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A jib or jib arm is the horizontal or near-horizontal beam used in many types of crane to support the load clear of the main support. [1] [2] An archaic spelling is gib. [3] Usually jib arms are attached to a vertical mast or tower or sometimes to an inclined boom.
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.
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 ...
An overhead crane, commonly called a bridge crane, is a type of crane found in industrial environments. An overhead crane consists of two parallel rails seated on longitudinal I-beams attached to opposite steel columns by means of brackets. The traveling bridge spans the gap. A hoist, the lifting component of a crane, travels along the bridge.
A davit (/ ˈ d eɪ v ɪ t /) [1] is any of various crane-like devices used on a ship for supporting, raising, and lowering equipment such as boats and anchors. [2]Davit systems are most often used to lower an emergency lifeboat to the embarkation level to be boarded.
The heaviest types of boom can rotate, effectively turning the tow truck into a sort of mobile crane, called a "rotator", and are usually reserved for incidents involving heavy vehicles. [3] In the past, [timeframe?] boom trucks used a "hook and chain" system where chains are looped around the vehicle frame or axle, then lifted by a boom winch ...
Disadvantages of this crane type are the higher power demand and increased maintenance requirement due to the increased number of moving parts. Knuckle boom crane arms are much lighter than boom truck cranes, and they are designed to allow for more payloads to be carried on the back of the truck that it is mounted on.