What is the primary purpose of an undercut?

To control the direction of the tree's fall and to prevent the trunk from splitting as it falls (Clause 4.3.1).

What safety distance should be maintained around a tree being felled?

A minimum safety radius of 1.5 times the height of the tree being felled should be cleared of all personnel (Clause 6.1).

What is a 'hanger' or 'lodged tree' and how should it be handled?

It is a tree that has been cut but is caught on another tree. This code advises extreme caution and recommends using a winch or other mechanical means to bring it down, not by felling the supporting tree.

What is the 'back cut'?

It is the main felling cut made on the opposite side of the tree from the undercut, leaving a small hinge of wood to control the fall (Clause 4.3.2).

IS 9561

: 1985

Code of practice for felling and conversion of trees into logs

CurrentSpecializedCode of PracticeMaterials Science · Timber and Timber Stores

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This code of practice outlines the standard procedures for the felling of trees and their subsequent conversion into logs for commercial or other uses. It details the techniques for making undercuts and backcuts to control the direction of fall, as well as methods for cross-cutting the felled tree into logs. The standard places significant emphasis on the necessary safety precautions for personnel and equipment during logging operations.

Code of practice for felling and conversion of trees into logs

Quick Reference Values

Undercut depth1/4 to 1/3 of the tree diameter

Back cut height above undercut2.5 cm to 5 cm higher than the horizontal cut of the undercut

Safety zone radius from fellingAt least 1.5 times the height of the tree being felled

Angle of undercutApproximately 45 degrees

Wedge usage recommendationFor trees with a diameter greater than 20 cm to control the fall

Practical Notes

Always assess the tree's natural lean, wind direction, and surrounding obstacles before starting the first cut.

Maintaining sharp and well-maintained tools is crucial for both safety and efficiency.

Never work alone during felling operations; a partner or spotter is essential for safety.