Chain Operator and Bystander Safety
There is risk of a potential serious injury or death to the machine operator, ground personnel, and bystanders from chain shot. A Chain Shot Event (CSE) occurs when a piece or pieces of cutting chain from the end of a broken saw chain in mechanized timber harvesting or processing is ejected at a high velocity. Chain shot typically originates near the drive end of the cutting system but can also originate from the guide bar tip area. Saw chain pieces usually travel in the cutting plane of the guide bar, but can deviate to either side. Although the "Shot Cone Zone" reflects the most likely chain shot path, deflections can occur, substantially expanding where chain pieces may travel. To minimize risk, operators should keep out of the Shot Cone Zone. Ground personnel and bystanders should be at least 230 feet away from cutting operations and out of the Shot Cone Zone.
Do not use saw chain that:
- Has broken twice.
- Is severely damaged.
- Has excessive saw chain stretch.
- Has broken or cracked components.
- Has loose rivet joints—if you can rotate the rivets with your fingers, they are too loose.
- Never engage in a cut with yourself, ground personnel, or bystanders in the Shot Cone Zone.
- Always cut as close to the ground as possible to reduce the distance that any potential ejected pieces could travel.
- Your cutting systems operates in challenging environments and depend on sufficient lubrication to minimize wear and extend the life of operation.
- Check the tension of your saw chain regularly. The recommended amount of force applied by the guide bar to tension saw chain.
Note: Following these best practices consistently will increase your safety and the life of your cutting system.
Chain Speed, Feed Force, Service Life & Safety
It is well recognized that higher chain speeds and/or applied feed forces (with attendant power input) generally equates to faster cutting speeds and shorter service life of the saw chain, guide bar, and drive sprocket. In general, higher chain speeds result in increased potential for chain breakage and potential injury. Never operate chain at speeds higher than recommended.