Review of Recent Crane
Accidents
1998 Incidents
There have been two very serious accidents involving cranes on the Outer
Continental Shelf (OCS) so far in 1998*.
The first serious accident occurred on May 10 when a platform crane failed
while offloading a rental crane and killed two workers. Ocean Energy is the
operator of the platform. Although this accident is still under
investigation, the early indication is that the crane was poorly maintained
and that mechanical failure contributed to the accident.
The second serious accident occurred on June
2 and it too involved the offloading of a rental crane. This event differed
from the first accident in that the operation of a crane did not factor into
the accident. The apparent cause of this accident was the improper
disassembly of the rental crane (human error - lack of proper training,
preparation, and supervision). One worker was killed and three others were
seriously injured. Amoco is the operator of the platform and Sundowner is
the contractor that was offloading the crane.
There have been at least six other minor
incidents that involved crane operations in 1998. Three incidents caused
significant damage to crane booms when equipment failed or the operator made
an error. Two other incidents appear to have been caused by improper or poor
techniques by "riggers" on supply boats. (For this report, riggers are
personnel that attach or unhook loads or otherwise assist with crane
operations. In many cases a rigger is a roustabout, roughneck, or a deckhand
on a work or supply boat. In giving these personnel this job "title," we are
not implying that they have any specialized skills or training to perform
this job.) One of these incidents resulted in a minor injury and the other
caused the spillage of 400 gallons of motor oil. The last incident caused no
damage or injuries when a fast line parted.
Another incident should be included with
these 1998 cranes incidents because it involves the hoisting of materials.
This accident involved a hoist used to move a blowout preventer (BOP) stack
and resulted in the year’s first fatality (February 6). A roughneck was
pinned between the BOP stack and a structural beam after one of the hoist’s
wire ropes failed. Apparently the wire rope had corroded, possibly leading
to its failure.
*On October 27, 1998, another
serious crane accident occurred. The crane operator was killed when the
crane broke from it’s pedestal while lifting a load. This accident is not
included in the report.
1997 Incidents
There were at least 10 crane incidents in 1997 according to
Accident/Incident forms and Accident Investigation Reports (referred to as
reports for the rest of this paper) contained in our Technical Information
Management System (TIMS). Incidents ranged from minor personnel injuries and
minor property damage to two accidents resulting in two fatalities.
Crane pedestals failed on two occasions
causing major damage to the cranes and one serious injury. Mechanical
failure caused these two incidents.
Two other incidents damaged crane booms as a
result of improper lifting techniques. One boom failed due to overloading
because the wrong boom angle was used to offload a rig. In the other, the
boom damage occurred when the boom pawl brake failed and the boom pivoted to
the surface of the Gulf. Both of these incidents may have been caused by
crane operator error. Fortunately there were no injuries in these two
incidents.
Slings were involved in three incidents.
Twice slings failed during the lifting operation, one failure resulted in a
fatality. In that fatality, the floorhand handling the tag line was
underneath the load when the sling failed. A second fatality occurred when a
sling snagged and broke off the valve on an accumulator bottle and the
escaping pressure blew the rigger across the rig floor. According to the
report, the probable cause of this accident was that the communication
between the crane operator and the rigger was not appropriate.
The other three incidents involved minor
injury to a rigger, minor injury to a person exiting a personnel basket, and
minor damage to an offloaded box of cuttings. These incidents are likely due
to human error.
1996 Incidents
There were at least ten crane incidents in 1996. Severity of the incidents
ranged from minor injuries and property damage to broken legs. There were no
fatalities associated with crane operations in 1996. Improper lifting and
mishandling loads (including personnel baskets) accounted for five of the
accidents. One personnel basket got snagged and dumped a worker out of the
basket. Two other personnel basket incidents resulted in workers breaking
their legs, one was exiting the basket during rough seas and the other when
the crane line slipped.
Mechanical failures resulted in two
incidents. In one incident, a rigger was struck by a falling cable after the
anti-two blocking device failed. Apparently this device may have been
damaged during previous heavy lifts but was not repaired. The other
mechanical failure involved the failure of the crane turntable.
Three incidents involved human error. One
involved a helicopter that clipped a crane boom. The crane operator erred
when he left the boom in wrong position after completing the crane
operations (helicopter pilot also erred by not properly judging landing
clearances). Another occurred when a new operator dropped a mud logging lab
on a work boat. The last incident involved the lack of communication between
a crane operator and personnel on a work boat. This incident damaged a
diesel transporter tank and resulted in a minor oil spill.
1995 Incidents
We found only five crane incidents for 1995. One incident resulted in the
fatality of a worker as he was lowered by a crane to detach the mooring
lines of a work boat. The worker fell into the Gulf and drowned when the
cable which the worker was attached to slipped off the crane hook.
Apparently the crane hook was not equipped with a proper safety latch to
prevent the cable from slipping off the hook. Another sling slipped off the
hook when a load shifted, fortunately this resulted in only minor damage.
On two separate incidents riggers were
injured when their fingers were caught between loads99 being moved by
cranes. The last incident resulted in 12 barrel diesel spill when a tank was
ruptured while offloading a snubbing unit during bad weather.
Attachment 1
summarizes all of the above mentioned incidents. There may have been other
crane incidents during these years, but we did not find them in the TIMS
database. In addition, we reviewed some other incident reports where it was
not readily apparent that a crane was actually involved. For example, a drum
of diesel fuel was dropped in the Gulf, but the form did not state what
activity caused the drum to fall into the Gulf. This incident may have
occurred while a crane was loading or offloading of the drum or it could
have happened while it was being moved with a hand truck.
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