Five Feet Under

March 1, 2007

OSHA requires sloping, shoring, or shielding for trenches 5 feet or more in depth—period, no questions asked—just do it. If buried in a cave-in, suffocation will occur in less than three minutes. At the very least, a cave-in survivor will suffer serious internal injuries. Yet amazingly, OSHA compliance is estimated at 30% in most states.

Certainly there are many contractors who place the highest priority in worker safety, OSHA compliance, and ongoing training. And their reward is invaluable—peace of mind and added productivity for their entire organization.

However, there are also contractors who feel that in certain “special” situations, trench protection is just not worth their time and trouble. Consider the following scenario pulled from an actual case:

An OSHA compliance officer was driving down a state highway when he noticed an employee in an unprotected trench. He photographed the top of the employee’s helmet, which he could just see over the lower lip of the trench, and also photographed the foreman (one of two competent persons on the site) standing on the lip of the trench. Upon stopping to conduct an inspection, the officer found three employees in the trench, putting a sleeve on a gas line. The trench measured 6 feet deep and just over 5 feet wide with vertical walls. The foreman said that he did not believe that cave-in protection was necessary in this trench, because it “should” have been less than 5 feet deep. At the resulting hearing, the competent person and the company’s safety director stated these points in their defense:

  • “The trench was no more than 4 feet deep when I left the area to take care of some things at the other end of the job.”
  • “We had no means of measuring the trench as there was neither a trench rod nor a tape measure near the trench.”
  • “Our safety department took no steps to discover trenching violations at this work site, as it was training season, and none of our employees was available to conduct inspections.”

These statements would be highly comical if not for the fact that such rationalizations could lead to catastrophic results. Despite ongoing efforts in outreach, compliance, training, and enforcement, some contractors still choose to ignore trench safety.

One recent cave-in caused the death of an excavator operator’s wife who was helping out her husband during his time of ill health. The wife and an employee were using a scoop bucket to dig a trench for a residential sewer line. As she walked along the edge of the 4-foot-wide, 9-foot-deep trench, a wall collapsed, dragging the 41-year-old wife and mother into the trench and burying her. The family thought of it as a freak accident, while unfortunately, authorities deemed it as one more in a series of commonplace trench cave-in fatalities.

“Most of those companies who specialize in large public works projects employ proper trench support methods and equipment,” says Ken Forsberg, president of Efficiency Production, a manufacturer of trench safety systems. “An example of where we might see some of the trouble is in the lesser-trained public works maintenance person who works for [or is contracted by] a municipality. They might not be aware of all the different trench safety options that are available to them,” he says. Consider the following incident:

Photo: Speed Shoring
Trenches of 5 or more feet in depth must be sloped, shored, or shielded.
Photo: Speed Shoring
Pipe installations can be dangerous.

A plumbing company was contracted to locate and repair two water leaks. The company’s backhoe was brought to the work site to excavate pavement and soil down to the water line where the first of two leaks was thought to be located. A trench box was rented and delivered to the site. The company’s backhoe was not large enough to handle the trench box, and a larger backhoe was rented and delivered to the site to help maneuver the trench box in and out of the hole.

Work to repair the first leak began with the master plumber and an apprentice excavating and shoveling an 8-foot-deep trench. It is not known if the trench box was used in this 8-foot-hole, but by the end of the workday, the first leak was repaired and the hole was filled with rock to a depth of 4 feet.
A few days later, the master plumber used the backhoe to uncover the second leak. The trench was 8 feet deep and was not shored. Perhaps the workers just didn’t want to deal with maneuvering the large trench box. As the master plumber stood in the trench and alerted those above ground that he had located the leak, the trench collapsed, burying him. It took emergency services more than seven hours to uncover and remove his body from the site.

From this incident, it is clear that all workers should be trained to recognize unsafe working conditions, and all workers should be trained on the use of appropriate trench safety equipment. “Some companies might not know that there is lighter-weight equipment that they can use, other than the large trench boxes often used by the large public works contractors,” says Forsberg.

As an example, the trend today is toward the use of hydraulic shoring, a prefabricated strut and/or wale system manufactured of aluminum or steel. Hydraulic shoring provides a critical safety advantage over timber shoring because workers do not have to enter the trench to install or remove hydraulic shoring. Hydraulic systems are light enough to be installed by one worker. They are also gauge-regulated to ensure even distribution of pressure along the trench line and can be adapted easily to various trench depths and widths.

Photo: Icon
A competent person must inspect trench work in progress before each shift.
Photo: Icon
Photo: Speed Shoring
In most states, OSHA notes only 30% compliance!

No Myth, Just Reality
Did you know that a disproportionate number (34%) of trench cave-in fatalities occur on a Monday? That’s because of rain or other changing conditions occurring over the weekend—making it all the more important for a competent person to inspect trench work in progress before each shift.
After a spike in trench cave-in fatalities in 2003, OSHA investigated 34 of the deaths, and here are just a few of the statistics from its report:

  • In 86% of the cases, a competent person was not onsite at the time of the fatality.
  • Of the fatalities, 82% occurred in companies with less than 50 workers.
  • More than 65% of the companies provided no trench safety training.
  • Up to 66% of the cave-ins involved trenches from 5 to 9 feet in depth.
  • Case files reflected that schedule time was more important than safety, 88% of the time.
  • At least 58% of the employees killed were installing pipe.

Manufacturers of trench safety equipment agree that many contractors cite financial issues as a reason for non-compliance. It costs money to slope, shore, or shield. They don’t realize that compliance means gaining both safety and productivity. They are not connecting the dots between non-compliance and the added expense of poor excavation practices that may cause utility line damage; increased excavation, material handling, and restoration; insurance and liability costs; fines and jail terms; and above all, loss of life.

Resources and Engineering Support
A decade ago, the prominent excuse for non-compliance was a lack of shoring equipment availability. Today the choices in equipment and service providers are plentiful. Where 10 years ago some rental companies were hesitant to invest in shoring equipment, now many large rental players are continually beefing up their trench safety departments. In fact, United Rentals has recently announced nationwide trench safety training for its customers at more than 60 of its branches.

Trench support system manufacturers provide turnkey operations that include pre-bid consultation, design, rental, sales, leasing, and field training—with a major emphasis on custom engineering.
The Icon Group, an underground engineering and distribution company, provides custom shoring solutions for numerous sites across the nation. One of its recent contributions included a substantial role in the New Jersey Department of Transportation Route 18 project. The Icon Group supplied the slide rail shoring system needed for underground work assigned to a South Plainfield, NJ–based contractor.

Conti Enterprises consulted with the Icon Group as to sheeting the required excavations for the jacking operations and the concrete bridge pier installation for the New Street Bridge. Systems designed and supplied by the Icon Group included jacking pits that were 38 feet long, 14 feet wide, and 16 feet deep. Icon Group also engineered a large system measuring 100 feet long, 20 feet wide, and 16 feet deep, for the installation of a large concrete bridge pier with four column stems that were poured in place.

“We also designed the system with a series of internal utility crossing frames in order to move around an existing DIP waterline running through the excavation,” says David Crandall, national sales manager for the Icon Group. “We have the capability to provide both cost-effective and site-specific slide rail system solutions for a variety of road and bridge projects.”

The Icon Group’s latest addition to its product line is a new transformer slide rail that can be used with rolling struts, fixed bracing, or raker braces. “This new rail innovation allows the customer to work on pipe, bridge, retaining wall, and remediation projects using the same rail with a variety of bracing schemes,” says Crandall.

Education Is Everything
“The promotion of our products has to do with safety in a nutshell. There is equipment for every application, and education in our business is everything,” says Steve Schulz, national sales manager for Speed Shore Inc. “A lot of us don’t recognize the dangers in our everyday lives. When you put a hole in the ground, it’s like a wound. It’s going to heal. We don’t know if it’s going to heal itself in 10 minutes, 10 hours, or 10 days—but it will cave in—and those who are not using any protection are betting that it’s not going to happen during the time that they are in the trench,” he says.

It’s no surprise that a utility contractor, for example, may equate profitability with how many linear feet of pipe are laid per day, and not in whether the job is done safely and efficiently. Resist the temptation. If you ignore trench safety because you think you will lay more pipe—or save more money—you might as well bury your head in the sand.