What 29 CFR 1926.1400 requires (plain English)
29 CFR 1926.1400 is the scope provision of Subpart CC: OSHA's comprehensive standard for cranes and derricks in construction. Cranes lift enormous loads over workers and the public, often near power lines, and their failures: tip-overs, dropped loads, boom collapses, and power-line contacts; are frequently fatal and can injure many people at once. Subpart CC (1926.1400 through 1926.1442) sets detailed requirements for assembly, inspection, operation, operator qualification, and power-line safety; 1926.1400 defines exactly which equipment those requirements cover.
The scope is defined functionally: the standard applies to power-operated equipment, when used in construction, that can hoist, lower, and horizontally move a suspended load. That three-part capability (hoist, lower, AND move horizontally) is what makes a machine a crane under the rule. Covered equipment includes articulating cranes, crawler cranes, mobile (truck and rough-terrain) cranes, tower cranes, pedestal and portal cranes, overhead and gantry cranes, sideboom cranes, service/mechanic's trucks with a hoisting device, and derricks, among others. The breadth of coverage reflects how many different machines perform crane work on modern construction sites.
The scope section also draws important boundaries. Subpart CC excludes certain equipment, for example, machinery that has been converted or adapted for a non-hoisting use (like a power shovel or concrete pump), digging equipment such as excavators and backhoes when used for digging, forklifts (except when configured to hoist a suspended load with certain attachments), automotive wreckers, and a handful of other specifically listed items. Knowing whether a machine is covered matters enormously, because if it is, the full weight of Subpart CC (operator certification (1926.1427), inspections, assembly/disassembly rules, and the power-line clearance requirements) applies.