Wood Chipper Safety

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Wood Chipper Safety
By Kyle Huggins
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Overview

• How wood chippers work
• Hazards
• Injury statistics
• Injury incidents
• Safe work procedures
• Summary

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Wood Chipper
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Chipper Components
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How Chippers Work

• Chipper machines cut tree limbs into small chips
• Limbs are pushed in the feed tray
• Chipper blades grab the material
• Wood chips thrown out of blades through discharge
  chute

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How Chippers Work

• Commercial grade wood chipper specifications
• Typically driven by engines exceeding 100hp
• Blades mounted to a flywheel
• Stores Kinetic Energy
• Resists changes in rotational speed
• Chipper blades typically rotate between
• 1000 and 2000 RMP

From http//en.wikipedia.org/wiki/Woodchipper
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Hazards

• Workers making contact with or being pulled into
  the chipper
• Hearing loss
• Injuries from flying debris
• These hazards may range from scrapes and cuts to
  amputation or even death.

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Hazards

• Struck-by a worker can be struck by material
  being thrown from the chipper blades
• Caught-in a worker can be pulled into the
  chipper blades
• Other Hearing loss from constant exposure to
  loud machinery

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Bureau of Labor Statistics Census of Fatal
Occupational Injuries

• Eleven workers died in wood chipper accidents
  from 1992-1997
• In 7 cases the worker was caught in the feed
  mechanism
• In 4 cases, victims were struck by the chipper
  hood
• In 1998 NIOSH received two additional reports of
  worker deaths from wood chippers

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Bureau of Labor Statistics Census of Fatal
Occupational Injuries

• These two classifications represent the majority
  of injuries involving wood chippers
• Many cases involved landscaping, tree trimming
  service crews, or the logging industry, not
  limited to new construction

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Non-Fatal Injuries

• Documentation of hearing loss is difficult to
  obtain because the effects are less immediate
  than struck-by or caught-in incidents
• Less than half of injuries, 43 out of 94 recorded
  incidents were non-fatal (1984-2002)

http//osha.gov/pls/imis/AccidentSearch.search?acc
_keyword22Chipper22keyword_liston
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Incidents Struck By

• Approximately 430pm on April 6, 1995
• An employee was struck by hood of a Morbank Eager
  Beaver wood chipper. He sustained fatal head and
  face injuries. The two latch pins on the hood
  and three mounting bolts had been removed before
  the accident and were found elsewhere on the
  machine. The hood was struck by the rotating
  chipper disc, ripping the hood off its hinge.
  The deceased employee was found approximately 10
  feet from the chipper.

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Incidents Caught In (Non-fatal)

• Approximately 430pm on August 29, 1996
• An employee operating a tree chipper hand feeding
  brush into the chipper when he was pulled into
  the machine and killed. The wood chipper was
  provided with a movable infeed tray which should
  be in the raised position when hand feeding and
  lowered to the ground when feeding from a Bobcat.
  The tree chipper had not been operated with the
  infeed tray in the raised position as required by
  the manufacturer during hand feeding.

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Incidents Caught In

• June 18, 1997
• A chipper became plugged with chips. A tree
  service company employee stopped the engine and
  disengaged the clutch but did not wait for the
  rotor blade to stop. The employee removed the
  blower tube connector plate from the discharge
  chute and put his hand into the chipper to remove
  the chips. Three fingers of the employees right
  hand were amputated by the rotor blades which
  were still turning.

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Safety Procedures

• Proper feeding technique
• Always stand to the side, never in front of the
  feed chute
• Lay smaller material on top of longer material,
  or if branches are too short use a push paddle or
  stick
• Feed branches butt-end first
• Never place hands or feet inside feed chute

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Safety Procedures

• Proper feeding technique using proper PPE
  (personal protective equipment)

• Hardhat
• Safety glasses
• Ear protection
• Gloves
• No loose clothing

From http//www.osha.gov/OshDoc/data_Hurricane_Fa
cts/chipper_machine.pdf
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Safety Procedures

• Ensure workers fully understand and comply with
  safe work practices
• Train workers in safe and proper feeding
  techniques
• Safety instructions and training should be in a
  language workers comprehend

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Safety Procedures

• Designate another employee as a safety watch and
  to assist the operator
• Ensure the area in front of the feed chute is
  free of tripping hazards
• Manufacturers should install additional safety
  features such as emergency shut-off devices

From http//www.health.state.ny.us/environmental/
investigations/face/05ny034.htm
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Summary

• Wood chippers use tremendous energy to grind tree
  debris into wood chips
• Injuries result from unsafe work practices and
  not wearing proper PPE
• Over half wood chipper injuries result in
  fatality

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Questions