A telehandler is most often used to lift and place materials at a distance other equipment can't readily reach. The one you select for your job needs to match the weight of the material to the height and reach capabilities of the machine.
That sounds fairly basic. Yet, ensuring the right combination of lift capacity and reach for the application is not. A mismatch can prove detrimental to the equipment, to the load and to anyone in the vicinity of the lift.
"Overloading or operating beyond the restrictions of the load chart can have severe ramifications, including dropping the load and/or tipping the telehandler over, or even causing permanent structural damage," says Luke Webber, product manager, Genie Industries. "For the safety of the operator and everyone on the jobsite, it is essential to understand the maximum lifting requirements in advance and select a telehandler designed to handle the expected loads and how high and how far you will be lifting or placing them."
Monitor center of gravity
A telehandler is susceptible to tipping due to overloading/extending because the center of gravity is constantly changing.
"As you raise the boom, the center of gravity will raise higher above the ground," says Steve Kirst, telehandler product manager, Mustang Mfg. "And because it's moving through an arc, the higher you raise the boom, the more the center of gravity shifts toward the back of the machine."
A telehandler is most stable when its "stability triangle" is large, explains Randy Reeves, sales manager, Xtreme Mfg. The stability triangle is the area formed between three imaginary points underneath the machine: one point below each of the two front wheels and one below the rear-axle pivot point. (The rear wheels are not factored into the stability equation because the rear axle typically oscillates.) The telehandler will not tip over as long as the center of gravity of the machine and its load remains inside the stability triangle.
Once you add a load and raise it, the center of gravity moves up and to the rear, toward the more narrow portion of the stability triangle. The higher the load is lifted, the narrower the area of the stability triangle below the load becomes, and the smaller the margin of error.
It may not be intuitive, but one of the most unstable conditions is with the boom fully raised, boom fully retracted and no load, says Lee Kramer, vice president of engineering, Xtreme Mfg. This condition is especially unstable when backing down a grade and when making a turn while on a grade.
Telehandlers are also more prone to tipovers because they are often moving. "Some other lifting machines such as cranes are firmly positioned, which eliminates some of the variables," Kirst points out. "A telehandler is much more maneuverable and susceptible to unsafe situations which an untrained operator may not be aware of. The positions of the load and the center of gravity can change quickly, which affects the stability. That's why it's important for operators to have the training required by OSHA."
Weight, height and reach
The main criteria for ensuring a proper match relate to the weight of the material and lift height and reach required.
Telehandler capacity and reach are inversely proportional, says Brian Boeckman, JLG Industries. "One of the most important things for contractors to understand prior to purchasing or renting a telehandler is the weight of the load they are trying to lift and how high they are trying to lift it," he stresses.
Weight information is available from materials suppliers. "There are some local industry norms, such as how much a bunk of OSB plywood or a cube of blocks weigh," says Kirst. "The difficult and more dangerous ones are unique items such as a big air conditioning unit, a big I-beam or a big wall panel. Then you must size your machine to the worst-case scenario, rather than the typical scenarios."