Abstract: A ring-supported lift crane is provided with a counterweight handling system to facilitate repositioning of the crane. The ring-supported crane includes a ring, a crane upper works and a crane lower works, a boom supported on rollers on the ring and a counterweight assembly also supported on rollers on the ring. The counterweight assembly preferably includes a counterweight carrier on which at least one stack of counterweight boxes or units are placed. A counterweight holder is interposed between the at least one stack of counterweight units and the counterweight carrier with a friction reduction device, such as rollers or slider pads, interposed between the counterweight holder and the counterweight carrier. When the ring-supported crane is to be repositioned for a second lift at a construction site, the counterweight holder with the stack of counterweight units is moved off of the counterweight carrier onto a separate counterweight support member, which may be mobile or stationary.

Abstract: A crane and an attachment comprising a counterweight support beam including a plurality of connected segments movable relative to each other, and having a fore end adapted to be connected to the crane upper works, and an aft end rearward from the rear portion of the upper works. The attachment also includes a moveable counterweight carrier adapted to carry a counterweight when the counterweight is supported thereon. The carrier is mounted on the support beam for movement along the length thereof. The attachment also includes a cylinder for selectively moving the counterweight carrier fore and aft along the beam, landing gear for normally supporting the aft end of the beam on the ground, and a backhitch pendant and a pendant cylinder interconnecting the aft end of the beam and the top of the mast for raising the landing gear from the ground incident to lifting a heavy load from the boom.

Abstract: An attachment for increasing the lifting capacity of a crane having a mobile lower works with an upper works including a rear portion rotatably mounted thereon and having a pivotally mounted boom and an upwardly and rearwardly projecting mast carried on the upper works with means for lifting a load from the top of the boom and rigging means interconnecting the top of the boom, the top of the mast and the rear portion of the upper works, including a counterweight support beam detachably connected to the crane upper works and extending rearwardly therefrom, a counterweight assembly including a movable carrier mounted on the support beam for movement along the length thereof, an actuator for selectively moving the counterweight carrier fore and aft along the beam, a leg for normally supporting the trailing end of the beam on the ground, and a rear pendant interconnecting the trailing end of the beam and the top of the mast for raising the leg from the ground incident to lifting a heavy load from the boom.