Oklahoma Case Report: 04-OK-056-01 |
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Summary
An 18-year-old heavy equipment operator died on August 6, 2004 from internal
injuries he received after being crushed between the lift arm and the
top edge of the rollover protection cage of a skid-steer loader. On July
24, 2004, the decedent was attempting to reinsert a pin that had slipped
out of the arm where the bucket was attached. He had lifted the safety
lap bar, stood up in the cab, and then pushed the lap bar back down on
the empty seat, which allowed the vehicle to run without the operator
in the seat. While attempting to move the lift arm up and down to reposition
the pin in the arm assembly, the decedent actuated the foot pedal and
the bucket moved up and back, pinning the victim between the lift arm
and the top edge of the rollover protection cage. Coworkers quickly responded
to the victim and removed him from the skid-steer loader. The decedent
was transported to the hospital and died 13 days later from his injuries.
Oklahoma Fatality Assessment and Control Evaluation (OKFACE) investigators
concluded that to help prevent similar occurrences, employers should:
- Ensure that skid-steer loader operators do not position themselves
outside of the operator’s compartment while the machinery is in
use.
- Ensure that skid-steer loader operators do not bypass or override
safety guards, switches, or devices and properly use seat belts and
restraint bars.
- Ensure that all equipment is secured before servicing and maintenance
are performed and that only authorized employees perform that maintenance.
- Ensure that employees are aware of the specific hazards and limitations
of the equipment they use and work around on job sites.
Introduction
On August 6, 2004, an 18-year-old skid-steer loader operator for a rock
crushing facility was killed while attempting to reinsert a pin in the
bucket/lift arm assembly. OKFACE investigators were notified of the incident
and an interview with company officials was conducted on October 8, 2004.
OKFACE investigators also reviewed the death certificate and Medical Examiner’s
report.
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Figure 1. Skid-steer loader
involved in the incident.
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Employer: Employer: The victim was employed at a rock
crushing facility. The company had been in business for 63 years and employed
45 people locally and over 1,000 across the country. The company had been
working at the site where the incident occurred for approximately six
years and was in operation six days per week. Between 6 and 12 employees
were working at the site at the time of the incident. The company had
a comprehensive safety and health program, which included task-specific
work procedures, an active labor/management safety committee, and a management
safety and health committee.
Victim: The 18-year-old worker had been a skid-steer
loader operator for approximately eight months, but had been employed
by the rock crushing company for only one week. He had completed the company’s
mandatory 24-hour new employee training and was performing work with which
he had experience. He was working alone at the time of the incident; however,
several other employees were nearby.
Training: Company personnel conducted all training and
kept documentation on file of all training completed. In addition to the
new employee orientation training, monthly safety meetings were mandatory
for employees. Training was conducted in various forms, including classroom,
on-the-job, video, and reviews of manufacturers’ manuals and company
procedures. Machine operators were provided with machine-specific training
and were tested for proficiency; it is unknown if the decedent had received
any of this specific training.
Incident Scene: The incident occurred at a rock crushing
facility on a day reserved for cleanup and equipment maintenance. The
decedent was working under a conveyor, which moved rock from the crusher
to large piles awaiting transport. The ground surface consisted of crushed
rock and gravel. The incident occurred near the end of the second work
shift at approximately 8:30 p.m.
Weather: The weather was cloudy and it started to rain
after the incident; however, prior to the incident, the ground and site
conditions were dry.
Investigation
On the day of the incident, July 24, 2004, the victim had been assigned
to use a skid-steer loader (Figure 1) to clean crushed
rock from underneath a rock conveyor. The material had accumulated there
during the week as rock was moved from the crusher to storage piles. After
the skid-steer loader had been running for approximately 16 hours, the
decedent noticed a pin, which held the bucket to the lift arm, had became
loose and slipped out of its seating. The pin (Figure
2) was threaded and it was not uncommon for one to become loose or
fall out. However, company policy specified employees should stop using
equipment when maintenance was needed. The decedent, who was still considered
to be in training, attempted to repair the loose pin.
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Figure 2. Pin attaching bucket
to lift arm. |
Operators gained access to the cab of the skid-steer loader through the
front, in between the lift arms, and over the bucket. The machinery was
operated using hand and foot controls.
The loader had a safety system in which the operator’s seat was
equipped with a lap bar (Figure 3) connected to interlocks
on the pedals. The machinery could not operate unless this bar was lowered
across the lap. Once the bar was lowered, the pedal interlocks were released
and the pedals could operate freely. In an attempt to repair the loose
pin, the decedent raised the lap bar and stood up with his feet inside
the operator’s cab. By standing up, his body was extended above
and in front of the protective operator’s cage. With the engine
still running, the victim put the lap bar down on the seat, releasing
the interlocks, so that the loader could function despite having no operator
in the seat.
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Figure 3. Skid-steer loader
operator's seat and lap bar. |
After activating the hydraulics for attachment operation (Figure
4), the decedent bent over and tried to reposition the pin. In the
process of maneuvering the lift arm and bucket, the decedent depressed
the foot pedal (Figure 5) that tilted the bucket up
and back. Unable to stop the lift arm from moving and unable to move out
of the way, the victim was pinned between the lift arm and the top edge
of the rollover protection cage. There was no one working directly with
the decedent; however, a coworker noticed the pinned employee, called
for help, and ran to his aid. Coworkers tilted the bucket back down to
release the victim, lifted him out of the loader, and started cardiopulmonary
resuscitation immediately. Emergency medical services arrived within 20
minutes and transported the victim to a local hospital. The victim was
flown by helicopter the next day to a major trauma center where he died
on August 6, 2004, nearly two weeks after his injuries.
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Figure 4. Button to control
attachment operation hydraulics inside the operator's cab.
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Figure 5. Pedal that was depressed to
raise bucket. |
Cause of Death
The Medical Examiner’s report listed the cause of death as internal
injuries due to blunt force trauma.
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Recommendations/Discussion
Recommendation # 1: Employers should ensure that skid-steer loader operators
do not position themselves outside of the operator’s compartment
while the machinery is in use.
Discussion: Employers should train employees to follow the safe operating
procedures for skid-steer loaders and the accompanying manufacturer’s
recommendations for operating and servicing. Supervision, testing, and
periodic retraining should also be included with proper instruction. Operators
should be instructed not to position themselves or any parts of their
bodies outside of the operator’s compartment while the machinery
is running. Furthermore, no one should pass or work under elevated portions
of the equipment unless well-maintained lift arm supports are used. Operators
should enter the loader only when the bucket or attachments are on the
ground or lift arm supports are in place. Supports, other than those provided
or recommended by the manufacturer, should not be used because they may
not be capable of supporting the load.
Recommendation #2: Employers should ensure that skid-steer loader operators
do not bypass or override safety guards, switches, and devices and properly
use seat belts and restraint bars.
Discussion: Employers should train employees on the safety features of
the skid-steer loader and the importance of their proper use. Occupational
Safety and Health Administration (OSHA) standards state that employees
must follow all company procedures and should not disengage, remove, or
bypass any switches, guards, or other safety devices. Operators should
be instructed not to bypass or modify the safety features, such as in
lowering the lap bar without being seated. Interlocked controls rely on
the operator being appropriately positioned in the seat in order to function
correctly. Interlock controls should also be inspected and maintained
regularly to ensure that they are in proper working order. In addition,
operators should be instructed to use seat belts. On some skid-steer loader
models, the seat belt may be part of the interlock control system. They
also protect the operator from being caught or crushed by the lift arms
or attachments and from being ejected during a rollover incident.
Recommendation #3: Employers should ensure that all equipment is secured
before servicing and maintenance are performed and that only authorized
employees perform that maintenance.
Discussion: According to OSHA regulations for motor vehicles, mechanized
equipment, and marine operations, all controls shall be in the neutral
position, with the motors stopped and the brakes set, unless work being
performed requires otherwise. Before a skid-steer loader is serviced,
the parking brake should be engaged, the bucket or other attachments should
be lowered to the ground, the engine should be turned off, and the key
should be removed from the ignition switch. In instances where the maintenance
cannot be performed with attachments on the ground, appropriate lift arm
supports recommended by the manufacturer should be used. Furthermore,
there may be instances where the operator’s manual requires the
engine to be running while maintenance is performed. In these events,
the manufacturer’s directions should be followed along with all
safety recommendations, including having two or more people work on the
task.
Employers should train operators and other employees who service and
maintain skid-steer loaders to read and follow all of the manufacturer’s
procedures. For operators not authorized to perform maintenance, they
should be instructed by employers on the proper procedures for taking
equipment out of service and safely exiting the loader. When operators
become aware that maintenance is required, they should stop using the
equipment until it is repaired. Before exiting the loader, the operator
should follow the steps listed above.
Recommendation #4: Employers should ensure that employees are aware of
the specific hazards and limitations of the equipment they use and work
around on job sites.
Discussion: Employees should be trained on the specific hazards associated
with the type of equipment they operate and with the type of work being
performed. The training should address the equipment, materials used,
environment, and all other conditions that could expose, or have the possibility
of exposing, the employee to hazards. Other workers should be trained
to stay away from the equipment and attachments while they are in use.
Operators of skid-steer loaders should not carry riders, use the equipment
as a manlift, or raise the lift arms or attachments over other workers.
Equipment manufacturers can be good sources of training information, including
safety recommendations, operator’s manuals, warning decals, instructional
videos, and operator training courses.
Additional information useful for training workers about skid-steer loader
safety can be found in a NIOSH
Alert: Preventing Injuries and Deaths from Skid Steer Loaders available
through the NIOSH web site at http://www.cdc.gov/niosh
or by calling 1-800-356-4674. The Alert is available in both English and
Spanish (http://www.cdc.gov/spanish/niosh/docs/98-117sp.html).
The Alert contains a tear-out
sheet (reprinted in English and Spanish in the Appendix) that summarizes
safety precautions for operators of skid-steer loaders. Posting this tear-out
sheet at the work site may serve as an additional means of communicating
safe work procedures to workers.
References
- National Institute for Occupational Safety and Health, Preventing
Injuries and Deaths from Skid Steer Loaders, DHHS (NIOSH) Publication
No. 98-117.
- Occupational Safety and Health Administration, 29 CFR 1926.600(a)(3)(i),
Subpart O – Motor Vehicle, Mechanized Equipment, & Marine
Operations
- Occupational Safety and Health Administration, 29 CFR 1910.211, Subpart
O – Machinery and Machine Guarding
Oklahoma FACE Program
The Oklahoma Fatality Assessment and Control Evaluation (OKFACE) is an
occupational fatality surveillance project to determine the epidemiology
of all fatal work-related injuries and identify and recommend prevention
strategies. FACE is a research program of the National Institute for Occupational
Safety and Health (NIOSH), Division of Safety Research. These fatality
investigations serve to prevent fatal work-related injuries in the future
by studying the work environment, the worker, the task the worker was
performing, the tools the worker was using, the energy exchange resulting
in injury, and the role of management in controlling how these factors
interact.
To contact Oklahoma
State FACE program personnel regarding State-based FACE reports, please
use information listed on the Contact Sheet on the NIOSH FACE web site
Please contact In-house
FACE program personnel regarding In-house FACE reports and to gain
assistance when State-FACE program personnel cannot be reached.
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