Poor Shoring Offers Little Protection from Cave-Ins

Plumbers weigh in on safety in and around excavations.
Poor Shoring Offers Little Protection from Cave-Ins
Members of the Oakland Fire Department attempt to rescue Rogelio Esparza from a 15-foot-deep hole when earth in the trench he was working in gave way below. Carlos Avila Gonzalez/San Francisco Chronicle/Polaris

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Note: This is the first of a two-part series on trench safety and the need for proper shoring. In Part 2 of the series, a cave-in survivor dispels the common belief that only deep trenches are dangerous. 

On Jan. 13, a plumber in Oakland, California, survived being trapped up to his waist in sand and dirt in a 15-foot-deep trench.

Rogelio Esparza, 41, was attaching a lateral to a mainline about 12:30 p.m. when the walls of the trench he was working in collapsed. Officials say plywood used to shore up the walls gave way, trapping the plumber’s feet in sand and debris in a 2- by-3-foot area.

“There was shoring, but I cannot speak to how adequate it was because it was destroyed by the time we got there,” says Mark Hoffmann, deputy chief, Oakland Fire Department. “I got there a couple hours after the initial crew so I’m just going with what the statements were, but apparently they were doing something reasonably routine.”

Related: Ditch the Risk: Shoring is Your Best Friend

Hoffmann says while Esparza was in the trench it collapsed into a lower void, along with the shoring.

“He had debris atop his lower legs, which pinned him down. Then all the dirt and sand fell in on that,” Hoffmann says. “The other interesting thing was whatever fill they put in years ago — a boatload of sand. As we would try to move stuff out, other stuff would sluff in from the edges of our shoring. At one point we pulled back and redid all our shoring, laying in more plywood and wire, cutting it precisely to fit the voids. It was a little challenging in that regard.”

Related: Lightweight Pneumatic Shoring Simplifies Trench Safety

Oakland firefighters, with assistance from the Alameda County Fire Department, brought in a large vacuum truck from the city’s sewer division to try and remove some of the sand. A heater also was lowered into the hole to prevent hypothermia.

Esparza, who was working for Star Rooter & Plumbing of Hayward, California, was pulled to safety about 2 a.m. Though cold and shaken, Esparza was alert and talkative and didn’t appear to be injured.

“He was taken to a hospital, but all his vital signs were normal and he didn’t have any outwardly visible injuries,” Oakland Fire Battalion Chief Lisa Baker told the San Francisco Chronicle.

Star Rooter was cited by the State of California Division of Occupational Safety and Health (Cal/OSHA) for a similar incident on Aug. 8, 2013, when it failed to ensure a 10-foot-deep trench was protected from cave-ins by an adequate protective device and failed to provide a stairway, ladder, ramp or other safe means of egress from a trench more than 4 feet in depth. The company was fined $3,640.

In March, 61-year-old Jim Spencer of Minatare, Nebraska, died after a trench in which he was working collapsed on him. Spencer was installing sewer lines for a home in an 8-foot-deep excavation.

According to the Scottsbluff Star Herald, police received a 911 call about 1:20 p.m. of an accident at a construction site. Rescuers arriving at the scene found workers digging to uncover a man trapped under a large amount of dirt. It took several minutes for EMS personnel to reach Spencer, who was pronounced dead at the scene.

Spencer was employed by Clau-Chin Construction of Alliance, Nebraska. A second worker, Seth Daniel Walton, 19, was injured in the collapse. He was taken to a local hospital, treated for minor injuries and released.

The U.S. Department of Labor’s Occupational Safety and Health Administration office in Omaha is investigating the cave-in. The construction company does not have a history of OSHA violations.

“This story on Mr. Jim Spencer’s death due to a collapsed sanitary trench really saddened me as a very long-time plumber,” says Keith Robert Mendel, president of Southcoast Plumbing Contractors in Boynton Beach, Florida. “I have had quite a few close calls in my 37 years in the trade. As of five years ago I put in all my contracts: ‘No excavating greater than 5 feet deep,’ which means it will require the GC to get involved and be responsible for any shoring or whatever it takes at another parties’ expense to make it safe for the plumbing contractor to install deep underground piping. 

“I feel all plumbing contractors need to include this important safety exclusion in all of their plumbing proposals and make sure it gets put into the contract. I also feel this is just as important for any contractor, no matter what the trade, when dealing with deep trenches, being a site or underground contractor or whomever to have this language in all their contracts. Our deepest sympathies go out to the family of Mr. Spencer.”

What other plumbers say:

 “Had a co-worker die the same way,” says Richard Webster of Florida. “Had to drive his work van off the job site.”

“Hey I get it, I see it every single day,” says Joel Tucciarone, a master plumber and owner of 72 Degrees and Cooling and The Plumber in Tonawanda, New York. “Shoring leaves the shop and is never used. The contractor cannot be on every single job all day long. If the tools are provided they need to be used. We can go round and round with this. I’m an owner and was an employee at one time. I feel and have gone both directions ... I bet if you put a question out there about shoring you will hear employees say it’s a waste of time, or even better, it gets in the way and takes too much work.”

David Dow, chair of the training committee of the North American Excavation Shoring Association (NAXSA) and co‑founder and vice president of TrenchSafety and Supply, offers these safety reminders:

The General Requirements Section of OSHA’s Subpart P provides a number of common-sense steps to help ensure worker safety. As with any OSHA Standard or other safety procedure, it is important to always remember that these are the minimum requirements to ensure safe job sites.

1. Surface encumbrances
To ensure their stability and integrity, they need to be removed or supported while an excavation is open. Examples include rocks, trees, telephone and utility poles, fire hydrants, etc. 

2. Underground installations
Examples include gas, electrical, water, sewer lines, etc. They must be:

  • Located and marked before beginning work. Property owners and/or utility companies should be notified at least 24 hours prior to digging, unless a longer time is required by local law. Some states require 72 hours advance notice. Most other states require 48 hours notice.
  • Protected, supported or removed while the trench is open

Most states have so-called “811 One-Call” laws. Simply dial 811 to contact the One-Call Center in your state.

3. Access and egress
These are fancy words for entering and exiting a trench. The requirements are:

  • In trenches that are 4 feet or more in depth, provide a means of access and egress
  • Spacing between ladders, stairs or ramps should not be more than 50 feet
  • No worker should have to travel more than 25 feet laterally to reach a means of egress (exit)
  • Ladders must be secured and extend 36 inches above the landing

In addition, it is important to use wood or fiberglass ladders where there is a possibility of electric shock. Many utility companies and contractors always use wood or fiberglass ladders to ensure there is never a problem.

A “Competent Person” must design all structural ramps used solely by employees. Further, a Competent Person qualified in structural design must design all structural ramps used for equipment. Usually this person will be a registered professional engineer.

Finally, the components used in structural ramps must be connected, be of uniform thickness, be constructed so that cleats and other connectors do not create a tripping hazard, and if ramps are used instead of steps they must be provided with cleats or other surface treatments to prevent slipping.

4. Exposure to vehicular traffic
Employees must be protected from being struck by motor vehicles. Also, employees must be provided with — and must wear — warning vests or other highly visible garments when exposed to traffic. Generally, employees are considered “exposed” when they are within the right-of-way. Signs, signals, barricades or flagmen may be required.

5. Exposure to falling loads
The law is simple. The objective is to protect employees from being struck by falling objects:

  • Employees are not permitted underneath raised loads
  • Employees are required to stand away from equipment that is being loaded or unloaded
  • Equipment operators or truck drivers may stay in equipment if it is properly equipped with a cab shield or adequate canopy

6. Warning system for mobile equipment
Preventing vehicles from falling or backing into a trench can be accomplished by providing:

  • Barricades
  • Hand or mechanical signals
  • Stop logs
  • Grading away from the excavation

Equipment with an obstructed view is required to have working backup alarms, or observers must be assigned when backing up. Suggestion: Caution your employees not to be complacent around backup alarms. On some projects, there are so many backup alarms, employees may ignore them.



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