Wednesday, December 3, 2014

Ramps & Grades

Traveling on Ramps and Grades
Potential Hazards:
  • There is a danger of tipover when traveling on ramps and grades.
Requirements and Recommended Practices:
 
  • Always look in the direction of travel.
     
  • Never turn on a ramp or incline. Turn prior to the ramp or incline to place forks in proper direction.
     
  • Keep a safe distance from the edge of a ramp.
     
  • Do not travel on ramps with slopes or other conditions that exceed the manufacturer's recommendation.
Traveling down ramp without load.
Figure 2. Traveling down ramp without load.



 
Traveling With a Load (Forks Upgrade)
Forklift operators should be aware of procedures to follow when traveling on ramps and other inclines with a load.

Potential Hazards:
  • Danger of tipover.

  • Danger of losing load.
Traveling with a load. Note that ramps should have railings or bull rails.
Figure 3. Traveling with a load. Note that ramps should have railings or bull rails.
Traveling up ramp with load.
Figure 4. Traveling up ramp with load.

Traveling down ramp with a load.
Figure 5. Traveling down ramp with a load.
Requirements and Recommended Practices:
  • When traveling with a load, the load should point up the incline, regardless of direction of travel.
     
  • Going up the incline:

    • Drive forward.

    • Forks pointed upgrade.

    • Use a spotter if load blocks the driver's view.

  • Going down the incline:

    • Drive in reverse.

    • Turn head and face downgrade.

    • Forks pointed up the grade.
NOTE: When walking with a pallet truck with or without a load, the forks should be pointed downgrade, regardless of direction of travel.





Traveling Empty (Forks Downgrade)
Forklift operators should follow certain procedures when traveling on ramps and grades without a load.

Potential Hazards:
  • Danger of tipover.
Traveling without a load. Note that ramps should have railings or bull rails.
Figure 6. Traveling without a load. Note that ramps should have railings or bull rails.
 
Traveling down ramp without load.
Figure 7. Traveling down ramp without load.
Requirements and Recommended Practices:
  • When traveling without a load, the forks should point downgrade, regardless of direction of travel.
     
  • Going up the incline:

    • Drive in reverse.

    • Turn head and face upgrade.

    • Forks pointed downgrade.

  • Going down the incline:

    • Drive forward.

    • Forks pointed downgrade.

Wednesday, November 5, 2014

Pedestrian Traffic

Pedestrian Traffic
Forklift operators should always be aware of conditions in their workplace, including pedestrian traffic. Forklift traffic should be separated from other workers and pedestrians where possible.

Potential Hazards:
  • Danger of striking pedestrians and objects
Requirements and Recommended Practices:
  • Yield right of way to pedestrians.
     
  • When a person or group of people walks across your planned route:

    • Stop.

    • Wait until the pedestrians pass by.

    • Proceed cautiously through any congested area.

  • If an area is cluttered, walk the route first to spot problems.

    • Check for situations that require a spotter and use one when traveling.

    • Warn pedestrians, by asking them to move, if there is not sufficient safe clearance.

    • Sound the horn at blind corners, doorways and aisles.

    • Sound the horn or other alarm when you back up.
Yield right of way to pedestrians.
Figure 2. Yield right of way to pedestrians.

Slow down, stop and sound horn at intersections and wherever your vision is obstructed.
Figure 3. Slow down, stop and sound horn at intersections and wherever your vision is obstructed.
Reminders for the Driver:
Sign posted in area with high pedestrian traffic.
Figure 4. Sign posted in area with high pedestrian traffic.
  • Slow down, stop and sound horn at intersections, corners, and wherever your vision is obstructed.
     
  • When provided, use flashing warning light or backup alarms when traveling in reverse.
     
  • Do not move the truck if you do not have a clear view of travel.
     
  • Use a spotter for blind spots.
     
  • Always look in the direction of travel.
     
  • Keep a clear view.
     
  • Start, stop, travel, steer and brake smoothly.
     
  • Signal to pedestrians to stand clear.
     
  • Do not allow anyone to stand or pass under the load or lifting mechanism.
     
  • When possible, make eye contact with pedestrians or other forklift operators.
Reminders for the Pedestrians:
  • Be aware that lift trucks cannot stop suddenly. They are designed to stop slowly to minimize load damage and maintain stability.
     
  • Stand clear of lift trucks in operation.
     
  • Avoid a run-in. The driver's visibility may be limited due to blind spots.
     
  • Be aware of the wide rear swing radius.
     
  • Use pedestrian walkways, or stay to one side of the equipment aisle.
     
  • Never ride on a forklift, unless authorized and the forklift is designed for riders.
     
  • Never pass under an elevated load.
Reminders for Plant Safety Managers:
  • OSHA requires that permanent aisles and passageways be free from obstructions and appropriately marked where mechanical handling equipment is used. [29 CFR 1910.176(a)]
     
  • Consider separating pedestrians from lift trucks by providing:

    • Pedestrian walkways,

    • Permanent railings or other protective barriers,

    • Adequate walking space at least on one side, if pedestrians must use equipment aisles,

    • Pedestrian walkway striping on the floor, if barriers cannot be used.

  • Install convex mirrors at blind aisle intersections.
     
  • Post traffic control signs.
     
  • Post plant speed limits.

Tuesday, October 28, 2014

Understanding the Workplace

  • Physical Conditions
  • Pedestrian Traffic
  • Ramps and Grades
  • Loading Docks
  • Narrow Aisles
  • Elevators
  • Enclosed and Hazardous Areas

Physical Conditions

  • Slippery Conditions
  • Obstructions and Uneven Surfaces
  • Floor Loading Limits
  • Overhead Clearance

Slippery Conditions
Slow down to a speed that you can maintain control.
Figure 2. Slow down to a speed at which you can maintain control.

Maintain contact with ground by crossing uneven areas at an angle.
Figure 3. Maintain contact with ground by crossing uneven areas at an angle.
Potential Hazards:
  • Danger of skidding when traveling on oil, grease, water or other spills.
     
  • Danger of tipover when traveling on ice, snow, mud, gravel and uneven areas.
Requirements and Recommended Practices:
  • Avoid the hazardous surface when feasible.
     
  • Spread absorbent material on slick areas that you cannot avoid.
     
  • Cross the slippery area slowly and cautiously.
     
  • Report the area to prevent others from slipping.
     
  • Post a sign or warning cones until the area can be cleaned.
     
  • Drive slowly! (Figure 2)
     
  • Maintain contact with the ground by crossing uneven areas at an angle. (Figure 3)
     
  • Clean up the oil or grease spill before proceeding. Driving over an oil or grease spot will enlarge the hazardous area.




Obstructions and Uneven Surfaces
Get off the forklift and remove the obstruction.
Figure 4. Get off the forklift and remove the obstruction.
Potential Hazards:
  • Danger of tipover when traveling over obstructions.
     
  • Danger of tipover in holes and bumps.
Requirements and Recommended Practices:
  • Keep all aisles clear.
     
  • Watch out for overhead obstructions.
     
  • Avoid the obstruction or get off the forklift and remove the obstruction. See Parking.
     
  • Never drive straight across speed bumps or railroad tracks. Cross slowly at a 45 degree angle.
     
  • Maintain steering control by keeping contact with the ground at all times.
     
  • If an area is cluttered, walk the route first to spot problems.
For additional information, see Operating a Forklift - Traveling & Maneuvering.




Floor Loading Limits 
Forklift weight exceeded the load limit of the flooring.
Figure 5. Forklift weight exceeded the load limit of the flooring.
Potential Hazards:
  • Danger of collapsing floor.
Requirements and Recommended Practices:
  • Observe posted floor loading limits.
     
  • Inspect the condition of the floor. Look for holes or weakened flooring, loose objects or obstructions, protruding nails or boards.
     
  • Inform supervisor immediately if flooring is defective.
     
  • Do not travel over surface that cannot support the weight of the lift truck, its load and its operator.
     
  • Do not enter a box car or semi-van without inspecting its floor and knowing its load limits.
For additional information, see Load Handling: Operating the Forklift.




Overhead Clearance
Ensure adequate overhead clearance.
Figure 6. Ensure adequate overhead clearance.
Potential Hazards:
  • Damage to lights, stacks, doors, sprinklers, pipes.
     
  • Damage to load.
     
  • Danger of tipover.
Requirements and Recommended Practices:
  • Be aware of the height of fixtures.
     
  • Do not travel with loads elevated.

Tuesday, October 7, 2014

Case Reports: Conclusions

Conclusions

National fatality data indicate that the three most common forklift-related fatalities involve forklift overturns, workers on foot being struck by forklifts, and workers falling from forklifts. The case studies indicate that the forklift, the factory environment, and actions of the operator can all contribute to fatal incidents involving forklifts. In addition, these fatalities indicate that many workers and employers are not using or may be unaware of safety procedures and the proper use of forklifts to reduce the risk of injury and death.

Recommendations

Employers

Reducing the risk of forklift incidents requires a safe work environment, a safe forklift, comprehensive worker training, safe work practices, and systematic traffic management.
NIOSH recommends that employers and workers comply with OSHA regulations and consensus standards, maintain equipment, and take the following measures to prevent injury when operating or working near forklifts.

Worker Training

  • Make sure that workers do not operate a forklift unless they have been trained and licensed.
  • Develop, implement, and enforce a comprehensive written safety program that includes worker training, operator licensure, and a timetable for reviewing and revising the program. A comprehensive training program is important for preventing injury and death. Operator training should address factors that affect the stability of a forklift—such as the weight and symmetry of the load, the speed at which the forklift is traveling, operating surface, tire pressure, and driving behavior.
  • Inform operators of sit-down type forklifts that they can be crushed by the overhead guard or another part of the truck after jumping from the overturning forklift. The operator of a sit-down type forklift should stay with the truck if lateral or longitudinal tip over occurs. The operator should hold on firmly and lean away from the point of impact.
  • Train operators of stand-up type forklifts with rear-entry access to exit from the truck by stepping backward if a lateral tip over occurs.
  • Ensure that operator restraint systems are being used on sit-down type forklifts. Since 1992, forklift manufacturers have been required to equip new sit-down type forklifts with operator restraint systems. Many manufacturers of these forklifts offer restraint systems that can be retrofitted on older forklifts. Many of the fatalities resulting from overturns of sit-down type forklifts might have been prevented if the operator had been restrained. The overhead guard of the forklift is generally the part that crushes the operator's head or torso after he or she falls or jumps outside of the operator's compartment. The risk of being crushed by the overhead guard or another rigid part of the forklift is greatly reduced if the operator of a sit-down type forklift remains inside the operator's compartment. Because many forklifts are not equipped with a restraint system and operator compliance is less than 100% on forklifts equipped with a restraint system, operators of sit-down type forklifts should be instructed not to jump from the operator's compartment but to stay inside by leaning in the opposite direction of the overturn.
  • Train operators to handle asymmetrical loads when their work includes this activity.

Forklift Inspection and Maintenance

  • Establish a vehicle inspection and maintenance program.
  • Retrofit old sit-down type forklifts with an operator restraint system if possible.

Lifting

  • Ensure that operators use only an approved lifting cage and adhere to general safety practices for elevating personnel with a forklift. Also, secure the platform to the lifting carriage or forks.
  • Provide means for personnel on the platform to shut off power to the truck whenever the truck is equipped with vertical only or vertical and horizontal controls for lifting personnel.

Workers on Foot

  • Separate forklift traffic and other workers where possible.
  • Limit some aisles to workers on foot only or forklifts only.
  • Restrict the use of forklifts near time clocks, break rooms, cafeterias, and main exits, particularly when the flow of workers on foot is at a peak (such as at the end of a shift or during breaks).
  • Install physical barriers where practical to ensure that workstations are isolated from aisles traveled by forklifts.
  • Evaluate intersections and other blind corners to determine whether overhead dome mirrors could improve the visibility of forklift operators or workers on foot.
  • Make every effort to alert workers when a forklift is nearby. Use horns, audible backup alarms, and flashing lights to warn workers and other forklift operators in the area. Flashing lights are especially important in areas where the ambient noise level is high.

Work Environment

  • Ensure that workplace safety inspections are routinely conducted by a person who can identify hazards and conditions that are dangerous to workers. Hazards include obstructions in the aisle, blind corners and intersections, and forklifts that come too close to workers on foot. The person who conducts the inspections should have the authority to implement prompt corrective measures.
  • Install the workstations, control panel, and equipment away from the aisle when possible. Do not store bins, racks, or other materials at corners, intersections,or other locations that obstruct the view of operators or workers at workstations.
  • Enforce safe driving practices such as obeying speed limits, stopping at stop signs, and slowing down and blowing the horn at intersections.
  • Repair and maintain cracks, crumbling edges, and other defects on loading docks, aisles, and other operating surfaces.

Workers

  • Do not operate a forklift unless you have been trained and licensed.
  • Use seatbelts if they are available.
  • Report to your supervisor any damage or problems that occur with a forklift during your shift.
  • Do not jump from an overturning, sit-down type forklift. Stay with the truck if lateral or longitudinal tip over occurs. Hold on firmly and lean in the opposite direction of the overturn.
  • Exit from a stand-up type forklift with rear-entry access by stepping backward if a lateral tip over occurs.
  • Use extreme caution on grades, ramps, or inclines. Normally you should travel only straight up and down.
  • On all grades, tilt the load back if applicable, and raise it only as far as needed to clear the road surface.
  • Do not raise or lower the forks while the forklift is moving.
  • Do not handle loads that are heavier than the rated weight capacity of the forklift.
  • Operate the forklift at a speed that will permit it to be stopped safely.
  • Slow down and sound the horn at intersections and other locations where vision is obstructed.
  • Look toward the path of travel and keep a clear view of it.
  • Do not allow passengers to ride on forklift trucks unless a seat is provided.
  • When dismounting from a forklift, always set the parking brake, lower the forks, and neutralize the controls.
  • Do not drive up to anyone standing in front of a bench or other fixed object.
  • Do not use a forklift to elevate workers who are standing on the forks.
  • Do not elevate a worker on a platform unless the vehicle is directly below the work area.
  • Whenever a truck is used to elevate personnel, secure the elevating platform to the lifting carriage or forks of the forklift.
  • Use a restraining means such as rails, chains, or a body belt with a lanyard or deceleration device for the person(s) on the platform.
  • Do not drive to another location with the work platform elevated.

Thursday, September 25, 2014

Case Reports

The cases presented here were investigated by the NIOSH Fatality Assessment and Control Evaluation (FACE) Program. The case reports were selected to represent the most common types of fatal forklift incidents: (1) forklift overturns, (2) workers struck, crushed, or pinned by a forklift, and (3) falls from a forklift.

Case 1-Forklift Overturn

On September 18, 1996, the 43-year-old president of an advertising sign company was killed while using a sit-down type forklift to unload steel tubing from a flatbed trailer. He was driving the forklift about 5 miles per hour beside the trailer on a concrete driveway with a 3% grade. The victim turned the forklift behind the trailer, and the forklift began to tip over on its side. The victim jumped from the operator's seat to the driveway. When the forklift overturned, the victim's head and neck became pinned to the concrete driveway under the falling-object protective structure (overhead guard). An inspection of the forklift revealed that the right-side rear axle stop was damaged before the incident and was not restricting the lateral sway of the forklift when it turned. Also, slack in the steering mechanism required the operator to turn the steering wheel slightly more than half a revolution before the wheels started to turn. The forklift was not equipped with a seat belt [NIOSH 1996b].

Case 2-Forklift Overturn

On April 25, 1995, a 37-year-old shop foreman was fatally injured after the sit-down type forklift he was operating overturned. The victim was turning while backing down an incline with a 4% grade. The forklift was transporting a 3-foot-high, 150-pound stack of cardboard with the forks raised approximately 60 inches off the ground. No one witnessed the incident. The victim was found with his head pinned under the overhead guard. The forklift was not equipped with a seat belt [California Department of Health Services 1996].

Case 3-Forklift Overturn

On November 25, 1996, a 41-year-old male laborer was fatally injured when the sit-down type forklift he was operating fell off a loading dock and pinned him under the overhead guard. The forklift was not equipped with a seat belt. The loading dock had large cracks in the surface and was in need of extensive repair. It was raining when the victim left the storage building to lift a load from the back of a pickup truck. Evidence indicates that either the victim's forklift was too close to the outer edge of the loading dock (which crumbled) or the right front tire was caught in a large crack in the loading dock, causing the forklift to overturn [Indiana State Department of Health 1996].

Case 4-Worker Struck by Forklift

On October 19, 1995, a 39-year-old female punch press operator at a computer components manufacturer was fatally injured while performing normal work tasks at her station. A forklift was traveling in reverse at high speed toward the victim's work station. A witness observed the forklift strike a metal scrap bin (about 3 by 5 by 3½ feet), propelling it toward the punch press station. The bin hit the press and rebounded toward the forklift. There it was hit once again and shoved back against the corner of the press, striking and crushing the victim against the press [NIOSH 1996c].

Case 5-Fall from Forklift

On July 21, 1997, a 36-year-old male electric-line technician was fatally injured after falling from and being run over by a forklift. While the operator was driving the forklift, the victim was riding on the forks. As the operator approached an intersection, he slowed down and turned his head to check for oncoming traffic. When he turned his head back, he could not see the victim. He stopped the forklift, dismounted, and found the victim underneath the right side of the forklift [NIOSH 1997a].

Case 6-Fall from Forklift

On September 24, 1997, a 61-year-old male maintenance manager of a shelter for the homeless died after falling 7 feet from a safety platform that had been elevated by a forklift. The victim had been raised in a steel-framed, cage-type safety platform that had not been secured to the forklift. The victim removed a fluorescent light bulb from its fixture and stepped to one side of the safety platform. When the victim shifted his weight from the center of the platform to the outer edge, the safety platform toppled off the forks. The victim fell about 7 feet, struck his head on a concrete floor, and was subsequently struck by the steel safety platform [NIOSH 1997b].

Case 7-Fall from Forklift

On September 6, 1995, a 47-year-old male assistant warehouse manager was fatally injured while working with a forklift operator to pull tires from a storage rack. The two workers had placed a wooden pallet on the forks of the forklift, and the victim then stood on the pallet. The operator raised the forks and victim 16 feet above a concrete floor to the top of the storage rack. The victim had placed a few tires on the pallet when the operator noticed that the pallet was becoming unstable. The victim lost his balance and fell, striking his head on the floor [NIOSH 1996a].

Tuesday, September 16, 2014

Preventing Injuries and Deaths of Workers Who Operate or Work Near Forklifts Part 2

Background

Forklifts, also known as powered industrial trucks, are used in numerous work settings, primarily to move materials. Each year in the United States, nearly 100 workers are killed and another 20,000 are seriously injured in forklift-related incidents [BLS 1997, 1998].
Forklift overturns are the leading cause of fatalities involving forklifts; they represent about 25% of all forklift-related deaths

Fatality Data

The following paragraphs summarize information about fatalities involving forklifts. The information is from databases that identify work-related fatalities in the United States.

National Traumatic Occupational Fatalities (NTOF) Surveillance System

In the United States, 1,021 workers died from traumatic injuries suffered in forklift-related incidents from 1980 to 1994. The NTOF Surveillance System uses death certificates to identify work-related deaths. These fatalities resulted from the following types of incidents:
Type of Incident% total victims
Forklift overturns22
Worker on foot struck by forklift20
Victim crushed by forklift16
Fall from forklift9

Census of Fatal Occupational Injuries (CFOI)

The Bureau of Labor Statistics CFOI identified 94 fatal injuries associated with forklifts in 1995 [BLS 1997].

Current Standards

Occupational Safety and Health Administration (OSHA)

OSHA has developed standards for powered industrial trucks (such as low- and high-lift trucks and forklift trucks) [29 CFR* 1910.178] and for forklifts used in the construction industry [29 CFR 1926.600; 1926.602].

*Code of Federal Regulations. See CFR in references.

Training

OSHA has promulgated the Final Rule for Powered Industrial Truck Operator Training [29 CFR 1910.178(l)], which became effective March 1, 1999. The standard requires operator training and licensing as well as periodic evaluations of operator performance. The standard also addresses specific training requirements for truck operation, loading, seat belts, overhead protective structures, alarms, and maintenance of industrial trucks. Refresher training is required if the operator is observed operating the truck in an unsafe manner, is involved in an accident or near miss, or is assigned a different type of truck.

Forklift Maintenance

OSHA requires that industrial trucks be examined before being placed in service. They shall not be placed in service if the examination shows any condition adversely affecting the safety of the vehicle. Such examination shall be made at least daily. When industrial trucks are used around the clock, they shall be examined after each shift. When defects are found, they shall be immediately reported and corrected [29 CFR 1910.178(q)(7)].

Forklift Operation

OSHA requirements for forklift operation are as follows:
  • On all grades, the load and load engaging means shall be tilted back, if applicable, and raised only as far as needed to clear the road surface. The forks shall not be raised or lowered while the forklift is moving [29 CFR 1910.178 (n)(7)(iii)].
  • Under all travel conditions, the truck shall be operated at a speed that will permit it to be brought safely to a stop [29 CFR 1910.178 (n)(8)].
  • The operator shall slow down and sound the horn at cross aisles and other locations where vision is obstructed [29 CFR 1910.178 (n)(4)].
  • The operator is required to look toward and keep a clear view of the travel path [29 CFR 1910.178(n)(6)].
  • Unauthorized personnel shall not be permitted to ride on powered industrial trucks. A safe place to ride shall be provided where the riding of trucks is authorized [29 CFR 1910.178 (m)(3)].
  • Forklift trucks shall not be driven up to anyone standing in front of a bench or other fixed object [29 1910.178 (m)(1)].

Fair Labor Standards Act (FLSA) and Youth Employment

The FLSA [29 USC 201 et seq.] (the primary law governing the employment of youth under age 18) includes work declared hazardous for youth by the Secretary of Labor. Hazardous Order No. 7, Power-Driven Hoisting Apparatus Occupations, prohibits workers under age 18 from using forklifts and similar equipment in nonagricultural industries [29 CFR 570.58]. In agricultural industries, minors under age 16 are prohibited from using forklifts [29 CFR 570.71 (a)(3)(ii)].

United States Code.
Not all working minors are covered by the FLSA. The regulations in agriculture do not apply to minors working on their parents' farms. Also exempted are youths aged 14 and 15 who are working under carefully regulated conditions in a bona fide vocational agriculture program.

American Society of Mechanical Engineers (ASME)/American National Standards Institute (ANSI)

ASME/ANSI B56.1-1993 requires the following [ASME 1993].

Maintenance and Safety Equipment

  • Brakes, steering mechanisms, control mechanisms, warning devices, lights, governors, lift overload devices, guard and safety devices, lift and tilt mechanisms, articulating axle stops, and frame members shall be carefully and regularly inspected and maintained in a safe condition (ASME/ANSI B56.1-1993m 6.2.7) [ASME 1993].
  • When work is being performed from an elevated platform, a restraining means such as rails, chains, etc., shall be in place, or a body belt with lanyard or deceleration device shall be worn by the person(s) on the platform (ASME/ANSI B56.1, §4.17.1[b]) [ASME 1993].

Operation

  • An operator should avoid turning, if possible, and should use extreme caution on grades, ramps, or inclines. Normally the operator should travel straight up and down (ASME/ANSI B56.1, §5.3.8[d]) [ASME 1993].
  • The operator of a sit-down type forklift should stay with the truck if lateral or longitudinal tip over occurs. The operator should hold on firmly and lean away from the point of impact (ASME/ANSI B56.1, §5.3.18[d]) [ASME 1993].
In addition to the above regulations, employers and workers should follow operator's manuals, which are supplied by all equipment manufacturers and describe the safe operation and maintenance of forklifts.

Tuesday, August 19, 2014

Preventing Injuries and Deaths of Workers Who Operate or Work Near Forklifts

Alerts briefly present new information about occupational illnesses, injuries, and deaths. Alerts urgently request assistance in preventing, solving, and controlling newly identified occupational hazards. Workers, employers, and safety and health professionals are asked to take immediate action to reduce risks and implement controls.

Notice to the Reader

The first edition of this Alert applied only to forklifts operated in a sitting position. However, this new edition includes a recommendation for employers and operators of stand-up forklifts with rear-entry access (see tear-out sheet and pages 6 and 7). In addition, the revised Alert contains several minor changes in wording to improve clarity.

WARNING!
Workers who operate or work near forklifts may be struck or crushed by the machine or the load being handled.
Workers: If you operate or work near forklifts, take these steps to protect yourself.
  • Do not operate a forklift unless you have been trained and licensed
  • Use seatbelts if they are available
  • Report to your supervisor any damage or problems that occur to a forklift during your shift
  • Do not jump from an overturning, sit-down type forklift. Stay with the truck, holding on firmly and leaning in the opposite direction of the overturn
  • Exit from a stand-up type forklift with rear-entry access by stepping backward if a lateral tip over occurs
  • Use extreme caution on grades or ramps
  • On grades, tilt the load back and raise it only as far as needed to clear the road surface
  • Do not raise or lower the forks while the forklift is moving
  • Do not handle loads that are heavier than the weight capacity of the forklift
  • Operate the forklift at a speed that will permit it to be stopped safely
  • Slow down and sound the horn at cross aisles and other locations where vision is obstructed
  • Look toward the travel path and keep a clear view of it
  • Do not allow passengers to ride on forklift trucks unless a seat is provided
  • When dismounting from a forklift, set the parking brake, lower the forks or lifting carriage, and neutralize the controls
  • Do not drive up to anyone standing in front of a bench or other fixed object
  • Do not use a forklift to elevate workers who are standing on the forks
  • Elevate a worker on a platform only when the vehicle is directly below the work area
  • Whenever a truck is used to elevate personnel, secure the elevating platform to the lifting carriage or forks of the forklift
  • Use a restraining means such as rails, chains, or a body belt with a lanyard or deceleration device for the worker(s) on the platform
  • Do not drive to another location with the work platform elevated
sit-down forklift
Typical sit-down type forklift
The National Institute for Occupational Safety and Health (NIOSH) requests assistance in preventing injuries and deaths of workers who operate or work near forklifts. Most fatalities occur when a worker is crushed by a forklift that has overturned or fallen from a loading dock.
NIOSH investigations of forklift-related deaths indicate that many workers and employers (1) may not be aware of the risks of operating or working near forklifts and (2) are not following the procedures set forth in the Occupational Safety and Health Administration (OSHA) standards, consensus standards, or equipment manufacturer's guidelines.
This Alert describes seven incidents resulting in the deaths of seven workers who were either operating or working near forklifts. In each incident, the deaths could have been prevented by using proper safety procedures and equipment and by following the provisions of the OSHA standards.
NIOSH requests that editors of trade journals, safety and health officials, industry associations, unions, and employers in all industries bring the recommendations in this Alert to the attention of all workers who are at risk.

Friday, August 8, 2014

Protecting Young Workers: Prohibition Against Young Workers Operating Forklifts

Safety and Health Information Bulletin
SHIB 03-09-30
This Safety and Health Information Bulletin is not a standard or regulation, and it creates no new legal obligations. The Bulletin is advisory in nature, informational in content, and is intended to assist employers in providing a safe and healthful workplace. Pursuant to the Occupational Safety and Health Act, employers must comply with hazard-specific safety and health standards and regulations promulgated by OSHA or by a state with an OSHA-approved state plan. In addition, pursuant to Section 5(a)(1), the General Duty Clause of the Act, employers must provide their employees with a workplace free from recognized hazards likely to cause death or serious physical harm.

Purpose

The purpose of this Safety and Health Information Bulletin is:
  1. To inform employers that youth employment regulations (29 CFR 570) promulgated under the Fair Labor Standards Act prohibit most employees under the age of 18 years from operating forklifts for non-agricultural operations;1
  2. To remind employers that all forklift operators who are 18 years old or older must be trained and certified as competent to operate forklifts; and
  3. To identify additional resources for employers to ensure a safe and healthful workplace for all workers.

Background

The Directorate of Science, Technology and Medicine was informed by the Atlanta OSHA Regional Office, the Boston OSHA Regional Office, and the Wage Hour Division (WHD) of the Employment Standards Administration (ESA) of two recent, fatal forklift accidents involving underage operators that occurred in warehouses in Georgia and Massachusetts. Both accidents involved operators under 18 years of age. Given the significant number of young workers employed, especially during the summer months, OSHA and WHD believe that it is important to remind all employers of the regulations that prohibit workers under 18 years of age from operating specified hazardous machines and equipment, including forklift trucks in non-agricultural operations.

Accident Descriptions

Massachusetts Accident
The forklift operator was a 16-year-old male hired as a summer helper to label bins and move stock by hand around the warehouse.
The warehouse has a forklift, and it was common practice to leave the forklift's operating key in the ignition switch when the forklift was not being operated. Prior to the accident, the victim was observed operating the forklift several times, most recently on the morning of the accident. He was advised several times by a number of employees not to operate the forklift.
The victim was not trained nor was he certified as competent to operate the forklift.
There were no witnesses to the accident. However, it is believed that the victim boarded the forklift, without putting on the seatbelt, raised the forks with an empty pallet to a height of approximately 10 feet, and drove down the left side of the loading dock ramp. The ramp slopes away from the building at an angle of approximately 33 degrees on the left side near the street level (Figure 1).
Figure 1 - Demonstrates a slope of approximately 33 degrees from the wall of building
Figure 1 - Demonstrates a slope of approximately 33 degrees from the wall of building
There was a stack of empty pallets across the bottom of the ramp, and it appears that the victim was attempting to place the empty pallet on top of the stack before the close of business. With the forks raised to a height of approximately 10 feet on a 33 degree slope, the forklift's center of gravity may have shifted, creating an unstable condition and causing the forklift to topple sideways (Figure 2). Refer to 29 CFR 1910.178 Appendix A, for further discussion concerning stability of powered industrial trucks. The victim was crushed under the truck.
Figure 2 - Forklift toppled sideways
Figure 2 - Forklift toppled sideways
Georgia Accident
A foreman's 15 year-old step-son was killed while the youth was operating a forklift at the warehouse.
The victim was being shown how to operate the forklift and was practicing picking up and moving empty pallets. He had just unloaded a pallet in the warehouse and had picked the empty pallet off the floor when he lost control of the forklift. The police investigator stated that the forklift "suddenly went backward, crashing open a closed loading bay door and drop[ping] four feet to the ground. The victim fell off [the forklift,] and the forklift landed on top of him." The victim was pinned to the ground and sustained massive chest injuries.

The Fair Labor Standards Act

Regulations promulgated pursuant to the Fair Labor Standards Act prohibit individuals younger than 18 years of age from engaging in specified hazardous occupational activities. 29 CFR 570.58 - Occupations involved in the operation of power-driven hoisting apparatus (Order 7), paragraph (a) (5), specifically prohibits employees under 18 years of age from operating forklifts in non-agricultural employment.
Additional orders promulgated pursuant to the Fair Labor Standards Act prohibit operation of other machines that are hazardous to workers under 18 years of age. These orders include:
  • Order 2, driving a motor vehicle and being an outside helper on a motor vehicle;
  • Order 5, operation of power-driven wood-working machines;
  • Order 8, operation of power-driven metal forming, punching, and shearing machines;
  • Order 10, operation of power-driven meat- processing machines, including meat slicers;
  • Order 11, operation of bakery machines;
  • Order 12, operation of paper-products machines; and
  • Order 14, operation of circular saws, band saws, and guillotine shears.
A complete list of occupational activities deemed to be unsafe for employees between 16 and 18 years of age can be found at: http://www.dol.gov/esa/regs/compliance/whd/whdfs43.htm.

OSHA Powered Industrial Truck Standard, 29 CFR 1910.178

OSHA's standard for powered industrial trucks, 29 CFR 1910.178, contains requirements for powered industrial truck design and construction, operator training, truck operations, and maintenance.
29 CFR 1910.178(l) requires that "[t]he employer shall ensure that each powered industrial truck operator is competent to operate a powered industrial truck safely, as demonstrated by the successful completion of the training and evaluation." This standard also contains requirements regarding: training program content and implementation, refresher training and evaluation, avoidance of duplicative training, and certification.
WHD sticker - No operators under 18 years of age

Other Information

In May 2002, the Secretary of the Department of Labor, Elaine Chao, launched the YouthRules! Initiative to increase public awareness of Federal and State rules concerning young workers. The YouthRules! web page is a gateway providing quick access to information about Federal and State labor laws that apply to young workers. The web page includes information designed to educate teens, parents, educators, and employers concerning the hours youth can work, the jobs youth can do, and how to prevent workplace illnesses and injuries. The web page contains a link to the Fair Labor Standards Act Advisor on "Prohibited Occupations for Non-Agricultural Employees" which includes the prohibited occupations for 14- and 15-year-old youth workers, as well as a list of hazardous occupations, which are prohibited for workers under 18 years of age. Another link of the Advisor, "Prohibited Occupations for Agricultural Employees" includes the prohibited agricultural occupations for youth younger than 12, 12- or 13-year-old workers, and 14- or 15- year-old workers.
OSHA also has a webpage for young workers, http://www.osha.gov/SLTC/teenworkers/index.html, which contains occupational safety and health information relevant to young workers.
In 2002, the Wage and Hour Division of the Employment Standards Administration initiated a "STOP" sticker program. As part of that program, WHD developed a sticker that can be applied to forklifts to provide a warning regarding the prohibition against workers under 18 years of age operating a forklift. http://youthrules.dol.gov/posters.htm

Conclusions

Employers have the responsibility to comply with 29 CFR 1910.178 in order to ensure the safe operation of powered industrial trucks at their facility. In addition, since Order 7 of Hazardous Occupations prohibits employees under 18 years of age from operating forklifts, employers must make certain that workers under 18 years of age are not permitted to operate forklifts under any circumstances. Employers who employ individuals younger than 18 years of age also must be cognizant of other employment activities prohibited for young workers under the Fair Labor Standards Act. Employers, educators, parents, and young workers all are encouraged to visit the DOL and OSHA web pages for additional information on creating and maintaining compliant, safe and healthful work environments.

Wednesday, July 30, 2014

Load Composition Part 5

Stability
Longitudinal stability is lost when the center of gravity moves too far forward.
Figure 13. Longitudinal stability is lost when the center of gravity moves too far forward.

Maintaining stability of a powered industrial truck is easier once you understand a few basic principles. There are many aspects of a vehicle's stability:
  • The Stability Triangle
  • Longitudinal Stability
  • Lateral Stability
  • Dynamic Stability
NOTE: This discussion focuses on sit-down counterbalanced forklifts. "Counterbalanced" means that the truck is weighted in the back with counterweight so that it will not tipover when the load is placed on the front. The counterweight is located between or behind the rear wheels and provides a weight in the back to "counterbalance" the weight of the load in the front. For a brief summary of other types of forklifts, see Types and Fundamentals.
 
The Stability Triangle

When the vehicle is loaded, the combined center of gravity (CG) shifts toward line B-C. Theoretically the maximum load will result in the CG at the line B-C. In actual practice, the combined CG should never be at line B-C.
Figure 14. When the vehicle is loaded, the combined center of gravity (CG) shifts toward line B-C. Theoretically the maximum load will result in the CG at the line B-C. In actual practice, the combined CG should never be at line B-C.

The forklift will not tip over as long as the Combined Center of Gravity of the truck and load system remains within the Stability Triangle.
Figure 15. The forklift will not tipover as long as the Combined Center of Gravity of the truck and load system remains within the Stability Triangle.

If the CG shifts outside the boundaries of the stability triangle, the truck will tipover.
Figure 16. If the CG shifts outside the boundaries of the stability triangle, the truck will tipover.
Almost all counterbalanced powered industrial trucks have a three-point suspension system, that is, the vehicle is supported at three points. This is true even if the vehicle has four wheels. The truck's steer axle is attached to the truck by a pivot pin in the axle's center. When this point is connected to the front wheels with imaginary lines, this three-point support forms a triangle called the stability triangle (Triangle ABC where Point A is the pivot point in the rear axle and Points B and C are the front wheels). (Figure 14) [A-4.1, 29 CFR 1910.178 Appendix A] So long as the center of gravity remains within this stability triangle, the truck is stable and will not tip over.

When the forklift is not loaded, the location of the forklift's center of gravity is the only factor to be considered in determining its stability. In Figure 14, the center of gravity is between the axle of the steer wheels at A and the drive wheels at B-C and it is marked with the arrow as the Vehicle Center of Gravity (Unloaded).
In Figure 15, the combined center of gravity of the forklift and its maximum load shifts forward toward the load so that it is now located on the line representing the front axle, at the very edge of the stability triangle. While the loaded forklift is still theoretically stable, in practice the combined center of gravity should never reach this line because sudden stops, starts, and turns could shift the center of gravity further out and destabilize the forklift. 

As seen in Figures 16 and 17, a shift of the center of gravity occurs as the forklift is loaded. The forklift is more stable when it is properly loaded than when it is unloaded. However, improper loading, such as loading the forklift beyond its capacity, or loading an oversize or wide load without adjusting the weight, will cause the forklift to tipover, either laterally on its side or longitudinally forward. The direction of the tipover will depend on where the combined center of gravity shifts outside the stability triangle.

Additional Information:

The Powered Industrial Truck Standard has a non-mandatory Appendix which more fully describes the forces involved and includes figures and definitions:
[29 CFR 1910.178 Appendix A]
  • Lateral stability is a truck's resistance to overturning sideways.
  • Dynamic stability refers to the idea that an unloaded forklift's center of gravity and a loaded forklift's combined center of gravity can shift outside of the stability triangle as a result of certain movements, such as sudden stops and starts, turns, or operating on grades.
  • Line of action is an imaginary vertical line through an object's center of gravity.
  • Load center is the horizontal distance from the fork's or other attachment's vertical face to the line of action through the load's center of gravity.
  • Moment is the product of the object's weight times the distance from a fixed point (usually the fulcrum). In the case of a powered industrial truck, the distance is measured from the point at which the truck will tipover to the object's line of action. The distance is always measured perpendicular to the line of action. [29 CFR 1910.178 Appendix A]
The combined center of gravity of the truck and load system shifts forward outside the stability triangle, as the load's moment is greater than the vehicle's moment, and the forklift tips forward, pivoting on the front axle or fulcrum.
Figure 17. The combined center of gravity of the truck and load system shifts forward outside the stability triangle, as the load's moment is greater than the vehicle's moment, and the forklift tips forward, pivoting on the front axle or fulcrum.

The forklift teeters and finds its balance point. As the load is added to the seesaw, the moment is increased on the right side. The loaded forklift reverses and finds a new balance point at its combined center of gravity.
Figure 18. The forklift teeters and finds its balance point. As the load is added to the seesaw, the moment is increased on the right side. The loaded forklift reverses and finds a new balance point at its combined center of gravity.
View Animation


Use extra caution when carrying loads that approach a vehicle's maximum design limits.
Figure 19. Use extra caution when carrying loads that approach a vehicle's maximum design limits.
Requirements and Recommended Practices:
  • Maintain stability. Keep the combined center of gravity within the stability triangle.
  • Do not accelerate rapidly or brake suddenly. Sudden changes in direction may also shift the combined center of gravity outside the vehicle's stability triangle and destabilize it.
  • Do not turn rapidly. The combined center of gravity may shift outside the stability triangle and may cause the vehicle to tipover to the left or right.
  • Never turn on a grade or ramp. Even a 10 percent grade may shift the combined center of gravity outside the stability triangle and cause the vehicle to roll over laterally.
  • Cross an obstacle (railroad tracks, beam, pot hole) at a 45 degree angle, so both wheels do not elevate simultaneously.
  • Maintain control of your vehicle at all times. Adjust your speed to match the conditions. Be aware and anticipate dangerous motions and avoid them.
  • Consider the dynamic forces that result when the vehicle and load are put into motion. The weight's transfer and the resultant shift in the center of gravity due to the dynamic forces created when the machine is moving, braking, cornering, lifting, tilting, and lowering loads, etc., are important stability considerations. [A-7.1. 29 CFR 1910.178 Appendix A]
  • When determining whether a load can be safely handled, the operator should exercise extra caution when handling loads that are close to the truck's stated capacity.

    If an operator must handle a maximum load:
    • The load should be carried at the lowest position possible,
    • The truck should be accelerated slowly and evenly, and
    • The forks should be tilted forward cautiously.
  • However, no one rule can cover all eventualities. [A-7.2. 29 CFR 1910.178 Appendix A]
     

Wednesday, July 23, 2014

Load Composition Part 4

Balance
Stability Triangle formed by connecting the three support points of a powered industrial truck's suspension system.
Figure 8. Stability Triangle formed by connecting the three support points of a powered industrial truck's suspension system.
Understanding why forklifts tipover and why loads become unstable and fall is very important to preventing accidents. Important factors that affect a forklift's balance are:
  • Center of Gravity

  • Shifting Center of Gravity
Center of Gravity

Potential Hazards:

While operating a forklift, be aware of the following:
  • Tipover

  • Falling load
Use special care when carrying a wide load. Turn slowly to prevent the load from shifting.
Figure 9. Use special care when carrying a wide load. Turn slowly to prevent the load from shifting.
Requirements and Recommended Practices:
  • Distribute the weight evenly when carrying irregular sized loads (Figure 9). [29 CFR 1910.178 App A]

  • Keep the center of gravity of the load as near as possible to the center going horizontally across the forks.

  • Keep the center of gravity of the load as near to the front wheels as possible.
     
Shifting Center of Gravity

The Center of Gravity (CG) is in the center of a symmetrical load but is off center in an irregular load. In the third example, the CG is outside the boundaries of the object.
Figure 10. The Center of Gravity (CG) is in the center of a symmetrical load but is off center in an irregular load. In the third example, the CG is outside the boundaries of the object.

A 4,000 pound truck is balanced by a 4,000 pound load.
Figure 11. A 4,000 pound truck is balanced by a 4,000 pound load.

Notice the center of gravity of the load and truck system shift forward toward the front wheels as the load is engaged.
Figure 12. Notice the center of gravity of the load and truck system shift forward toward the front wheels as the load is engaged.

 
All objects have a specific center of gravity. Gravity is a force that always pulls objects toward the earth's core. Center of gravity means the point on an object at which all of the object’s weight is concentrated and all of the parts balance each other. For symmetrical loads, the center of gravity is at the middle of the load in terms of the load’s length, width and height. (Figure 10). Since the capacity of the forklift is based on the assumption of a cube having the center of gravity in the middle, the shape and position of the actual load are key factors when determining whether a load can be carried safely.

When a load is placed on a forklift, the key concept is the combined center of gravity of the forklift and the load. For example, a typical unloaded forklift weighing 4000 pounds may have its center of gravity about 10 inches (25.4 cm) above and two feet (0.6 m) behind the front axle, about half way up the truck body. The heavy counterweight located toward the rear of the forklift places the center of gravity toward the rear, which keeps the forklift from tipping forward. In the meantime, a 4,000 pound load consisting of a cube with even weight distribution has a CG in its center. When the load is placed on the forklift, the combined center of gravity of the forklift and the load will move forward, but the forklift will not tipover so long as the weight of the load is centered and does not exceed the capacity stated on the data plate. But if the load is too heavy, or if it is placed at the end of the forks so that the load center distance is increased, the excessive load moment will cause the forklift to tip forward. Remember, when the forklift engages a load, the combined center of gravity of both the load and the truck system shift forward from the center of gravity of the unloaded forklift. (Figure 11 and 12)


Potential Hazards:

Be aware of tipover or falling loads while:
  • Operating a forklift, as the center of gravity shifts.
     
  • Engaging or depositing a load.
Requirements and Recommended Practices:
  • Handle loads within the capacity of the truck as stated on the data plate. [29 CFR 1910.178(o)(2)]

  • Do not operate a forklift if the back wheels begin to lift off the ground. This is an indication that the forklift is overloaded. The center of gravity has shifted too far forward over the axle of the front wheels and the forklift may teeter on the wheels.

  • Handle only stable or safely arranged loads. Exercise caution when handling off-center loads that cannot be centered. [29 CFR 1910.178(o)(1)]
  • Tilt the mast forward cautiously when positioning the load onto the stack. [29 CFR 1910.178 App A]

  • Never travel with the load elevated. Elevating the load increases the load center distance by shifting the center of gravity upward and forward, making the forklift and the load less stable (Figure 5).

  • Adjust long or high (including multiple-tiered) loads which may affect capacity. [29 CFR 1910.178(o)(3)]

  • Keep the center of gravity of the load as low to the ground and as close to the front wheels as possible:

    • Carry the load at the lowest position possible, 4 to 6 inches from the ground.

    • Tilt the mast back and position the heaviest part of the load against the carriage.

    • Travel with the mast tilted back to stabilize the load.

Wednesday, July 2, 2014

Load Composition Part 3

Maximum Load Moment
Lifting a 5 lb box directly up has the effect of lifting 5 lbs.
Figure 5. Lifting a 5 lb box directly up has the effect of lifting 5 lbs.

 As the distance increases from the shoulder, the moment, or apparent weight increases so that a 5 pound box seems to weigh 12 pounds.
Figure 6. As the distance increases from the shoulder, the moment, or apparent weight increases so that a 5 pound box seems to weigh 12 pounds.
View Animation
The way in which weight is distributed changes the amount of weight the lift truck will safely carry. You can experience this for yourself by doing the following activity:

Lift a 5 pound box. As you extend your arms, the center of the box’s weight moves a greater distance from your body, so the box feels heavier and you will tend to fall forward. The same idea of increasing the load center distance applies to a playground see-saw: the farther you sit from the middle, the more you increase the load center distance and the more force you put on that end. The same principle—increasing the load center distance—can cause a forklift to tipover.

When the load center distance increases, it is actually increasing something called the "Load Moment":

Load Moment is the product of the object's weight multiplied by the object’s distance from the fulcrum, which is a fixed point that acts as the pivot point. On a sit-down counterbalanced forklift, the fulcrum or pivot point is the axle of the front wheels. It is this product, or Load Moment, which determines how much overturning force is being applied to the forklift.

Load Moment = Weight X Distance

Because the overturning force depends on both the weight of the load and the load’s distance from the pivot point, a forklift’s capacity is always stated in terms of both: the load’s weight and its load center distance. For example, if a forklift’s capacity as stated on its data plate is “3,000 pounds at a 24 inch load center,” this means that the Load Moment cannot safely exceed 72,000 inch-pounds (24-in. x 3,000 lb = 72,000 inch-pounds.) If the load center distance for the actual load is greater than the standard 24 inches, the only way to keep the Load Moment from exceeding 72,000 inch-pounds is to reduce the load. The easiest way to determine the maximum load when the load center distance is greater than the distance stated on the data plate is to divide the maximum Load Moment by the actual load center distance. For example:

If a load is 60 inches long (30-inch load center) then the maximum that this load can weigh is:   

72,000 inch-pounds / 30 in-load center = 2,400 pounds
Improperly distributed loads may tip the forklift if the maximum load moment is exceeded.
Figure 7. Improperly distributed loads may tip the forklift if the maximum load moment is exceeded.
Potential Hazards:

While carrying a load near the maximum allowable capacity, be aware of the following:
  • Danger of tipover

  • Danger of losing load

  • Danger of being struck by falling load
Requirements and Recommended Practices:
  • Calculate a maximum allowable load moment to determine whether an unusual load, such as one that is longer than 48 inches (i.e., the load center distance would be greater than 24 inches) or that has an offset center of gravity (i.e., uneven weight distribution) can be handled safely.

  • Minimize the load center distance measured from the back of the forks to the center of the load. This allows the forklift to carry more weight.

    As illustrated in Figure 7, a truck that has a 4,500 pound capacity at a 24-inch load center will tipover if a 60-inch load is positioned lengthwise. Positioning the load in this way increases the load center distance to 30 inches and increases the load moment by 27,000 inch-pounds.

    In Figure 7 the forklift safely carries the 4,500 pound load at a load center distance of 24 inches, but tips over when the load center increases to 30 inches. Here's the calculation: 30 inches X 4,500 pounds = 135,000 inch-pounds
    24 inches X 4,500 pounds = 108,000 inch-pounds The load moment is increased by 27,000 inch-pounds.

    If the load center distance is 30 inches, the only way to keep the maximum allowable load moment within 108,000 inch-pounds is to limit the weight of the load to 3600 pounds:

    30 inches X 3600 pounds = 108,000 inch-pounds
     
  • Use extra caution when handling extra heavy loads that may approach the truck's maximum capacity. For example, when handling a maximum load, the load should be carried at the lowest position possible, the truck should be accelerated slowly and evenly, and the forks should be tilted forward cautiously. However, there is no one rule for all situations.

  • Maintain control of the vehicle at all times. The operator is responsible for handling the truck. Drive slower when carrying a load near the maximum allowable.

  • Do not exceed the stated capacity of your truck. Know its mechanical limits.

Friday, June 27, 2014

Load Composition Part 2

Safe Load Capacity
Improperly distributed loads may tip the forklift if the operator exceeds the stated capacity of the truck. This forklift can carry 4,000 pounds at a 24 inches load center, but only 2,666 pounds at a 36 inches load center.
Figure 4. Improperly distributed loads may tip the forklift if the operator exceeds the stated capacity of the truck. This forklift can carry 4,000 pounds at a 24 inches load center, but only 2,666 pounds at a 36 inches load center.
Requirements and Recommended Practices:
  • Estimate the safe load capacity with oversized loads.

  • If the stated load center is exceeded, compensate by reducing the weight of the load.

  • Consult the forklift manufacturer’s instructions when handling large or unusually configured loads.

  • Tip: Use field calculations to estimate the reduced lifting capacity if manufacturer’s instructions are not available. This calculation method will not produce exact load reduction figures. Use this method only as a guideline. The forklift manufacturer is the source of more precise information.
Field Calculation of Safe Load Capacity

Assume a situation where a forklift truck that has a 5,000 pound capacity at a 24 inch load center needs to handle a load whose center is 28 inches from the front face of the forks in the horizontal direction. The first thing to recognize is that the actual load center distance of 28 inches exceeds the standard load center distance of 24 inches on which the 5000 pound capacity is based, so the safe load capacity is actually less than 5000 pounds.

To estimate the truck's safe load capacity at a 28-inch load center, take the rated load center and divide it by the actual load center. Then multiply this number by the stated capacity to get the new approximate safe load capacity:

24 in/28 in x 5,000 lb = 4,285 lb (approximate safe load capacity)

Using the example in Figure 4, take the stated standard load center of 24 inches and divide it by the actual load center of 36 inches. Multiply this number by the stated capacity of 4,000 lb to get the new approximate safe load capacity:

24 in/36 in x 4,000 lb = 2,666 (approximate safe load capacity)

Monday, June 23, 2014

Load Composition

As the center of gravity for the load moves forward, the lifting capacity for the forklift decreases.
Figure 1. As the center of gravity for the load moves forward, the lifting capacity for the forklift decreases.
The stated capacity of a forklift only applies to the load center indicated on the data plate. If the load is not centered at the specified position, the forklift's capacity will be reduced. Loads come in all shapes and sizes, not just symmetrical boxes. The load size, position, and weight distribution critically affect the forklift's capacity and the stability of the truck. Consider the following factors before engaging a load:
  • Weight, Size, and Position
  • Safe Load Capacity
  • Maximum Load Moment
  • Balance
  • Stability
Weight, Size, and Position
The same 4500 pounds weight loaded properly (top) will exceed the rated capacity of 4500 pounds if the rectangular box is positioned lengthwise (bottom).
Figure 2. The same 4500 pounds weight loaded properly (top) will exceed the rated capacity of 4500 pounds if the rectangular box is positioned lengthwise (bottom).
Load weight, weight distribution, size, shape, and position are key factors affecting the stability of the forklift. Forklifts are designed to carry a capacity load at a standard load center, commonly 24 inches. This means that the forklift’s capacity was determined as if the load were a cube whose weight is evenly distributed (i.e., whose center of gravity is exactly in the center of the cube) and which is resting on a standard pallet having dimensions of 48 inches by 48 inches. With such a load, the horizontal distance from the center of the load to the vertical part of the forks would be 24 inches. Of course, most loads are not perfectly shaped cubes having their center of gravity exactly in the middle of the cube. To the extent that the load differs from this theoretical load — such as if it is irregularly shaped, has unbalanced weight distribution, or is not centered on the forks — the capacity may be reduced.

Potential Hazards:

While arranging a load, be aware of the following:
  • tipover
  • Loss of steering control (Shifting too much weight forward raises the rear wheels.)
  • Falling load
  • Collision
Requirements and Recommended Practices:
  • Do not exceed the capacity of the forklift that appears on the forklift's data plate (sometimes called the "nameplate"). If the load is oversized, irregularly shaped, or loaded incorrectly, the actual load center distance could exceed the stated load center distance, causing the truck's capacity to be exceeded. (Figure 2).

  • Always minimize the distance from the front wheels to the load center. Load a large rectangular box widthwise across the forks of the truck as in Figure 2. Placing a large rectangular load lengthwise causes the load center to shift forward further away from the front wheels, exceeding the truck's capacity and lifting the rear wheels off the ground.

    The heaviest weight should be loaded as close to the masts as possible.
    Figure 3. The heaviest weight should be loaded as close to the masts as possible.
  • Load as close to the front wheels as possible to minimize the load center distance. Load the heaviest part toward the mast. (Figure 3)

  • Position the load in a way that will shorten the load center distance.