Accurate locates, PPE and communication all play a role in getting a directional bore done safely
For directional drilling contractors, safety is paramount on the job site. It’s not only about keeping workers protected from potential hazards, but also about effectively completing a job. If you can’t get the work done safely, where is the assurance that more work will be coming your way in the future?
On a directional drilling job, proper safety procedures begin before the drill even starts running.
“Before arriving at the job site, you must have all underground utilities located,” says Stacy Long, product safety engineer with Ditch Witch. “This includes any privately owned utilities, such as sewer lines. Not all utilities are members of the one-call service and those utilities must be contacted as well.”
Long recommends marking in white paint the anticipated area for entry and exit pits and the drill’s bore path so the person performing the locating work is aware of where exactly excavation will be occurring.
“After all the existing underground utilities have been located, survey the area for any evidence of underground utilities that may have been missed,” she says. “If there are any questions about the locates, or you think a utility was missed, contact the locator. Then verify the locates by potholing to the depth of the intended bore path.”
Once you know what underground utilities already exist on the job site, you’ll have a better idea of what other safety measures will have to be taken into account.
“For example, if you’re drilling within 10 feet of an existing electric line, then that job would be classified as ‘electric’ and additional precautions may be required,” Long says. “This can include electrically insulated boots for the tracker and drill operator, and electrically insulated gloves within reach of the drill operator.”
Other personal protective equipment requirements important for directional drill workers include:
Hard hats, if there are overhead hazards or the job site requires it
High-visibility vests, if working around traffic or near a roadway, or if the job site requires it
Hearing protection, dependent on the noise level of the equipment or in the area
All personal protective equipment should be inspected periodically to ensure it is in good condition and safe to use. Any damaged equipment should be replaced immediately. Also consider any traffic or pedestrian control measures that may be needed to ensure a safe work site, Long says.
Once the actual drilling begins always track the bore head. “If you are drilling parallel to an existing line, tracking should be done more frequently to ensure the tolerance zone is maintained,” Long says.
Tolerance zones vary across the country — typically 18 to 24 inches on each side of a marked utility — so contractors must be aware of the rules they’re operating under and not encroach upon a tolerance zone during the bore. Since distortions in the electromagnetic field can affect the accuracy of a locate, the tolerance zones are in place for a reason — to prevent accidents.
If the intended bore path crosses a utility, Long says contractors should pothole at that point and visually verify that the drill head and backreamer will clear the utility.
“Consider the size of the backreamer and leave enough space for the backreamer to clear the utility on the pullback,” Long says.
Communication between the drill operator and the tracker is also vital to ensuring the drill stays along its intended path and doesn’t encounter hazards.
“The drill operator relies on the tracker for guidance to effectively maneuver around obstacles and the tracker relies on the operator to use the information and keep them out of harm’s way,” Long says. “The tracker is the eyes for the drill operator. They must collaborate and be on the same page. On most job sites, a two-way radio is used.”
Even better? Wireless headsets to keep the hands free. Whatever is the preferred option for communication, drill operators and trackers should rely on more than just hand signals.
“Hand signals can be used, but visibility may hinder the use of hand signals, so they should not always be relied upon,” Long says.
A sometimes overlooked aspect of job site safety is employees’ understanding of a company’s safety policies, says Dr. Samuel Ariaratnam, a professor and construction engineering program chair at Arizona State University, as well as immediate past chairman for the International Society for Trenchless Technology. Just because a proper safety protocol is spelled out in a manual, doesn’t ensure it is followed out in the field. He recommends companies test employees on safety procedures, and make sure that any written safety materials are provided in the language an employee is fluent in.