March, 2024- All materials handling equipment, from counterbalance forklifts to sideloaders, reach trucks to reach stackers, are classified based on the safe amount of weight they can lift— their nominal capacity.
Several real-world factors influence this “safe working load limit,” including the truck’s counterweight, the type of mast, weight and deration effect on the truck (to lower the rating), and the height and reach at which the load is held. Even tire pressure, weather, ground conditions and inclination can influence the outcome.
It is difficult for industrial companies that operate lift equipment to know all these different variables, so to help accommodate some of these factors, machinery manufacturers use a crucial parameter: the load center. Every load has a center of gravity—the point at which the weight is focused. This might be the physical center of the load but, if the load is heavy at one side and light at the other, it won’t be.
When forklift manufacturers talk about load centers, they refer to the distance between the center of gravity of the load being lifted (which may differ from the physical center point) and the inner heel of the forklift’s forks. It is a critical factor in determining the maximum weight capacity and stability of a forklift or sideloader, and basically says the machine is safe when used “in this specific way.”
LOAD CENTER
The truck’s load center is usually expressed in inches or millimetres, and whether the operator adheres to this therefore varies depending on the size, shape and weight distribution of each load being lifted. So, each truck’s nominal capacity comes with a caveat: it is based on a pre-determined load center, typically 23 to 28 inches (or more, depending on the fork length). If the load center is 23 inches, the truck’s capacity will decrease as the load’s weight shift s further away from the fork heels. If one exceeds the rated load center, the machine becomes unstable and can tip over. That’s because the load’s weight shift s too far away from the back of the forks, causing the center of gravity to shift too far forward or backward. This can be dangerous for the operator and anyone nearby, as the forklift may tip over or drop the load unexpectedly.
To prevent accidents and ensure safety, it is important to know the load center of the load you are handling and the nominal capacity of the machine.
The machine is easy, it’s in the specification documents and ratings plate, but how do you determine the load center of a load, particularly if it is uneven, and not on a pallet? Even if one does know the load’s own center of gravity and load center, can you be sure every load is held within the specific distance from the heel of the forks?
Even the best trained and most capable operator cannot know in every case, perhaps until it is too late.
Baumann sideloader features a lithium-ion battery. The vehicle is built for managing large, heavy loads safely.
The screen identifies the weight of the load and how much of it is on center
OPTIONS
To overcome this issue, there are usually two options. First is to use a larger capacity machine with a greater margin for error; this comes at a price, however, as larger trucks cost more. The second option implemented by most forklift manufacturers are measures to minimize risk.
Some use sensors at the top of the mast to detect any oscillation. Builtin scales determine the current lift height and the load weight, a central controller unit processes all the data and sends control signals to the mast’s drive motor to take specific counter-movements.
Others restrict the mast travel speed and angle to minimize sway and combine it with counter measures in the axle to reduce the tipping effects. Depending on one’s point of view, these tools give operators either a greater level of confi dence, or a false sense of security.
In truth, none calculate the load center. The load center is a difficult concept to factor in when working in the real world, so these systems are inelegant solutions to a difficult problem.
Baumann sideloaders are rated at 600mm or 700mm load centers. The manufacturer’s nominal capacities mean that every load below the capacity can be safely carried when the load center is respected.
SafeLoad Assistance uses sensors in the truck chassis to monitor the forces acting on the front and rear axles to determine the level of safety.
“When we calculate the capacities of our trucks, we also must factor in the lifting height and outreach of the mast,” says Baumann Sales Director Fabio Bernieri. “We also add body tilt, tilting carriages, pantographs and many additional factors into the equation.”
Despite the careful calculations, lifting a load at the fork tip or just not realizing it exceeds the truck capacity can lead to dangers in the warehouse.
“For much of the past decade, we have sought a solution and tried many different methods of determining how to help operators respect the load center,” says Bernieri.
After its research and testing, Baumann developed SafeLoad Assistance.
MEASURE AND RESOLVE
SafeLoad Assistance uses sensors in the truck chassis to monitor the forces acting on the front and rear axles to determine the level of safety. Software in the cabin processes the forces and calculates the relative tipping point of the truck in relation to these forces.
It therefore bypasses the load center problem and provides a more accurate and reliable guide to the safe operating level. A simple screen in the cabin shows the safety levels relative to the truck’s tipping point.
Operators can respond instantly to the warning to prevent dangerous situations from occurring. Costly or harmful levels of damage to products, building infrastructure, machines, operators, and pedestrians can be dramatically reduced.
Furthermore, the machine can measure the number of times the safe level is exceeded, and managers can assess operator capabilities and machine suitability.
“This is a game changer,” says Baumann Managing Director Klaus Pirpamer. “A decade ago, this is something we could have only dreamed about. We have spent many years looking at this. The technology has evolved to allow us to find the right way to answer the load center question, to give the accurate levels of safety the market has always desired.”
The biggest challenge was finding the best way to consider all the many variables at play, comments Riccardo Bove, a technical director with the company. “We tried different methods. Some were extremely promising in accurately predict the tipping point, but because it is a crucial safety measurement, the system must be infallible. Th at is perhaps the reason why no company has been able to solve the problem, until now.”
COST BENEFITS
Bernieri says Baumann believes that companies using forklift s and sideloaders can see a reduction in operational costs when using SafeLoad Assistance. “Often, our equipment is supplied on contracts that include maintenance. Components that are used as designed are more durable, so maintenance costs are reduced; also, there is the likelihood that you will reduce avoidable material damage costs.”
While making sure lifting is safe, SafeLoad Assistance is also “detecting and monitoring what and how the driver is working,” notes Bernieri. This could be an issue if operators object to such monitoring. But then others might be encouraged to use the product as a means of promoting best practices.
Baumann USA, 855/334-2909, cavaionbaumannusa.com.
