Based on the data of the Central Statistical Office from 2010/2011, mechanical vibrations (vibrations) constituted an important factor of harmfulness in the workplace. They ranked 7th in terms of a nuisance right after the chemical hazards and insufficient lighting of the workplace. It may come as a surprise, but research clearly shows that mechanical vibrations transmitted to the operator's body can seriously affect their health.
For this reason, newer and newer vibration damping systems are used, and the working time with such devices is shortened. In today's article, we will discuss the impact of mechanical vibrations on human health, as well as present the latest design solutions implemented by leading manufacturers of construction equipment.
DIVISION OF MECHANICAL VIBRATIONS
At the very beginning, mechanical vibrations should be properly separated into local and general vibrations. The first one concerns vibrations transferred directly to human upper limbs. General vibrations, on the other hand, penetrate his body through the legs and back. Why is this division so important? Because it is the place where the vibrations penetrate the human body that further negative health effects will depend.
Operators of manual combustion, pneumatic and hydraulic devices are particularly exposed to local vibrations, i.e. those transmitted by human hands. The processed elements may also be a source of unfavorable vibrations. On the other hand, drivers of heavy construction and agricultural machinery encounter general vibrations. People who work near industrial machinery are also at risk. Then vibrations are transmitted from the ground directly to the feet, and then to the entire body of the operator.
THE INFLUENCE OF LOCAL VIBRATIONS ON THE HUMAN BODY
Research conducted by specialists around the world has shown that mechanical vibrations are not indifferent to the functioning of the human body. For this reason, even a group of lesions was identified, called "vibration syndrome", which in many countries - including Poland - has been recognized as an occupational disease.
People struggling with this disease suffer, among others for disorders in the vascular, nervous, and osteoarticular systems. A common symptom of the vibration syndrome is the paling of the fingers, i.e. "White finger disease". It is associated with pathological changes in the vascular system that cause cardiac arrest. This state may last from several to several dozen minutes. The long-term impact of mechanical vibrations on the operator's hands also has negative neurological effects. These people may experience numbness in the hands and fingers, including disturbance of the sense of touch and a decrease in sensitivity to temperature changes.
EFFECT OF GENERAL VIBRATIONS ON HEALTH
General vibrations, i.e. those transmitted to the human body through his feet, legs, and back, have a negative impact, among others on internal organs and skeletal systems. This type of vibration is particularly exposed to the lumbar spine. In the case of internal organs, the lesions are, among others, the digestive system and organs of the chest. Interestingly, general vibrations can also cause other disorders, such as problems with visual acuity or problems with motor coordination.
HOW TO PROTECT YOURSELF AGAINST MECHANICAL VIBRATIONS?
First of all, attention should be paid to the total, daily working time with devices generating mechanical vibrations. The limit value for local vibrations for 8 hours of operation is 2.8 m/s². For general vibrations it is 0.8 m/s². Another issue is personal protective equipment. It is recommended to use special anti-vibration gloves, which can reduce vibrations transmitted to the operator's hands by up to 60%. In the case of general vibrations, it is worth equipping yourself with vibration-damping shoes, knee pads, and elbow pads. It should also be noted that low temperature and wind intensify the effects of vibrations. Hence, it is recommended - if possible - to wear insulated clothing that minimizes the effects of mechanical vibrations to some extent.
HARDWARE SOLUTIONS DAMPING MECHANICAL VIBRATIONS
Finally, let's talk about innovative technologies used in construction equipment by leading manufacturers. The HAPS system, with which the Cobra mk1 and Cobra TT series Atlas Copco demolition hammers are equipped, deserves attention. The element responsible for the damping of vibrations is a system of flat springs with bumpers located inside the device. The HAPS system allows reducing the value of vertical vibrations to 2.5 m/s². Additionally, the equipment is equipped with an airbag that dampens vibrations transferred to the handles. They too were mounted on special springs. All these functionalities allow you to safely use the device for a long time. Similar design solutions were used in Ammann equipment. The level of vibrations transmitted to the operator's arm in the latest devices does not exceed 2.5 m/s².
The operators of soil compactors also struggle with the problem of harmful mechanical vibrations. However, leading manufacturers of this equipment, such as Wacker Neuson or Husqvarna, are increasingly using special vibration damping handles. The solution that eliminates the impact of adverse vibrations on the operator's body is the choice of a remotely controlled compactor. For example, the reversible vibratory plate Wacker Neuson DPU 80r Lem770 makes it possible. Some Scanmaskin floor grinders for concrete floors are also equipped with a remote control mechanism.
