Use required protective systems when working in a trench

By Amy Materson

The accident: Two laborers were installing conduit in an 8-foot-deep by two-foot-wide trench. The crew leader, who was digging the trench with a backhoe, left the area to go to the company trailer. The two laborers continued to work alone. A short time later, another member of the crew found that the trench had collapsed, covering the two men. Emergency workers responded to the jobsite and uncovered the laborers, who could not be revived. The cause of death was listed as skull fractures.

The bottom line: A post-accident investigation determined, due to the depth of the trench and the sandy composition of the soil, shoring and shielding should have been used. No protective system had been placed at any point in the trench. Also, the contractor had hired nearly two dozen new employees who started work the day of the incident. None of the new hires had received any orientation or training by the company, and the employer had no formal safety program.

Take the right steps

The fatality rate for excavation work is much higher than that of the general industry, with crushing injuries as the largest single cause of death. Without appropriate protective systems, trench walls can collapse and cave in at any time. Whenever an excavation is greater than 5 feet in depth, the use of a protective system is required. When working in a pit deeper than 5 feet, take the following precautions before entering the trench:

• Ensure the outside perimeter is barricaded, and post safety signs.

• Check the protective system used before entering the excavation. The side walls must be stabilized with shoring materials made of wood and/or metal.

• Check the edges of the excavation for cracks or weak areas. Don’t place heavy materials such as spoils or equipment on the edge.

• Make sure you enter and exit the pit properly. Never jump into an excavation.

• After the work is complete, back-fill as soon as possible.

• Know your company’s emergency response plan.

Trench safety should be addressed in depth during your training. For more information on the topic, view the National Institute for Occupational Safety and Health’s web-based training at http://www.cdc.gov/niosh/docs/2006-133d/ and click on “View the Trench Safety Awareness Web-based training.” A tips card you can share with fellow workers can be found on the OSHA website here: http://www.osha.gov/Publications/trench/trench_safety_tips_card.pdf. You can also download toolbox talks on the subject from Caterpillar’s Safety website at https://safety.cat.com/cda/files/673688/7/Excavations+and+Pits_V0311.1.pdf.

Information for this Safety Watch is from an accident report, SAFETY.CAT.COM, OSHA’s Safety and Health Regulations for Construction, the Center for Disease Control’s NIOSH Fatality Assessment and Control Evaluation Program and web-based training program. It is for general information only.

Invisible vapors can be deadly when welding

The accident: A worker was repairing a truck body alone in his company’s shop, using an arc welding system to weld pieces of steel together and then attach them to the body near the rear of the truck. Another employee heard an explosion and saw the shop on fire, but was unable to help his coworker. The welder was pronounced dead at the hospital.

The bottom line: A post-accident investigation determined the welder had been using a 55-gallon steel drum as a work surface while repairing the truck. Investigators concluded he had accidentally burned through the lid of the barrel with his welding rod, igniting vapors present inside. The medical examiner determined head trauma resulting from the explosion, rather than the fire, killed the welder.

Always perform arc welding and other hot work applications in a designated safe location. If you’re welding an object that cannot be moved, all of the moveable fire hazards in the work area should be relocated at least 35 feet from the work site. If fire hazards are present that cannot be moved, ensure fire protection is in place.

What’s inside?

When welding, cutting or heating, remember direct penetration of sparks – or even just heat transfer – can introduce a fire hazard on the other side of the material you’re welding. If you’re welding on or near a drum or barrel, find out what the container holds. Drums or other hollow structures that previously contained toxic or flammable materials should be filled with water or cleaned, ventilated and tested prior to welding. Before applying heat, vent the container to release built up pressure.

If full containers are within 35 feet of your work area, cover them with a fireproof blanket before beginning welding. Don’t take chances with empty containers. Any remaining vapors or flammable coatings could ignite, so move any empty containers out of the work area. In this accident, the welder used an old barrel as a work surface. The incident would have been prevented had the welder removed the barrel from the area and used a proper table instead.

Fire prevention

If you’re unable to implement normal fire prevention precautions due to the nature of the welding operation, don’t work alone. OSHA standards require additional personnel instructed in the specific nature of the fire hazard present to guard against fire during and immediately after welding.

Information for this Safety Watch is from an accident report, OSHA’s Safety and Health Regulations for Construction standard number 1926.352 and NIOSH’s Fatality Assessment and Control Evaluation Program. It is for general information only.

Avert danger by knowing where moving equipment is at all times

The accident: A skid steer operator was backdragging a section of a concrete contractor’s yard used for concrete testing. A cement truck driver approaching the construction trailer failed to use the sidewalk, instead walking through the area behind the skid steer. A coworker realized the skid steer operator could not see the driver, and called out to the driver to move from the path of the skid steer. The truck driver did not react to the warning, and the skid steer backed over him, killing him.

The bottom line: A post-accident investigation determined the skid steer operator thought the victim was inside the trailer and had not seen him walk behind the skid steer. Although the company had a written safety program, there was no formalized equipment training program. The investigation also found that employees had failed to wear safety vests.

Alert and aware

When you’re working around equipment that is in motion, always remain alert. Knowing what is in front of, behind you, beside you and above you is the best way to stay safe. Additionally, your employer will provide additional protection for you. Ask your foreman about the following:

Barriers – If you’re working on a fixed worksite or in the yard, concrete barriers should be in place to separate machines from commonly-used walkways. Portable barriers are also helpful, as they are generally brightly colored and provide high visibility to both operators and workers on foot. Avoid walking on the wrong side of the barrier.

High-visibility clothing – The American National Standards Institute has a hi-vis guideline that, when properly enforced, will increase the likelihood of an equipment operator seeing you. Ask your foreman to provide you with a high-visibility vest.

Clearance policy – Your employer should have a policy in place that dictates you maintain a safe distance from mobile equipment and use designated pathways. Learn this policy and follow it. Avoid unapproved pathways.

Training programs – Your comprehensive training program on heavy equipment operation will include backing procedures. If you’re in the operator’s seat, use an assigned spotter to help you ensure your path is clear.

Backup alarms – The equipment you use will have an audible backup alarm or may have electronic sensors installed. If you’re on foot, keep your ears open for the sound of an alarm.

Information for this Safety Watch is from an accident report and the Center for Disease Control’s National Institute for Occupational Safety and Health Fatality Assessment and Control Evaluation Program. It is meant for general information only.

Learn your load limits when trailering heavy equipment

The accident: Going down a busy Interstate, a construction supervisor was hauling a backhoe on a trailer. The backhoe flipped off the trailer, falling onto a minivan. Both the minivan and backhoe slid down an embankment, with the backhoe landing on top of the minivan. The accident killed one person and injured three others.

The bottom line: Witnesses said they saw the driver lose control of the truck just before the backhoe broke loose from its tie downs. The driver had previous citations for speeding and for unregistered/improper equipment.

Best practices

The majority of trailer accidents are attributable to human error rather than mechanical failure. Proper trailering requires a combination of knowledge, training and patience. Before you load a piece of equipment, you must know the rated capacity of the trailer, the tie down points, all hardware and your towing vehicle. It’s also crucial to know how and where to position the load on the trailer. If you position the equipment too far forward, you’ll lift the front of the towing vehicle and lose steering control. Too far back and you’ll lose traction and braking.

By the numbers

You’ll find the trailer’s capacity on the unit’s data plate. Exceeding capacity not only interferes with acceleration, handling and braking ability, it can also cause tire damage and premature axle and bearing failure. Check your truck’s Gross Vehicle Weight Rating and ensure you won’t exceed the Gross Combination Weight Rating when you add the trailer, load and other cargo.

Don’t drive the machine onto the trailer unless you’re trained to do so. Approximately half the fatal accidents that occur during equipment transport happen during loading or unloading of equipment. If possible, back the equipment onto the trailer so you can drive it off when unloading. If you don’t have a spotter, use the edge of a deck board as a reference point to drive in a straight line.

Using the weight of the machine, you’ll be able to calculate the Aggregate Working Load Limit to determine the number and capacity of tie downs. Whenever possible, use manufacturer-specified points and inspected, safety-rated tie-down assemblies. You should use at least Grade 70 transport chain and retire it if the chain has wear greater than 10 percent. Never use chain that is stretched, broken or twisted.

Check it again

Do a final walk around and check for anything you missed. Loose items left on the equipment can become a projectile. Once you’re on the road, you’re required to stop and check the load after 50 miles, and then every 150 miles or three hours of travel time, whichever comes first.

The information in this Safety Watch is from an accident report and from Vista Training’s Silver Series web-based training program “Transporting Heavy Equipment.” For more information, visit www.vista-training.com/the. This Safety Watch is for general information only.

Don’t work on equipment unless you have the proper training

The accident: An employee was repairing a 60-foot telescopic boom lift that had a malfunctioning counterbalance valve. He loosened the valve from underneath the rear of the lift and then climbed onto the lift’s base to access the valve from the front of the lift, positioning him directly under the boom. He loosened the valve further, which released the pressure from the hydraulic system. The raised boom collapsed onto the worker, crushing him between the boom and the base. The cause of death was asphyxia from chest compression.

The bottom line: A post-accident investigation determined the company had not performed this type of repair work in the past, and the worker was not qualified to repair the lift. Furthermore, no lockout/tagout procedure had been implemented, allowing the lift’s boom to fall when hydraulic components were removed.

Follow the rules

Never attempt to repair a piece of equipment you are not trained to work on. ANSI specifications require a qualified person to repair the aerial lift according to manufacturer’s recommendations. Tony Groat, executive vice president of American Work Platform Training, notes that simply being a mechanic does not qualify you to work on all equipment. “Even being qualified on one model AWP does not qualify you to repair other types and models. They have different operating characteristics, safety devices and controls.”

Your employer will also conduct a job safety analysis to identify potential hazards. In this instance, an analysis would have determined a failure to either block the boom while in a raised position or lockout the hydraulic system could result in a boom collapse.

Step by step

If you are qualified to make adjustments or repairs, take the following precautions:

• Power stopped, with starting means inoperative

• All controls in the off position

• All operating systems secured from inadvertent motion by breaks, blocks, etc.

• Elevating assembly lowered to down position or secured by blocking or cribbing to prevent dropping

• Hydraulic oil pressure relieved from all hydraulic circuits before loosening or removing hydraulic components

• Safety props or latches installed where applicable

• Any further precaution recommended by the equipment manufacturer.

Only after a job safety analysis is completed and lockout/tagout procedures have been implemented, should you begin work on the lift.

Using personal protective equipment can save you from a variety of injuries

The accident: A worker was installing pipe for a newly laid building foundation in a shallow trench while a fellow crew member used a skid steer to backfill with sand. The dirt at the edge of the trench was wet, causing the machine to shift and then tip forward striking the worker’s head. He was pronounced dead at the hospital from head trauma injury.

The bottom line: The worker was employed by a subcontractor who had signed a written contract with the general contractor that stipulated the sub would comply with all OSHA regs and specified that all workers wear hard hats. However, neither the victim nor the operator was wearing a hard hat. No representative of the GC was on site during the accident.

Although it is impossible to determine if personal protective equipment – including hard hats, safety vests and safety glasses – would have changed the outcome of this accident, hard hats have been shown to reduce the severity of injuries in a range of circumstances. Your employer will have a written policy on the use of PPE, and you should receive training on what items to use as part of your regular safety training program. Your employer is also required to have this equipment available for you, but it is your responsibility to use it properly and to understand the limit of the protection such equipment provides.

Head injuries – Using a hard hat will protect you from impact, penetration and some electrical injuries. If you have long hair, ensure it is covered and out of the way.

Foot/leg injuries – Foot guards and safety shoes will protect you from hazards such as sharp objects and hot surfaces, as well as helping you to maintain balance on wet surfaces.

Eye/face injuries – Goggles, helmets and shields will protect you from flying chips or fragments and from sparks, as well as keeping dust and dirt out of your eyes.

Respiratory injuries – When working in environments contaminated with vapors, fumes or gases, use a NIOSH-approved respirator. Make sure the unit fits properly and you have been trained on respirator use prior to work.

Hearing loss – Prolonged exposure to high noise levels can cause irreversible damage. Use earplugs made of a material that self-forms to the ear, such as foam, waxed cotton or fiberglass wool. Clean them regularly or replace with new earplugs.

Remember, PPE will not save you from every accident. Being aware of the hazards your current job presents and using a common sense approach is your best way to avoid injury.

Information for this Safety Watch was compiled from an accident report, the Center for Disease Control’s NIOSH Fatality Assessment and Control Evaluation Program and OSHA’s guideline on personal protective equipment. It is meant for general information only.

Don’t risk falling when working above ground

The accident: A crew was working in a cement plant that was under construction. A worker climbed on a balcony approximately 50 feet above the ground to retrieve a tank that had been placed on the balcony, and fell through a 48-inch-diameter opening for an air duct installation. At the hospital, the worker was pronounced dead from multiple blunt force trauma injuries.

The bottom line: A post-accident investigation determined the opening’s cover, which was composed of six scaffold planks held together with nailed 2-by-4s, had been removed and partially disassembled. There were no signs in place to warn workers about the opening. The victim, who had been in the United States for less than a year and spoke only Spanish, had worked for the company for just five months when the accident occurred but had received fall protection training. Although he was wearing fall protection equipment, it was not tied off.

Recognize the risk

Falls pose a serious risk to construction workers, accounting for one-third of fatal injuries overall and 40 percent of fatal injuries to Hispanic workers. Even though the company the victim worked for had a bilingual safety program in place that included an injury and illness prevention program, he did not follow the procedures in which he’d been trained.

Your company will have a plan in place for working around an elevated opening. If you follow the procedures, you will greatly minimize the danger you and your coworkers face.

Watch for signs. Floor openings will be clearly marked with “Opening: Do Not Remove” in letters at least one inch high, and in a language you understand. Before you begin work, take note of where floor openings are located.

Leave the covers in place. Floor openings will be covered with material capable of supporting twice the weight of the employees, equipment and materials placed on a one square foot area, or 400 pounds, whichever is greater. The cover will be secured in place to prevent accidental displacement. Never try to move or remove this cover.

Always wear fall protection and use it properly. Inspect your fall protection prior to starting work to ensure it is in good condition, and remember to tie off when working near an elevated opening. Using a safety harness and lanyard only works when you tie off.

If you notice an opening that is not marked or has a missing or damaged cover, notify your company’s competent person immediately so the hazard can be controlled before you begin work.

Information for this Safety Watch was compiled from an accident report, the Center for Disease Control’s NIOSH Fatality Assessment and Control Evaluation Program and the U.S. Department of Labor’s Bureau of Labor Statistics. It is for general information only.

Don’t get pinned

Safe operation starts with the basics

The accident: The contractor instructed an excavator operator to move dirt, clear debris and fill a trench, and then left the jobsite. Upon his return, he saw the excavator – which was an older model that had been purchased used – positioned over the trench, with the operator pinned to a tree and crushed by the machine. The contractor reached into the cab and pushed the joystick to free the operator; however, the cab rotated, pinning him to the tree as well. Although the contractor was able to free himself, the operator was already dead.

The bottom line: A post-accident investigation determined that although the excavator had a lock lever that disabled boom and arm movements as well as the swing function, the lock had not been activated. The cab door was open, indicating the employee was exiting the cab, and the bucket had not been lowered to the ground. Investigators reached the conclusion the victim had inadvertently bumped the excavator’s left control joystick with his leg, causing the machine to rotate counterclockwise and pin him to the tree. The cause of death was determined to be asphyxia from crush injuries and thoracic compression.

Forming good habits

The first – and easiest – step in preventing an accident such as this is as simple as developing a safe routine and sticking with it. Keep the following checklist in mind before exiting the machine:

• Lower the bucket or other attachment and position to prevent accidental movement

• Set the swing lock or brake and the parking or traction brake or lock

• Ensure the engine is no longer running

• Lock the ignition or starting circuit and remove the key.

And note: extra caution should always be exercised with older machines not equipped with current safety features.

Value your competent person

Your company’s competent person will have evaluated the site prior to work to identify potential issues. For this accident, a planning stage survey could have pinpointed the tree as a safety hazard because of its proximity to the trench. An appropriate control measure such as trench relocation would have prevented the accident. Ask if any risks were found during site evaluation, and if so, what control measures were taken to protect you and your fellow workers.

Information for this Safety Watch was compiled from an accident report, the Center for Disease Control’s NIOSH Fatality Assessment and Control Evaluation Program and the Association of Equipment Manufacturers. It is for general information only.

Electrical problems

Recognize, evaluate and control hazards to stay safe

By Equipment World Staff

The accident: A four-man crew was adding space to an existing building by erecting a brick wall. The workers had set up scaffolding, and were pouring grout and inserting rerod into the bricks. One of the workers lifted the 20-foot 1/2-inch section of rerod and made contact with a 4,800-volt primary electrical line. No one on the site was trained in CPR or first aid. The worker was later pronounced dead.

The bottom line: A post-accident investigation determined the workers had no training in either scaffold erection or electrical safety, and had placed the scaffolding too close to the power line. The investigation also found the employer had no safety program in place, and no supervisors were on site at the time of the accident.

Before you begin

Your employer should have the company’s competent person conduct a site evaluation prior to beginning work to identify both existing and potential hazards and take corrective action. Never begin work before a jobsite survey is completed.

Prior to beginning overhead work, or work around electricity, you should complete a comprehensive safety training program. This training will instruct you in safe work practices, hazard recognition and avoiding unsafe conditions, as well as identifying the person you should contact if a safety question arises.

Expect danger

When working overhead with electricity, don’t automatically assume the proper precautions have been taken. If you’re working on a scaffold, you need to be trained in scaffold safety. Proper training will ensure you are able to erect the scaffold properly, and at a safe distance from power lines or other hazards. Also, always assume every line is live. Even if you’re dealing with an electrical current that isn’t strong enough to kill you, the shock could cause you to fall, resulting in injury or death.

First aid facts

What should you do if a coworker is shocked?

• Never touch the victim if he or she is still in contact with the electrical current.

• If you can’t shut down the current, pry the victim from the circuit with a non-conducting material such as dry wood.

• Have someone call emergency services and remain with the victim.

• If the victim is conscious, do not allow them to move.

• Apply pressure to bleeding wounds, and elevate the injured area.

• If unconscious, check for breathing.

• If the victim isn’t breathing, perform CPR. Do this quickly – you have only minutes.

Information for this Safety Watch was taken from an accident report, the CDC’s National Institute for Occupational Health and Safety and the Fatality Assessment and Control Evaluation Program. It is intended for general information only.

Knowledge is the key to staying safe during demolition

Accident: An ironworker for a steel erection company was performing demolition work on a hollow block wall inside a building. An opening had been cut in the wall for a doorway, leaving 16 inches on either side, and leaving the header beam suspended without support. After noting that a nearby train track was producing building vibration, the company attempted to stabilize the header with epoxy and lumber supports. Prior to installation of the channel posts, the worker began to remove the lumber to minimize the risk of fire when welding the posts. The entire channel iron header assembly broke loose, falling on his head and shoulders. Because the assembly weighed approximately 4,000 pounds, a jack was necessary to remove the beam from the victim. He died several days later from blunt force head trauma.

The bottom line: An investigation determined the contractor did not consult with the engineer who designed the structural support system, and therefore was unaware the changes made were not compatible with the demolition plan. The investigation also determined the boards were of an unusual size, unmarked and securely fastened, so the victim could have concluded the lumber was an architectural detail that could safely be removed.

Know what you’re getting into – When performing demolition on a structure, it’s crucial to have access to the building’s design plans before beginning work. Your employer will have a demolition plan on hand; make sure the actions you are performing are compatible with the plan.

Note inconsistencies – If you see something you don’t expect on the site – in the decedent’s case, it was wood affixed to the edge of a masonry wall – don’t try to figure out the situation yourself. Although any temporary shoring system should be approved and marked, don’t assume it always will be. Contact the foreman or call the office before you do something that can’t be undone.

Overcommunicate – In this accident, employees were concerned enough about the vibration from the railroad tracks to put in the support system. However, that information never got to the victim, who viewed the lumber as a fire hazard. Ask to see the job order form the general contractor to verify the work actually to be performed and to confirm you’re taking the appropriate course of action. EW

Information for this Safety Watch came from an actual accident, OSHA and the Fatality Assessment and Control Evaluation Form from the Center for Disease Control’s NIOSH. It is for general information purposes only.