Open trenches are common on large construction sites. Pipe fitters of all types (fire protection, plumbing, gas lines, telephone, etc.) need to dig up the earth in order to install underground piping for future use. What most people don’t realize is how dangerous an open trench can be. For the workers, an improperly formed ditch can spell certain death if a cave-in should occur. Safety precautions may seem like an annoyance but they exist for one single reason: to preserve life. I was superintendent of a large Los Angeles based contractor for almost twenty years. During that time, I did my best to conform to all guidelines and applicable laws when it came to construction safety. I believe the one area that is most important for following rules and regulations is when a trench must be dug. This article will discuss common safety practices for excavation.
Have you ever heard the term “competent person”? OSHA has devised training guidelines for anyone working in or around an open trench. The course is simple and can be acquired for free through local trade schools or your local trade Union. Typically, there must be one competent person around an open trench while work is being performed. If you work near or around an open trench, ask if there is a competent person on site. If not, ask if you can acquire training. What you learn could potentially save your life or someone else’s.
Does your ditch have the proper slope? The general rule is as follows: any open ditch that exceeds five feet in depth must maintain a 1 to 1.5 slope – for every one foot that you dig, you must go “out” 1.5 feet and maintain this slope for the length of the ditch. Although five feet may not seem that deep, even a three-foot ditch can feel exceptionally deep if you are lying on your chest and working inside the ditch. In such a situation, if you are face-down and working in a three-foot deep ditch and a cave-in occurs, you are basically trapped face down. A collapsed mound of dirt can crush your rib cage and prevent you from taking a single breath, and this can happen in a matter of seconds. Always create the proper slope when digging a ditch, even when the depth does not exceed five feet.
Before you dig, call DIG ALERT. Unless you have an on-site engineer to reveal locations of local pipelines, you should simply call and notify Dig Alert two days prior to excavation. When you notify them, they in turn notify the utility companies who then have 48 hours to show up and clearly mark where their respective pipelines cross the intended ditch. This system was implemented in September, 1976 after a construction crew was killed when they accidentally ruptured a petroleum pipeline on Venice Blvd. in Culver City, California. Nine construction workers died and an entire city block burned to the ground as a result of that accident. The good news about Dig Alert: it’s free! There are zero fees whatsoever. The bad news: if you don’t have a permit to dig, you might be forced to get one as Dig Alert may notify the local city that you are intending to dig a trench.
Prior to digging, make sure there is a clear path available for vehicles to drive around the open trench. Make sure the vehicle path does not come too close to the ditch or the weight of the vehicle may cause a cave-in.
Try to keep two workers on site at all times. Although this can make a project more expensive, it is extremely dangerous for only one person to work inside of a trench. If an accident or cave-in should occur, a solo worker may become incapacitated and unable to call for help.
Another obvious but often forgotten safety precaution: cones and barricades. You should barricade the trench and string yellow caution tape from barricade to barricade. And if you can manage it, try to use barricades with flashing lights. Most construction workers will scoff at the idea of excessive barricades and say “we don’t need them!” But what you must realize is this: the barricades are not for the workers, they are for the average person who might be walking by the open ditch at midnight or two in the morning when it’s dark and there’s nobody else around. There have been countless occurrences where a pedestrian stepped into an open trench and was injured. There have also been situations where a vehicle was driven into an open, unmarked trench. When in doubt – add more barricades!
Tools, where are my tools? If you are going to create a trench, place a sheet of plywood nearby and lay your tools on it. Keep a standing rule that all hand tools, nuts, bolts, etc. must be returned to the sheet of plywood. This will avoid loss of tools and and/or pipeline components.
Those simple guidelines can potentially save your life or even a stranger’s life. They will also help in overall productivity and ensure a smoother installation. For complete information on trench safety, you should contact your local OSHA office and request their excavation guidelines.