Skip to main content

General Saw Safety Guide

View PDF

General Saw Safety Guide

Rip saws are among the most productive machines in a rough mill — and among the most demanding when it comes to operator safety. The single greatest hazard is kickback: the sudden, unpredictable ejection of material from the saw, which can range from a minor event to a serious or fatal injury. Effective rip saw safety combines well-maintained safety equipment, properly trained operators, disciplined procedures, and active management involvement.

Mereen-Johnson is committed to providing equipment, information, and training to reduce the risk of injury. Our machinery is equipped with material containment systems designed to direct material out the outfeed or dust chute — but that containment system is only one component of a comprehensive safety program. This guide covers the full scope of rip saw operator safety.

Important: This guide provides general safety guidelines. Mereen-Johnson’s machinery is designed and manufactured to meet or exceed ANSI standards at the time of manufacture, but standards change regularly. Contact your local OSHA office for the latest risk-minimization requirements, and always follow OSHA’s Lock Out/Tag Out standard (29 CFR 1910.147).

For the complete reference, view the full General Saw Safety Guide PDF.

Safety First: The Non-Negotiables

Before operating any Mereen-Johnson rip saw, every operator and maintenance team member must understand these fundamentals:

  • Read and understand the manual before operating the machine or starting any electric motor
  • Disconnect and lock out the main power source every time before opening any access door to the saw chamber or servicing the machine
  • Everyone working on the machine must have their own lock on the disconnect
  • Wait for the arbor motor and blades to come to a complete stop before leaving your workstation or performing any maintenance or adjustments
  • Never assume the power is off — always verify that lock-out/tag-out is in effect when servicing the machine

Management’s Role in Operator Safety

A low-risk plant environment is the shared responsibility of management and workers, but management owns the framework. Managers who oversee rip saw operators play a critical role in establishing, maintaining, and enforcing safety policies:

  • Make employee safety the top priority and ensure proper safety procedures are clearly defined and enforced
  • Confirm shortcuts aren’t being taken and that all safety equipment — PPE, guards, access-limiting screens, and switches — is frequently checked for proper operation
  • Ensure safety, operations, and maintenance personnel have read the manual and viewed all information on operation, kickback containment, and minimizing kickback danger

Operator Selection and Training

The majority of accidents occur when there’s been a change in operators, or when personnel are unfamiliar with the risks of rip saw operation.

Operator Selection

Not all individuals are mechanically inclined or capable of recognizing imminent danger. A qualified rip saw operator must have the ability to recognize a dangerous situation and quickly decide what to do, a safe attitude, an understanding of the operation and material, and consistent practical judgment. Management must judge operator competence carefully.

Operator Training

Only a rigorous training program conducted by a qualified operator or instructor with rip saw experience will adequately prepare a new operator. Key training principles:

  • Mereen-Johnson’s Field Service Department provides a comprehensive training program with the installation of a new machine. Operators who will provide future training should attend the installation training period
  • Training is most effective when all operators have read the entire operating manual before training is conducted, and must include viewing all Mereen-Johnson operations and safety videos
  • Operators must be trained to recognize unusual events — when starting the machine, they must wait and listen for unusual noises that may indicate a malfunction. Frequent jams, vibration, poor performance, and feeding problems should all be observed and reported

If you need additional personnel trained, contact Mereen-Johnson to discuss your options.

Personal Protective Equipment (PPE)

Employees must always wear appropriate Personal Protective Equipment when operating a rip saw:

  • Eye protection at minimum as described in ANSI/ISEA Standard Z87.1-2015. Always wear certified full face shield protectors and safety glasses
  • Ear protection in the form of approved earplugs or ear muffs
  • Steel-toed, rubber-soled shoes for solid footing and foot protection
  • No loose-fitting gloves or clothing, ragged sleeves, or similar — loose items could become entangled and pull the operator into the machine
  • A ballistic apron designed for rip saw operator protection, covering at minimum from the neck to mid-thigh. One is supplied free with every new Mereen-Johnson rip saw, and additional aprons are available

Operating the Rip Saw Safely

Safe operation comes down to disciplined habits and never defeating the machine’s safety systems:

  • Check for wrenches and tools left in the machine before operating
  • Locate the lumber stack where the operator won’t have to pass across the feed path to get the next board
  • Never run any machine without all guards, interlocks, and anti-kickbacks in place and fully operational
  • Feed material only from the infeed — never feed material from the outfeed, because the blades will eject material toward the infeed
  • Stand to the side of the lumber when manually loading
  • Erect a barrier behind the infeed to protect non-operating personnel. The barrier should extend from below the feed bed to the height of the saw, and to the right and left of each side. No one should pass behind the infeed or outfeed until all material has left the machine
  • Never modify the mechanical or electrical design without written consent of Mereen-Johnson
  • Keep clear of the moving feed bed at all times
  • Never remove strips or debris while the machine is in operation
  • Start the feed bed only when the arbor is running at full speed (or when the saw blades have been adjusted clear of the cut)
  • Operate only with sharp tooling — the cut will deteriorate and the sound will change as tooling dulls. Use sharp saw blades with matched diameter on each setup; mismatched diameters cut into the feed slats, affecting cut quality and increasing kickback risk

Lock Out / Tag Out

Always disconnect and lock out the main power when changing tooling, performing maintenance, or removing jammed material. Every person performing maintenance must have and use their own lock. Conform to all local, state, and Federal lock-out laws and follow OSHA’s “Control of Hazardous Energy Sources” standard (29 CFR 1910.147).

The proper lock-out/tag-out sequence:

  1. With main power on, stop the saw with the E-stop. Wait for the motor and arbor to come to a complete stop
  2. Lock Out and Tag Out the machinery before performing maintenance
  3. Open the saw chamber access door now that the mechanical door interlock has been deactivated
  4. Confirm each person working on the equipment has and uses their own lock on the power supply

Understanding and Reducing Kickback Risk

A kickback is an accidental ejection of debris or material out of the rip saw. Kickbacks occur without warning, vary in intensity, and can cause major injury. Understanding what increases kickback risk is the foundation of rip saw safety.

Factors That Increase Kickback Risk

  • Improper PPE — leaves operators unprotected when a kickback occurs
  • Sticky, bent, or worn anti-kickback fingers — the single most important mechanical safety system
  • Incorrect machine settings for the material being processed — feed speed and press roll settings must match the material (species, thickness, number of rips, and other factors all matter)
  • Poor lumber quality — rough, split, round-edged, tapered, withered, or loose-knotted lumber is more likely to kick back
  • Frozen or ice-covered lumber — allow it to thaw completely to minimize slippage and binding
  • Improper pressure head adjustment — material too thin for the pressure head setting loses contact with the containment system
  • Feeding lumber in layers — never “book,” stack, or feed more than one layer; the anti-kickback system only contacts the upper board
  • Feeding lumber side by side — differences in thickness can interfere with the anti-kickback system
  • Changing material direction once the feed system has taken hold — this can bind the blades into the material
  • Net rip width less than 1/2 the material thickness — the material may fall during operation, increasing kickback likelihood
  • Worn or improperly adjusted anti-kickback system — gaps between the feed bed and kickback system greatly increase risk
  • Bent feed bed slats or worn press roll covers — these may not properly contain material

Important: Anti-kickback devices will not reduce the occurrence of kickbacks — they reduce the likelihood of operator injury when a kickback occurs. Because lumber is unpredictable, there is always a possibility of kickback. Properly maintained safety devices, PPE, and risk-management procedures together are what protect operators from serious or fatal injury.

Anti-Kickback System Maintenance and Adjustment

The anti-kickback finger system is the most important mechanical safety device on the rip saw, and it requires specific, disciplined maintenance.

Critical Specifications

  • Outer shield (movable or fixed): Set to .31″ below the feed table
  • Anti-kickback fingers: Between .03″ and .06″ below the table. If you cannot hold this tolerance, advise Mereen-Johnson
  • Lower finger: 1.75″–2.00″ above the table top
  • Height adjustment (if equipped): Not greater than .06″ above the table
  • Dust collection minimum: 680 CFM, 4″ W/G at openings, 5000 FPM velocity
  • Never operate the saw without the Outboard Swinging Skirt or Outboard Cover in place

Daily Anti-Kickback Maintenance

  • Make a daily check for proper adjustment, free-fall ability, and excess wear. Fingers should always swing freely and return to their original positions
  • Check for wear by comparing fingers in the area of greatest use to the sharpness of fingers at the ends where they’re seldom used. Replace all worn or bent fingers immediately
  • Keep fingers clean and free of debris using filtered dry air at least once per 8-hour shift (in compliance with dust containment codes)
  • Never oil the anti-kickback fingers — oil causes sawdust to accumulate, making the upper fingers stick in the up position and the lower fingers stick in the down position, defeating the system
  • Keep upper fingers lowered and lower fingers up until the machine is off and the arbor has completely stopped

Finger Replacement

  • Replace ALL anti-kickback fingers at least once every 1,600 hours of operation — and every time they are worn, bent, dull, dirty, or stuck
  • Never re-sharpen anti-kickback fingers — this changes the finger angle to the material and can defeat the system. Contact Mereen-Johnson for precision laser-cut hardened OEM replacements
  • Always keep the kickback protective belting (the flap on the inside of the second set of upper infeed fingers) in place and in good condition

How to Remove a Lumber Jam

Removing a jam safely is a lock-out/tag-out procedure:

  1. Press the E-stop to shut down power to the machine
  2. Turn off all power after the machine comes to a complete stop
  3. Lock out and tag out the machine, then either:
    • If the material has not contacted the saw blade: Insert a piece of properly sized sheet steel to deflect the fingers upward and off the board, pull the board through the infeed, and remove the sheet steel
    • If the material has contacted the saw blade: Raise the arbor and press roll mechanisms, then pull the material through the outfeed

Conveyor Safety

For operations with conveying equipment, basic conveyor safety rules protect everyone working nearby:

  • Do not start the conveyor until all personnel are clear
  • Keep all stopping and starting devices free from obstructions and easily accessible
  • Never ride, stand, sit, walk, or run on the conveyor at any time
  • Do not load the conveyor beyond its capacity and design limits
  • Keep all safety guards on the conveyor and in safe repair while running
  • Keep loading and unloading points clear of obstructions
  • Only trained personnel should operate conveyors or perform maintenance (with starting devices locked out)
  • Alert personnel to entanglement hazards from long hair, loose clothing, and jewelry
  • All personnel should know the location and function of all start/stop controls, and report unsafe practices to a supervisor

Dust Hazards: Inhalation and Combustibility

Depending on the type, species, and condition of material being processed, airborne contaminants may pose a risk:

  • Inhalation risk: OSHA regulations on wood dust apply, and many state regulations specify acceptable conditions. Contact your state and local authorities for inhalation risk information. An approved dust mask or respirator may be required
  • Combustibility: Wood dust is combustible. Inadequate containment, removal, and material handling are factors that may contribute to an explosion. Contact your local, state, and national fire prevention agencies for information on preventing this potentially extremely dangerous hazard

Related Maintenance and Reference Guides

Safety, maintenance, and proper operation work together. For additional support, review these related resources:

Need Operator Training or Safety Support?

Mereen-Johnson’s Field Service Department provides comprehensive operator training with every new machine installation, and additional training is available for new personnel or as a refresher for existing teams. Proper training is one of the most effective investments you can make in operator safety — the majority of rip saw accidents involve operators unfamiliar with the equipment’s risks.

Contact Mereen-Johnson or call (612) 529-7791 to discuss operator training, replacement anti-kickback fingers and safety components, or any safety-related question about your rip saw.