Tree Felling S T U D E N T M A N U A L March 29, 2005

Transcription

1 Tree Felling S T U D E N T M A N U A L March 29, 2005

2 2 STUDENT TRAINING MANUAL Prerequisites: None Objectives: You will explain and demonstrate how to fell a tree. Rationale: Proper felling techniques promote better efficiency and fewer injuries. Learning Objectives Explain the procedure to bring down a tree which is hung up. Explain preparations necessary before felling a tree. Describe the three most common notching methods. Explain the hazards associated with improper notching techniques. Demonstrate how to fell a tree. Learning Methods Self-learning + On-the-job Self-learning + On-the-job Self-learning + On-the-job Self-learning + On-the-job Self-learning + On-the-job EVALUATION METHODS Knowledge Test Knowledge Test Knowledge Test Knowledge Test Skill Check STUDENT RESOURCES Gas chain saw Safety chain saw pants, boots, eye wear, hard hat, and gloves

3 TREE FELLING 3 Learning Steps 1. Read the Learning Guide. 2. Follow the steps outlined in the Learning Guide. 3. Clarify any questions or concerns you may have. 4. Complete the Practice and Feedback. 5. Complete the Evaluation.

4 4 STUDENT TRAINING MANUAL Lesson 1: Hung Up Trees Learning Objective:Explain the procedure to bring down a tree which is hung up. Learning Method:Self-learning + On-the-job Evaluation Method:Knowledge Test Introduction Trees often fall on power lines, and it is the responsibility of the lineman to remove the tree in a safe manner. The following is a procedure to remove hung up trees: The line must first be de-energized. Utilize a heavy machine (i.e. loader, dozer, boom truck) to remove the tree.

5 TREE FELLING 5 Alternatively, use long ropes to drag the butt away. STOP DANGER Do not attempt to cut the butt shorter with a chain saw. Do not attempt to use levers to pry the butt over. The procedure to remove hung up trees does not include using levers or power saws, because a tree may roll, kick back, or act unpredictably when attempts are made to move it. The danger of falling limbs is also a consideration.

6 6 STUDENT TRAINING MANUAL Lesson 2: Felling Site Preparation Learning Objective:Explain preparations necessary before felling a tree. Learning Method:Self-learning + On-the-job Evaluation Method:Knowledge Test Introduction Wind Check Overhead Check Fall Path Line of Retreat Before a tree can be felled using a power saw there are a number of considerations the worker must be aware of. Safety to the worker is the consideration that should never be forgotten. Trees should not be cut if the wind is swaying the top of them. The wind may cause the worker to lose control of where the tree will fall. Before felling a tree, the worker must ensure that there are no dangling limbs or dead branches that could fall when the cutting proceeds. Dangling limbs often exist, especially if there has been some prior felling in the immediate area. It is against the Occupational Health and Safety Regulations to work in the vicinity of a tree that is hung up. Many workers have been accidentally maimed or killed on the job for violating this rule. The worker must choose a viable fall path for the tree to take when it is toppled. Normally trees will have a natural lean, and the tree should be felled in the direction of the lean. Trees without a lean can be felled in any direction, but preferably in the direction of any slight breeze. Trees should not be felled where the potential exists to damage public or private property. A tree faller must be sure that there is a fast line of retreat away from the tree when it falls. Prepare your escape route at a 45 degree angle from

7 TREE FELLING 7 the opposite of the line of fall. Other things to remember when planning and preparing an escape route are: Walk your escape route to ensure it is clear. If you have more than one escape route, walk them all. If there are obstacles, clear them. Escape route should be at least 4.5 m long. On hills, escape routes should be uphill. If a tree has hazards, make alternate escape routes. Use natural clearings if possible. All snow and brush must be removed from around the tree to ensure a fast retreat.

8 8 STUDENT TRAINING MANUAL Lesson 3: Cutting Techniques Learning Objective:Describe the three most common notching methods. Learning Method:Self-learning + On-the-job Evaluation Method:Knowledge Test Notching There are only three acceptable notches. The dimensions of the notch must be strictly followed to help ensure safety for the faller. Important Points For all notches, the depth of cut into the tree should be 1/3 the diameter of the tree. The face opening of a notch should be equal to the depth of the notch.

9 TREE FELLING 9 Practicing Notches Backing Cutting It may take some practice to make the cuts properly. Therefore, it is a good idea to practice making notches on a stub of wood. It is important that the notch has a defined corner (i.e. the two saw cuts must meet at a common point). This is best accomplished by starting with the angled cut first, and secondly using the more accurate horizontal cut to meet it. The V Notch may be slightly more difficult to execute because both the cuts are at angles. The inexperienced faller may have difficulty making the second cut form a corner with the first. The proper back cut has three qualifications: It is a horizontal cut that begins on the opposite side of the notch.

10 10 STUDENT TRAINING MANUAL The back cut is made 1-2 inches above the notch s corner. The back cut is stopped when there is one inch of hinge wood left, or the tree begins to topple, whichever comes first. When the tree begins to topple, set the saw down and retreat. STOP DANGER Never cut through to the notch with the back cut. ---Note--- Wedges can be driven into the back cut if the saw chain gets pinched or stuck.

11 TREE FELLING 11 Lesson 4: Improper Notching Learning Objective:Explain the hazards associated with improper notching techniques. Learning Method:Self-learning + On-the-job Evaluation Method:Knowledge Test Introduction The dutchman notch is a term used for an improper notch. Often the tree will fail to fall when the dutchman closes. Even more dangerous, a barber chair may result. This condition is extremely dangerous because, when the tree splits it happens with violent speed and power, as outlined below.

12 12 STUDENT TRAINING MANUAL Trees that fail to fall must be pushed down by a heavy machine. Cutting through the hinge wood with a chain saw would be an unacceptable practice for getting the tree down. Ensuring that notches are properly made prior to back cutting will eliminate this condition. Felling Process Checklist The following points summarize the felling process: Prepare the felling site and escape route. Make the notch close to the ground. Make the horizontal back cut (always leaving hinge wood). When the tree begins to topple set the saw down. Move quickly along the escape route until the tree hits the ground.

13 TREE FELLING 13 Lesson 5: How to Fell a Tree Learning Objective:Demonstrate how to fell a tree. Learning Method:Self-learning + On-the-job Evaluation Method:Skill Check

14 14 STUDENT TRAINING MANUAL Skills Practice 1. Safety: 0. Uses safety apparel 0. Plans a safe fall path 0. Plans and clears an escape path 2. Prepares notch 0. 1/3 depth of cut 0. Opening is equal to depth of cut 3. Fells tree 0. Horizontal cut 1 to 2 inches above notch 0. Hinge wood left when tree begins to topple 0. Sets down the saw 0. Uses the correct escape route

15 TREE FELLING 15 Summary To summarize this module, you have learned: How to deal with hung up trees. How to prepare for felling. The three notches. The results of poor notches. Practice Feedback Review the lesson, ask any questions and complete the self test. Evaluation When you are ready, complete the final test. You are expected to achieve 100%.

16 16 STUDENT TRAINING MANUAL Review Questions T / F 1. Trees that are hung up should be dropped with a heavy machine. T / F 2. There is always a danger of limbs falling off hung up trees. T / F 3. It is ok to work around hung up trees if the wind is in your favor. T / F 4. Levers can be used to pry the butts of hung up trees. T / F 5. The wind must be considered when felling. T / F 6. Trees with loose and dangling branches can be felled as long as hard hats are worn. T / F 7. Your escape route should lead to, and end at the nearest tree. T / F 8. The back cut should be made at a 45 degree angle. T / F 9. The depth of a notch and it s face opening should be 1/3 the diameter of the tree. T / F 10. The back cut must never cut through the hinge wood. T / F 11. Wedges should be driven into the notch if the chain gets stuck. T / F T / F 12. Improper notches can result in trees that don t fall. 13. The barber chair is caused by leaving too much hinge wood.

17 TREE FELLING 17 Review Question Solutions 1. T 2. T 3. F 4. F 5. T 6. F 7. F 8. F 9. T 10. T 11. T 12. T 13. F