Basic Information about Jib Cranes
When you need a jib crane, remember to always tell us as much as you possibly can about your intended use of the jib crane.
- What is the actual weight of the load you are lifting?
- How often you will be using the jib crane?
- Describe the load.
- What is the required height of lift?
- What is the required length of jib arm and angle of slew?
- Do you need single or two speeds?
- What controls – pendant or radio remote?
- What will be the power supply?
- What is the general environment
- Are there any special requirements?
HELPFUL HINTS
Make of jib crane
These days most European jib cranes are inherently safe and operator friendly. They do not break down unless you abuse them. However, when you buy a jib crane make sure that it is a well proven make with excellent local spares and service backup as a guarantee may be of little use to you if the spare parts are not readily available.
Working load
The Safe Working Load, or Working Load Limit, is the maximum load which can be safely lifted by the jib crane. Tell us the actual load you are lifting and do not round it up yourself. Also tell us how often you will lift the load. We will then be able to propose the most appropriate jib crane type and model to suit your needs.
Swing jib crane duty
Jib crane duty ranges from light to very heavy and we are best able to advise on this after carefully considering all the other information you let us have.
Nature of load
Tell us as much as possible about the load, its size, shape and what it consists of.
Height of lift
This is measured from the hoist hook in its lowest position (usually the floor) up to its highest position. If possible, tell us the exact height of lift required.
Headroom
This is the distance between the highest point of the jib crane structure and the load hook in its highest position. Some jib cranes are designed to be low/close headroom so that you can maximise the height of lift within the constraints of your building.
Over braced or under braced
An over braced jib crane gives maximum hoist travel along the jib arm but requires more headroom above the jib arm.
An under braced jib crane gives maximum height of lift for any given building height constraints but has a reduced length of hoist travel along the jib arm.
Length of jib arm
This is usually measured from the jib arm pivot point to the far end of the arm.
Pillar mounted or wall mounted
A pillar mounted jib crane is free standing and can be bolted down to an existing floor if suitable, or to a concrete foundation block cast into the existing floor.
A wall mounted jib crane can be bolted onto an existing wall or to an existing building column.
Slewing angle
The slewing angle is normally around 270° but can be up to 360°. If there are obstructions to the swing this angle can be reduced to whatever is required.
Slewing method
Slewing (jib arm rotation) can be by manual push/pull or for larger loads can be electrically powered.
Speed of lift
Some jib crane applications only need single speed hoisting and travel but two speed (fast and slow) is essential where precise load positioning is required or where the load is such that it is safer to make the initial lift at a slow speed. Some manufacturers now offer variable speed.
Jib crane travel functions
These days most jib crane hoists are electrically powered but a cheaper option is to have manual operation. This is not recommended over 1.5 tonnes and the trolleys tend to travel in ‘jerks” of one or two feet at a time so accurate load positioning is difficult. Electric power travel is best because the hoist travels along the jib arm effortlessly with the simple push of a button and you can have either single speed or two speed operation.
Control
Most jib crane hoists are supplied with a low voltage pendant control which is a push button box suspended from the hoist unit on a cable or suspended from a separate cable festoon track so that the operator can stand well away from the load. The pendant can be any length to suit the job.
Another option is remote control by either radio or infra-red. Radio control is the more versatile but bear in mind that the operator does not need to be in sight of the jib crane to operate it so care should be taken to ensure that the handset is only used by responsible people and with great care. Infra-red requires line of sight between the handset and the receiver on the jib crane and this can be a safety feature but the receivers on the jib crane must be cleaned regularly otherwise they get dusty and will not function.
All controls can be supplied with a key operated isolator switch for security and safety. We recommend that all remote-control hoists are equipped with a spare plug-in pendant as a backup just in case the remote control fails, often the handsets get lost, damaged or need charging.
Safety features
Most jib crane hoists these days are fitted with overload protection preventing the hoist unit from lifting more than its safe working load. Slipping clutches are sometimes used for this purpose and they also prevent over hoisting and over lowering. Limit switches also prevent over hoisting and over lowering.
Environment
Indoor, warm, and dry or outdoor, cold, and wet?
Is the atmosphere hazardous requiring explosion or fire-resistant measures? Is there a lot of dust or other contaminants?
Enclosure protection
Most jib cranes are protected to IP55 (dust and water resistant) as standard which covers most normal environments, but you may wish to consider additional protection for jib cranes which are permanently outdoors. An outdoor jib crane should also be fitted with a hoist weather protection canopy.
Chain hoists / wire rope hoists
Chain hoists are cheaper and usually preferred up to 5 tonnes, they require less maintenance, tolerate more abuse, chain can last 30 times longer than wire rope, more allowance for side pulling, and they have a true vertical lift.
Wire rope hoists tend to be quieter, smoother, have faster lifting speeds and are generally preferred over 5 tonnes especially for long lifting heights and for heavy duty use. There are other pros and cons and we will advise on these according to your specific requirements.
Pneumatic power supplies
Most pneumatic jib cranes operate on an air pressure of approx. 90psi or 6 bar, but it is important to realise that they need a reasonable volume of air supply to operate properly. Typically, pneumatic hoists up to 2 tonnes capacity consume air at approx. 22 litres/second.
Electric power supplies
In the UK it is normal to use 400volt 3 phase 50Hz power supplies, but some hoists are available for use with 110volt or 220volt single phase.