SOG #110 - Ventilation Saw

PURPOSE

To establish a uniform method for the proper use of the saw and proper ventilation techniques.

GENERAL

You should be properly trained on the ventilation saw prior to using it.

There are two types of kickback that can be encountered with the improper use of a chainsaw.  Both types are the result of an equal and opposite reaction that occurs when the chain is suddenly stopped.  This kickback movement is so fast that the operator cannot react quickly enough to avoid serious injury.

ROTATIONAL KICKBACK is the violent reaction, which occurs when the chain at the upper section of the nose is suddenly stopped, thereby dangerously driving the bar nose in an upward arc towards the operator.

LINEAR KICKBACK is a push reaction, which can occur with the saw blade buried in the cut when the cut closes, pinching the chain along the top rails of the bar.

KICKBACK MAY OCCUR WHEN:

·        The upper section of the nose or tip of the guide bar touches an object.

·        The wood closes in and pinches the saw chain in the cut.

·        Tip contact in some cases may cause a lightning-fast reverse reaction, kicking the guide bar up and back towards the operator.

·        Pinching the chain along the top of the guide bar may push the saw rapidly back towards the operator.

Any of these reactions may cause you to lose control of the saw, which could result in serious personal injury.

As a ventilation saw user, we will take several steps to keep our cutting jobs free from accident or injury:

·        With a basic understanding of kickback, you can reduce or eliminate the element of surprise.

·        Keep a good firm grip on the saw with both hands when the engine is running.  Use a firm grip with thumbs and fingers encircling the chainsaw handle.  A firm grip will help you reduce kickback and maintain control of the saw.  Don't let go.

·        Make sure that the area in which you are cutting is free from obstructions.  Do not let the kickback zone of the guide bar contact any obstructions while you are operating the saw.

·        For ventilation cutting, always cut at full RPMs.

·        Do not overreach or cut above shoulder height.

·        Follow manufacturer's sharpening and maintenance instructions for the saw chain.

·        Only use replacement bars and chains specified by the manufacturer or the equivalent.

Operation

In the field, you should follow certain procedures for the use of your saw to insure safe and efficient operation.

Basic rules for safe operation of the ventilation saw include:

·        Wear full turn-out gear including gloves and SCBA.

·        Keep a firm grip on the saw.

·        Avoid cutting across your body.

·        Cut with full RPMs.

·        Avoid the bar's kickback zone.

·        Do not attempt to operate saw without completion of your department's training for the use of a power tool.

WARM UP

As another safety feature, your Cutters Edge ventilation saw is equipped with one-step starting.  To take advantage of one-step starting, the saw must be warmed up prior to going on the roof.

To warm up the saw after you have reached the scene of operation, use the following starting procedure:

1.      Pull out the choke.  NOTE: Remember not to touch the throttle while starting the saw.

2.      Step on the back handle and grip the top handle firmly.

3.      Pull the starter handle upward sharply a few times until the engine fires.

4.      Push the choke in and pull the starter handle again to start the engine.

5.      Squeeze the trigger quickly once to set the idle.  Allow the saw to warm up, then touch the momentary contact switch to shut it off.  It is now ready for use.

THE TS-10 SLING

Carry the saw up ladders by attaching the tool sling.  Loop the hook on the end of the sling around the top handle and clip it to the D-ring on the sling.  Attach the other end of the sling to the back handle in the same manner.

Once on the roof, remove the sling and place it in your pocket or out of your way.

WARNING: Never operate the Cutters Edge Ventilation Saw with the sling attached.

IMPORTANT: Always operate the saw with a minimum of two people on the roof for safety.  One should operate the saw and the other act as backup and as eyes and ears for the operator.

·        Always wear full protective gear, along with a face shield, goggles or safety glasses.

·        Sound the roof for the safest operator position.

·        Select and prepare an alternate escape route.

·        Position yourself properly and prepare to cut.

STARTING PROCEDURE ON ROOF

Since you have properly warmed up the saw, you can start it now using the one-step starting procedure.  After positioning yourself properly, securely holding the saw in place, simply pull the starter handle upward.  The saw will start and you will be ready to cut.

CUTTING

When ready to begin cutting, choose a position that is safe and comfortable.  Cut with the saw held to one side of your body, locking your top elbow, if possible.  Avoid cutting with the saw directly in line with or across your body.

INSPECTION CUT

Once on the roof, first make an inspection cut to determine the thickness of your roofing materials.  Slide back the D-8 to its fully retracted position, then make the inspection cut as you normally would, keeping the saw at ninety degrees to the rafter, feeling for and rolling the rafter.

Turn the saw off and visually determine the thickness of the roofing materials and then adjust the D-8 to the necessary setting.  Start the saw and make your ventilation cuts.

PENETRATION CUT

To begin your penetration cut, hold the saw at an angle of approximately forty-five degrees to the roof.  This positions the highest number of cutters in contact with the roof surface for optimum penetration speed.

Plunge the bar in aggressively for penetration, but don't penetrate any deeper than necessary.  This will prevent the inadvertent cutting of hidden dangers, such as rafters, wiring or braces.

After you have penetrated the roof surface, increase the angle of your saw up to ninety degrees.  This places a greater number of cutters in contact with the broad surfaces of the rafters, increasing your sensitivity of feel.

If it feels like it is taking too long to penetrate, you may be directly on a rafter.  Simply move your cut over a few inches and begin to cut again.

ROLLING THE RAFTERS

When you feel a rafter, pull the saw up and allow it to cut only the roof decking as you roll over the rafter Then return to your previous depth of cut until you encounter another rafter to roll.  This preserves roof integrity and provides you with another measure of protection.  If the D-8 depth gage is properly set it will not be necessary to roll the rafters.