The straight dirt on light compaction

When your customer is working in asphalt and has an area to cover that exceeds what a plate can handle, they can use a walk-behind roller. According to Salinas, the walk-behind roller is to asphalt what the trench compactor is to soil.

"Sometimes they're used in heavily unionized areas where a guy is paid differently if he's sitting vs. standing," notes Salinas.

How do you know when a job calls for one of these machines over a rammer or a plate? "The economy of scale needs to fit the application," says Salinas. "It's dictated by the size of the contractor and the size of the job. A rental rate is less than $100 per day for a rammer and several hundred for a trench roller."

Good questions
The only way to ensure customers get the best machine for their job is to ask the right questions. The first, most important question for rental personnel to ask their customer is what type of material they are working in, soil or asphalt. If the answer is soil, you need to find out if it's cohesive or granular. Price at Bomag says it's a good idea to also ask if they're working in native backfill or engineered fill. Native backfill is more likely to contain a combination of soils with pebbles and gravel mixed in throughout. "Engineered fill is screened and well-graded material that is very compactible," he says.

The next question to ask is what size job they are doing. You need to know in order to suggest a machine with the right capacity.

"Also ask if it's a confined area, such as a trench or a large open area, such as a slab," says Conrardy. "This will determine whether a plate or roller would be used on a gravel material, for example."

Price notes that you should also find out from your customers if they prefer equipment powered by gas or diesel.

Features to note
Some of the most important features to note on today's light compaction equipment include those that minimize hand-arm vibration. Europe has already implemented HAV (hand-arm vibration) ratings for equipment which regulate how long an operator can use the equipment before a break is required. While sources agree it will be years before the United States adopts such regulations, everyone believes they are inevitable. With that in mind, manufacturers are working to reduce hand-arm vibrations through innovations such as low-vibration handles. Ingersoll Rand, for example, offers an exclusive padded handle on its rammers to help reduce such vibration, says Russ Warner, product marketing manager for light compaction equipment.

Other new features aim to assist operators in achieving optimum compaction. Bomag, for example, recently introduced its Economizer, an option on its model BPR 65/70 reversible plate. The Economizer measures how compact the soil is as the operator works, helping him or her to avoid overcompaction. While the option increases the cost of the machine by eight to 10 percent, Price says the cost is justifiable by looking at the increase in productivity that results from avoiding overcompaction.

Price points out that overcompaction is a big problem on jobsites when the operator is unaware that soil can become too compact and thus, less stable, after too many passes with a plate, rammer or roller. When this occurs, excess energy breaks down the soil particles, introducing more air voids. What's more is the excess energy, once it is no longer being effectively absorbed by the soil, bounces back up into the machine, causing wear and tear on the machine and undue fatigue for the operator.

Tell your customers
Aside from the features worth pointing out to customers for their convenience, there are also things to note regarding safety. "Safety precautions are always highlighted with operational warning labels, as well as in the operator's manual," says Conrardy at Wacker. "Anyone renting any type of equipment should make sure they are familiar with these instructions and warnings before operating a machine."

Warner at Ingersoll Rand recommends practicing the start procedure with employees so they can properly convey the information to customers before they leave your yard. "They need to be comfortable explaining the choke or throttle procedures to customers," he says.