The suspended weight applied to the crane, including the weight of lifting hard-ware such as hook block, shackles, and slings.