Tree Trimming Techniques - SaskPower 4 Book 1/13. TREE... · 2005-03-29 · inexperienced tree trimmer. Stubs are undesirable for two reasons: • They can kill a tree. • They can

March 29, 2005

S T U D E N T M A N U A L

Tree Trimming Techniques

Copyright 2004 by the Training and Development Centre, SaskPower. All Rights Reserved

2 S T U D E N T T R A I N I N G M A N U A L

Prerequisites: • Possession of the certifications required for the tools and

equipment used in tree trimming.

Objectives: You will describe and perform the proper method to trim a tree.

Rationale: Proper techniques provide for healthier trees, cost efficiency and personal safety.

Learning Objectives• Explain the procedure used to trim limbs from a tree.• Describe the “directional” pruning methods.• List the recommended tree clearances from utility conductors.• Demonstrate the procedure to trim a tree in the vicinity of utility

conductors.

Learning Methods• 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• Skill Check

STUDENT RESOURCES

• Hard hat, gloves, safety glasses, methyl hydrate, tree trimming truck.

T R E E T R I M M I N G T E C H N I Q U E S 3


Learning Steps1. 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.



Lesson 1: Limbing ProceduresLearning Objective:Explain the procedure used to trim limbs from a tree.Learning Method:Self-learning + On-the-jobEvaluation Method:Knowledge Test

Tree Facts

Branch Collars

All tree limbs have a “collar” that exists at the point where the limbprotrudes from it’s source branch. On some limbs it is highly visible andon others it’s not. The branch collar is the area where the protectivecovering would form should the branch be trimmed off.

Stubs

Stubs are short branches that remain after being trimmed by an



inexperienced tree trimmer. Stubs are undesirable for two reasons:

• They can kill a tree.• They can make the tree unsafe.

Stubs can kill a tree because they dry out and rot. The rot works it’s wayback to the main leader, and begins to destroy the whole tree. Stubs alsoincrease the chance of the tree being infected with a disease.

Stubs left on a tree will rot and make the tree unsafe long before the treedies. Wind will often blow down a rotten tree, and damage to propertyand life may result.

Foliage

Foliage may consist of leaves or needles. It is critical that tree trimmersdo not remove too much foliage when trimming trees. Over trimmingmay lead to shock and the death of the tree.

The general rule is that no more than 1/3 of the leaf bearing surface ofthe tree should be trimmed. Breaking this rule may result in the death ofthe tree, and subsequently a poor public image for the utility.



Limbing Methods

Single Cut Method

A tree trimmer using this method starts cutting on the top of the limb andcontinues until the limb is severed. The single cut method is used forcutting small and lightweight branches. The cut should be made as shortas possible without removing the collar.

Figure 1. Cut the Limb Without Removing the Branch Collar

The single cut method is not recommended for coniferous trees, such asspruce, because the limbs are generally heavy. When using the single cutmethod, a heavy limb will fall before the chain saw has cut through thelimb, this will cause the limb to rip bark off the tree. The ripping of barkdamages the health of the tree.



ABC Method

Heavy limbs must be trimmed using the ABC Method. Failure to usethis method for heavy limbs may result in bark being ripped from thetree as the branch falls.

Figure 2. “C” Cut Must Not Removal Collar

The ABC method is as follows:

• The first cut (A) is the undercut, and it’s depth should be about 1/3of the way through the diameter of the limb. It should be about .3meters from the leader.

• The second cut (B) should be made about 1/2 inch away from the Acut. The cut starts on the top side of the branch.

• The final cut is (C) made at the leader. Be careful not to leave a stub.Don’t remove the branch collar.



Lesson 2: Directional PruningLearning Objective:Describe the “directional” pruning methods.Learning Method:Self-learning + On-the-jobEvaluation Method:Knowledge Test

Rule for Directional Pruning

Trees can be trained to grow away from overhead wires or other privateproperty. Limbs that must be removed should be taken back to laterals(side branches) that are at least 1/3 the size in diameter of the branchbeing removed.

In the above picture, the horizontal limb may be trimmed since thelateral is at least 1/3 of the diameter of the limb to be trimmed. If thelateral was less than 1/3 of the cut-off limb, then there is a good chance,that the lateral would not survive, the lateral would likely dry out androt. If the lateral was less than 1/3 of the diameter of the cut-off limb,then it would be best to remove the whole branch at the central leader.



Pruning to encourage horizontal growth is best accomplished byremoving the largest vertical limbs back to the large horizontal limb.

Once again, the remaining limb’s diameter cannot be less than 1/3 of thediameter of the cut off limb.

Removal of Central Leader

It is permissible to remove the central leader provided that no more than1/3 of the leaf bearing surface is removed, and the remaining limb’sdiameter is not less than 1/3 of the diameter of the central leader.

The central leader should be cut using the ABC Method and the final cutmust not remove the branch bark ridge as illustrated below.





Lesson 3: Trimming DistancesLearning Objective:List the recommended tree clearances from utility conductors.Learning Method:Self-learning + On-the-jobEvaluation Method:Knowledge Test

Introduction

SaskPower has established the following guidelines for clearances fromtrees to overhead circuits.

• Primary conductor - 3 metres• Secondary runs - 2 metres• Services & telephone - .5 metres

These guidelines should be followed but there are situations where theyare not practicable. The limits may be reduced according to your owndiscretion.

---Note---It may be beneficial to obtain the property owner’s concerns, andinform them of your intentions before starting trimmingoperations.



Lesson 4: Tree Trimming ProcedureLearning Objective:Demonstrate the procedure to trim a tree in the vicinity of utility

conductors.Learning Method:Self-learning + On-the-jobEvaluation Method:Skill Check



Skills Practice

1. Safety:

0. Does not trim Elm trees between April 13 and July 31

0. Wears safety apparel (eye, harness, head, etc.)

0. Sterilizes the saw for elm trees

0. Maintains safe limits of approach to powerlines

0. Uses hot line tools, if necessary

2. Uses the ABC Method correctly when necessary.

0. 1/3 undercut first

0. “B” cut meets “A” cut

0. Does not leave stubs

0. Does not remove collar or Branch Bark Ridge

0. Does not rip the bark when dropping any limb

0. Does not violate limbing 1/3 rule

0. Does not violate foliage 1/3 rule

3. Maintains minimum clearances after trimming

0. Primary (3.0 metres)

0. Other lines (2.0 metres)

0. Services and SaskTel (.5 metres)



Summary

To summarize this module, you have learned:

• How to trim limbs in order to prevent damage and maintain the health of the trees.

• How the 1/3 rule applies to limb and foliage removal.• The tree trimming clearances from lines.

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 toachieve 100%.



Review Questions

T / F 1. Small light limbs can be trimmed using a single cut with a chain saw.

T / F 2. Stubs cause a safety concern because of rot.

T / F 3. Stubs can kill a tree.

T / F 4. Light limbs should be cut using the ABC method.

T / F 5. It is proper to trim up to 1/2 of the leaf bearing surface of a tree.

T / F 6. Trimming can permanently encourage the direction of tree growth.

T / F 7. A trimmer should not trim a branch if it’s source branch is only twice as long.

T / F 8. Trees should be trimmed at least 3 metres from services.

T / F 9. The rules require that services and secondary runs have the same trimming clearances.



Review Question Solutions

1. T

2. T

3. T

4. F

5. F

6. T

7. F

8. F

9. F

Documents

Tree Trimming Techniques - SaskPower 4 Book 1/13. TREE... · 2005-03-29 · inexperienced tree trimmer. Stubs are undesirable for two reasons: • They can kill a tree. • They can