Preventing Overloads When Operating Bucket Trucks

Knowing bucket capacity and how to read a jib load chart are two critical elements of aerial device operation. While both tasks are straightforward, staying within the allowable capacity of the unit is very important. The platform capacity and material handling capacity provided by the manufacturer are not recommendations – they are absolute maximum capacities that ensure the machine is not overloaded. Overloading equipment can result in overturning or boom failure. Equipment damage may occur, resulting in costly repairs and a shortened, useable life for the aerial device. 

Know How Much Everything Weighs

Fully-equipped linemen with PPE plus tools and materials for typical line maintenance can quickly add up to 700 pounds or more for distribution work and upwards of 1,000 pounds for transmission work. Bucket capacity is identified on the ID plate and inside of the basket on most aerial devices. Be aware also of dual-rated buckets that may be available from some manufacturers with different capacities based on configuration and use as a material handler. Before climbing in, linemen should verify that their weight, tools, and PPE doesn’t exceed the capacity of the bucket.  

If gear is not labeled with its weight, use a small, portable scale to verify total weight before loading the bucket. Once you have weighed a tool or piece of gear that you use often, mark it with a small tag or permanent marker so that you will know next time. 

The platform is not a warehouse, load only what is needed for the specific job.  Store other items securely in the truck storage areas.

Practice Proper Jib Use if Equipped

If not equipped with a material handling feature from the manufacturer, the aerial device is not to be used to lift material with the platform or boom. The platform is not intended to handle material—only tools and equipment the operator can carry within the platform capacity.   

Proper jib use requires an understanding of how to read a load chart, plus knowing the upper boom angle, jib angle, and load radius as specified on the load chart. Maximum permissible load on the jib varies depending on the boom and jib configuration. It’s necessary to verify the setup before a load is lifted.  

While different bucket, boom, or power line positions dictate what angle the jib can be used, the upper boom angle must be verified by looking at the angle indicator located on the boom. In addition, some jibs extend, which will increase the radius of the load, thereby decreasing capacity.  A trial run with the boom and jib positioned as needed will provide the information necessary to confirm jib capacity. Keep a non-conductive measuring tape handy to verify load radius. The next step is to confirm that the weight of the object to be lifted is less than the maximum jib load for any configuration, from picking the load to placing the load.  Load charts are typically located near the controls at the boom tip, visible to the operator. 

Change Your Plans if Need Be

If a company is finding that their current equipment bucket or jib would be overloaded for a task to be performed, determine what rated capacity would better meet the application. Then use several machines if possible, such as a digger derrick with the aerial, to aid in accomplishing the task or purchase/rent the proper equipment. In any case, always encourage proper operator behavior, not to abuse the equipment by overloading, putting themselves in danger. 

How technology helps change behavior 

Terex Utilities collaborated with customers to create an operator aid that would help inform linemen of a potential overload situation. The Terex Load Alert™ system consists of wireless sensors that measure boom angle, jib angle, jib extension length, jib load, and bucket load. Visual and audible warnings at the upper controls warn the operator if the equipment approaches 90 percent of the maximum allowable capacity. By providing real-time feedback, including maximum allowable and actual capacities of bucket and jib, linemen can take corrective measures to prevent overload situations. 

Surprising outcomes 

For companies that have implemented the Terex Load Alert™ system, several unexpected outcomes have occurred. Initially, there was push back from operators who felt like “Big Brother” was watching. But as trucks with the Load Alert™ system have now been put in the field, linemen are surprised to find they were unintentionally overloading the basket or jib and can take immediate corrective action. The system aids during training, on what they should be doing; and operators can be more accurate in set-up, estimated weights, angles, and other factors. The system’s feedback was critical in changing behavior when it mattered most. 

In addition, as data is monitored, it can also be output through any telematics system. Utilities can track historical occurrences of overload situations and use the information to perform required inspection and maintenance as necessary due to damage. It can also guide training needs and aid in determining what is needed for future equipment purchases. 

Follow Safe Work Practices

Ultimately, it’s all about the numbers. Operators are responsible to calculate loads in the bucket and on the jib and verifying them against available capacity. New technologies can aid that process, increasing accuracy but cannot replace the operator’s knowledge and following proper work practices.