Odds are you expect to leave work today, drive home and start again tomorrow.
Based on figures from the U.S. Bureau of Labor Statistics, an average of 4.5 people started work today on a construction job with the same plan as you. Instead their drive home was to the morgue.
According to the National Institute for Occupational Safety and Health construction jobs make up 7 percent of the workforce but account for 21 percent of fatalities.
The real costs of taking safety shortcuts on the construction jobsite are staggering. NIOSH reported 1,186 construction industry fatalities in 2005. In the ten years between 1992 and 2002 there were 12,075 construction fatalities. The NIOSH Fatal Occupational Injury Cost Sheet for Construction, September 2006, shows the cost to society for each of those deaths averaged $1.15 million dollars.
Below, we examine three common hazards on the jobsite – a work zone incident, a fall and a trench cave in. Each accident has a different outcome. Each is preventable.
Bob’s employer is a small asphalt paving company. Today’s job involves paving a new residential street entrance off a busy road. Bob is following the paving machine as it lays down a lift of asphalt, checking the quality of the pavement.
While Bob has his back to the busy highway watching the paving machine, a dump truck filled with asphalt backs into the work zone to refill the paver. The truck’s backup alarm sounds but the beeps don’t register with Bob. While looking down at his phone to check messages, he takes a quick step back, turning to hurry off to another part of the job. Bob collides with the back edge of the truck’s trailer and breaks his arm.
The Prescription for Prevention
A construction site is saturated with noise. Alarms and beeps Bob would once notice are now so commonplace their warnings no longer make it into his brain. The same is true for blinking lights and bold colors.
Providing safety seminars both on and off-site can help rekindle a worker’s motivation to work safe. Programs can be tailored to fit a specific jobsite and are often at no charge to the contractor. Sources for safety programs are labor unions, trade associations, OSHA, privately funded training firms, local colleges and many Web sites. Accident prevention products also are an option.
Construction worksites that combine pedestrian and vehicle traffic require the development of an internal traffic control plan.
- Designate a traffic coordinator at the site. Require all accidents and near-miss events be reported. Make sure the coordinator is aware of any peculiar hazards on site, has emergency contacts for the area and can reach you. Compensate him for the additional responsibilities of his job.
- Discuss methods of communication with equipment operators and any independent vehicle drivers working on the project site. Train all workers to use common hand signals. Have a designated person check radios on all vehicles entering the jobsite to make sure they work.
- Where possible, design the workspace so blind spots are eliminated.
- Post and verbally notify all drivers and operators of a predetermined speed limit while working on the site. Enforce it.
- Mark high risk areas around specific pieces of equipment and jobs where workers on foot are prohibited.
Working on scaffolding on a windy, warm afternoon, Jim power washes a retaining wall near a tollway reconstruction site. The scaffolding does not include guardrails and Jim and his co-workers are in harnesses in poor condition. Since it looks like a quick job, the crew doesn’t properly tie off their equipment.
Bob loses his balance in a sudden wind gust. His slack harness fails to catch him and there is no secondary safety system, like a guardrail or net, to stop his fall. He drops off the scaffold and falls onto the raw rebar below him. He arrives at the hospital with multiple puncture wounds and a severe head trauma.
The Prescription for Prevention
According to the U.S. Bureau of Labor Statistics, falls from scaffolds, roofs, iron and concrete structures account for one third of construction site fatalities.
Consider these additions to your fall prevention program.
- Before the project begins, discuss potential hazards with the owner and architect/engineer.
- If renting fall protection equipment, have the rental company look at the plans and site so they can recommend safety protections systems designed to work with other equipment on site.
- If the rental fall protection equipment has been on the site for an extended time, have the rental company inspect the lines, harnesses, braces, etc., and replace any systems that are not in perfect working order.
- Be aware the changing demographic of your crew members may require different equipment than in previous years. Have equipment of several sizes on site for shorter or heftier workers. Equipment also should be gender specific.
- Supply a common means of communication in the event weather conditions change quickly and workers need to get off the scaffolding.
Bill is working with two other men, one operating a backhoe digging a narrow, deep trench in soil that has been saturated with rain. The weather is clear today but standing water has not been pumped from the site, making the area slick.
The trench is initially 4 feet deep with an eventual depth of 12 feet and 16 feet in length. It’s late in the afternoon. Bill and the other workers just want to get a start on the job and then go home. Since the hole is only 4 feet deep today, no shoring or trench box has been placed in the trench. The backhoe operator is piling excavated mud near the edge of the trench, which adds to the pressure on the trench wall.
While Bill walks into the trench and bends over to check for debris, the backhoe operator inadvertently nudges the wet dirt piled on the side of the trench. The excess dirt and the ground under it crumble into the trench, burying Bill in heavy mud. Despite the best efforts of the crew and rescue workers, Bill dies.
The Prescription for Prevention
Most trench collapse rescues result in a body recovery. The Electronic Library of Construction Occupational Safety and Health says the fatality rate for trench excavation work is 112 percent higher than the rate for general construction.
There are four types of trench accidents. Each type can result in a different injury or death. (An OSHA PowerPoint presentation can be found at this site.)
- Spoil pile slide: If the spoil pile reaches a critical height or sharp slope, becomes saturated with rain or is in a high vibration area, it can slide back into the trench or cause the trench wall to fail. Usually this type of cave-in does not cause serious injury but can become increasingly dangerous during the rescue operation if more of the sidewalls collapse. Trench protection – which should have been in place before the accident happened – will now have to be installed in order to rescue the worker.
- Shear wall collapse: Most frequently found in trenches being dug in clay or layered soil, this happens when a fault line in the soil gives way. This can occur even when excavated material is piled at the recommended 2-foot distance. An average collapse contains about 2 to 3 yards of soil, weighing 6,000 to 9,000 pounds. A shear wall collapse can result in death.
- Belly slough: This usually happens on sites near underground utilities or where running water is in the trench. A tell-tale fracture line will appear near the bottom trench wall and is an indicator of an impending collapse. The belly of the wall rapidly collapses into the trench, usually suffocating the worker inside.
- Lip slide: This happens when the spoil pile is too close to the trench. Weight from the soil pile or vibrations from nearby equipment or traffic can cause the trench lip to fracture and send the spoil pile material into the trench. The trapped worker can usually be rescued but the lip slide is often an indicator of a potentially more hazardous collapse.
OSHA penalties for excavation cave-ins have increased and OSHA has red-flagged trench safety as a Special Emphasis Program. In a 2001 case where a worker was killed and another injured, the company was fined $350,000 and damages of more than $8.8 million were awarded to the surviving worker. Most of the fatal injuries happen in small companies with fewer than 10 employees.
For a spot repair situation such as Bill’s, Rich Ellis of Griswold Machine and Engineering (website) suggests an aluminum 4-inch wall box to protect workers. Ellis notes the aluminum box is lighter than a heavier production steel box and could be placed with the backhoe already in use at the site.
Have an OSHA-trained competent person check the site and protective systems daily. The competent person should be trained in soil analysis to determine the stability of the trench. Sidewalls saturated with rain can become unstable. When damp soil is exposed to dry air during excavation it can dry out and lose its ability to stand on its own.
Another layer of prevention
Preco Integrated Safety Solutions (website) has a proactive radar system that can be installed on construction vehicles. The PreView Collision Warning system will detect stationary and moving objects up to 26 feet away and alert the driver.
The Safety Vision (website) system can be adjusted to give you views of all the blind spots near the machine. The Safety Vision RoadRecorder 6000 can be mounted on the vehicle and will record the equipment’s movement. If an incident happens, you have a video recording of the accident.
Construction sites using high intensity lighting at night can still have problems with darker shadows behind and around equipment. Intec Video Systems, (website) camera and monitor systems have a low lux rating to give you a clear video image in extreme low-level lighting conditions.
GME offers aluminum and steel trench shields for work in light and heavy production trenching. Information is available at this site.
Safety Training Resources
- Trenchsafety.org, in cooperation with Auburn University, Alabama, offers an online trench safety tutorial.
- The Centers for Disease Control has a multimedia trench safety program that can be found at www.cdc.gov/elcosh.
- United Rentals offers a series of safety training programs, including the Excavation Competent Person. Go to www.UR.comfor additional information.
- The Underground Contractors Association in coordination with the Construction Safety Council offer free safety training DVDs. Check www.uca.org.
- The American Road & Transportation Builders Association in association with the National Safety Council offers the OSHA 10-hour roadway construction safety course, www.artba.org/.
- The National Workzone Safety Information Clearinghouse has downloadable roadway safety programs. wzsafety.tamu.edu/.
- The Federal Highway Administration’s “FHWA Work Zone Mobility and Safety Program” has professional level and community safety training. www.safety.fhwa.dot.gov.
- The American Traffic Safety Services Association conducts inexpensive roadway safety training programs. Upcoming dates and locations can be found at: www.atssa.com/cs/course_information/courses_by_state.
OSHA has developed alliances with the Laborers’ International Union of North America and the International Union of Operating Engineers to supply training on road building and general construction sites. Information can be found at: osha.gov/dcsp/ote/index.html.
Center for Disease Control
Bureau of Labor Statistics
National Safety Council
Construction Safety Council
Steve Winter, PRO-TEC
Preco Integrated Safety Systems
Intec Video Systems
Underground Contractor Association