Solution Summary: Quieter Skid Steer
Quieter skid steers are designed to limit noise exposure from loud equipment engines by enclosing the operator or controlling fan speeds.
Description:
Quieter skid steers use engineering controls to limit noise exposure. Skid steers use diesel engines to level or move earth and gravel. These quieter machines are designed to reduce the amount of noise from the engine that reaches the operator. The sound level at the operator’s ear is reduced by insulating operator cabins and controlling cooling fan speeds.
Through the use of specially designed engine fans and operator cabin enclosures, the noise entering the skid steer’s cabin is limited and operator exposures are reduced. Sound pressure levels on the construction site, however, may still be above the OSHA Permissible Exposure Limit and workers may need to wear hearing protection for more than intermittent visits.
Caterpillar Skid Steer Loaders
- Model: 272D XHP
- Engine: 110 horsepower
- Rated Operating Capacity: 3,700 pounds
- Vehicle Weight: 9,304 pounds
- Vehicle Height: 7 feet 0.3 inches
- Fuel: diesel
- Operator Sound Pressure Level: 85 dBA (OSHA’s Permissible Exposure Limit for an 8-hour time-weighted average is 90 dBA)
- Sound Pressure Level Prior to Re-design: 101 dBA (OSHA’s Permissible Exposure Limit for an 8-hour time-weighted average is 90 dBA)
- Noise Control Methods: isolation cabin
John Deere Skid Steer Loader
- Model: 333E
- Engine: 100 horsepower
- Rated Operating Capacity: 3,300 pounds
- Vehicle Weight: 9,425 pounds
- Vehicle Height: 7 feet, 1 inch
- Fuel: diesel
- Operator Sound Pressure Level: 85 dBA (OSHA’s Permissible Exposure Limit for an 8-hour time-weighted average is 90 dBA)
- Exterior Sound Pressure Level: 105 dBA
- Noise Control Methods: cooling fan speed control and isolation cabin
Bobcat Skid Steer Loaders
| Model | Engine (horsepower) | Rated Operating Capacity (pounds) | Vehicle Weight (pounds) | Exterior Sound Pressure Level (dBA) |
| S850 | 92 | 3,950 | 7,900 | 102 |
| T870 | 99.2 | 3,525 | 10,072 | 104 |
- Height: 6 feet, 11.4 inches
- Fuel: diesel
- Operator Sound Pressure Level: approximately 85 dBA (OSHA’s Permissible Exposure Limit for an 8-hour time-weighted average is 90 dBA)
- Noise Control Methods: isolation cabin, new engine mounts
Risks Addressed:
Over time, exposure to noise levels at or above 85 decibels will lead to permanent hearing loss. The NIOSH Recommended Exposure Limit (REL) for occupational noise is 85 decibels on an A-weighted scale as an 8-hour time weighted average (U.S. Department of Health and Human Services, 1998). OSHA limits noise exposure to 90 decibels, also on an A-weighted scale and as an 8-hour time weighted average (U.S. Department of Labor, 2008). A-weighting is an adjustment that gives lower frequencies less weight or significance than higher frequencies. An A-weighted sound level more closely resembles the human ear’s response to noise.
The American Conference of Governmental Industrial Hygienists (ACGIH) assigned noise a Threshold Limit Value (TLV) of 85 dBA as an 8-hour time weighted average. Exposure to 88 dBA is limited to 4 hour, exposure to 91 dBA is limited to 2 hours, exposure to 94 dBA is limited to 1 hour and so on (ACGIH, 2013).
Noise exposure has also been associated with temporary hearing loss, decreased perception of noisiness and masking, increased stress, fatigue, disturbance of sleep and decreased concentration and mental performance (Osada, 1988). Noise-induced hearing loss starts in the higher frequencies (3,000 to 6,000 Hz) and slowly develops from chronic exposure to excessive sound. Sound must exert a shearing force on the hair cells lining the inner ear to be perceived, and if the force is too strong, cell damage and cell death can occur (Berger et al., 2003).
How Risks are Reduced:
Skid steers use diesel engines to level or move earth and gravel. These quieter machines are designed to reduce the amount of noise from the engine that reaches the operator. Through the use of isolated cabins and controlling the use of cooling fans and other noisy components of the machine, the sound level at the operator’s ear is reduced.
While there are no published sampling data on these specific controls, safety and health experts believe exposure to noise can be significantly reduced through the use of noise control techniques. The extent of the reduction is dependent on the type of work being performed, the size of the engine, the amount of noise in the environment, the level of effort required by the machine, and the operator’s proximity to the engine.
Industrial hygienists use sound level meters or noise dosimeters to determine noise levels and recommend the use of quieter techniques to prevent hearing loss and reduce the risk of accidents. Proper maintenance and retrofitting existing equipment can decrease excess sound as well (Suter, 2002).
One manufacturer, John Deere, states that its skid steer’s enclosures reduce sound levels to 85 dBA.
Another firm, Bobcat, claims that "Noise levels are reduced by 60 percent due to new engine mounts that decreases vibration and noise levels."
Effects on Productivity:
Lower noise levels are expected to reduce stress and fatigue, and increase the concentration and mental performance of workers. Improved worker health, comfort and concentration may lead to greater productivity. Reduced sound levels can also lower the risk of accidents as communication among workers is easier and more effective.
Additional Considerations:
Data from OSHA and the Bureau of Labor Statistics indicate that 60 to 80 deaths each year result from vehicles backing over workers. The danger is greater in industries that use larger vehicles, such as trucking, highway construction, and sanitation. There are many ways to reduce the risk of backovers. First, the need to back vehicles should be reduced to the extent possible. When backing is necessary, traffic control plans should be used to keep vehicle and people on foot separated. Vehicles can be equipped with backup alarms, cameras, and proximity sensing devices and drivers should use spotters. Workers on foot should be required to wear high-visibility clothing when they will be near moving vehicles. Drivers, spotters, and pedestrians should receive general and site-specific training on preventing backovers.
The use of diesel-powered equipment poses the risk of carbon monoxide exposure, especially in areas where airflow is reduced. Steps to control exposure are important because the gas is invisible, odorless and tasteless. Poisoning by carbon monoxide can occur quickly indoors, but working outdoors does not ensure operators won’t be overcome. Small, inexpensive personal monitors should be worn by the operator to warn of unacceptable exposures. Equipment should not be left idling to cut down on carbon monoxide and to conserve fuel.
As is the case with any construction equipment, users should follow manufacturer scheduled maintenance recommendations and comply with any applicable local, state or federal regulations.
Contributors:
Andrew Kingston and Michael R. Cooper - Aria Environmental, Inc.
Bruce Lippy - CPWR
Availability
Caterpillar Skid Steer Loaders
To obtain information, visit Caterpillar dealer locator
or contact 1-309-675-1000
Bobcat Skid Steer Loaders
To obtain information, visit Bobcat dealer locator
or contact 1-800-743-4340
John Deere Skid Steer Loaders
To obtain information, visit John Deere dealer locator
or contact 1-800-503-3373
