Read a crane load chart by first looking at the top axis. The first number on the top axis is the gross vehicle weight. In the other two columns, you will find arrows that indicate the weight load for each axle, which depends on what additional accessories are loaded. Use this information to determine lift capacity, lift range, lift angle and crane in motion weight limits.
Determine lift capacity by looking at the legend along the top of the crane load chart. This shows the ratings that apply when using a certain amount of counterweight with the outriggers extended a certain distance. (This will vary according to the crane.) From here you graph out the specific lift the crane is needed for.
A crane also has a lift range chart. This diagram illustrates how much boom length is needed to pick up and lift a load a certain distance and certain height. The lift angle chart shows the maximum lift if you use a luffing or fixed jib. The luffing jib allows the angle to be automatically adjusted from the operator's cab. With a fixed jib, the angle remains fixed. For both, as the angle of the lift increases, the maximum load capacity decreases.
Finally, there is a chart that shows the lift capacity for a pick and carry. This specifies the total weight that the crane is able to lift at a 360 degree angle while stationary on wheels. It also specifies the total weight that the crane can support while rolling slowly with the weight at a zero degree angle and the total weight that the crane can support while moving at a given speed.