Towing Speed
Prudent speed must always be observed to avoid excessive sway of towed equipment. Operators must adhere to instructions in the operator's manual regarding safe towing speeds. Road and weather conditions will also determine safe speed.
Parked Chipper
When disconnecting the chipper from the truck, make sure to chock the wheels to prevent the chipper from rolling away and causing damage to the: equipment, property damage or personal injury. A detached chipper must have the wheels chocked while parked.
You should leave the safety chains attached to the truck until you are sure the chipper and wheel chocks are stable. Never leave the keys in the ignition of a detached/parked or unattended chipper!
Safe Work Procedures
Any brush and wood chipper, like any cutting machinery, is only as safe as the people who operate and maintain it. Lack of training or a complacent attitude towards safety can result in tragedy, when using a machine designed for the sole purpose of drawing in and cutting material; be it a tree limb, or your entire body.
Don’t believe that a self-feeding chipper is safer than a rotary drum type; both are cutting machines that must be treated with equal respect. Complacency when operating a chipper can lead to unsafe work practices and, ultimately, to a serious injury or death. Make sure that the machine is in proper working order when it goes on the job. Read the manufacturer's operations and maintenance instructions. Replacement warning decals can be ordered through the Equipment Department, if the decals on your chipper are illegible.
  • All chippers must be equipped with in-feed chute deflector flaps, as provided by the manufacturer. Keep all shrouds and guards in place and unaltered.
  • The quick stop/reverse mechanism must function properly, or the chipper is not to be used until repaired.
  • Maintenance shall be performed only by those persons authorized by the manager/ supervisor and trained to perform such operations. Malfunctioning equipment or repairs performed by an unqualified person can lead to accidents.

Never let an untrained person operate a chipper. Training shall be provided concerning the: proper operation, feeding, starting and shutdown procedures for the chipper being used. Part of the training should be a period of observation of an employee's work performance to be certain they are paying heed to the warnings and fully understand the operation.
Personal Protective Equipment
Head (hard-hat), eye (safety glasses) and hearing (ear plugs, canal caps or muffs) protective equipment shall be worn when in the immediate area of a chipper.
Hand protection (snug fitting, non-cuffed gloves) shall be worn when the employee is exposed to the likelihood of: puncture, abrasion or laceration injury while chipping - for instance, while chipping branches and wood with thorns.
Climbing equipment, body belts. full body harnesses and/or lanyards shall not be worn while operating a chipper or within 20 feet of an operating chipper to prevent the potential of entanglement.
Work Site Set-up
  • Traffic control around the job site shall be established prior to the start of chipping operations, along roads and highways.
  • Chippers should be placed in firm level locations.
  • Never back a truck or trailer when it is practical to go forward.
  • Always have someone behind the unit to direct the driver when backing. If the driver loses sight of the spotter, they must stop.
  • When attaching a chipper to a truck, back the truck to the chipper; don't pull the chipper to the truck. This has been the cause of many back injuries and pinched fingers.
  • Avoid pulling in driveways with chippers, if the only way to get out, is to detach the chipper and move it out of the truck's path, by muscle power.
  • Do not operate the chipper directly below or in close proximity of the tree being trimmed or removed. You may be struck by a falling limb and may not be able to communicate with the person aloft.
  • Noise from chippers makes it difficult for workers on the ground to hear shouted warnings, from climbers in trees. Climbers must be sure workers on the ground are in the clear, before dropping wood.
  • When feeding a chipper during roadside operations, the operator shall feed the chipper in a manner that prevents him/her from stepping into, traffic or being pushed into traffic, by the material that is being fed into the chipper. In most cases, it is safest to feed from the curb (right) side of the chipper. Feed the chipper from the side of the in-feed chute, so that:
  1. The chance of being struck by brush as it is pulled into the chipper is minimized.
  2. You do not have to step over the limbs being fed.
  3. You are in a position to operate the feed/safety control bar.
  • Be certain, at all times, to have firm footing when operating and using the chipper.
  • Brush and logs shall not be allowed to create hazards in the work areas. Brush and wood should be stacked in a way, that makes it easy for the operator to feed the chipper. In most cases, that means that the butt ends of the brush should face the in-feed chute.
  • Ground workers must ensure that climber's ropes are not entangled in the brush being chipped.
  • Plan to have one person at a time do the feeding. If two persons are chipping, coordinate the flow of work so that one person is feeding brush, while the other is picking up the next material to be chipped. The person not doing the feeding should keep watch over the feeder and remain in close proximity with an unobstructed path, to emergency shut-off devices on the chipper. Watch out for the other person, as well as yourself.
  • Keep children and curious by-standers well outside of the established work site.

Chipper Operation
Preparing to start the chipper
Before starting the chipper verify that:
  • The clutch is disengaged.
  • The chip discharge chute is pointed in a safe direction.
  • The chipper hood lock pin or hood bolts are secured.
  • The in-feed chute is free of tools or foreign objects.
  • The feed control bar is in neutral.
  • All personnel are clear of the area.
  • Never operate the chipper without making sure that the manufacturer's disc or drum hood fastener(s) are securely installed. Failure to do this will allow the chipper hood to slam to the open position, and possibly injure or kill someone.
  • Keep flammable materials, oils, rags and debris of all sorts away from the exhaust system.
  • When using a winch in chipper operations, the operator shall ensure that the winch cable is properly stored, and out of the way before initiating chipper operations.
Starting the chipper
Follow the manufacturer's guidelines for starting the motor and engaging the clutch.
After starting the chipper:
  • Idle the engine long enough to warm it up. Slowly engage the clutch.
  • Slowly raise the engine RPM to full throttle.
  • Check feed control bar and hydraulic feed roller operation.
  • Check clutch operation; if it engages too easily, it may need adjustment.
  • Never leave a chipper running or with the key in it when unattended. Remove and pocket the key during any maintenance and/or when leaving the chipper unattended.
  • The brush chipper discharge chute or cutter housing cover shall not be raised or removed, while any part of the chipper is turning or moving.
  • DO NOT open the chipper hood without letting the chipper disc or drum come to a complete stop. WAIT at least 3 minutes before pulling the chipper hood pin. This means 3 minutes after it has come to a complete stop - not after it has almost stopped.
  • Stay out of the chip discharge area when the chipper is: running and the disk or drum is turning, even if brush is not being fed into the chipper. Chips discharge at high velocity and can cause serious injury.
Vital Chipper Operation Safety Reminders:
  • Never place hands or other parts of the body into the in-feed hopper of an operating chipper!
  • Never lean into, kick or push material with your feet into the in-feed hopper of a chipper!
  • Never attempt to unclog, service or clean the in-feed or chute area while the chipper is running, or parts are moving!
  • Never stand on the feed table of a chipper!
Feeding the Chipper
  • If you wear a watch, ring, necklace or bracelet that is exposed to getting snagged on the job, remove it before beginning to work.
  • Brush and logs shall be fed into chippers, butt or cut end first, from the side of the feed table centerline, and the operator shall immediately turn away from the feed table when the brush is taken into the rotor or feed rollers.
  • While material is being fed into the chipper in-feed hopper chute, pinch points continually develop within the material being chipped and between the material and machine. The operator shall be aware of this situation and respond accordingly.
  • Never feed vines or vine-type material directly into feed rollers. Cut the vines into 4 to 5-foot lengths and lay them on top of longer material.
  • Never take chances pushing wood too far into the in-feed of the chipper. Small branches shall be fed into chippers with longer branches, or by being pushed with a long wooden stick.
  • Never use tools, such as rakes or shovels, to push brush through or to clear the in-feed chute. Use a long-forked branch to guide material; it can be chipped with no harm if taken by the rollers - you can’t.
  • Never feed material containing rocks, nails, wire or foreign debris into the chipper. Anything other than brush will not only dull chipper knives but may cause knives to break and could damage the disc or drum, bearings or anvil, or cause projectiles to be thrown from the machine.
  • Never put sweepings through a chipper. Sweepings can fly back in your face or ruin chipper blades. It is better to throw fine material directly into the dump box. Avoid coming into contact with chips known to have poison ivy mixed in the debris.
  • Always feed the larger, or butt end, of branches into a chipper first. Never feed limbs small end first. Stubs can catch on gloves or clothing.
  • Never attempt to hold onto brush after it starts through the chipper. If material becomes jammed in the feed system, reverse the feed rollers to dislodge the material.
  • Feed large-diameter material while smaller pieces are going through the feed system. Smaller pieces will partially open the feed rollers, making it easier for the feed rollers to allow for the large-diameter pieces to be fed.
  • The in-feed end of large pieces should be cut at a sharp angle, to avoid violent thrashing, when a blunt end contacts the rollers.
  • Material too large for the chipper opening must be cut to the capacity of the chipper. Do not force material into the chipper; if it needs to be cut to size, do so before attempting to chip the piece.
  • Keep a hand saw or chain saw handy when chipping large diameter or multi-limbed material.
  • Do not operate the chainsaw inside the feed table or within 10 feet of another person.
  • If using a chainsaw, you must wear chainsaw leg protection, most often chaps, while using the saw. Hand saw use does not require the use of leg protection.
  • If using a chainsaw, either pre-cut the material with chipper turned off, or cut the material at a position away from the operating chipper, to avoid material catching on chaps, as it is drawn into the chipper.
  • Large-diameter wood can cause the engine to lug. Do not let the engine slow down to the point that it stalls or plugs the chipper. When you hear the engine slowing down, push the feed control bar to neutral to stop the feed rollers. When the engine regains full RPM, pull the feed control bar and resume chipping. Machines with feed sensors do this automatically.
  • If material becomes wedged in the in-feed hopper or rollers, shut the engine off and remove the key before attempting to dislodge stuck pieces.
Never feed chippers while they are being moved by the truck and driver.
When performing maintenance to a chipper, follow Lockout/Tag-out procedures.
Control of Hazardous Energy: Lockout/Tag-out Procedures
When a worker, hereafter referred to as the "authorized person," is doing mechanical work, there are safety precautions that must be taken to prevent accidental injury: caused by moving or elevated parts, or the release of stored energy, such as hydraulic pressure. Failure to do so could result in a serious, potentially maiming or fatal injury. The authorized person performing maintenance/repair shall comply with lockout/tag-out procedures.
Sequence for Securing Equipment
  1. The authorized person shall notify the crew and/or affected employees that maintenance/ repair is to be done and that such equipment must be shut down and secured.
  2. The authorized person shall refer to the manufacturer's manual for proper procedures, as needed.
  3. If equipment is in an operational mode, it shall be shut down by normal procedures.
  4. Rotating parts, such as chipper blades, shall be stopped before maintenance/repair. Keyed ignition systems must be in working order.
  5. Keys shall be removed and pocketed by the authorized person. When there is no keyed ignition system, the battery cables or ignition coil wire shall be disconnected.
  6. The power take-off should be disengaged before servicing or repairing tasks, such as hose replacement, are undertaken. All hydraulic tools should be disconnected before equipment is adjusted or serviced.
  7. An employee should never attempt to stop a hydraulic leak with his or her body.
  8. Materials/parts that must be raised or disconnected and suspended shall be properly secured, such as with an appropriate sling or jack stand. Flywheels, such as chipper cutter heads, are to be blocked to prevent pinch points.
  9. The authorized person shall ensure that equipment is isolated and inoperable before proceeding with maintenance/repair.
  10. No piece of equipment being serviced or repaired shall be started, energized or used by any worker who is not under the direction of the authorized person.
  11. When the engine must be running for tuning or adjustment, special care must be given to moving parts.

Restoring Equipment to Service
When maintenance/repair is complete, and equipment is ready to return to normal operation, the following steps shall be taken by the authorized person to restore the equipment to service:
  1. Check for loose parts or tools that may have been left in the immediate area, to prevent accidental contact with moving or electrical components, when the equipment is engaged.
  2. Ensure that all guards are in place, properly secured, and all employees/bystanders are in the clear.
  3. Confirm that controls are in neutral.
  4. Reconnect key, cable or plug wires.
  5. Notify affected employees that equipment is ready to return to service.
Daily Maintenance
  • Check engine crankcase lubricating oil level; add lubricating oil, as needed.
  • Check radiator coolant level; add coolant, as needed, and remove debris from radiator.
  • Check fuel tank liquid level; add fuel, as needed.
  • Check all lights; replace lights, as needed.
  • Check trailer brake break-away switch.
  • Clear feed chute of chipper before operating (remove all foreign objects, stones, bolts, bottles, cans, etc.).
  • Check operation of the jack stand and that it is properly stored and secured.
  • Check hydraulic oil level; add hydraulic oil, as needed.
Weekly Maintenance
  • Check cooling system hoses and clamps.
  • Check all engine belts for tension and condition (fan, alternator, governor).
  • Check fuel tank and fuel lines for leaks and seepage, and that filler caps are in place.
  • Check battery liquid levels; this does not apply to maintenance-free batteries.
  • Check tire condition for cuts and proper inflation pressure.
  • Check wheel bolts and nuts; tighten, as required.
  • Check cutting head drive belts and proper tension. Loose belts cause belt slippage and wear along with poor performance; too much tension causes excessive stress on engine clutch bearings and the cutting head bearing.
  • Lubricate cutting head shaft bearings. Do not over grease bearings. Keep radiator clear of debris and sawdust.
  • Check over the entire chipper for loose or missing bolts and nuts; replace and tighten bolts and nuts, as required.
  • Check condition of cutting knives (blades)
  • Knives (Blades)
  • Keep blades sharp. Dull blades tend to reject material, sometimes forcefully. Dull knives cause excessive load on the chipper engine - sharpen them.
  • Visually check blades for cracks and evidence of loosening. Replace or tighten, as necessary. Broken or cracked knives are replaced using a matched set of new or reground blades.
  • If knives need to be changed, refer to the manufacturer's manual section covering the chipper make/model.
  • When changing blades, make sure blades and wedges are clean and free of any bumps or battered places which are not perfectly flat.
  1. Parts are of correct manufacturer's quality and application for the chipper.
  2. Refer to the manufacturer's manual for replacement and adjustment procedures.
  3. Cylinder cavities are clean.
  4. Ejector screws are turned back on wedges.
  5. Knives (blades) and wedges are firmly seated.
  • Replace all blade bolts, nuts or wedge block adjusting screws when changing blades.
  • Necessary torque wrench and adapters are available.
  • Wedge screws are properly torque.
  • Knives are absolutely the correct knives for the chipper! Use of the improper knife/blade can cause serious injury or death to persons, as well as serious damage to the chipper.
  • Knives (blades) are correctly adjusted.
  • Inspect the bed knife/cutter bar. Adjust; flip over the bed knife/cutter bar when blades are changed. Failure to do so will greatly affect performance.
  • Run the chipper and then re-torque before starting to chip brush or wood with new sets of knives (blades); re-check tightness periodically.