Compact And Efficient: The Jib Crane
The jib crane, with its horizontal jib supporting a moveable hoist, is often used in workshops or facilities where no space exists for an over head travelling crane. Jib cranes are well suited due to their side-to-side swing horizontal arc movement. The jib crane, composed of the jib (which is basically just a horizontal beam) with a mounted shuttle or hoist, can be mounted on a wall or the floor. Jib cranes, mounted onto the floor or similar stable foundation, have a higher load rating. These cranes can also incorporate full or partial rotation when cantilevered (meaning a design where the beam is supported on only the one end).
Industrial cranes differ in terms of product specifications, features, and applications. Performance specifications to consider include load capacity, vertical available lifting height, and horizontal available span. In terms of features, these cranes (like the Cambellhowe jib crane) fall into the category of “boom” crane. This dictates that these cranes have a long beam that is structurally reinforced so that it will not bend. The jib is supported or held aloft by guy wires running from its top to a vertical mast, or pillar, that is itself stiffly braced; the guy wires set the angle at which the jib leans. Along the entire length of the jib runs a pulley system whose cables or chains are wound and unwound around a drum, or cylinder, that is placed at the jib’s base and is turned by a motor.
The cable dropping from the top of the jib is attached to loads and lifts them vertically. The loads may also be moved from side to side by having the jib pivot, or rotate, on its base around the mast. A travelling jib crane is comprised of a pulley system suspended from a wheeled carriage (or trolley) moving along the length of the jib. In order to ensure that the cranes do not tip, over and above the usual practise of mounting the hoisting machinery, special ballast weights are added. The jib crane, like its counterparts is very heavy and even the smallest malfunction can lead to grievous bodily harm, so jib crane maintenance needs to be strictly adhered to.
The three examples of jib cranes include: the free standing, the mast type and the wall mounted jib crane. Free standing cranes on a concrete foundation, can stand up by themselves and allow for 360˚ rotation. They can be base plate mounted, foundation mounted, or sleeve insert mounted. Mast type jib cranes are more cost effective and still offer 360˚ rotation without a large mounting foundation as is required by free standing models.
Finally, the wall mounted crane is capable of only 200˚ rotation. Their design can be either cantilever or tie rod supported. A truck jib crane(truck mounted crane) also exists, this is simply a jib crane mounted on a heavy modified truck, often using unsupported telescopic booms which, for convenience sake, have collapsible sections.
