Excavations in Construction/Trenching

Summary

This video highlights the dangers of trenching in construction, where over 40 workers die each year due to cave-ins. It underscores the importance of OSHA regulations that require employers to provide protective measures like sloping, shoring, and shielding to ensure worker safety. The video demonstrates how these protections can prevent fatalities by showcasing real-life incidents and explaining the proper safety systems. It emphasizes the role of competent persons in inspecting trenches and choosing the right protective equipment based on soil type. The message is clear: following these safety measures is critical to saving lives on construction sites.

Takeaways

• 😀 More than 800 construction workers die every year in the U.S., with trenching being one of the most dangerous tasks.
• 😀 On average, 40 workers lose their lives annually due to trench cave-ins, and these accidents can happen within minutes.
• 😀 Deaths from trench cave-ins are preventable through proper protective measures and adherence to OSHA guidelines.
• 😀 Employers are legally required to provide a safe working environment and necessary protective equipment for trench work.
• 😀 A competent person must conduct trench inspections at the start of each shift, after rainstorms, and when conditions change.
• 😀 OSHA requires that trenches 5 feet deep or greater must have protection from cave-ins, using systems like sloping, shoring, or shielding.
• 😀 Soil types are categorized by OSHA as stable rock, type A, type B, and type C, with specific safety measures for each type.
• 😀 Sloping involves cutting back trench walls at safe angles, depending on soil type, to prevent cave-ins.
• 😀 Shoring uses support systems, such as aluminum hydraulic cylinders, to prevent trench walls from moving or collapsing.
• 😀 Shielding involves using trench boxes or similar devices to protect workers from cave-ins when inside the trench.
• 😀 Employers must follow OSHA's excavation standards, as shown by the difference in safety outcomes when using proper protective systems like trench boxes.

Q & A

What is one of the most dangerous types of construction work?

Trenching is one of the most dangerous types of construction work, with an average of 40 workers dying every year due to trench-related accidents.

How quickly can workers be killed or injured in a trench cave-in?

Workers can suffer death or serious injury within minutes of being caught in a trench cave-in.

What is the responsibility of employers when it comes to trench safety?

Employers are responsible for providing a safe workplace, ensuring required protective equipment is used, and following OSHA's safety rules to prevent trench accidents.

What happened in the tragic trench incident described in the video?

In the incident, five workers were installing a sewer pipe in a trench without protective systems. When one side of the trench collapsed, two workers were able to escape, but three others were buried and suffocated by the soil.

What is a 'competent person' in the context of trench safety?

A competent person is someone who can recognize hazards in a trench and has the authority to take immediate actions, including stopping work, to eliminate those hazards.

What are the different soil types classified by OSHA for trench safety?

OSHA classifies trench soil into stable rock, type A, type B, and type C, with stable rock being the safest and type C being the least stable.

What are the key protective systems required by OSHA for trenches deeper than 5 feet?

For trenches deeper than 5 feet or those showing signs of cave-in, OSHA requires protective systems such as sloping, benching, shoring, or shielding to prevent cave-ins and protect workers.

How does sloping protect workers in a trench?

Sloping protects workers by cutting back the sides of the trench so that the walls slant away from the trench. The degree of slope depends on the soil type, with specific regulations for stable rock, type A, B, and C soils.

What is shoring, and how does it protect workers in a trench?

Shoring uses support systems, such as timber or aluminum hydraulic systems, to prevent the trench walls from moving and protect workers from cave-ins. The system is installed based on the soil type, trench depth, and width.

What is the purpose of a trench box in trench safety?

A trench box, also known as a trench shield, is used to protect workers inside the trench from cave-ins. It consists of large plates held apart by cross-members and is designed to shield workers from soil collapses.