When performing a trenching or excavation project it is crucial to ensure that you are always following all appropriate safety procedures. Not being proactive and aware of the hazards that can take place on the jobsite can result in tragic incidents. In order to help others avoid such incidents from occurring, we sat down and interviewed Jarrett Patrie, Branch Manager of our Edmonton Trench Safety branch, to share some of his key safety tips. Keep reading for all his expert advice on staying safe while working in trenches!

What should be considered when determining how to make a safe excavation?

According to Jarrett, there are six main things you want to consider when you’re getting started or prior to beginning your excavation:

1. Hazard Assessment: The first thing he recommends doing is conducting a thorough hazard assessment which is a necessary first step to identify any existing hazards on your job site. Once you’ve identified all your potential hazards, you can then place control measures to mitigate those risks.
2. Call before you dig: Jarrett emphasizes the importance in calling before you dig. You want to make sure all your utilities are located, marked and exposed as required.
3. Depth of Excavation and Soil Type: Figuring out the depth, excavation, and soil type is vital information that will allow you to best decide the protective measures for your workers.
4. Surcharge Loading: Jarrett discusses the importance in considering if there any structures or activities near the excavation that may impose additional loads upon the soils.
5. Different Forms of Protection: He advises having a detailed plan to either shore, shield or slope the excavation to the required angle to prevent a trench collapse from happening.
6. Means of Egress: Lastly, he reminds us to take into consideration the means of egress. When working in a trench, you must remember that ladders are required no further then eight meters from the worker.

Can you use a combination of sloping and shielding for an excavation?

Jarrett reassures us that you can in fact use a combination of sloping and shielding for an excavation. He does however note that you want to ensure the trench box is rated for the full depth of the excavation and that the shielding system extends at least 18” above the vertical side of the excavation. This will help to protect workers from any roll off from above materials.

What is the max depth you can excavate before you require a protective system?

To figure out the max depth you can excavate before requiring a protective system, Jarrett recommends referencing your local OH&S Regulations as all provinces may have slightly different requirements. For instance, in Alberta the max depth allowed is 1.5M whereas in British Columbia it is 1.2M. If however, a worker is still at risk within the excavation, all alternatives need to be considered to protect the worker.

What are some additional hazards that you can encounter on a job site?

It’s always important to be extra cautious and consider all possible hazards that could exist on a job site, even if they are not as common.

Jarrett warns others to look out for the following before continuing with an excavation project:

• Congested Worksite: You want to make sure your jobsite is completely clear and that there is no moving equipment or street traffic that could interfere with the project. Jarrett always ensures that he is completely aware of his surroundings so that he can apply the appropriate safeguards.
• Suspended Loads: Before starting your excavation, make sure there are no suspended loads from pipes or trench boxes being lifted. Jarrett also advises using tag lines.
• Line Strikes: It is also crucial to look out for line strikes from overhead or buried utilities as well as to ensure all utilities are located and marked accordingly.
• Working at Heights: When working on the edge of a 10’ excavation, you must take the same protective measures you would if you were working on a 10’ roof.

What is the difference between shielding and shoring?

Shielding and shoring often get confused with each other but luckily Jarrett provided some definitions to help us differentiate the two! According to the OHSA definition, shield means a structure that is able to withstand the forces imposed on it by a cave-in and thereby protect workers within the structure. Shoring on the other hand, means a structure or system that supports the sides of an excavation and which is designed to prevent cave-ins.

As we all know, safety is extremely important, especially when working in the construction industry. However if you take the proper precautions, are always aware of your surroundings and follow the safety tips above, you are bound to make your next Trench Safety project a safe and seamless one!

Watch this video to see the full interview with Jarrett Patrie.

For more information on our Trench Safety team visit http://coopertrenchsafety.ca/ or call 1-844-5-TRENCH.