Load Charts: Do you know how to read them?

March 02, 2020 | Blog | Crane Operator | Cranes | Joe Toth

Many times, we take for granted the tools we have at our disposal on our job sites and in our workplace. Cranes and other hoisting equipment are all too often tools that we take for granted. We look at the massive amou

nts of weight and variety of materials that they are continually handling, with what looks like ease. But there are so many factors that go into these calculations of what a crane can lift and move about the workplace. Are you familiar with what may affect your crane’s ability to move the materials that are expected of it?
What is your role on the job site you are working on? Is there a crane involved in the operations taking place? What do we need to be picked up, moved, or placed with the crane we have available?

The ability to read a crane capacity or load charts are so critical that even minor changes will have a massive bearing on what the crane can do.
What are the ground conditions of the site we intend to place the crane on?
What is the weight we expect to apply to the crane, and how far do we need to go with it?
Just because you have a 300 Ton Capacity Crane, does not mean that everywhere it can reach, it will be able to handle that “maximum” amount of weight. This can only be achieved in the ideal conditions for that crane, in its maximum configuration, at its shortest radius. Determining the highest amount of weight to be hoisted is the first step in ascertaining the correct crane for the job.

Counterweight plays a significant role in what a crane can handle. Because it does just what it says in its name, counters the applied load/s. The crane must be able to counteract the leverage of whatever load is applied to the other end of the system; otherwise, the load will end up turning over the crane with disastrous results.

Parts of line are another major deciding factor on a crane’s lifting abilities. This is achieved by the mechanical advantage of blocks and pulleys. Each part of line has its individual capacity.
If you do not have the correct amount of cable capacity, you will never reach what the crane is capable of doing.
The difference of one part of line to ten parts of line can be hundreds of thousands of pounds. Always be aware of what a single part of line can lift on its own, and the effects of multipart reeving on your machine.

Attachments for your crane are also a dictator of overall capacity. The primary intent of these devices are meant for increasing height, or reach, so significant capacity losses will take place once the jib or extensions are erected on the crane. The operator and lift director must always be aware of their operating conditions and configurations, and what lifting capacity is possible for each setup.

These are just a few of the limiting factors of crane capacity.
The moral of the story always be aware of the equipment limitations and to know what conditions will change your capacity. Colorado Crane Operator School offers many types of classes that can ensure that you have the information and knowledge to make proper decisions for the lifts being made on your job site.