Operating a forklift, also known as a lift truck, can be dangerous if not done correctly, so it is critical that operators fully understand all aspects of their equipment to avoid safety mishaps. One of the most important things to understand about a forklift is its load center. If the load is not centered properly, the weight of the load can imbalance your forklift and cause it to tip over, resulting in injury or even death.
This guide discusses what a forklift load center is and how to determine the load center to ensure safe operation.
What Is the Load Center on a Forklift?
A load center on a forklift is the distance from the face of the forks to the load’s center of gravity, according to the Occupational Safety and Health Administration (OSHA). Many forklifts have counterweights at the rear of the vehicle to compensate for the load at the front.
Because different lift trucks center the load in different ways, you should be fully aware of how your specific model of forklift balances the weight so you can operate it safely. The capacity of each forklift is rated for specific load centers, and off-balance loads can make the forklift prone to tipping.
Where to Find a Forklift’s Load Center
You can find the forklift’s load center on the forklift’s data plate. Usually, a forklift has a 24-inch load center, which accommodates the commonly used 48-inch pallet. Loads should not exceed the rated load center of a lift truck (as found on the data plate).
Visualizing Forklift Load Center
A good way to visualize the load center of a forklift and how it works with the machine’s center of gravity is to use the example of a lever. A lever is a simple machine using a rigid beam of some kind and a fulcrum. Force is applied to one end of the beam (the input force), which causes an output force to be applied to the other end of the beam. The fulcrum serves as the load center.
Here are some key terms that will help you understand this concept.
- Fulcrum: The point on which a lever rests and where it pivots.
- Center of gravity: The point where the weight of something is concentrated and where it must be supported to achieve equilibrium.
- Load center: The distance from the face of the forks on the forklift to the load’s center of gravity.
- Stability triangle: The imaginary lines connecting the two points on either side of the forklift’s steer axle to the pivot pin in the center of the axle, forming a triangle.
- Load capacity: The measurement of how much weight a forklift can lift.
- Load moment: The object’s weight multiplied by the object’s distance from the fulcrum.
How the Forklift Stability Triangle Works
The forklift’s stability triangle is what keeps a lift truck upright when lifting loads. The triangle is made up of imaginary lines connecting three points: the two points on either side of the steer axle, and the pivot pin in the center of the axle.
As long as the vehicle’s center of gravity stays within this triangle, which utilizes the vehicle’s center of gravity, it will not tip over. If the load exceeds the rated load center, the vehicle’s center of gravity may be outside the stability triangle, causing instability.
How Load Moment Impacts Forklift Stability
Another key term for forklift operators to understand is load moment, which is the object’s weight multiplied by its distance from the fulcrum. Imagine if you carried something close to your body, and then you tried carrying it with your arms extended. The latter would be a lot harder to do, and it would be proportionally harder the heavier the object was. That’s because the load moment is changing the farther the object is carried from your body, and the same is true for forklifts.
How Load Capacity Impacts Forklift Stability
As noted in the example above, the amount of weight a lift truck is carrying has a lot to do with the stability of the forklift, as does how far away from the forklift’s center of gravity the load is. You should always check your machine’s data plate to understand what the forklift’s proper load center is. The lift height can also affect the forklift’s load capacity.
It is absolutely vital that you ensure the load center of a forklift isn’t overloaded or loaded improperly, as this will create a tipping risk. You can calculate load capacity using the following formula: weight rating x center load distance. The forklift’s specified load center is found on the data plate.
What Impacts a Forklift’s Stability
Overloading, lifting irregularly shaped loads, or exceeding the maximum load can all impact a forklift’s stability. Here are the top three factors that affect a forklift’s stability and its center of gravity.
- Load size and weight distribution: The size of the load as well as how that weight is distributed can quickly shift the center of gravity of the load outside the triangle of stability, so you must fully understand the limitations listed on the data plate of the vehicle.
- Capabilities for lift, tilt, and load manipulation: When the forklift moves the forks up or down or changes direction, this can also cause the center of gravity to shift dramatically.
- Attachment use and size: Forklift attachments, such as a side shift, used to nudge the forks left or right during operation, have their own weight and can also impact where the center of gravity is as well as the rated lift capacity of your forklift.
How to Safely Load a Forklift
Safe loading is fundamental to overall forklift safety, because if a load isn’t loaded properly, it may shift the center of gravity into the danger zone just by how it’s loaded. Here are four tips to ensure that you are loading the lift truck safely.
- Do not exceed load capacity. No matter how much you want to move a larger weight, if it exceeds the rated capacity on the data plate, you risk tipping your machine.
- Place heaviest loads close to the forklift mast: Just like you pull a heavy object close to your body to carry it, you should do the same with a forklift.
- Minimize the distance between the front wheels and load center. The closer a load is to the front wheels and front axle, the less the center of gravity shifts.
- Shorten the load center distance. Whatever you can do to shorten this distance, the better it will be for your forklift’s stability.
How to Choose the Right Forklift for Your Job
There are many different types of forklifts, and they all are suited for different kinds of jobs. Some are small and maneuverable, excelling at moving smaller loads quickly in tight spaces like a warehouse, while others are designed for slow, heavy lifting. Here are four tips for choosing a forklift:
- Consider how much weight you need to lift. If you need a lot of weight lifted, you’ll need a forklift with a high load maximum weight, but if not consider opting for the smaller, more maneuverable models.
- Look at the site conditions and terrain. If you have a tight space, loose earth, or uneven terrain, you need a forklift that can handle these conditions.
- Decide if you need additional attachments for the job. Certain jobs may require specific attachments, so determine which you’ll need before choosing.
- Ensure your forklift is the right size for the job site. You need to understand how large of a forklift your job site can accommodate before you rent or purchase one.
Common Types of Forklifts and Their Uses
Forklifts come in all shapes and sizes, each having its own specialty. Understanding each of the different types helps you determine which one best fits your company’s needs. Here are six of the most common types and what they do.
- Warehouse forklift: A warehouse forklift is one of the most common types. It looks a little like a golf cart with twin forks. They are speedy, agile, and best suited for smaller loads—although some heavy duty models can elevate up to 25,000 pounds.
- Counterbalance forklift: This forklift has forks in the front and a counterbalance in the back to help with material handling. They don’t have extending arms, so they can move directly to the load.
- Telehandler: Also called a reach or telescopic forklift, this vehicle has a boom and an extendable arm. It is best for reaching into tight spaces, odd angles, and high into the air.
- Heavy-duty forklift: Also called a large-capacity forklift, it typically has a higher lifting capacity than a warehouse forklift. Some can lift up to 36,000 pounds using hydraulic levers.
- Rough-terrain forklift: Often best for construction sites where the terrain is difficult, a rough-terrain forklift uses sturdy pneumatic tires to give them better balance and stability on rough or uneven ground.
- Pallet jack: Also called pump trucks, they are about the smallest forklift you can get. They can lift small loads into tight spaces and are popular in warehouse settings where you just need a compact, agile option to move lightweight pallets.
It may seem like you need a physics degree to operate a forklift, but the truth is you just have to understand your forklift and operate within the confines of its data plate. Don’t rush the job; carefully measure and load things properly, be aware of your truck’s capacity, and then maneuver carefully.
If you’re ready to rent a forklift for your business or your next project, we’ve got you covered at BigRentz. Check out our forklift equipment rental page for some great options that fit your needs and budget.