Tipover

Statistics indicate that forklift tipover claims at least twenty-five lives each year in the United States. How does tipover occur, what are the causes, and how can it be prevented  

The OSHA results of the study presented in Table 10-3 list the following causes  

Another study of forklift tipover in California showed this incident to be the leading cause of powered industrial truck fatalities from 1966 to 1980. This research revealed that 66 fatalities occurred as a result of tipover. Table 10-4 highlights the data from this study. 

In a 1995 study conducted in Ontario, Canada, some 6,000 recorded injuries associated with forklift trucks were identified. In 60 percent of the cases, the operator of the lift truck was involved in the incident. According to the data, 17 workers died and 143 were critically injured. Primary injury causes included  

Falling or jumping from the lift truck Carbon monoxide exposure 

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According to the Center for Construction Research Training, an average of 26 construction workers die each year from using aerial lifts, which include elevated platforms such as scissor lifts. With aerial lifts, the major causes are falls, electrocutions, and collapses or tipovers. The OSHA alert on scissor lifts cautions that using the... 

Where possible, have a powered industrial truck lift the portable dock plate to prevent workers from being injured. Stay clear of the movement of the lift truck and plate. When not in use, store plates flat on the floor. If placed against a wall, the angle of the ranq) must be proper to prevent a struck-by tipover incident. 

Table 10-4. Causes of Forklift Tipover Fatalities in California 1966- -80...

In a study of 804 injuries and incidents involving narrow-aisle lift trucks, tipover accounted for 127 of the reported claims, or 16 percent of the total. In the case of a narrow-aisle truck tipover incident, the truck can tip three different directions forward, rearward, and onto its side. Of the 127-tipover incidents, 64 percent involved tipover onto the side of the lift truck, 12 percent were forward tipovers, and 11 percent were rearward tipovers. Those that occurred in an unknown direction accounted for 13 percent of the total incidents. 

During tipover, operators take a certain action. This smdy revealed that four actions were commonly performed ejected, jumped, jumped/ejected, and stayed. Operators junq>ing during narrow-aisle truck tipover occurred the most often note the data in Table 10-5. 

Twenty-six of the twenty-nine operators that stayed in the operator s conq>artment during tipover incidents reportedly received minor or no injuries. In three of the incidents the injury severity was imknown. The minor injuries were superficial, i.e., cuts, bruises, and scrapes. Those incidents where the operator did not remain in the operator s compartment accounted for all of the injuries major or fatal. 

The direction of the tipover and the associated severity of the injury is identified in Table 10-6. This portion of the study shows that in the cases where the operator stayed within the confines of the operator s compartment, no major or fatal injuries were reported to have occurred. 

Descriptions of the more serious narrow-aisle tipover incidents are identified below. 

Rearward tipover occurred employee jumped and was pinned by the forklift he suffered a broken leg. 

Table 10-5. Operator Action versus Direction of Tipover...

Table 10-6. Direction of Tipover versus Injury Severity ...

Of the 93 tipover fatalities in this study, being pinned by the mast and overhead guard was the cause of more than half the deaths. Table 10-8 identifies the details in this phase of the study. 

Table 10-7. Fatal Work-Related Injuries Investigated by OSHA 1984-89 Involving Lift Truck Tipover or Rollover...

Operator turns sharply with a container of liquid a sinq>le tipover becomes an environmental... 

Most lift trucks have four wheels however, the stability of the lift truck is controlled by the two front wheels and the center of the rear axle. The front wheels carry the load the rear wheels are for steering. The center of gravity is one of the major problems with forklifts. Speeds as low as 5 mph can tip a lift truck. Forklifts have a narrow wheel base, which contributes to tipover. 

For operator protection, the lift truck manufacturers recommend the following operator guidelines in the event of tipover ... 

For a stand-up-operated lift truck, the manufacturers recommend that the operator step out of the rear of the lift truck in event of a tipover. The entrance for the operator in a narrow-aisle truck would provide an open access to an immediate exit. However, there may be a few situations where exiting the truck could provide for more danger to the operator. 

For this reason, seat belts on counter-balance trucks have become the norm. In addition to a seat belt is a modified operator s seat that includes a wrap-around shoulder support system, referred to as a wing seat. On other models, the base of the seat may be modified to include bolsters on each side to prevent the body from sliding out of the seat during tipover. The operator would still have to brace his feet, hold onto the steering wheel, and lean away from the tilt. It should be noted that a tipover occurs in approximately 1.5 seconds. This does not provide much time for anyone to plan response actions once the tipover has begun. As a result of the seat and seat belt improvements, the operator is provided with an added margin of safety. 

The wing seat concept was first developed by Clark Equipment Company in the early 1980s. They funded research to determine what could be done to prevent tipovers. They began the research with ideas about what devices should be placed on lift trucks to protect operators during tipover. 

Some have argued that operator training is the key to preventing injuries and fatalities during tipovers. Is training more basic than seat belts and wing seats Can an employer rely on each operator to follow prescribed safety rules provided in the classroom Many safety professionals insist on both training and the use of safety equipment. 

Tipover usually occurs because of operator error. As an added safeguard to counter operator error, the wearing of seat belts and the use of wing seats make sense. Despite the fifteen years of operator-seat modifications and seat belt installations on counterbalance lift trucks, the toll of injuries and fatalities continue. The seat belt may not be a perfect device that is readily accepted by operators and management, but the use of such safety devices surely contributes to reducing the numbers of injuries and deaths. The use and enforcement of these devices should be a part of every operator s training. 

Never turn on a ramp. Be alert to potholes, drop-offs on roadways, and other obstacles that could tip the truck. Never travel with an elevated load, and never turn with an elevated load because of the high potential for tipover. 

The training of operators must include classroom interaction and the use of visual aids. Many of the various details of lift truck movement such as tipover, tip forward, counterbalance, stability triangle, lateral and longitudinal stability must be discussed. Trainees must know each model s specific details for operation. Couple this with the different kinds of lift trucks counterbalance, narrow-aisle, walkies, stock-chasers, etc., and it s obvious that there are many details involved in operating a powered industrial truck. 

Suruda, Anthony, et al, Avoiding Rollover/Tipover. Material Handling Engineering. June 1997, pp. 71-75. 

Swartz, George. Forklift Tipover A Detailed Analysis. Professional Safety. January 1998, pp. 20-24. 

Seat belt and seat. Ensure the seat belt is functional and intact. The seat should be secure and equipped with wings or hip bolsters to aid the operator in event of a tipover. 

Dynamic lateral tipover A lift truck falling onto its side when in motion either forward or reverse. The term refers to a forward-traveling lift truck that falls to one side in a turn. 

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