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Usually jib arms are attached to a vertical mast or tower or sometimes to an inclined boom. In other jib-less designs such as derricks, the load is hung directly from a boom which is often anomalously called a jib. A camera jib or jib arm in cinematography is a small crane that holds nothing but the camera. [4]
The jib was slewed by a mechanism on the ground, and bearings at the top of the tower and where the extension met the ground allowed it to turn. [ 1 ] [ 2 ] The winch on each arm was powered by two 52 horsepower (39 kW) electric motors for hoisting and two 14 horsepower (10 kW) motors for slewing, and a 18 horsepower (13 kW) motor for slewing ...
The "hammerhead", or giant cantilever, crane is a fixed-jib crane consisting of a steel-braced tower on which revolves a large, horizontal, double cantilever; the forward part of this cantilever or jib carries the lifting trolley, the jib is extended backwards in order to form a support for the machinery and counterbalancing weight. In addition ...
A level-luffing crane is a crane mechanism where the hook remains at the same level while luffing: moving the jib up and down, so as to move the hook inwards and outwards relative to the base. [ 1 ] Usually the description is only applied to those with a luffing jib that have some additional mechanism applied to keep the hook level when luffing.
It was a luffing-jib tower crane manufactured by Favco that was 200 feet (61 m) tall at the time of the collapse. The accident occurred when workers were attaching a new steel collar to anchor it to the building at the 18th floor, as part of an operation to extend the crane upwards. [ 6 ]
In 2007, Tishman Construction Corporation of New York completed a row of steel columns at the perimeter of the construction site. Two tower crane bases were erected, each base containing a functioning luffing-jib tower crane. By the end of 2007, the tower's footings and foundations were nearly complete. [10]
Animation of main and jib boom articulation. Titan is a large self-propelled crane vessel with the tip of its main boom standing at 374 feet (114 m) above the typical water line and a lifting capacity of 385 short tons (349 t). [3] In 1957, it was claimed to be the largest floating crane in operation. [7]
Early French crane loading coal for a gasworks. A bulk-handling crane is one that, instead of a simple hook that can handle a range of slung loads, has an integral grab for lifting bulk cargoes such as coal, mineral ore etc. Where the grab is a two-piece hinged bucket, it is known as a shell grab or shell bucket. Working the grab requires extra ...