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Mechanized felling is a term describing the use of any cutting attachment mounted on a carrier. The cutting attachment may be a single or dual blade shear, circular or chain saw, or auger, and may also be equipped with stem holding and/or accumulating capabilities. The majority of mechanized felling carriers are rubber tired; however, crawler type units are increasingly in use on wet sites. Mechanized felling reduces worker exposure, thus making a safer, more efficient operation. However, chainsaws continue to be needed both to cut trees too large for the felling machine cutting head and during felling machine downtime. Many of the guidelines for rubber tired skidder operations can be applied to rubber tired felling machines.

1. Follow the same general prestart and starting guidelines for mobile woods equipment as for mechanized felling units.

2. Know and understand the capabilities and limitations of the felling machine.

3. Only a trained operator shall operate the machine.

4. Carefully survey the ground, timber, and stand conditions and recognize the hazards before mechanized felling operations begin.

5. Use extreme caution when mechanically felling on windy days. Check wind speed and direction.

6. Do not operate mechanical felling equipment during adverse weather conditions or when lightning is present.

7. Do not exceed rated cutting, accumulating, or carrying capacities of the machine.

8. Maintain safe operating distances from all ground workers and other logging operations of at least two tree lengths. Some mechanized felling units, such as high speed saw head machines, require greater minimum safe distances, such as 300 feet or more. 9. Keep the load low for machine stability.

10. When operating on a slope, work only up and down the slope. Do not cut trees at an angle.

11. Always look behind when backing.

12. Be alert to overhead hazards such as dead snags and large limbs which may fall unexpectedly during the felling operation.

13. Do not leave a hung tree. Safely use the felling attachment to push a hung tree to the ground.

14. Attempt to throw trees in cleared areas to avoid lodging trees and damaging the residual stand.

15. When bunching stems make neat, even piles for easier skidder pickup.

16. If trees are manually limbed with chainsaws, fan out the trees to give easier access for workers on the ground.

17. Properly sharpen and maintain the shearing or cutting mechanism for safe, efficient cutting action.

18. Regularly clean the machine of accumulated debris, oil, and grease to reduce fire risks.

19. When stopped, lower attachment to ground, set the brake, and remain near the unit during the cool down period.

20. When performing routine maintenance or repair work to the felling attachment always ground the equipment. If work must be performed with the attachment raised, place a block under the attachment and rest it on the block. Place metal stops on the hydraulic cylinder rods to prevent "leak down" or sudden fall due to loss of hydraulic pressure.

21. When using a mechanized felling machine equipped with a high-speed disc sawhead, follow these important guidelines:

a. Never operate the sawhead within 300 feet of any person Never direct the chip discharge toward other workers, operations, or occupied buildings. Chips or other debris may be discharged at high speed for a considerable distance.
b. Inspect the sawhead and tooth retaining hardware at the start of every shift or as directed by the manufacturer. Replace loose, damaged, or dull teeth immediately. Replace the teeth bolts when replacing teeth and when rotating them.
c. "Stump" a rotating disc to stop the movement.
d. Use caution when moving and maneuvering with an engaged sawhead.
e. Leave the cab only after the sawhead disc has stopped.
f. Use eye and hand protection when repairing and sharpening saw teeth.
g. Use a tool or stick to turn the saw chain or disc when performing maintenance and repair. Replace all damaged parts immediately.
h. Remove accumulated debris on sawhead only after chain or disc has stopped.

©2005 National Timber Harvesting and Transportation Safety Foundation