Let’s Keep All Workers Safe During Trenching and Excavation Activity
“Excavation and trenching are some of the most dangerous activities we face in pipeline construction, but the hazards can be mitigated”.
It can happen in an instant. Contract crew workers are down in a trench, when suddenly, the trench walls collapse, burying the workers under potentially thousands of pounds of soil. It’s a nightmare when it happens to a crew you are providing oversight for, but these types of incidents happen, and they are tragic. I’m telling you with proper inspection they are also preventable.
The fatality rate for pipeline excavation work is 112 percent higher than the rate in general construction. Additionally, the number of trench collapse fatalities has doubled from 2016 to 2018. These statistics emphasize the need for all our Applied Inspectors involved in excavations to take the proper steps to secure our trenches so that injuries and fatalities don’t occur on your watch.
“Workers are not always fully cognizant of what the hazards are and how dangerous this work can be.”
Cave-ins can occur at excavation sites for several reasons, from an unfamiliarity with the hazards in the soil type, to a lack of training due to worker turnover, to trying to complete the work as quickly and inexpensively as possible.
Competent Person” doesn’t always mean capable. One key is to help people realize that you don’t need to sacrifice safety for efficiency when conducting trenching operations.
“I am a firm believer that you can be efficient, fast and profitable while still protecting your employees and your operation,” Proper training can help people realize that.
When cave-ins occur, a cubic yard of soil can weigh up to 3,000 lbs. and suffocation can occur in as few as three minutes. Pipeline construction foremen should ask themselves, “Do I want to have to worry about getting someone out of a trench within three minutes, or do I want to make sure the trench walls don’t collapse in the first place?”
Although cave-ins may be the first hazard that comes to mind when thinking about trenching and excavation, there are many others that we see every day, like falls from heights or ladders, workers being struck by natural elements or equipment, and electrocution. All Applied Inspectors overseeing excavations should take the time to familiarize themselves with each hazard and work to mitigate them before and during excavation activities.
A quick understanding of soil mechanics will improve you as an inspector and overall excavation safety.
Understanding soil mechanics is the first step toward safer trenching and excavation. Soils fall into one of four categories – stable rock, type A (e.g., clay), lose & crumbly, type B (e.g., angular gravel, silt), or soft and shifty, type C (e.g., gravel, sand). Occurrences of stable rock are rare, so as an inspector you should be prepared to work with some type A, but mostly type B and type C is what we end up working with.
The contractor usually has a competent person conduct an inspection and test to identify the kind of soil(s) involved and the properties of those soils; contractors can then use that information to determine the best solution for protecting worker safety.
It’s important to keep in mind that soil conditions can and will change throughout a project due to weather changes, movement of materials and similar factors. So, the competent person should conduct daily inspections of the work site and make any necessary changes to see that work is performed in as safe a manner as possible.
Once the soil type is determined, the next step is to determine the best method for securing the trench, considering its depth and width. Depending on these and other factors, there are a several ways to secure the trench.
Sloping. This involves slanting the soil away from the trench. The degree to which the soil must be sloped will depend on the type of soil.
Benching. This process involves cutting back soil in a step-like fashion. This method should only be used for cohesive soils and it is not an option for Type C.
Shoring. This involves using support systems such as hydraulic cylinders to create a barrier between the workers and the trench walls.
Shielding. This method uses systems such as trench boxes (use plates used to brace the sides of the trench) to protect workers from cave-ins.
Whichever protective system is chosen, workers must understand that they need to stay within that system to keep themselves safe.
It’s not just about having the systems in place and having them correctly engineered. It’s very important for workers to understand that if they go outside the confines of the systems, they are exposing themselves to hazards.
Near Misses Reported in August
There was traffic in and out of a location with construction and fracking. Sharing the road caused huge dust clouds and diminished visibility to zero at times.
We called Frac Safety and held the trucks back. They brought in one at a time and ordered a water truck to begin watering roads in the vicinity to keep the roads watered, preventing low visibility and health issues caused by the dust. We provided the gate guard with a number to call to have the area watered anytime dust starts being a problem. A supervisor will drive the road two times every shift in addition to his beginning his shift driving the road to report conditions.
When we arrived at the location to check up on a sub-contractor who was hydro-vacing, we found that the sub-contractor was gone. They had left all of the pot holes unattended and unprotected. We were able to stand by until the contractor was back to the location and backfilled the holes that were 12 feet deep. The largest concern was the location of the holes that were next to a school drop off location and in homeowners’ back yards.
It was discussed with the individual that they cannot leave locations unattended and unprotected.
A rental company arrived to load up and haul out two 20' long storage buildings. He had two trucks, one of them previously loaded with a tele-handler. He had loaded the first con-ex onto the truck without the tele-handler and was attempting to drag the building from one truck onto the other trailer by dragging with the loaded tele-handler.
When observed we shut down the operation. We had the truck off load the building and use the trailer winch to winch the building off the ground and onto the trailer with the loaded tele-handler.
While working alone, an employee helping an X-Ray tech became sick. He was lightheaded, started vomiting, and was disorientated due to the heat.
We moved the employee to a truck to cool off and drink water. We talked with the X-Ray tech and reminded him that he needed to watch over his crew, making sure they stay hydrated and take breaks throughout the day.
An employee was backing up a forklift without a spotter. The operator realized that there wasn’t a spotter behind him.
He immediately stopped and waited for the spotter to reassume position behind him where he could see the spotter’s signals.
We've recently moved into a section of rolling hills where we would be lowering pipe into that section.
Before work began, I stopped the entire crew for a safety meeting. Instead of side booms being spread out a joint and half like normal, I asked for them to be every joint to avoid a tipping issue risk. It worked out well and a near miss was avoided.
We are pleased to announce that we have partnered up with Boot Barn to offer all Applied Consultants inspectors a 15% discount on all purchases “work related” from the Boot Barn, Nation Wide. Be sure to tell them you work for Applied Consultants and use the key word: “Safety First” to receive the discount.
August Winners
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Bronze – Craig Rawle |
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