Saws Context Manual PDF

Saws Context Manual VERSION 1 UPDATED July 1, 2024  Table of Contents Introduction 3 Chainsaws 3 General Chainsaws 3 Ventilation Chainsaws...

Saws Context Manual VERSION 1 UPDATED July 1, 2024  Table of Contents Introduction 3 Chainsaws 3 General Chainsaws 3 Ventilation Chainsaws 3 Safety Precautions 4 Minimum Protective Equipment 4 Fuel 4 Chainsaw Anatomy 5 Cut-off Saw 10 Safety Precautions 10 Cut-off Saw Anatomy 12 Starting Procedures 12 2  Introduction The St. John’s Fire District utilizes gasoline-powered saws to support re and rescue operations. This particular context manual covers chainsaws and cut-off Typically, power saws save time and are critical to providing support that will have a direct impact on tactical objectives. Therefore, the daily morning checks and required maintenance is necessary to ensure that the saw is in a state of operational readiness. Chainsaws Chain saws are a versatile tool. They can be used for Ventilation, Forcible Entry, and clearing downed trees. Chain saws are primarily used on emergency incidents to cut through Class A roo ng materials (wood and asphalt roof coverings) during vertical ventilation operations. The District mainly utilizes Stihl Chainsaws. Stihl is the manufacturer of preference. Due to the many different makes and models of power equipment used by the District, it is beyond the scope of this Context Manual to provide detailed speci cations for each piece of equipment. Please refer to manufacturer speci cations. District chainsaws are identi ed in two categories based on its primary use: General and Ventilation. General Chainsaws Chainsaws are carried on all District re apparatus. The chainsaw is primarily used to clear roadways of downed trees. The standard con guration is an 18-inch Bar with a standard chain. In the event of signi cant weather events, the District has designated saws that are equipped with longer bars. Ventilation Chainsaws The ventilation chainsaw is con gured with the intent to be utilized for ventilation. Ventilation saws are manufactured speci cally for the re service and differ greatly from a regular chain saw. The ventilation saw is equipped with a specialized HD air lter. Moreover, the ventilation saw features a robust chain designed for rescue operations. 3 fi fi fi fi fi fi fi fi fi fi fi fi  Safety Precautions Caution must be used when cutting through any material with a high revving chain saw; kickback from the saw can cause serious injury. If kickback occurs, the violent reverse action of the kickback will actuate the inertia chain brake or drive the chain brake handle back into the operator’s hand, engaging the chain brake and stopping the movement of the chain. Therefore, it is imperative that the user properly hold and operate the saw. Safety precautions must be taken with running saws so that no body parts are placed in the cutting path of the saw. Avoid using the saw above your head. The most effective position to operate the saw is below the chest line where the operator has good visibility and can maintain control of the saw. Do not let the chain contact anything except the material you are cutting. A running chainsaw shall never be set down without the chain brake engaged. The chain brake shall be engaged when moving (not operating) a running saw. DO NOT OPERATE CHAIN SAWS AT FULL THROTTLE WITH NO LOAD FOR MORE THAN 5-10 SECONDS. Minimum Protective Equipment Gloves, hearing protection, eye protection, helmet, and steeled-toed boots are required, at minimum, to operate a saw. During all training evolutions and non- emergency responses, chaps will be worn at all times to protect the operator. Fuel There are two different types of gas engines used in power tools: 2 cycle engines and 4 cycle engines. Chainsaws and Cut-off Saws are 2-cycle engines, and require a pre-mixed fuel/oil blend to properly lubricate the combustion chamber of the engine. All 2-cycle fuel should be pre-mixed in a labeled as “MIXED FUEL” in a yellow can to ensure that it is not inappropriately used with the wrong equipment. ONLY use the fuel can labeled “MIXED FUEL” to refuel saws. All other front-line power tools, such as generators and powered fans, have 4-cycle engines that use high octane unleaded fuel. NOTE: Bar Oil shall and 50:1 fuel mix is to be stored at the Station. These items shall not be stored on the re apparatus. 4 fi  Chainsaw Anatomy Starting Procedures The St. John’s Fire District endorses two starting methods: On the ground or On the groin. At no time will a saw be started using the drop method. In addition, all chain saws will be started with the chain brake engaged. Squeeze the throttle trigger and set the run switch to the “choke” (cold start) position. If the saw is already warm, set to “warm start” position. 1. Confirm the chain brake is engaged. 2. Depress the throttle safety, pull the trigger and engage the choke by moving the Master Control Lever (MCL) to the Cold start/Choke position. 3. If so equipped, press the decompression button. 4. Place saw on ground or on the groin while holding firmly, pull the starter rope until the engine fires and tries to run. 5. Move the MCL to the Warm start setting. 6. Pull start the engine repeating steps 3-4 7. When the saw begins to run. The master control switch will automatically move to the run position. 8. Release the chain brake and run the saw at a low throttle speed for 5-10 seconds. 9. Ensure the saw idles well. If not, continue to run at low speed until it will idle well. 10. Allow the saw to idle for 30-60 seconds until warm. 11. Run the saw at moderate to high speed and verify functionality. 5  Daily Visual Inspection Daily visual checks are performed at the start of each working shift to ensure saws are in good repair and ready for use. 1. Fuel (full). 2. Bar Oil (full). 3. Visually inspect the saw for cleanliness, clean or wipe off as necessary. 4. Extend the starter pull cord fully and inspect for damage or fraying. 5. Ensure the chain is rotating the correct direction. 6. Inspect each tooth on the chain, carbide teeth – replace if missing 3 in a row or a total of 6 teeth. 7. Check the chain tension and adjust if necessary (only adjust the tension on a cold chain). 8. Check all working positions of the chain brake. 9. Store with the Master Control Lever (MCL) in the stop position and the chain brake on. Daily Function Inspection Daily functional checks are performed at the start of each working shift to ensure the saw functions properly and to address preventative maintenance measures. 1. In a well-ventilated area, perform the Starting Procedures for the saw. 2. Let the saw warm up at an idle speed for 30 to 60 seconds. 3. The operator can let the saw idle on a pad or soft ground while monitoring it, or the user can properly hold the saw in both hands during the warm up period. 4. Once the saw is warm, properly hold the saw and slowly rev up the saw to full RPM two to three times. 5. Check the proper operation of the chain brake. 6. Check to see if the chain and bar are being properly oiled by revving the saw’s RPM up and pointing the tip of the bar approximately 4 to 6” from a light- colored surface. The user should see oil droplets appear on the surface. 7. At idle, shut off the saw by switching the master control switch to “stop.” 8. Flip the master control lever up to the “stop” position. Move the master control lever to the “run” position. A hot engine usually can be restarted in the “run” position without choking. 9. Leave the master control switch in the “stop” position. 10. Engage the chain brake 6 The Chain Brake Push black hand-guard on top of saw towards nose of the bar to engage the chain brake. Do this before moving a running saw (Critical Safety Factor). When ready to cut, pull the hand-guard towards the hand-grip to release the chain brake. The hand-guard will be in the off position when the chain is moving. The chain brake should always be engaged when the saw is stored. Adjusting Chain Tension The chain tension should be checked regularly. 1. Turn tension-adjusting screw clockwise to increase the chain tension. 2. Proper cold tension: As tight as possible without causing binding. Chain tie- straps should remain in contact with bar along bottom rails and move freely along bar. 3. Starting with “cold tension”, chain will stretch and droop as it heats up, limbers up, and/or wears in operation. It should be adjusted anytime chain tangs hang almost out or completely out of bar rails at point shown. 4. Adjustment of “warm chain”: tighten until tanks move halfway up into bar groove. Check tension after bar has cooled, because only a cool chain can be tensioned accurately. Chain tension Chain tension adjustment screw adjustment screw 7 Replacing a Chain 1. Loosen bar retaining nuts with appropriate tool, then back off bar adjusting screw enough to remove chain from bar. Finish removing nuts and side cover. Remove chain. When reinstalling, be sure carbide teeth on top of bar point towards bar tip, and drive teeth engage drive sprocket. 2. Be sure bar adjusting pin is engaging bar properly before installing side cover. Install side cover and nuts, hand tighten. 3. With screwdriver or chain saw tool, turn adjusting screw clockwise to take up slack in chain. While turning adjusting screw, always lift up on bar tip with other hand. 4. Tighten chain until slack is removed but not so tight that chain cannot be moved back and forth on bar freely. 5. When correct tension is achieved, and while holding up on bar tip, tighten nuts to secure bar. Flooded Saw Procedure If the saw won’t start after attempting the normal start procedures and/or has obvious fuel/liquid coming out of the muffler, it is most likely flooded. The term “flooded” refers to the combustion chamber having excessive amount of unburned fuel in it which will diminish the ability of the spark plug being able to ignite the plug is too “wet”. The fuel air mixture will not burn properly. In order to have the best chance of starting a flooded saw, try the following 2-person routine: Ensure the saw is set to “run” position. Ensure it is not in the “choke” position. Place saw on ground and have one person secure it so the second person can pull on the starter rope and hold the saw throttle in the “full on/wide open” position. Pull on the starter repeatedly until saw fires (it may take upwards of 20 pulls). Do not release the throttle/trigger during this operation -saw will usually attempt to start a couple times, keep pulling starter, and keep holding throttle open. Once the saw fires and continues to run (probably poorly at first), continue to hold throttle wide open until saw clears out and runs well at wide open. Run saw between idle and wide open for a minute or two, long enough that saw runs well and is no longer spitting gas/oil mixture out of the exhaust. You should see the muffler dry out and burn off all the fuel that was on it. 8  Idle Ensure saw idles well, if not, continue adjustment to run it at medium high speed until it will idle well. Shut saw off and restart it a few times without “choke” to ensure it is cleared up. If saw won’t start after 30-40 pulls, let it sit for an hour or 2 and re-try to start. If it still won’t start, initiate a Work Order Ticket for saw repair. Minor Maintenance Remove the carburetor box cover by loosening the cover knob. Check the air filter. Ensure the spark plug boot is not damage, frayed, or dry rotted. Check the spark plug, adjust electrode gap if necessary. Spark plug may be fouled up from too much oil in the mixture or flooding. 9  Sawyer Kit All District re apparatus are out tted with a Sawyer Kit to ensure proper protective equipment is available to personnel operating chainsaws. The Sawyer Kit will store spare chains and tools. The following items shall be maintained in the Sawyer Kit bag. (1) Helmet with ear protection (1) Pair of Chainsaw Chaps (1) Chainsaw Scrench (2) Spare Chainsaw Chain (1) Ventilation Saw Chain (Truck Companies Only) Cut-off Saw Circular saws are a very versatile. They can be out tted with many different blade types that can cut almost any material that we encounter. With the right cutting blade installed, the saw can be used for: Ventilation: Commercial, industrial, peaked roofs, and at roofs all covered with a variety of roo ng materials. Forcible entry: Security bars, roll up doors, reproof doors, reinforced doors and windows, chains and locks. Heavy rescue: Building collapse, industrial accidents, natural disasters, recoveries, and more. Vehicle extrication: Aircraft, buses, tractor- trailers, passenger cars, auto res, farm and Industrial accidents. Safety Precautions Be sure sparks from the cutting operation cannot reach flammable surroundings. Examine cutting wheel before each use. Wheels should have no cracks, nicks, or flaws. NEVER operate unit without a safety guard. Moving the blade into a cut too quickly can cause blade to shatter. If a wheel shatters, carefully examine the wheel guard for damage. A damaged wheel guard must be replaced to protect the operator. NEVER use saw to cut asbestos wrapped pipes. Kickback can also occur using the cut-off saw causing a very hazardous situation. To avoid kickback and serious injury, use the following guidelines when operating a circular saw: 10 fi fi fi fi fi fl fi  Always use a high speed blade. Always use the correct blade for the material you’re cutting. When operating the saw, the user must have one hand rmly placed around the front handle, with the other hand rmly holding the throttle assembly handle. Always have the blade guard in place and adjusted to the correct angle to assist you with your cut. Always avoid using the saw above your head. The most effective position to operate the saw is below the chest line. Start your cut in such a way that you can predict what will happen after the cut is complete. Always cut at full throttle. Start your cut gently, do not force or squeeze the blade in. Move the blade slowly while controlling your throttle and blade RPM. Only use the blade’s cutting edge when cutting. Always try to cut with the blade fully vertical. Make your cuts using only the bottom half of the blade. This may require the user to “tilt” the saw down so the bottom of the blade is available to cut with teeth. 11 fi fi  Cut-off Saw Anatomy Starting Procedures 1) Depress the throttle safety and the throttle trigger simultaneously 2) With both triggers depressed move the slide control to START 3) Set choke according to engine temperature -First setting engine is cold -Second setting if engine is hot (off for 5min) 4) Press primer bulb 7-10 times 5) While cut-off machine is on the ground, ensure you have firm footing, hold the handle with your non dominant hand, and press the machine against the ground with your opposite knee 6) Pull the starter with your dominant hand until you feel it engage- then give it a brisk strong pull *Do not let the starter grip snap back-it may break 7) After the engine turns over, set choke to the second setting, start the engine repeating steps 5 and 6 8) Once the engine is running, squeeze the throttle trigger fully and let run at full throttle for approx. 30s (The slide control will move to “I” when the trigger is squeezed 9) When the engine is warmed up set the choke to the third setting *If the carburetor is set correctly the wheel should not rotate while engine is idling To Stop- Move slide control to “0” 12  Daily Visual Inspection Daily visual checks are performed at the start of each working shift to ensure cut- off saws are in good condition and ready for use. Fuel ( ll at 3⁄4) Most brous/composite 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 the blade should be replaced if 6 or more tips (or 3 tips in a row) have 50% or more of the carbide missing, or the tips appear to be worn or rounded. Cutting Wheels Types and Use There a several different cutting wheel blade types. Most saw blades are designed for a speci c material to cut. Composite Abrasive Wheels Used for both wet and dry applications Suitable for cutting Asphalt, Concrete, Stone, Ductile cast pipes, Steel (cannot be used to cut railway tracks) Diamond Abrasive Wheels -Most diamond cutting wheels are suitable for wet cutting suitable for cutting Asphalt, Concrete, Stone, Bricks, Pipes, Iron, Steel (up to 10mm thick) *Short names appear on the sides of the wheel. It is a combination of letters and numerals up to four digits. The letter indicates use of the wheel, numerals indicate the performance class of the diamond cutting wheel A-asphalt, B-concrete, BA-concrete & asphalt, S-stone, SB*-stone & asphalt, *steel-not suitable for continuous cutting 13 fi fi fi  Minor Maintenance Air Filter Remove screws from filter cover. Remove the filter cover and clean it. Remove the auxiliary and main filter insuring dirt does not enter the intake area. Refit the filter cover. Tighten screws Tightening the V belt Prior to tensioning the ribbed v-belt the nuts must be loosened and the tensioning nut must point towards the 0. Turn the tensioning clockwise approximately 1/8 turn. Continue turning up to the stop. Tighten the nuts. Remove the Cutting Wheel To remove cutting wheel place locking pin through the bore in the cast arm. Use the combination wrench to loosen and remove hexagon head screw. Remove the front thrust washer. Replace wheel and reverse steps. (note the arrows indicating the direction of rotation) 14  Inventory Identification The District saws are labeled with an Inventory Identi cation Number. This number is utilized for inventory tracking and maintenance reporting. Maintenance Reporting Maintenance Reporting for saws utilizes a dual system that includes the generation of a Work Order Ticket and the application of an Out of Service Tag. The Work Order Ticket shall be generated in Vector. In conjunction with the Work Order Ticket, a physical out-of-service tag is to be af xed to the asset. The tag will notate: Date: Enter the date of reporting. SER. #: Enter the Inventory Identi cation Number. Example: SW025 Location: Enter the Station and Unit where the asset is assigned. Problem: Provide a provide a description of the problem. Signed by: Enter your name. 15 fi fi fi Stihl MS391 Displacement 3.9 cu in. Engine Power 3.3 kW Powerhead Weight 13.67 lbs Fuel Capacity 20.3 oz Chain Oil Capacity 11.8 oz Stihl MS362 Displacement 3.9 cu in. Engine Power 3.3 kW Powerhead Weight 13.67 lbs Fuel Capacity 20.3 oz Chain Oil Capacity 11.8 oz 16 17 18 19 20 21