Chapter 6 Cranes Cranes are broadly classified as either fixed (permanently installed) or mobile types.
Chapter 6 Cranes Large cranes are typically operated from inside a cab, which moves with the crane to maintain a good view of the load.
Chapter 6 Cranes Loads must be lifted only from directly above. Side pulling is not permitted.
Chapter 6 Cranes If a crane operator lacks a good view of the load at all times, an assistant nearby can provide crane directions through hand signals.
Chapter 6 Cranes Gantry cranes consist of a hoist on a horizontal beam, which is supported by legs that roll along the floor.
Chapter 6 Cranes Overhead cranes are similar to gantry cranes except the hoist and bridge beam are supported by overhead beams.
Chapter 6 Cranes Jib-crane booms are supported at only one end but can be configured in several different designs.
Chapter 6 Cranes Mobile cranes are crane assemblies that are mounted on a mobile platform. The platform may use a variety of forms of mobility depending on the intended application.
Chapter 6 Cranes An outrigger increases a mobile cranes footprint, which improves stability.
Chapter 6 Cranes Telescoping-boom cranes have the ability to extend or retract the boom, providing significant versatility to its reach.
Chapter 6 Cranes The boom of a lattice-boom crane is constructed of a lightweight, open structure that allows these cranes to have particularly long booms.
Chapter 6 Cranes The lift capacity of a mobile crane is determined primarily by the horizontal distance of the load from the crane.
Chapter 6 Cranes Lift capacity tables are used to determine the maximum allowable load weight for a particular crane with certain lift distances.
Chapter 6 Cranes The inspection of a hoist trolley should include checking the spacing on trolley wheels. The wheels must be close enough to provide a secure attachment to the beam but not so close as to impede free travel.