TRENCHING SAFETY

TRENCHING SAFETY
YAWAR HASSAN KHAN

Hazard: Trench collapses cause dozens of fatalities
and hundreds of injuries each year.
Trenching deaths rose in 2003.

Never enter an unprotected trench.

Always use a protective system for trenches 5
feet deep or greater.

Employ a registered professional engineer to
design a protective system for trenches 20
feet deep or greater

Protective Systems:
 Sloping to protect workers by cutting back
the trench wall at an angle inclined away
from the excavation not steeper than a
height/depth ratio of 11
2 :1, according to the
sloping requirements for the type of soil.

Shoring to protect workers by installing
supports to prevent soil movement for
trenches that do not exceed 20 feet in
depth.

Shielding to protect workers by using
trench boxes or other types of supports
to prevent soil cave-ins.

Always provide a way to exit a trench--such
as a ladder, stairway or ramp--no more than
25 feet of lateral travel for employees in the
trench.

Keep spoils at least two feet back from the
edge of a trench

Make sure that trenches are inspected by a
competent person prior to entry and after
any hazard-increasing event such as a rainstorm,
vibrations or excessive surcharge
loads.