January/February 2006
Skid-steer loaders are essential in many scrap recycling facilities, yet they can pose safety hazards when not properly maintained or operated. Here’s some advice on how to use this equipment safely.
By Chris Munford
Skid-steer loaders are recycling industry workhorses. They are small but powerful and maneuverable. They are versatile and can work in spaces that are too small for other equipment. They can perform a variety of jobs under varying conditions. And, like many machines, they can kill you if you’re not careful.
During much of the 1980s and 1990s, a U.S. worker was killed in a skid-steer accident every 68 days, on average, according to statistics collected by the National Institute for Occupational Safety and Health (NIOSH). Accident frequency increased in the 1990s compared with the 1980s as the popularity of these loaders increased. The number of fatalities could have been much higher, as some accident reports did not fully document the type of equipment used. Many more workers were maimed or otherwise injured in skid-steer incidents. Fortunately, manufacturers have since added additional safety features, and many companies and government programs now better educate workers about proper skid-steer operation. Like any piece of machinery, however, a skid-steer remains dangerous when used improperly or without required safety equipment and procedures.
Nearly 60 percent of all skid-steer fatalities result when a worker is pinned between the frame and the bucket or lift arms of the machine, according to NIOSH. Rollovers also account for a high percentage of deaths, though workers have also been run over by skid-steers or pinned between the loader and another object.
Two separate database systems have been employed by NIOSH over the years to collect data on skid-steer loader accidents in the United States. The first, the National Traumatic Occupational Fatalities Surveillance System (NTOF), was in use from 1980 to 1992. From 1992, the institute began to use the Fatality Assessment and Control Evaluation Program (FACE). The Census of Fatal Occupational Injuries (CFOI), part of the U.S. Bureau of Labor Statistics, also collects such statistics.
Over a 17-year period from 1980 to 1997, the NTOF and FACE databases recorded 91 fatalities due to skid-steer accidents along with their causes (when known). (See the Skid-Steer Fatalities table at right.)
Some have suggested that skid-steer fatalities could be much higher than the NIOSH figures. An additional 65 fatalities between 1980 and 1992, for example, were attributed to operators or other workers being pinned between the frame of a vehicle and the bucket or lift arms, but no loader type was specified in the accident reports. Some of these incidents likely involved skid-steer loaders, but it’s impossible at this point to know how many.
Understanding the Machine
Skid-steers are front-end loaders that employ differential “skid” steering. Most models have four wheels, though some have permanently mounted tracks. The engine and a counterweight are typically sited behind the operator. This makes these machines smaller and more maneuverable than conventional equipment with equivalent load capacity and power.
Skid-steers are designed to be compact. This places the operator in close proximity to the lift arms and bucket. The operator’s seat and controls are located between the lift arms and in front of the lift-arm pivot points. This means the operator must enter and exit through the front of the machine and over the bucket. More than a few fatalities have been caused when the operator inadvertently activated the controls while entering or exiting the machine, or when a worker was outside the operator enclosure attempting to work on or clean the machine. In many cases, accidents occurred when safety mechanisms were bypassed, modified, or removed altogether. Exiting the vehicle improperly—such as to the side, which involves moving over or beneath a lift arm—has also caused a significant percentage of skid-steer injuries and fatalities.
Even when the operator is properly seated inside the vehicle, with the safety belt and other safety mechanisms in use, improper operation of the vehicle can result in accidents. Skid-steers, for instance, can become unstable when overloaded. Loading beyond the manufacturer’s stated limitations moves the machine’s center of gravity farther forward and can cause rollovers.
As with any moving vehicle, excessive speed increases the chance and the severity of a skid-steer accident. Carrying heavy loads at high speed with the bucket raised can also lead to instability and loss of control. In general, the higher a skid-steer’s bucket is raised and the heavier the load, the less stability the machine has. Thus, the machine should be operated with the bucket in a low position to improve stability. On the other hand, operating the machine with the bucket too low can prove hazardous when moving over uneven ground or across curbs
or other obstacles.
Other factors can also pose safety hazards. Winter is a particularly hazardous time due to slippery surface conditions and the possibility of the machinery becoming clogged. A number of fatalities have occurred when workers attempted to clear snow, ice, or frozen mud from skid-steers. Irregular terrain, debris, and steep slopes or inclines can also be factors, especially in rollovers.
Building in Safety
Despite the fatality statistics, skid-steers are safer today than ever before. The number of safety features that are standard equipment on these machines continues to increase. Some of the most common features include:
Interlocking Control Systems: Developed in the early 1980s, such systems require that a nonoperational control or fixture—such as a seat belt or restraint bar—be secured or activated before the unit’s operational controls can function. Some machines connect the lift arm control to use of the seat belt. Other machines connect the lift arm control to a bar that must be lowered in front of the operator.
Safety Switches: One type of interlocking control system is a seat-activated safety switch. The switch controls an electrohydraulic lift arm lock that prevents movement of the lift arms when the operator leaves the seat.
Protective Structures and Restraints: Side screens for the operator’s “cage” (known as the rollover protective structure, or ROPS), restraint bars, and seat belts have long been standard features on skid-steer loaders.
Lift-Arm Supports: These pin- or strut-type supports protect workers when working near the machine with the bucket in a raised position while the controls are unattended.
Emergency Exit: When the operator can’t exit through the front of the machine, emergency exits allow escape through the roof or the rear of the cage.
Skid-steers’ system reliability and durability have also improved. In addition, manufacturers offer retrofit packages to add new safety features to older machines. Most skid-steer makers also provide safety videos and other training aids to their customers.
Training and Experience
Avoiding skid-steer loader accidents is most often a matter of following procedures and using common sense, but training and awareness of the dangers involved with loader operation also play a large role. Familiarity with the machine is paramount. Training and experience are the foundation.
A skid-steer can seem deceptively simple to operate. In reality, activating these machines puts multiple systems into operation simultaneously, meaning that the operator must often carry out several functions at the same time. This can confuse the novice. In such cases, it’s normally best for the operator to remove his hands and feet from the controls. Releasing pressure on the controls will cause all machine functions to stop.
Maintaining balance is critical since that governs the stability and turning capability of a skid-steer. When empty, most machines will have 60 to 70 percent of their weight over the rear axles. Weight shifts forward when the bucket is loaded, and the operating characteristics of the unit will change. If overloaded, the machine becomes excessively front-heavy, which reduces its stability and handling. Every skid-steer has a manufacturer’s rated operating capacity, which the operator must know and must not exceed. In general, the bucket should always be kept as low as possible when traveling or turning.
Most skid-steers have hydrostatic drives that respond instantly to the operator’s controls. This is a desirable handling quality, but it also heightens the dangers when the operator is outside the cage while the skid-steer is on. Activation of the controls while outside the cage, intentionally or accidentally, has caused a significant percentage of skid-steer injuries and fatalities.
Steep slopes and rough terrain should be avoided when possible. The skid-steer should be operated up or down a slope rather than across it. When the bucket is loaded, the heavy end of the skid-steer should be pointed uphill. In addition, the operator should maneuver around obstacles rather than over or through them.
The proper loading and unloading of a skid-steer also bears mention. A few basic procedures should be followed. The operator must engage the load, raise the bucket, back away from the material pile, and then lower the bucket. After proceeding to the unloading site with the loader arms down, the operator should stop, raise the arms, and move forward slowly until the bucket is over the unloading point.
Common sense should tell the operator never to lift, swing, or otherwise move a load near or above a coworker, but there are factors even an experienced operator might not have encountered. Consider the following situations, which have at times resulted in unusual or bizarre skid-steer accidents and injuries:
• When handling loose material, such as rocks, lifting the arms too high and rolling the bucket back too far can cause the load to cascade into the operator’s enclosure.
• Avoid dumping over fence posts or similar obstructions that could enter the operator’s enclosure if the skid-steer tipped forward.
• When backfilling, consider whether a trench wall could collapse under the skid-steer’s weight.
• Never undercut a high embankment, which could give way and bury the skid-steer.
• Take note when overhead power lines or cables are present.
It should go without saying that the operator’s protective cage and its side screens should never be removed when the skid-steer is in operation. Likewise, available safety mechanisms should be operable and in use at all times. When entering or exiting the skid-steer, the machine should be turned off, the controls locked, and the brake engaged.
Following Safety Guidelines
In addition to manufacturers’ safety features, a host of regulations and guidelines now govern the manufacture and operation of skid-steer loaders. Regulating agencies include the Occupational Safety and Health Administration (OSHA). This department’s regulations do not specifically address skid-steer loader operation, but they do require employers to protect workers from a number of hazards associated with operating and maintaining machinery. These requirements relate to such aspects as operator safety restraints, operating procedures, rollover protection, machine guarding, and maintenance procedures.
None of these factors will protect a worker, however, if safety features are bypassed or improperly maintained, or when guidelines and procedures aren’t followed. Here’s a set of guidelines that, when observed, can help prevent most skid-steer accidents:
1. Heed Safe Operating Procedures
• Operate the loader from the operator’s compartment, never from the outside.
• Stay seated when using the loader controls.
• Work with the seat belt fastened and the restraint bar in place.
• Keep arms, legs, and head inside the cab while operating the loader.
• Load, unload, and turn on level ground as much as possible.
• Travel and turn with the bucket in the lowest position possible.
• Operate on stable surfaces only.
• Do not travel across slopes. Travel up or down, with the heavy end of the machine pointed uphill.
• Keep coworkers and bystanders out of the work area.
• Never remove, disable, or override safety devices.
2. Enter and Exit the Loader Safely
• Enter the loader only when the bucket is flat on the ground or when lift-arm supports are securely in place.
• When entering the loader, face the seat and keep a three-point contact with handholds and steps.
• Never use the machine’s foot or hand controls for steps or handholds.
• Keep all walking and working surfaces clean and clear.
• Before leaving the operator’s seat, lower the bucket to the ground, set the parking brake, and turn off the engine.
3. Maintain the Skid-Steer in Safe Operating Condition
• Follow all of the manufacturer’s instructions.
• Keep the foot controls free of mud, ice, snow, and debris.
• Regularly inspect and maintain the skid-steer’s interlocking controls, safety belts, restraint bars, side screens, and operator’s cage.
Skid Steer Fatalities, 1980-1997
Reported Cause of Incident Fatalities Percentage
Pinning between the bucket and frame of the 54 59.3
machine or between the lift arms and frame
Rollovers 17 18.7
Crushing incidents in which no further information 5 16.5
was provided in the accident report
Pinning between skid-steer and another object 2 2.2
Operator or bystander run over 1 1.1
Other/Unknown 2 2.2
TOTAL 91 100
Source: NIOSH data.
Chris Munford is a writer based in New Jersey. He formerly held editing positions with American Metal Market, Platt’s Metals Week, and Metal Bulletin.
Skid-steer loaders are essential in many scrap recycling facilities, yet they can pose safety hazards when not properly maintained or operated. Here’s some advice on how to use this equipment safely.