Logging operations

Hazards involved with felling include falling or rolling trees; falling or snapping branches; cutting tools; and noise, vibration and exhaust gases with chain-saws. Windfall is especially hazardous with wood and partially severed root systems under tension; hung-up trees are a frequent cause of severe and fatal accidents. All workers involved in felling should have received specific training. Tools for felling and for dealing with hung-up trees need to be onsite. Hazards associated with cross-cutting include the cutting tools as well as snapping wood and rolling stems or bolts, particularly on slopes.

In spite of major efforts and progress by regulators and manufacturers to improve chain-saws, they remain the single most dangerous type of machine in forestry. Most serious accidents and many health problems are associated with their use.

Hazards involved with debranching include cuts with tools or chain-saws; high risk of chain-saw kick-back; snapping branches under tension; rolling logs; trips and falls; awkward work postures; and static work load if poor technique is used.

With good machine design and careful operation, accident risk with feller-bunchers is relatively low, except when chain-saw operators work along with the machine. Health hazards, such as vibration, noise, dust and fumes, are significant, since base machines often are not built for forestry purposes. Feller-bunchers should not be used on excessive slopes, and the boom should not be overloaded, as felling direction becomes uncontrollable.

Accident rates in harvester operation are typically low, though accident risk rises when chain-saw operators work along with harvesters. Maintenance of harvesters is hazardous; repairs are always under high work pressure, increasingly at night; there is high risk of slipping and falling, uncomfortable and awkward working postures, heavy lifting, contact with hydraulic oils and hot oils under pressure. The biggest hazards are static muscle tension and repetitive strain from operating controls and psychological stress.

Manual skidding is increasingly rare in industrial logging but continues to be practised in subsistence logging, particularly for fuelwood. It is limited to short distances and usually downhill, making use of gravity to move logs. While logs are typically small, this is very heavy work and can be hazardous on steep slopes. Efficiency and safety can be increased by using hooks, levers and other hand tools for lifting and pulling logs. Chutes, traditionally made from timber but also available as polyethylene half-tubes, can be an alternative to manual ground skidding of short logs in steep terrain.

Accidents involving forwarders are typically similar to those of tractors and other forestry machines: overturning, penetrating and falling objects, electric power lines and maintenance problems. Health hazards include vibration, noise and hydraulic oils.

Using human beings to carry loads is still done for short logs like pulpwood or pit props in some industrial harvesting, and is the rule in fuelwood harvesting. Loads carried often exceed all recommended limits, particularly for women, who are often responsible for fuelwood gathering. Training in proper techniques that would avoid extreme strain on the spine and using devices like back packs that give a better weight distribution would ease their burden.

Hazards occur during installation, operation and dismantling of the cable system, and include mechanical impact by deformation of the cabin or stand; breaking of cables, anchors, spars or supports; inadvertent or uncontrollable movements of cables, carriages, chokers and loads; and squeezes, abrasions and so on from moving parts. Health hazards include noise, vibration and awkward working postures.

Because of the high production rates required to make the use of such equipment economical, the number of workers employed on helicopter operations is much larger than for other systems. This is true for landings, but also for workers in cutting operations. Helicopter logging can create major safety problems, including fatalities, if precautions are disregarded and crews ill prepared.

In manual loading of timber, physical strain and workloads are extremely high. In both manual and mechanized loading, there is danger of getting hit by moving logs or equipment. Mechanized loading hazards include noise, dust, vibration, high mental workload, repetitive strain, overturning, penetrating or falling objects and hydraulic oils.

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1. What are the main hazards involved with felling?

2. What is the most dangerous type of machine used in forestry?

3. Where should feller-bunchers not be used?

4. Why is the maintenance of harvesters hazardous?

5. Where is manual skidding practised?

6. What are the accidents involving forwarders?

7. Why is using human beings for carrying loads very dangerous?

8. What are the hazards occurring in cable logging?

9. Why can helicopter logging create major safety problems?

10. What do manual and mechanized loading hazards include?