Many variables including loader size, bucket size, lift height, truck size, jobsite layout and underfoot conditions can impact the productivity of a material loading operation.

“Improperly sizing a loader (loading tool) to a truck (hauling unit/target) can be detrimental in obtaining efficiency of a jobsite,” notes Scott Schmidtgall, product application specialist for medium wheel loaders, North America, Caterpillar. Many items must be considered to make a decision on what bucket size and loading height constraints need to be met. “Know what your current actual production targets are as well as what the future production is intended to be. Material density, production targets, peak times, realistic idle times all come to mind very quickly as areas that cause pain if they aren’t understood well.”

Define production requirements for the operation. Once that is established, then match machine size and bucket size in relation to the material being handled and the necessary discharge height. “Matching the machine and bucket with the production requirements and considering the working schedules of the operation will help put the right machine on the site,” says Nick Rogers, product specialist/inside sales coordinator, Liebherr USA, Co. Construction Equipment Division.

“Ensuring the loader is properly sized for the application and equipped with the appropriate bucket, ground-engaging tools and tires is an important first step for optimizing loading efficiency,” says Grant Van Tine, product marketing manager, wheel loaders, John Deere Construction.

“By understanding the correct pass matching between your truck and loader, you’ll get the most amount of material loaded in the shortest period of time,” says Chris Connolly, product manager, wheel loaders, Volvo Construction Equipment. “This is especially critical in high-productivity applications like a quarry or plant.”

Yet, there is more to sizing a machine than simply productivity. “The loader must be able to handle the volume of the material, both in terms of power and stability,” says Connolly. “If the machine doesn’t feel stable while lifting or traveling with a loaded bucket, it is not only dangerous, but can also shorten the service life of the machine significantly. This can also have a major impact on the confidence level of the machine operator.”

Typically, a wheel loader is sized based on the common truck size and traffic at the site. If trucks are not lined up and waiting throughout the day, you may be able to use a smaller loader.

“There are several factors that need to be considered including weight capacity of the truck, the materials that will be loaded, and their densities,” says Van Tine. “Often, there is a desired number of passes to load trucks (two to three, for example). From that, customers will choose a loader that can handle the bucket size needed for their materials and meet the loading height requirements of the trucks.

“In some applications, height is the most important factor when sizing a loader,” he adds. Some manufacturers offer high-lift models specifically to address these applications.

One often overlooked factor is the correct tire pressure for the application. “Tire pressure impacts traction, stability, fuel consumption and productivity, in addition to wear,” says Van Tine. “John Deere offers an optional tire pressure monitoring system on 644L to 844L wheel loaders that is fully integrated with JDLink telematics, enabling contractors to monitor tire pressure remotely.”

Read more: Tips to Maximize Loading Efficiency