Metropolitan Engineering Consulting and Forensics

GREEN JOB HAZARDS: WIND ENERGY, WIND FARMS, WIND TURBINES, FIRE AND CRANE SAFETY

One man was injured when a multi-million dollar crane that was used to perform repair operations tipped over Friday morning, on August 8, 2014.

The Mower County Sheriff’s Office says a crane was working at a wind turbine site near the intersection of County Road 8 and 180^th Street, about five miles south of Grand Meadow, when it tipped over at about 7:15 am. Authorities said the crane tipped over on one end, and the impact crushed the cabin.

According to officials, the driver did escape the tipped vehicle, but the man had to receive treatment at a Rochester hospital. He reportedly was in stable condition by the afternoon, and he did return home to Wisconsin the day after he received medical attention. A company spokesperson said the crew was involved in routine wind turbine repair when the incident occurred. Somehow, an automatic safety feature malfunctioned and the crane tipped over.

Workers said no load was on the lift at the time it tipped over on end, but that the machine had a boom of about 300-320 feet. A light wind was reported, but no heavy gusts were noted.

The U.S. Occupational Safety and Health Administration attempts to protect workers in the wind energy from these sorts of terrible incidents. It has several rules regulating the use of cranes and similar machinery while constructing or repairing turbines. Here are a few key regulations:

Cranes and their controls must be inspected by a designated competent person before they can be used.
The crane must rest on a firm, stable surface.
There must be at least 10 feet of safe working clearance from overhead electric power lines.

Besides wind, other weather conditions can increase the risk of a work site accident. Hydraulics in the crane can be affected by temperatures below 10 degrees Fahrenheit. Rain, snow and fog can also reduce a crane's lifting capacity, as well as its stability on the ground. Water can seep into the brakes or clutch, making safe operations potentially impossible.

Wind turbines generate electricity from wind, and are being manufactured and installed all across the nation. Wind energy employers need to protect their workers from workplace hazards and workers should be engaged in workplace safety and health and need to understand how to protect themselves from these hazards.

While this is a growing industry, the hazards are not unique and OSHA has many standards that cover them. This page provides information about some of the hazards that workers in the wind energy industry may face.

Hazards and Controls of the Wind Energy Industry

The most common hazards are:

Fatalities/Incidents

Wind Energy workers are exposed to hazards that can result in fatalities and serious injuries. Many incidents involving falls, severe burns from electrical shocks and arc flashes/fires, and crushing injuries have been reported to OSHA. Some examples are given below:

On August 29, 2009 at 08:30 hours a 33-year-old male lineman was shocked as he grasped a trailer ramp attached to a low boy trailer containing an excavator. The excavator was being operated in anticipation of being off-loaded from the trailer. The trailer was parked on a rural aggregate road adjacent to an access road for a wind turbine generator. The excavator operator rotated the upper works of the machine prior to moving the machine from the trailer. During the rotation the boom contacted a 7,200 volt primary rural power line. The power line was approximately 12 feet from the road with the trailer parked approximately two feet from the road edge. The injured worker had entry wounds in his hands and exit wounds in his feet. He was transported by EMS, treated and admitted for observation at a local hospital. He was discharged approximately 24 hours later and returned to work the following day.
On 05/10/09, the victim was working in the bottom power cabinet of a wind turbine. He was checking the electrical connections and came into contact with a bus bar and arc flash erupted, causing injury to the victim. Afterward the victim was taken to a hospital by their technician and was met by the ambulance on the way. After arriving at the hospital he was later transferred by med-vac to another hospital in Oklahoma City and was treated for injuries. On 06/02/09, the company was notified by a representative of the hospital that the victim was deceased.
On November 11, 2005, worker #1 and two coworkers were removing and replacing a broken bolt in the nacelle assembly of a wind turbine tower that was approximately 200 feet above the ground. They were heating the bolt with an oxygen-acetylene torch when a fire started. Worker #1 retreated to the rear of the nacelle, away from the ladder access area. While the two coworkers were able to descend the tower, Worker #1 fell approximately 200 feet to the ground, struck an electrical transformer box, and was killed.
At approximately 11:40 a.m. on June 17, 1992, a worker attempted to descend an 80 ft. ladder that accessed a wind turbine generator. The worker slipped or fell from the ladder and was killed. The victim was wearing his company-furnished safety belt, but the safety lanyards were not attached. Both lanyards were later discovered attached to their tie-off connection at the top of the turbine generator.
A site foreman was replacing a 480-volt circuit breaker serving a wind turbine. He turned a rotary switch to what he thought was the open position in order to isolate the circuit breaker. However, the worker did not test the circuit to ensure that it wasdeenergized. The worker had placed the rotary switch in a closed position, and the circuit breaker remained energized by back feed from a transformer. Using two plastic-handled screwdrivers, the employee shorted two contacts on the breaker to discharge static voltage buildup. This caused a fault, and the resultant electric arc caused deep flash burns to the worker's face and arms and ignited his shirt. The worker was hospitalized in a burn unit for 4 days.

Resources

Additional information on wind energy can be found at the links below:

Department of Energy's Wind Energy Page

GREEN JOB HAZARDS: WIND ENERGY - FALLS

Workers who erect and maintain wind turbines can be exposed to fall hazards. Wind turbines vary in height, but can be over 100 feet tall. Exposure to high winds may make work at high elevations even more hazardous. OSHA has different fall protection requirements for construction (installation of towers) and general industry (maintenance).

During installation, workers may need to access individual turbine sections to weld/fit individual sections together, run electrical or other lines, and install/test equipment - often at heights greater than 100 feet. Construction workers on wind farms when exposed to fall distances of 6 feet or more must be protected from falls by using one of the following methods:

Maintenance work involving wind turbines is generally considered to fall under OSHA’s general industry standards. Such workers when exposed to fall hazards of 4 feet or more must be protected by a standard railing. If such a railing is not possible then the workers must be protected from falls through the use of personal protective equipment such as a personal fall arrest system or a safety net.

Additionally, general industry workers engaged in maintenance of the wind turbines may have to climb up the turbine towers using fixed ladders. While climbing a fixed ladder (exceeding 20 feet in length) on these towers, a ladder equipped with a cage or well must have a landing platform every 30 feet; a ladder not so equipped must have a landing platform every 20 feet. See 29 CFR 1910.27(d)(2). Ladder safety devices may be used on wind tower ladders over 20 feet in unbroken length in lieu of cage protection. No landing platform is required in these cases. See 29 CFR 1910.27(d)(5).

Some additional resources on fall protection are provided below:

For further information on fall hazards, OSHA’s Fall Protection pages for General and Maritime industries and Construction Industry should be consulted.

GREEN JOB HAZARDS: WIND ENERGY - CONFINED SPACES

During manufacturing of equipment, wind energy employers need to look at the spaces that workers enter to determine if they meet OSHA’s definition of a confined space. By definition, a confined space:

Is large enough for an employee to enter fully and perform assigned work;
Is not designed for continuous occupancy by the employee; and
Has a limited or restricted means of entry or exit.

Some confined spaces have recognized hazards, such as low oxygen environments, which can pose a risk for asphyxiation, or accumulation of hazardous gases. These confined spaces are called permit-required confined spaces and require additional safety. precautions.

Wind energy employers also need to look at the hazards of the confined spaces to determine whether those spaces are “permit-required” confined spaces (PRCS). By definition, a PRCS has one or more of these characteristics:

Contains or has the potential to contain a hazardous atmosphere;
Contains a material with the potential to engulf someone who enters the space;
Has an internal configuration that might cause an entrant to be trapped or asphyxiated by inwardly converging walls or by a floor that slopes downward and tapers to a smaller cross section; and/or
Contains any other recognized serious safety or health hazards.

If workers are expected to enter permit-required confined spaces, the employer must develop a written permit space program and make it available to workers or their representatives. The permit space program must detail the steps to be taken to make the space safe for entry.

The configuration of all Nacelles will classify them as confined spaces and during the maintenance activities inside the Nacelles, workers may be exposed to hazards from electrical motors, gears, etc. Those hazards may classify a Nacelle to be a PRCS. Technicians working in Nacelles should make sure to perform air sampling (such as for low oxygen levels or other hazardous gases) prior to entering a Nacelle. It is recommended that the technician should always carry a portable gas monitor in their toolkit and make sure that it is maintained properly.

For further information on confined space hazards, OSHA's page on Confined Spaces should be consulted.

Some additional resources on confined spaces are provided below:

GREEN JOB HAZARDS: WIND ENERGY - LOCKOUT/TAGOUT

"Lockout/Tagout (LOTO)" refers to specific practices and procedures to safeguard employees from the unexpected energization or startup of machinery and equipment, or the release of hazardous energy during service or maintenance activities.

Approximately 3 million workers service equipment and face the greatest risk of injury if lockout/tagout is not properly implemented. Compliance with the lockout/tagout standard prevents an estimated 120 fatalities and 50,000 injuries each year. Workers injured on the job from exposure to hazardous energy lose an average of 24 workdays for recuperation. In a study conducted by the United Auto Workers (UAW), 20% of the fatalities (83 of 414) that occurred among their members between 1973 and 1995 were attributed to inadequate hazardous energy control procedures, specifically lockout/tagout procedures. Wind turbines have lots of internal machinery and equipment, including blades that need to be maintained. Workers performing servicing or maintenance may be exposed to injuries from the unexpected energization, startup of the machinery or equipment, or release of stored energy in the equipment. Wind farm employers must implement lockout/tagout procedures outlined in OSHA standards. See 29 CFR 1910.269(d) and 29 CFR 1910.147.

The following are some of the significant requirements of a Lockout/Tagout procedure required under a Lockout/Tagout program.

Only authorized employees may lockout or tagout machines or equipment in order to perform servicing or maintenance.
Lockout devices (locks) and tagout devices shall not be used for any other purposes and must be used only for controlling energy.
Lockout and Tagout devices (locks and tags) must identify the name of the worker applying the device.
All energy sources to equipment must be identified and isolated.
After the energy is isolated from the machine or equipment, the isolating device(s) must be locked out or tagged out in safe or off position only by the authorized employees.
Following the application of the lockout or tagout devices to the energy isolating devices, the stored or residual energy must be safely discharged or relieved.
Prior to starting work on the equipment, the authorized employee shall verify that the equipment is isolated from the energy source, for example, by operating the on/off switch on the machine or equipment.
Lock and tag must remain on the machine until the work is completed.
Only the authorized employee who placed the lock and tag must remove his/her lock or tag, unless the employer has a specific procedure as outlined in OSHA's Lockout/Tagout standard.

Some additional general resources on Lockout/Tagout are provided below:

June 26, 2007 Letter of Interpretation - Clarification of LOTO procedures for servicing and maintenance of wind turbines
Lockout/Tagout Program
Lockout/Tagout eTool
OSHA Fact Sheet [PDF^*]
OSHA's Enforcement Policy [PDF^*]
NIOSH Alert: Preventing Worker Deaths from Uncontrolled Release of Electrical, Mechanical, and Other Types of Hazardous Energy

GREEN JOB HAZARDS: WIND ENERGY - FIRES

Wind turbines may have fire hazards because of the electrical parts and the combustible materials such as insulation or the material of construction used in the turbine housing (Nacelle) or lubricants involved in its operation.

Wind energy employers should train workers about fire hazards at the worksite and about what to do in a fire emergency. This plan should outline the assignments of key personnel in the event of a fire and provide an evacuation plan for workers on the wind turbines. Where employers require workers to use portable fire extinguishers, workers must be trained in the general principle of fire extinguisher use and the hazards involved with incipient stage fire fighting.

Workers should be made aware that while fighting initial fires, toxic gases can be generated and oxygen can be depleted inside Nacelles, and they can be exposed to such gases or can be asphyxiated from lack of oxygen.

If the employer chooses to use a fixed extinguishing system inside Nacelles, then the freezing point of the extinguishing medium and the safety of workers (exposure to toxic gases and depletion of oxygen) including emergency escape method should taken intoconsideration.

In addition to the fire extinguishing mechanisms (whether the use of fire extinguishers or a fire extinguishing system or both), fire detection systems and emergency alarm systems should be installed inside Nacelles to give an early warning to workers to escape. If such systems are installed, they must be maintained in operable condition, see 1910.160(c) and 1910.165(d).

Workers should know exactly what to do and how to escape in a fire emergency. Wind turbines should be provided with quick escape descent devices for workers to escape in the event of a fire or other emergency.

OSHA’s Fire Safety page should be consulted for additional information on fire hazards.

Fire Safety Advisor is available as an additional resource in mitigating fire hazards associated with Wind Turbines.

Green Job Hazards: Wind Energy - Medical and First Aid

Wind farms are normally located in remote locations, away from a hospital or other emergency treatment facilities. This is a major concern if a worker gets hurt – how will they be treated quickly? Wind energy employers should determine the estimates of emergency medical service response times for all their wind farm locations for all times of the day and night at which they have workers on duty, and they should use that information when planning their first-aid program. The employers must ensure that medical personnel are available for advice and consultation, and that someone who is trained is available to provide first aid. See OSHA's web page on Medical Services and First Aid for Electric Power Industry pertaining to Two-Person Rule and 4-minute Rescue.

Trained first-aid providers must be available at all wind farms of any size, if there is no nearby clinic or a hospital. If a worker is expected to render first aid as part of his or her job duties, the worker is covered by the requirements of the Occupational Exposure to Bloodborne Pathogens standard. This standard includes specific training requirements.

OSHA’s Electric Power Generation, Transmission, and Distribution standard requires that workers are trained in cardiopulmonary resuscitation (CPR), because a worker who may be exposed to an electric shock may experience a sudden cardiac arrest. In such adverse situations, automated external defibrillators (AEDs) can also assist in preventing a potential death. AEDs should be provided at wind farms and workers should be trained in how to use them. This training can be done when CPR training is provided to workers.

For further information on medical and first aid, OSHA’s Medical and First Aid page should be consulted. OSHA’s publication on First Aid Program [PDF^*] is another resource that can be used.

GREEN JOB HAZARDS: WIND ENERGY - CRANE, DERRICK AND HOIST SAFETY

Cranes, derricks, and hoists will be used to move the large, heavy loads during wind turbine installation and maintenance. Fatalities and serious injuries can occur if cranes are not inspected and used properly. Many fatalities can occur when the crane boom, load line or load contacts power lines and shorts electricity to ground. Other incidents happen when workers are struck by the load, are caught inside the swing radius or fail to assemble/disassemble the crane properly. There are significant safety issues to be considered, both for the operators of the diverse "lifting" devices, and for workers who work near them. See OSHA’s General Industry standards at 29 CFR 1910.179 and 29 CFR 1910.180, and Construction standard at 29 CFR 1926.1417 [PDF^*] for specific crane requirements.

Cranes are to be operated only by qualified and trained personnel.
A designated competent person must inspect the crane and all crane controls before use.
Be sure the crane is on a firm/stable surface and level.
During assembly/disassembly do not unlock or remove pins unless sections are blocked and secure (stable).
Fully extend outriggers and barricade accessible areas inside the crane’s swing radius.
Watch for overhead electric power lines and maintain at least a 10-foot safe working clearance from the lines.
Inspect all rigging prior to use; do not wrap hoist lines around the load.
Be sure to use the correct load chart for the crane’s current configuration and setup, the load weight and lift path.
Do not exceed the load chart capacity while making lifts.
Raise load a few inches, hold, verify capacity/balance, and test brake system before delivering load.
Do not move loads over workers.
Be sure to follow signals and manufacturer instructions while operating cranes.

Since Wind Turbines are installed in windy areas, the affects of wind speeds need to be taken into consideration for lifting activities. Stability can be an issue when the boom is high and the wind coming from the rear, front, or side of the crane can cause the load to sway away from the crane, increasing the radius and thus possibly decreasing the crane capacity.

An employer needs to determine the wind speeds at which it is not safe to continue lifting operations. Load charts do not generally take wind speeds into consideration. If the load chart or the operating manual does not have information on wind speeds and derating information, the crane manufacturer should be consulted. The procedures applicable to the operation of the equipment, including rated capacities (load charts), recommended operating speeds, special hazard warnings, instructions, and operator’s manual, must be readily available in the cab at all times for use by the operator. See 29 CFR 1926.1417(c) [PDF^*]. The maximum allowable wind speed and derating information need to be posted conspicuously in the cab or on the load chart

Extremely cold weather conditions can have an impact on crane and lifting operations. When temperatures drop below 10o F appropriate consideration should be given to crane hydraulics, and possible derating of the crane.

Bad weather such as rain, snow or fog, can also have adverse impact on lifting. Equipment and/or operations must be adjusted to address the effect of wind, ice, and snow on equipment stability and rated capacity. See 29 CFR 1926.1417(n) [PDF^*]. During thunderstorms, a crane boom can become a lightning rod. If there is an indication of possible thunderstorms, lifting activities should be suspended and the boom should be lowered to a safe position, and workers should leave the area. If the crane is struck by lightning, it should be thoroughly inspected prior to putting it back into service.

Heavy rain along with high speed winds also can affect crane operations. Water can get into components such as brakes or clutches, and render them inoperable. When these conditions exist, operators should wait until the components are dried out.

The following resources are available:

GREEN JOB HAZARDS: WIND ENERGY - ELECTRICAL

Workers in wind farms are potentially exposed to a variety of serious hazards, such as arc flashes (which include arc flash burn and blast hazards), electric shock, falls, and thermal burn hazards that can cause injury and death. Wind farm employers are covered by the Electric power generation, transmission, and distribution standards and, therefore, are required to implement the safe work practices and worker training requirements of OSHA's Electric Power Generation, Transmission and Distribution standard, 29 CFR 1910.269.

Workers need to pay attention to overhead power lines at wind farms. The hazard is from using tools and equipment that can contact power lines and workers must stay at least 10 feet away [PDF^*] from them, because they carry extremely high voltage. Fatal electrocution is the main hazard, but burns and falls from elevations can occur at the wind farms. Some resources on electrical hazards are provided below:

GREEN JOB HAZARDS: WIND ENERGY - MACHINE GUARDING

The production of a wind turbine involves thousands of parts -- gears, blades, and many other such parts. Manufacturing wind turbines, therefore, will involve machines of various configurations and may expose workers to hazards of moving parts of the machines if they are not safeguarded properly.

Additionally, the moving parts associated with the turbine if not guarded properly may have the potential to cause severe workplace injuries, such as crushed fingers or hands, amputations, burns, or blindness. Employers must ensure that the workers are protected from the machine hazards and workers should make sure that the rotating parts and points of operation of machines are properly guarded prior to using them. More information on machine guarding can be found on the OSHA website.

Some additional resources on machine guarding are provided below:

GREEN JOB HAZARDS: WIND ENERGY - RESPIRATORY PROTECTION

Manufacturing turbine blades involve operations like buffing and resurfacing, which may expose workers to harmful gases, vapors and dusts. Workers must be protected from the inhalation hazards through the use of ventilation. If the ventilation alone is not adequate, then workers may also need to use appropriate respirators.

Use of respirators may give a false sense of security and workers should understand the limitations of the respirators. For example, during heavy exertion the respirator seal is often compromised, which allows the chemical to enter the breathing zone (without being filtered) through the gaps between the respirator and the face. In such situations a worker who is not adequately trained may think that he or she is being protected. It is, therefore, essential that workers be provided training in the proper use of respirators and their limitations. In addition, they must be trained on the proper storage and maintenance of respirators.

Respiratory protection can be effective only if:

the correct type of respirator is used,
it is readily available,
worker knows how to put it on and take it off, and
it is stored and kept in working condition based on the manufacturer's recommendations;