Chainsaw Safety and Operation

Introduction to Saws

• The St. John's Fire District uses gasoline-powered saws to support fire and rescue operations.
• Power saws are critical in providing support that will have a direct impact on tactical objectives.

Chainsaws

• Chainsaws are versatile tools used for Ventilation, Forcible Entry, and clearing downed trees.
• They are primarily used to cut through Class A roofing materials (wood and asphalt roof coverings) during vertical ventilation operations.
• The District mainly uses Stihl Chainsaws.
• Chainsaws are categorized into two types based on their primary use: General and Ventilation.

General Chainsaws

• Carried on all District fire apparatus.
• Used to clear roadways of downed trees.
• Standard configuration: 18-inch Bar with a standard chain.
• Designated saws with longer bars are used during significant weather events.

Ventilation Chainsaws

• Configured for ventilation operations.
• Manufactured specifically for the fire service and differ from regular chainsaws.
• Equipped with a specialized HD air filter.
• Feature a robust chain designed for rescue operations.

Safety Precautions

• Caution must be used when cutting through materials with a high-revving chain saw to avoid kickback.
• Kickback can cause serious injury.
• Properly hold and operate the saw to avoid kickback.
• Avoid using the saw above your head.
• Check the proper operation of the chain brake before starting the saw.

Chain Brake

• Engage the chain brake by pushing the black hand-guard on top of the saw towards the nose of the bar.
• Release the chain brake by pulling the hand-guard towards the hand-grip.
• The chain brake should always be engaged when the saw is stored.

Chain Tension

• Check the chain tension regularly.
• Adjust the chain tension by turning the tension-adjusting screw clockwise.
• Proper cold tension: As tight as possible without causing binding.
• Adjust the chain tension after the bar has cooled.

Replacing a Chain

• Loosen the bar retaining nuts and back off the bar adjusting screw.
• Remove the chain and reinstall it with the carbide teeth on top of the bar pointing towards the bar tip.

Flooded Saw Procedure

• If the saw won't start after attempting normal start procedures, it may be flooded.
• A flooded saw occurs when the combustion chamber has an excessive amount of unburned fuel.
• Follow the 2-person routine to start a flooded saw.

Fuel

• Most saw blades can be installed and cut in either direction.
• A used blade with less than 80% of the blade remaining should be replaced.
• Carbide tips should be inspected every shift for wear and replaced if 6 or more tips have 50% or more of the carbide missing.

Cutting Wheels

• There are several different cutting wheel blade types.
• Most saw blades are designed for a specific material to cut.
• Composite Abrasive Wheels are used for both wet and dry applications.
• Diamond Abrasive Wheels are suitable for wet cutting and can cut asphalt, concrete, stone, bricks, pipes, and iron.

Minor Maintenance

• Air Filter: Remove screws, clean the filter, and refit the filter cover.
• Tightening the V-belt: Loosen the nuts, point the tensioning nut towards the 0, and turn the tensioning clockwise approximately 1/8 turn.