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Date Reviewed:  February 21, 2023

It's Preventable

All accidents and deaths pertaining to trenching and excavating are preventable. Some of the contributing factors are:

•Inadequate hazard assessment

•Improperly sloped walls

•Incorrect shoring materials

 

Trench Entry

Under no circumstances should you enter a trench and/or excavation deeper than 1.2 metres (4 feet) unless it is properly sloped or shored as per Sask OHS Regulation 260.  Ladders, steps, or ramps must be installed in the trench no more than 8 metres from any worker.  A competent worker must remain at the surface of the trench to alert workers in the trench if there are any unsafe conditions developing.

 

Equip Yourself with Knowledge

With underground facilities, the smallest incident can cause incredible destruction. You can prevent disasters by following these basic steps:

•Plan your work

•Call before you dig

•Hand expose facilities

Both excavators and owners of buried facilities are responsible for preventing damage to underground facilities. Make sure you do your part.

 

Contact Sask 1st Call - 1-866-828-4888

 

What Can Happen to You

If you are in an unsafe trench or excavation you could suffer not only yourself, but endure hardships amongst family and friends:

•Internal injuries

•Life-long disabilities

•Financial losses

•And possible death due to suffocation (soil weight)

Are you willing to take this risk?

Some Common Hazards with Trenching & Excavating

•Underground and overhead facilities

•Equipment

•Cave-ins

•Hazardous gases

•Collection or seepage of water

•Use of inadequate materials

•Failure to install safeguards

•Soil types

•Surcharge loading

 

Are You Prepared for the Unexpected?

No one can predict a trench or excavation cave-in yet when a cave-in does happen you only have seconds to respond. The development of an emergency response plan for a rescue must be included in the site hazard assessment.

 
Soil Classifications

How you secure a trench depends on the soil type. Make sure you know what type it is (Refer to current OH&S Legislation):

Type 1 Soil:

Hard  in consistency, very dense in compactive condition.  Can be penetrated only with difficulty by a small sharp object.

Type 2 Soil:

Hard  in consistency, dense in compactive condition.  Can be penetrated with moderate difficulty by a small sharp object.

Type 3 Soil:

Stiff  in consistency, compact in compactive condition.  Can be penetrated with moderate ease by a small sharp object.

Type 4 Soil:

Firm to very soft in consistency, loose to very loose in compactive condition.  Is easy to excavate with hand tools.

If an excavation contains soil of more than one type, the employer must operate as if all of it is the soil type with the least stability.

 

Get a Professional

When designing the construction of a safe trench and/or excavation, nothing can take the place of experience and knowledge. If you have any doubts - get additional help. A small doubt could signal a large catastrophe.

 
Sloping

Use the applicable legislation to find the sloping angle for your specific job. For reference, here's a chart for 45-degree angle slopes:

 

Shoring

Read the manufacturer's specifications to find out proper installation procedures and how the shoring is designed to be used. Each type of shoring can be different:

•Lumber

•Air

•Hydraulic

•Cages

•Other methods designed by engineers

Remember - always stay in the protected area of the trench. Even one step out is too far.

 

Inspection

Changing conditions and time itself can make a previously safe trench hazardous. Keep a constant eye on the condition of the trench and the equipment you are using.

 

It's Not Child's Play

Watching children at play in a sandbox will give you an understanding of their fascination with moving earth and heavy equipment. Unfortunately, sometimes children don't know to stay away from the real thing.

Talk to your children about the dangers of heavy equipment and trenches. Explain that the workers who work in trenches have special equipment and knowledge so they can be safe. Children can easily get hurt in these areas.

Sometimes, adults don't know when to stop either. If you need to do any work to your house or cottage that requires you to dig a trench (such as sewer lines) you may be getting in over your head.

Use Professionals-they will do a safer and better job.

 

Think About Others

Trenches can be completely safe if you use proper equipment, follow legislation, and use safe work procedures. Make sure you and your co-workers work as a team - protecting yourselves and each other. You also need to make sure other people cannot be injured in trenches. Never leave an unprotected trench open. Use barricading, fencing, or even backfill it. You may save the life of a child.

For more information, refer to current applicable Occupational Health and Safety Legislation.