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Trend Analysis
We reviewed the information available for the 34 incidents from 1995 to
present (34 Accident/Incident/Pollution Forms and 20 reports) to try to
categorize the types of crane incidents that occur on the OCS and to see
if we could identify trends among the incidents. Here are the categories
that we looked at:
- Equipment
failures by type (i.e., booms, pedestals, slings)
- Human
error incidents
- Frequency
of injuries and fatalities
- Injuries
by job type
- Summary
Equipment Failure By Type
Equipment failure was listed as the
cause of 17 out of 34 incidents. The types of equipment, number of
failures, and fatalities and damage associated with each type of
equipment failure are listed below in Table 1:
TABLE 1
- EQUIPMENT
FAILURE BY TYPE
| Equipment type |
Number of
failures |
Number of
fatalities |
Property
damage associated with failures |
| Wire rope |
3 |
1 |
Minor damage |
| Boom
equipment |
3 |
0 |
Major damage to
the booms |
| Crane
pedestal |
3 |
0 |
Major damage to
cranes |
| Boom |
2 |
2 (in one incident) |
Major damage to
the booms |
| Sling |
2 |
1 |
Minor damage |
| Crane hook |
2 |
1 |
Minor damage in
one incident |
| Line slippage |
1 |
0 |
No damage |
| Oil storage tank |
1 |
0 |
Minor damage and
minor oil spill |
The forms and reports also
indicated that when booms, boom equipment, and crane pedestals failed,
it often resulted in significant damage to the cranes.
Trend - One type of equipment does not
seem to fail more often than another type of equipment. However, the
analysis shows that when equipment fails, the results can be deadly and
cause significant damage to the crane and surrounding facilities. The root
causes for the equipment failures were not usually stated in the reports.
Human Error Incidents
Human error was listed as the cause of 12
out of 34 incidents. We looked at the injuries and damage that resulted
from human error and compared that to the injuries and damage resulting
from equipment failure incidents. Tables 2
and 3 below show the injury
and damage results from the 12 incidents that were attributed to human
error.
We also looked at determining what job type
was responsible for making the error that lead to the incident. The
personnel that can make human errors associated with crane incidents are
crane operators, riggers, and other personnel involved in the crane activity
(such as workers in a personnel basket). Unfortunately it was not possible
to clearly determine who was responsible for causing most of these
incidents. Ultimately, the crane operator is responsible for the safety of
each lift.
TABLE 2
- INJURIES/FATALITIES RESULTING FROM HUMAN ERROR INCIDENTS
Number of incidents |
Injuries and fatalities |
7 |
No injuries |
4 |
Minor injuries
(includes broken bones and severed finger) |
1 |
One fatality |
TABLE 3
- DAMAGE RESULTING FROM HUMAN ERROR INCIDENTS
Number of incidents |
Property damage |
3 |
No property
damage |
6 |
Minor property
damage |
1 |
Major property
damage |
2 |
Minor oil spills
(no environmental damage) |
Trend
- Human error incidents had only one fatality out of 12 incidents (8%),
while there were five fatalities associated with the 17 equipment
failure incidents (29%). Major property damage occurred once with the
human error incidents (8%), while major property damage occurred in six
of 17 equipment failure incidents (35%). Judging from this information,
incidents attributed to human error appear to much less likely to cause
fatalities (8% to 29%) and result in major damage (8% to 35%) than
incidents caused by equipment failures.
Three incidents attributed to bad weather
could also be considered as human error incidents if the crane operator
erred in judgment to make the lift despite the poor weather conditions.
However, there was not enough information to make that determination. There
were no significant injuries or damage associated with the bad weather
incidents.
Frequency of Injuries and Fatalities
Nineteen incidents had at least some type
of injury. Seven fatalities are associated with six incidents. The other
13 incidents had serious, moderate, or minor injuries. (We noted that
there does not seem to be consistent definitions for serious, moderate,
and minor injuries. For this report, severed fingers and broken bones
are considered minor injuries.) Fifteen incidents did not cause any
injuries.
Trend - Injuries occur with more than
half (19 out of 34 or 56%) of the crane incidents. Injuries are often
serious and fatalities are not uncommon.
Injuries By Job Type
We identified four types of workers (job
types) that could be injured in a crane incident: 1) crane operator;
2)riggers, roustabout, floor hand, work boat deck hand, or other person
assisting with the crane operations (all categorized as riggers in this
section); 3) personnel in personnel basket; and 4) personnel not
associated with the crane operations. There were seven fatalities and 20
injuries.
TABLE 4
- INJURIES/FATALITIES BY JOB TYPE
Job type |
Number of Incidents |
Number of Injuries and Fatalities |
| Crane operators |
2 |
2 minor injuries
(includes broken bones) |
| Riggers |
11 |
6 fatalities
10 injuries ranging from minor to serious |
| Personnel basket |
4 |
4 minor injuries
(includes 2 broken legs) |
| Personnel not
involved with crane operations |
2 |
1 minor injury
(broken leg). Another incident involved the removal of a rental crane
and it resulted in 1 fatality and 3 serious injuries |
Trend
- Riggers appear to be at a much greater risk of injury and death than
any other personnel during crane operations.
Summary of Trend Analysis
As you can see, crane accidents can be
very serious. Equipment failure or human error can lead to death. We
believe the most significant finding of our analysis is that riggers
appear to be at the greatest risk during crane operations. Seven
fatalities have occurred since January 1995, all of which involved
riggers or other personnel working around cranes. Crane operators
appeared to be less at risk because they were not among any of the
fatalities, nor did they sustain any major injuries.
The above analysis could also lead you to
believe that equipment failures cause more crane incidents than human error.
However, the workgroup believes that human error likely played significant
contributing roles in those incidents listed as being caused by equipment
failure. We found that almost 75% of the reports (14 out of 19) listed the
cause of the accidents as mechanical failure (several incidents are still
under investigation and the specified causes could change), while human
error was only listed as the cause in six of the reports (several accidents
had multiple cause categories and slip/trip/fall and bad weather were listed
as the causes in one report each). This percentage is almost directly
inverse of what you would expect to find if you buy into the adage that 80
percent of all accidents are due to human error.
Our identification of trends in crane
incidents is limited to the simple analysis discussed above. We do not
believe it is possible to do a more detailed analysis because much of the
information needed to conduct such an analysis is not available. While most
of the forms and reports provide a very good description of the incident,
many do not provide sufficient data and analysis about why the accident
occurred. Information that is missing includes the experience and training
of the personnel involved in the accident; operator/contractor training and
maintenance programs; job procedures; condition of the equipment; and
maintenance and training records. We believe that this type of information
holds the key to accurately identifying the causes of many accidents.
The purpose of the above discussion is not to
criticize the authors of the reports, but to point out that there is room
for improvement in these reports. Right now the reports do an adequate job
of telling us what happened, but they don’t do a good enough job of
explaining why it occurred. In our opinion, the Bureau must significantly improve
the method of investigating, analyzing, and reporting the root and
contributing causes of accidents if the Bureau is going to use these reports in
understanding why accidents occur. We believe that Bureau must rethink how it
conducts accident investigations and how it reports them and not just tell
the current investigators and authors of the reports to do a better job.
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