Within the general scope as defined in Section I, B30.3 applies to construction tower cranes, powered by electric motors or internal combustion engines, and any variations thereof which retain the same fundamental characteristics. The scope includes cranes of the above type that adjust operating radius by means of a boom luffing mechanism, or by means of a trolley traversing a horizontal boom, or by means of a combination of the two. Construction tower cranes may be mounted on fixed or traveling bases. Additional mounting means may include arrangements that permit the crane to climb in the structure being built, or that permit increasing the tower height as the structure rises and utilizing braces attached to the host structure as needed. The requirements of this volume are applicable only to cranes when used in lifting work. Permanently mounted tower cranes (refer to ASME B30.4) and mobile crane tower attachments (refer to ASME B30.5) are not within the scope of this volume.