Setting up the crane for task
To maintain it’s stability and to be able to work to it’s full capacity, the crane needs to be setup level, longitudinal and across.
To ensure the crane is setup level, use
- Bubble level indicator
- Use spirit level
- Newer cranes have digital level display built into them, both truck and superstructure part
Setting up on timbers
If you use timber packing to set up the crane, minimum 2 layers for each outrigger must be used. This is to ensure that the bottom layer utilized can be wider than the crane’s outrigger pad, and to connect all the bottom layer timbers into one solid pad. This is called ‘pigstying’.
– When pigstying timbers, second layer should be at right angle or 90 degrees to the first layer.
‘pigstying’ or ‘cribbing’
For cranes on tracks (crawler cranes) and cranes operating on rubber, capacity of the crane can be compromised if used on uneven ground because centre of gravity shifts downhill or sidewise, depending on a slope.
– Uneven ground can cause decrease in capacity of the crane
Front stabilizer/front jack
Front stabiliser is found on most truck mounted cranes, and it is located under the front part of chassis, in front of axles.
It provides for extra stability while lifting within the front lifting zone.
– When setting up, front stabiliser needs to be extended last.
– When packing up, it needs to be retracted first. This is to prevent the hydraulic ram being overloaded.
Configuring the crane computer
Crane configuration data must be entered in crane computer correctly in order for crane to function as intended. Different cranes have different computers.
Some of data that needs to be entered into the crane computer to ensure the crane is configured accurately includes:
- Amount of counterweight
- Boom and Fly Jib configuration
- Falls of rope (reeving, number of parts of rope reeved)
- Length of outriggers used
multiple rope falls reeving
EKS Grove crane computer
Liebherr Liccon computer: above F4 – counterweight; F5 – outriggers span; F6 – 360 degrees slew area; F7 – reeving of the hook block
Crane manufacturers specify that the crane computer is to be used as an aid to the crane operator and that operator needs to check for it’s accuracy.
To make sure the crane computer is functioning properly once the appropriate data is entered into crane computer, you can
– Compare the computer results to the crane load chart and manual measurements (measure the radius or height, where possible)
When positioning the crane to be set up, you need to check:
– Safe working radius – are the tasks to be undertaken within safe operating radius
– Positioning of the crane in relation to the tasks to be performed – is it correct position, are you too close, too far?
– Adequate clearances from all obstructions and hazards – can you perform all necessary motions safely?