Current plate compactors incorporate ergonomic features to minimize vibration to the operator.
Photo credit: Stone Construction Equipment
Remote-controlled trench compactors achieve the ultimate in vibration reduction -- the operator never actually touches the machine.
Photo credit: Wacker Neuson Corp.
Tiger Equipment Co. has worked diligently to reduce HAV in its light compaction equipment.
Photo credit: Tiger Equipment Co.
Dynapac shows a remote-controlled plate compactor, displaying the company's commitment to reducing vibration transmission to the operator.
Photo credit: Dynapac
Studies show there are some 1.5 to 2 million U.S. workers - and millions more worldwide - who are regularly exposed to Hand-Arm Vibration (HAV) during their work. Regular HAV exposure has been shown to be inextricably, medically linked to an irreversible, non-curable medical condition of the hands called Raynaud's Phenomenon, Vibration White Finger, or simply Hand-Arm Vibration Syndrome (HAVS).
For a long time, Europe has been aware of the problem and working toward a solution. There, equipment manufacturers are subject to BSEN5004:2006, a standard that outlines the essential requirements for the design of equipment so as to minimize workers' exposure to HAV. Here in North America, ANSI S2.70 was introduced in 2006, setting forth standards for employers to use as guidance in minimizing workers' exposure to vibration. For its part, ISO5349 provides a measurement template for manufacturers of vibrating equipment, but interpretation of these results is needed by the employer to assess how much usage will be allowable within the ANSI limits.
"There are currently no mandatory regulations that are in effect in the U.S.," notes Fabian Salinas, product manager, concrete and light compaction equipment at Dynapac. "[ANSI] has limits for the time an operator is allowed to use a particular piece of equipment for liability reasons. In Europe, they have strict regulations and requirements for how long an operator can use a particular piece of equipment, based on its HAV rating."
According to Charlie Trelease, president of Tiger Equipment, "Within Europe, there is great emphasis on the health and safety of its workers. While the U.S. has guidance for issues such as lifting regulations, there is really only minimal guidance with regard to the risk of vibration."
The prevalence of HAVS in European workers has led to an increased awareness among employers there. Now, the risk to employees is managed by law and those not following regulations face stringent penalties, not to mention leave themselves open to lawsuits from employees. With this in mind, the U.S. might begin to more strictly regulate HAV in order to minimize employers' liability and prevent lawsuits.How does this affect you?
Since HAVS affects equipment operators, and the responsibility for their health and well-being falls on those operators' employers, is this issue relevant to rental businesses? The answer is yes.
According to Trelease, there are many reasons why rental business owners need to be aware of the problem of HAVS. Perhaps most pressing - and fundamental - is the need to provide customers with the equipment they want and need.
"As more employers put in place programs for managing the vibration exposure of their workers, the need to assess how tasks are carried out will be of primary importance," he says. Vibration exposure can be managed a number of ways. Once the typical vibration exposure for each task is assessed, then the employer must ensure that the number of tasks carried out by a worker does not exceed the limit set in the ANSI standard, Trelease explains. This can be a problem, as many pieces of equipment available on the market today could restrict a worker to only one task per day, which potentially leaves the employer with a problem of workforce utilization or a backup of tasks.
"The most common solution to this problem is for employers to specify the use of low-HAV equipment that will significantly increase the safe usage time while still working within the limit set by the ANSI standard," Trelease says. "As employers begin to specify low-HAV equipment, the rental store will have to react to this by stocking low-HAV equipment."
He continues, "The rental stores may also find out that they will have a duty to their customers to ensure that they are aware of the risk from the effects of vibration by applying appropriate markings on equipment and providing guidance brochures within the store. Taking this action will limit the liability of the rental store."
Dave Schulenberg, compaction product manager at Wacker Neuson Corp., notes that promoting ergonomic equipment will require rental businesses to be aware of the standards and how they might change in the future. "It will also benefit the rental business to be aware of the impact on productivity. This knowledge will help them educate their customer, increase their productivity and in turn, develop a long-term relationship."
There is also the benefit of being perceived as offering high-quality equipment. "One effect for a rental operation is creating a perception that they carry equipment that end-users prefer because of the ease or comfort of use," says Salinas at Dynapac.
Shane McCannell, operations manager with Weber Machine U.S.A. Inc. adds, "Rental companies generally want to be able to provide the latest, safest equipment available, but sometimes if their resources are limited, their purchase decisions are driven by the customer base market demand. If they don't service the customer, the competition will.
Newer, more comfortable equipment will always be a draw, says Torsten Erbel, director of product management with Multiquip. "With a more comfortable 'feel' and less stress-inducing new equipment, renters will prefer the anti-vibration-equipped machines and move business toward that equipment," he says. "Existing older fleets will have to be updated to stay competitive."
Frank Wenzel, vice president of engineering at Stone Construction Equipment Inc., says rental businesses must do their part to offer equipment that reduces the stress and fatigue on operators. "Offering products that have a demonstrated track record of continual improvement in these areas, as well as representing manufacturers that provide these improvements, reflects well on the rental companies and promotes their concern for safe use and application of equipment," he says. "Additionally, alert workers tend to stay safe and not have accidents."
Much has been done over the past decade to make light compaction equipment easier on the operator. In most cases, it boils down to isolating the vibratory and impact forces so they are directed into the ground, where they are needed, and not into the operator, where they can be damaging.
"Dynapac has always had very low HAV in all of its compaction equipment," says Salinas. "This has predominantly been achieved with shock absorbers between moving parts and or operators and by adding support members to dampen energy in handles."
He adds, "All machines should carry an HAV rating in their documentation."
Schulenberg points to Wacker Neuson's rammers, which have been engineered to provide an optimum power-to-weight ratio. "This means that the rammers offer excellent performance with lower weight and are easy to operate," he says. "The handle is tuned so there is minimal minimal movement of the handle where the operator grips, resulting in lower HAV without sacrificing control of the machine."
Erbel at Multiquip notes that many hand-held machines have been redesigned to adopt anti-vibration or reduced-vibration handles. Also, some equipment, such as trench rollers and some plate compactors, can be equipped with cable or infrared remote control, removing the operator from direct contact with the machine.
Keep it running
With low-HAV requipment, maintenance takes on even greater significance than usual. "Maintenance is a key issue in controlling the risk of HAVS," says Trelease. "While most rental stores keep on top of maintenance schedules, it will be more important to ensure that a machine runs in its 'as new' condition. Attention to engine speed will be vital and daily checks for loose bolts will become essential as any loose parts on the machine will set up unwanted vibration within the machine that will adversely affect the vibration transmitted to the operator. The quality of any rubber isolators in the machine design will need to be checked and renewed, as these form the primary barrier against vibration transmission. Manufacturers of low-HAV equipment should provide a service program for their equipment to ensure optimum performance."
On the other hand, according to Salinas, many times increased protection in a piece of light equipment leads to end-users being less demanding on a machine. "So the reality is that the maintenance costs are mostly not affected."
What will it cost you?
Whether or not ergonomic and vibration-dampening technology adversely affect the cost of equipment is cloudy. "It can go both ways," says Wenzel at Stone. "Reducing the weight of a machine can end up as a benefit with regard to cost due to less use of steel, but if the reduction in weight causes the use of a more exotic material, then the cost may go up. Many times there are investment costs that are borne by the manufacturers, such as tooling or testing costs, that are considerered the price of doing business to provide a product to our customers that meets the changing expectations in the working world."
Salinas says, "The most obvious cost is the additional R&D that goes into a machine to be able to achieve higher standards in vibration dampening. Also, with the additional protection comes additional components that will add to the cost of a machine to manufacture."
Trelease notes that cost increase is tough to avoid, in some cases more than others. "When a manufacturer looks to make improvements to an existing design by offering a conversion kit for low HAV, it is difficult to avoid a cost to the customer," he says. "Where manufacturers have looked to design a low HAV machine from the ground up, there is no real effect on cost."
Schulenberg counters that rental businesses need to look at the big picture. "Ergonomic features can increase the cost of the machine but this is not always the case. It truly depends on the situation. Also, the long-term increase in profitability due to higher usage of the machine can also increase significantly more than the initial cost."
Of course, any increase in cost can be offset by the fact that a low-HAV machine tends to run better. "Design changes, retooling and related costs of materials almost always have an impact on the cost of the finished product," says McCannell. "Increased productivity and efficiency of the machine should defray some of the additional cost."
Wenzel says the proof is in the product utilization. "Working with equipment that does not wear you out by the end of the day is noticed and appreciated by end users," he says. "They remember the names and the brands that provide this service to them and often request the brand and model specifically when making rental decisions."
At the end of the day, rental businesses stand to benefit from being aware of the risks to customers from operating equipment. By offering machines that meet the latest safety standards, they are also providing equipment that is most comfortable to use. And when equipment is both safe and comfortable, customers need look no further for their equipment rental needs.
What is HAVS?
HAVS is characterized initially by tingling and/or numbness in one or more fingers in either or both hands. With increasing and prolonged HAV exposure, usually in the presence of cold temperatures, a whitening of one or more of the HAV-exposed finger(s) begins. These discrete attacks usually last five to 15 minutes, according to Donald E. Wasserman, MSEE, MBA, occupational vibration consultant from Cincinnati, OH.
As HAV exposure continues, the number and frequency of HAVS attacks worsen to the point where the worker could be progressively debilitated and no longer be able to work. The prognosis can even worsen in some instances, since one or more fingers could become gangrenous, and amputation might be required.
In the U.S. alone, typical prevalence of HAVS can be as high as 50 percent of an HAV-exposed workforce. Currently, the U.S. Occupational Safety and Health Administration (OSHA) has adopted no HAV standard, but does recognize the HAVS problem.