March 13, 2012
Near Miss – lesson learned:
On February 6, 2012 a significant near-miss occurred at a
B.L.Harbert International jobsite when a hoist hook suddenly failed while under
load. The hook was attached to an excavator bucket being used to lift a manhole
assembly. No injury occurred, no workers were exposed to the load at the time
of the failure. Sudden and catastrophic failure occurred within the threaded shaft
hidden from prior inspection under the locking nut.
Prior to this incident the site management had
implemented a procedure whereby all rigging components were inspected daily and
prior to use by qualified riggers, in addition a 3rd party rigging
supplier conducts on-site inspection of all rigging on a quarterly basis.
The failure occurred within a swivel hoist hook equipped
with washers as opposed to bearings at the point of swivel. This style hook
is designed to swivel only for positioning prior
to the hoist, not to swivel while under a load. Post incident
investigation has determined these hooks are frequently misapplied. In fact
some new hoisting devices were
identified as being delivered with improper swivel hooks installed.
Corrective action: removal from service of all swivel hoist
hooks not approved by the manufacturer to swivel while under load. These hooks
are to be replaced by swivel hoist hooks equipped with bearings andspecifically
approved by the equipment manufacturer for swivel while loaded.
Further corrective actions: (in addition to rigging policies
and programs in place)
- Upon arrival on site of any rigging component
the manufactures’ labels and warnings shall be carefully reviewed with the
competent person making determination if the equipment matches the task.
- Equipment limitations and warnings shall be
discussed as a safety meeting (JSA or toolbox talk) with appropriate personnel
- Rigging hardware such as hoist hooks and
shackles shall be installed on digging equipment only during hoisting
operations. Rigging remaining on buckets during digging operations is
Note: This hook is commonly used in the application
described above. When new, the manufacturer’s warning tag that accompanies this
“This hook is a positioning device
and is not intended to rotate under load”
Hoist hooks designed to rotate under load are available from
several sources – each will have a bearing (not washer) located between the
locking nut and point of swivel. Manufacturer’s information will clearly state
the hook is designed to swivel while loaded.
Frank Wampol, CHST
Corporate Safety Director