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U.S.
Department of the Interior
Minerals Management Service
Gulf of Mexico OCS Region |
Safety
Alert No. 207
December 18, 2002 |
Contact: Jack Williams
(504) 731-3012 |
Recently, an operator hired a
construction/rental crane contractor to remove an 18,000-lb. flare boom from a platform.
The rental crane was installed and the old flare boom was cut loose. During the
swinging of the load to begin lowering it onto the boat, the base of the east-west brace
attaching the rental crane to the platform failed. This caused the crane to be torn
suddenly from the platform and pulled overboard into the Gulf of Mexico. The
movement of the crane overboard caused the death of a crewmember who was in the path of
the falling crane.
This Safety Alert serves as a follow-up
to Safety Alert No. 202, issued on June 20, 2002.
Cause
1. The failure of the crane brace
was directly caused by a fault in the fundamental design of the way the crane was attached
to the platform. The crane was held in place by two braces welded to the platform,
one oriented east-west and one north-south. When attaching the east-west crane brace
to the platform, the contractor first welded the brace to a small I-beam. Then, the
I-beam was welded to the platform skid beam in such a manner that the I-beam/brace
attachment was outboard of the I-beam/skid beam weld and the I-beam ends were unsupported.
This created a cantilever effect that multiplied the forces on the I-beam to the
point that the I-beam failed when exposed to the full load of the lift.
2. The deficient fundamental
design was allowed because of organizational failures as follows:
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No
engineering calculations were required or employed by the Operator or Contractor to ensure
the adequacy of the attachment design; |
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No written
procedure for installing the crane was required or employed by the Operator or Contractor
to ensure competent review of field modifications of standard installation procedures. |
3. No written
Job Safety Analysis (JSA) or Job Hazard Analysis (JHA) was required or created by the
Operator or Contractor. A JSA analysis of the operation could reasonably have been
expected to have identified the hazard of positioning a crewmember within a zone that
would place him at risk in the event of a crane failure.
4. The load testing
of the crane prior to conducting the operation did not reveal the structural flaws of the
installation. This failure indicates the standard method for load testing cranes of
this type with the boom oriented only in one direction does not provide a true indication
of the ability of the crane to perform safely the full range of motion required to
complete a job.
5. The supervisors overseeing the operation failed to recognize the structural
deficiency of the installation. The supervisor installing the crane failed to
recognize that the cantilever method of using an I-beam as the base for the E-W brace was
significantly different from other methods of using an I-beam as a connector. This
likely caused a failure to discuss and review the installation method with company
management.
Possibly Contributing to the Failure
6. Possibly contributing to
the fatal accident was the lack of a formal, written procedure provided by the Contractor
or Operator that defined the steps and checkpoints of the construction job as a whole.
7.
Verbal communication misunderstandings between
the supervisors and on-shore management also possibly contributed to the accident.
Recommendations to Operators
The MMS recommends to the operators
that they thoroughly review the engineering of attaching any rental crane to a structure.
The MMS also recommends to the operators that they thoroughly prepare a written
procedure that defines the circumstances requiring supervisor, management or engineering
review of operations during the course of construction activities. The MMS
recommends that formal JSA/JHA’s be employed to identify risks to personnel prior to
major construction activities.
For details of the accident, see OCS
Report MMS 2002-076. Copies of the report may be obtained from the MMS Public Information
Office located at 1201 Elmwood Park Boulevard, New Orleans, Louisiana 70123
(1-800-200-GULF or local 504-736-2519).
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