Rent Smart: Brace yourself

Trench cave-ins are some of the most common construction accidents – and the most easily avoided if you use the proper safety equipment. Make sure your workers know how to correctly support a trench whether or not you’re renting the trench safety equipment.

Rental stores with trench safety divisions often have competent person training courses that cover OSHA requirements. Not only do you receive certification, you’ll also be able to obtain advice from rental experts on how to choose the right safety equipment for your job.

Rental prep
“OSHA requires trench safety protection in excavations and trenches deeper than 5 feet and some state OSHAs are even more stringent and require protection at 4 feet,” says Lance Palmer, regional sales and marketing manager, United Rentals trench safety division.

Trench rental divisions typically stock all types of trench safety equipment, including hydraulic shoring systems, steel and aluminum trench boxes, slide rail systems, panel systems, bracing and road plates. Other items, such as lasers, manhole and pipe testing equipment and air monitoring equipment are also available.

When you go to rent, be prepared to answer several questions about your project. Typically, the rental representative will need to know the depth, width and length of the area to be excavated, soil type, whether or not you plan to cross any utilities and what type of excavation equipment you’ll have access to, says Nat Brookhouse, director of marketing and communications, Sunbelt. (For a more comprehensive list of these questions, see the sidebar below.)

Shoring vs. shielding
Shoring normally suits smaller jobs, such as installing small-diameter pipe into a shallower area. Because it exerts pressure against the dirt walls to prevent a cave-in, it also works for jobs close to roadways or structures. “Hydraulic shoring is popular because it’s lightweight and can be installed by just one or two people,” Palmer says. “Shoring, however, has its constraints since the spacing of the shores limits the available workspace. This can be a sizable disadvantage on certain jobs.”

Shielding, on the other hand, should be used for deeper jobs where bigger pipe is being installed. Shielding systems – like a trench box – can be dragged along in the trench to protect employees, Brookhouse says.

When considering a hydraulic shoring system, make note of the trench’s width and depth. “These are two key factors in determining whether an aluminum system will be best,” Brookhouse says.

Yet another indicator of whether to choose shoring or shielding is the machine being used on the job. For example, aluminum shielding works well with rubber-tire backhoes, Palmer says. If you have a big job that requires an excavator, however, steel boxes tend to make more sense. “A steel box can handle being dragged, while an aluminum box should be set in place,” Palmer says.

Continuing education
United Rentals has a multi-level program in place to help customers meet regulatory compliance and ensure the safety of their crews. “We offer competent person and confined space training on a monthly basis, with a guaranteed class on the first Friday of every month,” Palmer says. “Our instructors understand the challenges of underground construction and have personal knowledge of equipment applications. They also participate in our customers’ safety meetings and offer Toolbox Talks on jobsites if asked.”

Sunbelt Rentals offers an eight-hour competent person training class and once completed, the new knowledge is put to use immediately. “At the time of (trench safety equipment) delivery, the selected shoring system’s tabulated data will be reviewed with the competent person to ensure that the system will meet all of the requirements of that job,” Brookhouse says.

Both rental companies stress the importance of having a competent person on the excavation site. “The competent person needs to ensure the safety of anyone entering the trench,” Brookhouse says. These responsibilities include precautions such as noting air quality and access into and out of the trench. “It’s also advisable to have proper rigging on hand to move the equipment, and in areas with pipelines nearby have gas monitors to detect possible leaks,” Palmer says. Always keep a few bridges and ladders available on your site as well for easy trench entrance and exit.

Other trench safety rental questions

  • What type/size of pipe will you be installing?
  • Will you be testing your pipe, and if so, do you need equipment to do this?
  • How long will the trench remain open?
  • Will you need a pipe laser for the job?