What is a Jib Crane?
Although it's referred to as a Jib Crane, the role of this equipment is to support manual or electric chain hoists. The kind of jib crane or chain hoist you opt for needs to be most suitable for your operation and the intended use, while a jib crane and chain hoist can be sourced from separate suppliers and we advise that you choose a reputable supplier who can offer you with the full lifting solution to make sure you receive a technically correct solution that is fit for purpose and a focus on safety.
With this in mind, here in this blog, we outline to you the purposes and attributes of a jib crane and how they can be beneficial to you.
Read on to discover more about these versatile pieces of equipment.
The Fundamentals of a Jib Crane
This is the most widely used kind of jib system because they can be installed pretty much anywhere including indoors or outdoors. Freestanding jib systems can be utilised underneath large bridge crane systems, or in open areas where they can support individual work cells. They can also be used outdoors at marinas or loading docks, and indoors for machining and assembly operations where multiple jibs can be used in parallel with the staged operation.
Often, freestanding jib crane systems can accommodate:
● Spans up to 50’
● Capacities up to 15 tons
● 360° of rotation
There are three key designs for freestanding jib cranes, in terms of how they can be mounted and installed:
Wall Mounted Jib Cranes
A wall-mounted jib crane fixes the bearings to an existing structure, for example, a building, column or a wall. If fixed to a wall, the jib crane would be limited to 180° of slew, but column-mounted units could rotate up to 270° varying on the installation itself.
You will have to assess the most suitable jib crane configuration for your operational needs, supply drawings outlining the imposed loadings on the structure, an example the wall or column and calculate a ‘maximum moment’ in force, which is generated by the combined weight of the load and lifting appliance when at the end of the jib, whilst factoring in the dynamic effects of lilting and lowering the loads.
These drawings need to be verified by a structural engineer and approval communicated to Hoist UK before installation of a wall-mounted jib crane.
Free-standing Jib Cranes
A free-standing jib crane possesses its specific column and when installed would be fixed to the ground. So that you can fix a free standing jib crane to the floor foundations with significant depths would be required to withstand the overturning moment. A tubular column allows for a full 360° slew but it’s important to note that if being used with an electric chain hoist the power supply has to be through slip rings unless stops are incorporated to prevent a full rotation.
A lower capacity or shorter radius jib crane needs to be fixed directly to the floor providing the floor specification is accurately known and has to be suitable and in good condition. For jib cranes with a bigger radius and load capacity, the most cost-effective outcome for mounting would be to cast directly into the floor but this would also involve moving it at a later date, an unattractive proposition. The alternative that is often a more suitable installation is a bolted connection which requires a base plate and fixings requiring more space around the base of the column, or the usage of chemical anchors.
Under-braced and Over-braced Jib Cranes
Under-braced and over-braced jib cranes are specified for how the cantilevered arm is supported. An over-braced jib has a tension member from the top of the king post to a point about two-thirds of the way down the jib arm. The plus side of this is that it has a lighter structure and one which allows the chain hoist to get as near as possible to the supporting structure giving the maximum effective travel.
It also facilitates the use of specific track sections instead of a rolled beam. The disadvantage is that more headroom is needed for a given height of lift. An under-braced jib has the cantilever support beneath the runway beam. This keeps the headroom required to the minimum - however, necessitates a heavier rolled beam and reduces the maximum effective travel.
In lots of applications, the jib will be slewed and a push travel trolley will be used. Caution is advised, particularly if the jib is high-mounted as pushing on the load will cause it to swing away from the vertical centre line of the jib. The more significant the distance between the load and the jib arm, the more accentuated the swing will be. Another option offering a more controlled movement would be a powered travel trolley, and there are various options available that provide powered slewing for the free-standing 360° style of the jib crane.
The Bottom Line
It goes without saying that jib cranes are ideally designed to handle high-volume lifts and provide an ergonomic means of moving material within a work cell or in conjunction with an existing overhead crane system.
So to reiterate, it's helpful for you to consider the following to ensure that you design a jib crane system that’s the most economical and most productive for your application:
Duty Cycle or Classification
Picking the right duty cycle or service classification allows you to ensure that the components are durable enough to withstand the load and usage requirements.
Area of rotation
Freestanding and mast-style jib cranes offer 360-degree rotation; wall-mounted cranes offer 180-degree rotation.
Height Under Boom
The distance from the floor to underside of the jib crane’s boom is the height under the boom. Also, factor in hoist size and lifting height required.
Overall jib crane height
Consider any attachments, such as electrical entry, so that the crane will be free from overhead obstructions.
The actual working span required
The working (or hook) distance is around the length of the boom minus ½ trolley length at each end. Power requirements: Will you have to power for your jib crane’s motor drive, its trolley, its hoist, or all three? Will the power supply be electric or air? Bottom or top entry? Indoor or outdoor use? These are all valid things that need to be questioned.
Crane and Lifting Services - Professional Crane Servicing & Repairs
Whether wall-mounted or floor-mounted, jib cranes are a type of overhead crane which are often used in smaller workspaces for unique lifting tasks and can be paired with overhead cranes to make them more versatile. Jib hoists and hoist cranes provide slew angles of between 180 and 360 degrees which supply even rotation, hoist travel and lift. These cranes can be modified with the addition of an elbow to improve flexibility in smaller spaces.
If you require a jib crane or gantry crane in Cardiff, look no further than Crane and Lifting Services Ltd. We have jib cranes for sale as well as the experience to recommend the best equipment for your requirements. To find out more about our range of hoists and Jib cranes to see what suits your requirements - please visit our website or contact us today to find out more, we’d be delighted to hear from you.