What is a Jib Crane?
Cranes are an important part of any type of civil engineering work. Different types of cranes are used on the basis of the amount of weight to be lifted and the area available for movement at the construction site. A jib crane is one such type. It consists of a pillar fixed to the wall or mounted on the floor. The pillar supports a horizontal jib or boom which has a movable hoist. The hoist is used to lift or lower a load with the help of a drum, or lift-wheel, which has a chain or rope wrapped around it. The drum is driven electrically or pneumatically, and can be operated manually. The lifting medium is usually a chain, although it may also be a fiber rope or wire cable. The load is lifted with the help of a lifting hook attached to the lifting medium.
The term "jib crane" covers all the cranes that have a rotating boom attached to a vertical mast and supporting a hoist that operates electrically or pneumatically. Jib cranes are not only used in construction business, but also on commercial and military ships. The most commonly used jib crane is the self-supported, floor mounted type. Jib cranes are extremely important in all kind of lifting processes because it relieves the overhead crane of much work and reduces the waiting time.
There are three main types of Jib Cranes :
- Floor-mounted Type
- Wall mounted Type (fixed)
- Wall mounted Type (traveling)
Floor Mounted Type
This is the most commonly used Jib crane. Floor mounted jib crane is a self-supporting jib crane having a vertical mast mounted on a concrete foundation. These types of cranes are generally used to share the load of main cranes. The construction of the crane is as described above. All these cranes can rotate 360 degrees and are manually operated.
Wall mounted type (fixed)
This type of crane is mounted horizontally on the wall and instead of a vertical shaft has a RCC column bracket mounting. The hoist mechanism is similar to the floor mounted type, but without a vertical boom. The RCC column bracket allows a maximum rotation of 200 degrees but covers the area near the bracket mounting without obstruction at floor level.
Wall mounted type (travelling)
The construction of this type is similar to that of fixed type with the only difference that the crane is able to cover the lengthwise area near the building columns without obstruction at floor level. The crane’s columns are specially designed and the crane instead of rotating, moves along a runway track suspended along building columns.