Toolbox Talk Excavation Safety
08 Jun 2020 - Flaaim
Almost all serious excavation accidents occur not in bad ground, but in so called “Good” ground.
Look at the myths and then at the real facts relating to trench excavations: -
- MYTH: Trenches in clay are safe.
FACT: 79% of fatal trench accidents occur in clay.
- MYTH: You do not need trench support if an experienced operative is in charge.
FACT: 75% of fatal accidents have occurred when an experienced operative has been in charge
- MYTH: You don’t need trench support when you dig, lay and backfill in one day.
- FACT: 74% of accidents have occurred in excavations that have only been open for a few hours/minutes.
Excavations must be subject to risk assessments. The risk assessments will identify the method of support or sloping / battering.
It is commonly thought that deaths associated with excavation collapses are due to the operatives being suffocated because they are completely buried, but this is not entirely true. Many of the deaths and a majority of the injuries involve operatives being partially buried. The injuries sustained are usually crushing injuries caused by the sheer weight of the collapsing material.
The accidents associated with excavations happen for many reasons, some of which are: -
- Shoring was not installed where required.
- Shoring failed because it was not frequently inspected or maintained.
- Employees worked beyond the shoring protection.
- Excavation walls and shoring were not inspected frequently for signs of movement or deterioration.
- Operative’s re-entered excavations without inspecting the walls or shoring after rain fall.
There are other contributory reasons for excavation accidents beside soil and shoring failures, such as: -
- Muck, sheet piles and construction materials being stored too close to the edge of the excavation.
- Failure to erect barriers and fencing around an open excavation, even if ‘inside’ the working area
- Plant and equipment operating too close to the edge of an excavation.
- Improper access/egress, damaged or missing ladders or alternatively no ramp.
- Operatives attempting to jump over excavations.
- Throwing materials down to those working within an excavation — use a bucket and rope to lower the tools down.
REMEMBER A CUBIC METRE OF EARTH WEIGHS OVER 1.5 TONNE.
REMEMBER THE BASIC RULE:
The sides of all excavations must be sloped / battered or supported as identified in the risk assessment