A crane’s load chart is the key to its proper operation. In order to use the crane with maximum efficiency and efficacy -- and to avoid failures and accidents, the load chart must be consulted and accurately translated.
Never take for granted that you already know the capacities for a particular crane -- even if you’ve worked with a very similar model before. Always check the load chart for specifics.
As they say, an ounce of prevention is worth a pound of cure. Reading the chart should be regarded as an important and necessary first step in the process of operating a crane.
Components of a Load Chart
The purpose of a load chart is to give you an exact readout of the crane’s capacities and features. Understanding each section and knowing why these data are important is imperative. The following is a brief overview of the sections most commonly found on crane load charts.
Dimensions - This section tells you the exact dimensions and weight of the crane. This is necessary information in determining the type of trailer to be used in transporting it. You’ll also find information about capacity with fully extended outriggers. This data is also imperative because if you must operate in a tight space with partially retracted outriggers, lifting capacities will change.
Additional Information Found in Load Charts
Many load charts will contain other information, too. For example, some will have a chart section dedicated to proper counterweight configurations. Some others have tipping capacity information for using the crane with partially extended and even fully retracted outriggers.
You may also find a strength readout discussing the limitations of structural materials. There is usually a substantial set of footnotes to accompany a load chart, too. This is an important resource, and should never be skipped over. The footnotes serve to provide guidelines and clarifications for proper chart reading. Footnotes are written in reference to a particular make and model of crane, and are not universal.
Always conduct a thorough read-through of the load chart before transporting or operating any crane. Operating outside the parameters specified in the chart is dangerous and can result in expensive equipment failure, injuries, and even fatalities.
Remember that several factors, such as unlevel ground, affect the actual capacities of a crane. When in doubt, consult a trusted industry professional for help.