BEAM CLAMPS (LEVER-ACTION)


Produced by:
Professional and Specialized Services,
Ministry of Labour,
Alert C7/0695
ISSN 1195-5228

HAZARD SUMMARY:

Two workers on a construction project were struck and killed when 
a structural steel beam being hoisted over them slipped out of a 
lever-action beam clamp.

The investigation revealed that the single clamp being used was 
too large for the beam and so did not grip the top flange 
securely.  It was also discovered that the clamp used a lever 
action for gripping.  When the tension on the hoist cable was 
released, the jaws of the clamp could open automatically and 
release its grip on the flange.

Clamps of this type do not meet the requirements of the 
Regulations for Construction Projects (O. Reg. 213/91, section 
172), which state that "a container, sling or similar device for 
rigging or hoisting an object, including its fittings and 
attachments . . . shall be so arranged as to prevent the object 
or any part of the object from slipping or falling."

Beam clamps that rely on the lever action of the jaws to provide 
the grip on the beam do not meet the requirements of the 
Regulations for Construction Projects and therefore should not be 
used for hoisting structural steel.

REQUIRED ACTION:

-  When a beam clamp is used for hoisting, it must be positively 
   attached to the beam, i.e. attached by a bolting mechanism or 
   similar device that will prevent the beam from slipping or 
   falling. 

-  An identification plate that clearly indicates the load rating 
   and the method of attachment to the beam must be affixed to 
   the beam clamp. 

-  When long or irregularly shaped beams are being hoisted, a 
   two-point beam attachment and a spreader beam should be used. 

-  The load must never be hoisted over workers.

For additional information, please contact the nearest office of 
the Ministry of Labour.