Chainsaw Safety

1. Chainsaws

• Components, maintenance, transport, starting, and use
• Prepared by Phil Renaud
• IntegriTREE Solutions

2. Things to add in 2025

• 90-15-5

90% of accidents happen within the first 15 seconds after the tree starts falling and within 5 feet of the stump

3. Chainsaw PPE

• Helmet
• Hearing protection
• Glasses
• Chainsaw protection trousers; blood stopper; boots

Whistle or some form of communication system Axe

• Wedges
• Pull rope
• Screen/visor

4. Carrying a saw

• Hold front handle firmly

Keep inertia hand brake engaged Keep engine mount facing outward; this is more ergonomic

• One may also hold it sideways

5. Mandatory Components

Chain catcher: catches the chain when chains break or fall off the guide bar.

Must be present and in good condition

Hand/Wrist Guard: protects hand & wrist from chain when it breaks or falls off the guide bar.

Must be present & in good condition

Throttle Interlock: locking mechanism on the rear handle preventing the accidental activation of the throttle button.

6. Mandatory Components

Chain Brake: activates springs that exert pressure on the sprocket preventing its rotation or stopping the chain rotation immediately. two ways to engage: deliberate action by rolling the wrist forward to apply pressure

Through a reactionary force called kickback (2 types)

Rotation & compression Only one way to disengage

Reach finger tips out to grip and pull back. Thumb must stay wrapped on the front handle

• Must be present and unaltered

Ensure the brake is functioning properly before every use. (Drop test)

7. SAW Components

• Guide bar 2)Chain 3)Inertia hand brake 4)front handle
• Oil reservoir 6)exhaust 7)throttle 8)Throttle Interlock
• Hand wrist guard 10)Back Handle 11)Gas reservoir
• Pull cord 13)Air filter cover 3 4 1 2 5 6 7 8
• 9 10 11 12 13

8. Saw Components

• Sprocket cover
• Chain catcher
• Spark arrester
• Sprocket cover nuts
• Felling dogs
• Tension screw

9. Saw Components

sprocket Chain catcher tensioner oiler Spark arrester

• Exhaust

10. Saw Components

• Air Filter
• Spark Plug
• Decompression Valve
• Inertia hand brake
• Pull cord
• Master start switch

11. Chainsaw tooth profile

12. Chainsaw reactionary forces

Chainsaws: most dangerous tools in untrained hands

The forces produced by chainsaws can be extremely dangerous from an unaware user

While cutting with the underside of the guide bar a pulling force is generated. The saw will seek to pull out of your hands

While cutting with the top side of the guide bar a pushing force is generated. The saw will seek to push back in towards you.

13. Reactionary forces (Kickback)

Rotational kickback happens when the upper tip of the guide bar contacts the wood first. This cancels the relation that exist between the depth gauge and the top plate of the cutter. This enables the tooth to cut too much wood leading to kickback

(kickback) is a real and ever present risk. One must remain vigilant at all times while using the saw. There are two types of kickback.

14. Reactionary Forces (kickback)

Compression Kickback. While cutting on the compression wood fibres of a log.

Weight of the log will compress (pinch) the bar in the kerf and the chain and will abruptly stop its rotation.

Saw will be pushed backwards into the abdomen of the user.

One must properly identify compression and tension wood before cutting into wood.

15. Reaction Forces (compression & tension)

Just like rope wood has compression and tension fibers.

Depending how a log lies will determine where these wood fibers are.

While cutting with a saw one must cut compression before the tension C.U.T.

16. Pre Start Procedures

• Before start

Make sure all safety components are present and in proper working order

• Chain brake
• Chain catcher
• Hand /wrist guard Throttle interlock Pac-n-go

PPE, Air Filter, Chain Tension/Brake, NO DROP START, Gas, Oil

17. Starting

• Starting

Hold firmly between your knees or on the ground with a foot in the rear handle

Full choke/ cold start position If present hit decompression valve

Pull on starter cord until it burps Once burped move to half choke / warm start position

Pull on starter cord till it starts

If it still won’t start you may have flooded it. Put the saw aside and wait

Once started hit the throttle lightly once to take out of choke and into idle position

Leave saw a few moments to warm up before revving it hard.

18. How to operate a chainsaw

While in operation chainsaws are dangerous tools. A safe and adequate use is of utmost importance to diminish the risks of injuries and accidents.

Must always be used with two hands at all times.

Right hand back left hand front.

Chainsaws are right handed.

One must be in an ergonomic and safe work position while cutting.

Feet well anchored on solid ground. Do not stand on loose rock or logs.

If the log is on the ground it is often preferable to put your knee down to cut. Avoid hunching over to cut when at all possible. This can lead to many lower back injuries

Always wear the required PPE while cutting.

19. How To Operate a Chainsaw

Never operate above shoulder height.

Basketball Travel rules (chainbrake) Shut it off when walking a distance.

Thumbs are firmly wrapped around the handles Let the saw do the cutting.

Do not force a saw out of a pinch.

Do not line up your body or face with the chain while in operation.

20. How to operate a chainsaw

It is all about...

• Safety
• & CONTROL

21. Directional face cuts

• Three types
• 45 degree Open face (70-90)

Humbolt.

Which of these is the safest method?