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OCR for page 159
4
Risk, the Operating Environment,
and Safety
-
SUMMARY
Ris1<9 inherent in every human enterprise9 is generally managed by individ-
ual or corporate judgments about perceived risks. Although this approach is
generally adequate for most routine circumstances, it is inadequate for complex
situations. Risl< in the complex marine operating environment has increased sig-
nificantly9 because substantial increases in the costs of marine casualties that
result in pollution have not been accompanied by a corresponding decrease in
the probability of accidents. The probability of accidents might be reduced
through improvements to organizational structure and processes9 professional
development operating practices9 and technology. Whether the combined ef-
fects of improvements in these areas could fully offset the increase in economic
. . .
rids < Is uncertain.
Mariners are inherently familiar with risl<9 not in probabilistic terms9 but
in practical threats to safety that must be avoided or accommodated in opera-
tions. Mariners must deal with threats continuously although they do not always
do so effectively. The marine operating environment is very complex and not
well understood even by those who operate in it. There can be substantial
differences in threats and exposure even within the same port and waterways
complex. There are no practical means for mariners to fully assess all the factors
that could affect the safety of vessel movements other than their professional
judgments. Their responses to threats reflect their accumulated experience and
professional competence as well as the risk management programs of their em-
ployers.
159
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160
MINDING THE HELM
Underlying causes of marine accidents have not been addressed method-
ically or effectively by most shipping companies, marine safety authorities, or
other interested parties. Furthermore, the available marine safety data are not
adequate to support this objective. No public agency in the United States is
systematically monitoring to detect problem ships, inadequate operating and
management practices, and substandard crews. Some proprietary monitoring is
conducted, but these data are usually not available. When accidents occur, pilot-
age is frequently an early target for blame. The overall result is that risl< manage-
ment in the marine operating environment depends to a great extent on percep-
tions of risk and personal judgment. Thus, symptoms of problems rather than
underlying causes are often treated. A more informed basis for problem solving
could be developed by careful assessment of safety performance, including iden-
tification and assessment of underlying causal factors in marine accidents and
preventative measures that might be applied.
INTRODUCTION
Risk is inherent in essentially every human enterprise. Managing risk is,
therefore, part of all decision making, whether personal or business related. A1-
though modern probabilistic approaches to risk management are available and
proven in other transportation sectors, these methods are poorly understood and
not widely applied in marine transportation. Major shipping accidents with oil
spills of enormous proportions Argo Merchant on the Grand Banks; Amoco
Cadiz off Brittany; Exxon Valdez in Prince William Sound; and in January 1993,
the Braer in the Shetland Islands-challenge the capabilities of the maritime
industry, flag-state and port-state governments, and international maritime orga-
nizations to manage risk more effectively. The first section of this chapter ex-
plains the framework for addressing risk in this report. Probabilistic risk con-
cepts and risk management practices based on these concepts are introduced.
Established techniques for quantitative risk management in other areas provide a
point of comparison for analyzing the traditional methods of risk management in
marine transportation. Risk management practices in marine transportation are
described. The first section concludes with an overview of the consequences of
risk.
The second section characterizes the marine operating environment and the
factors that complicate risk management in the marine navigation and piloting
stem. The complexity of risk management is not widely appreciated, even within
the marine. community. The third section examines safety performance. Trend
analysis practices in marine transportation are characterized, and causal factors
in marine accidents are discussed. The role of pilotage in reducing the probabil-
ity of marine accidents also is examined. The analysis concludes by offering
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RISK, THE OPERATING ENVIRONMENT, AND SAFETY
161
ways to improve risk management in the marine navigation and piloting system
through systematic application of quantitative risk assessment and safety analysis.
RISK
Decision Analysis and Risk
Decision Analysis
Decision analysis may be defined broadly as any activity that involves anal-
ysis for purposes of making a decision, or more narrowly as a specific approach
to analyzing decision situations. The components of modern quantitative deci-
sion analysis include decision trees (and more recently, influence diagrams),
subjective or statistical probability, and measures of utility (incorporating risk,
multiple attributes, and a time value of consequences). Underlying this quantita-
tive approach is the assumption of maximization of expected utility (Howard,
1988, 1992; Howard and Matheson, 1983; Raiffa, 1968; Simon, 1956~.
The importance each component (decision trees/influence diagrams, probabili-
ty? or utility) plays in any one particular decision analysis varies greatly; in
simple applications, a simple weighted sum of a few attributes done in a few
minutes may constitute one decision analysis while another may involve com-
plex combinations of computer models capturing the dynamics of uncertain
processes developed through many person years of effort.
(Bodily, 1992)
Risk Analysis
Risk analysis is an approach to risk control (North and Yosie, 1987) that
permits assessment and management of risks to an individual or an organization
due to hazards, deleterious effects, and damage to property. Risk analysis tech-
niques have been used for many years to manage potential hazards in transporta-
tion, occupational safety, manufacturing, and financial markets. These hazards
may include accidents or injuries, failures, or monetary losses (Covello, 19873.
Risk analysis has been described as comprising three primary components:
risk assessment, risk management, and risk communication (Figure 4-1~; (Bal-
son et al., 1992; Covello, 1987; NRC, 1989~. Risk assessment is the qualitative
or quantitative evaluation of the environmental, health, operational, or economic
risks that may result from some process, activity, or event:
To assess human health risks, for example, one would combine information
about a group's exposure to risky substances with information about the effects
of those substances on the human body to derive an overall characterization of
the risks a group faces (North and Yosie, 1987). Similarly, to assess environ-
mental impacts, one would use the exposure of an ecological group combined
with response information. Operational risks may be assessed by using the fre
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162
MINDING THE HELM
Risk Assessment
Source | >| Transport | >| Population ~;:
Characterization ~ and Fate ~ ~ Exposures ~ I
1`
Risk Characterization
Risk Management
DetermineDefine
Acceptable~ Management
RiskAlternatives
_ .
Evaluate ~
Alternatives r
Select and
Implement
Alternatives
I Risk Communication
· What levels of risk are present?
· What is significance of risks? >
· How are risks to be managed/controlled? .
All
Interested
Parties
FIGURE 4-1 Main components of quantitative risk analysis (from Balson et al., 1992).
quency of an accident or failure and a measure of the magnitude of the hazard-
ous operation. Economic risks may be assessed using estimates of the direct and
indirect costs of an incident and the frequency of the incidents.
(Balson et al., 1992)
Risk management is the process of determining whether an identified risk is
acceptable, and what action (if any) should be taken to mitigate or control that
risk. In this sense, risk management is a specific application of decision analysis.
Risk communication includes all purposeful exchanges of information about
health, environmental, or economic risks between interested parties. Through the
risk communication process, interested parties share information about the prob-
abilities of risks; the significance of such risks, and the decisions, actions, or
policies those parties can use to manage or control such risks (Chorssen and
Covello, 1989; Glickman and Cough, 1990; Graham et al., 1988; NRC, 1989;
Wilson, 1991~. This three-pronged approach to risk and decision analysis has
been successfully applied by utilities to manage environmental risk (Balson et
al., 1992), by banking operations to manage investment risks (Engemann and
Miller, 1992), by large diversified manufacturing enterprises such as General
Motors Corporation to manage business risks (Krumm and Rolle, 1992; Kusnic
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RISK, THE OPERATING ENVIRONMENT, AND SAFETY
163
and Owen, 1992), and by military planners to manage risks inherent in require-
ments and systems acquisition processes (Buede and Bresnick, 1992; Watson
and Buede, 19873.
Relationship Between Probabilistic Risk and Perceived Risk
Probabilistic risk is classically defined as the algebraic product of the proba-
bility of an adverse event occurring during a defined period and the cost (eco-
nomic, environmental, or social welfare) that would be incurred if the event
takes place. This definition assumes that reasonable values can be assigned to
the probability and cost of an occurrence. In many cases, values can be assigned
with reasonable certainty, although, until recently, this was seldom done. Most
business risk decisions have been and still are based on perceived risk, under-
stood here as the likelihood of adverse consequences derived from nonquantita-
tive interpretation of risk factors as well as from considerations that are often
nonquantifiable. Such considerations include experience-based human reactions
to unfamiliar circumstances and uncertainty. The formal process of determining
the full range of possible adverse occurrences and the values to be assigned to
their probabilities and expected costs can be quite involved and expensive. Still,
quantitative risk studies have become more common, particularly where they
may be used in gaining acceptance or permits for major construction projects.
The probabilities based on accident incidence data are epistemic, that is,
they represent a state of knowledge relative to a reference class. The reference
class is the set of past occurrences reflected in the knowledge base from which
the statistics derive. Therefore, the probabilistic risk is an estimate of actual risk,
just as is perceived risk. The difference is that probabilistic risk is quantitative,
based on an objectively constructed reference class, and testable against continu
. .
ng experience.
For reference classes where the rate of past occurrences has been too low to
construct a statistically relevant and significant knowledge base, methods have
been developed that provide reasonably accurate estimates of accident probabil-
ity. These methods use structured approaches to model the operations involved
and, through the use of tools such as hazards and operability studies, failure
modes and effects analyses, fault trees, and decision trees, provide quantitative
estimates of the probability of accidents. Values from statistically significant
data bases for similar operations are assigned to elements of the fault or decision
trees, where available. Expert judgment is used to assign values to those ele-
ments that are unique to the studied operations. These methods have been quali-
fied by testing them, with very good results, on models of operations where
accident rates are well documented by statistically significant data.
The results of probabilistic risk assessments are useful for examining the
effects of introducing new technologies and operational changes. These methods
have gained wide acceptance in recent years in the nuclear, aerospace, and pro
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MINDING THE HELM
cess-control industries. These techniques potentially could be used to assess ma-
rine operations where historical data is unlikely to yield a statistically significant
and relevant knowledge base.
Although subjective, estimates of perceived risk can be fairly accurate if the
risk decision is about familiar things or circumstances, but familiarity is often
not enough. The fear that many people have of flying is a good example. Most of
these people feel very safe riding to the airport in a car or taxi but become
anxious and concerned upon boarding the aircraft. More than sufficient data
exist to prove there is far greater probabilistic risk during the short automobile
trip than during flight. Many aircraft passengers are familiar with these statistics,
but the personal sense of danger is stronger aboard the aircraft than when using
ground transportation. This example illustrates a disparity between probabilistic
risk and perceived risk based on a subjective sense of the likelihood of bad
consequences, not the relative value (cost) of the consequences. In a subjective
assessment, the probability of bad consequences (that is, the perceived risk) is
heightened by unfamiliar surroundings, lack of control, and the severity of con-
sequences should a mishap occur. It is lessened by familiarity with the surround-
ings, ability to influence the outcome, and the possibility of a range of outcomes
including those with minimal potential harm.
As noted earlier, risk decisions based on quantitative models are rare in day-
to-day personal or professional lives. Instead, individuals and organizations react
to perceptions of risk that, for obvious threats and exposure, are reasonably
accurate. This accuracy level tends to reinforce an informal approach to risk
assessment. But all too frequently, perceived risk and probabilistic risk are sig-
nificantly different, and the latter goes unrecognized or inadequately accommo-
dated.
Businesses, like the individuals who operate them, do not always recognize
the actual cost of risk. In businesses or operations where the probability of an
accident is thought to be low, a structured method is seldom employed for as-
signing the cost of the risk. Efforts are usually made to keep the probability of an
accident at acceptable levels. But, for those very rare occurrences whose costs
can only be observed at very long intervals, the perceived risk may be distorted
by failure to recognize a significant change in cost. This appears to have been the
case in the marine industry during the 1980s.
Following a number of very large oil spills during the 1970s, significant
changes were made in the equipment and operating practices of tanker fleets,
reducing risk. The number of major oil spills decreased during the 1980s. How-
ever, following the pollution from the grounding of the Exxon Valde_ in 1989
and subsequent major oil spills, three factors the cleanup and compensation
costs incurred by those who spill oil, the Oil Pollution Act of 1990 (OPA 90),
and similar state-level pollution legislation acted together to increase the costs
to vessel owners (AWO, 1992a; Freudmann, 1991; OSIR, 1993a,b,c,k; Plume,
1991; Porter, 1991~. These changes apply to all merchant vessels involved in oil
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RISK, THE OPERATING ENVIRONMENT, AND SAFETY
165
pollution, not just tankers. OPA 90 also provided for preventative measures
involving marine traffic regulation and pilotage to reduce the likelihood of acci-
dents in Prince William Sound. Although operational costs attributable to these
measures would increase, risk would be reduced to some extent-a major objec-
tive of OPA 90.
The degree to which the probability of accidents would need to be reduced
to offset increased risk and the capability of marine transportation companies,
especially smaller ones, to reduce accident probabilities are not certain. Probabi-
listic risk assessments have been performed by some U.S. operating companies,
principally by large oil carriers, and might enable analysis of this issue, but these
studies are usually proprietary and none was available to the committee.
Marine safety could benefit from increased use of quantitative and qualita-
tive risk analysis in developing risk reduction strategies. This approach is a
proven methodology that could form a solid basis for identifying, developing,
and evaluating the risk reduction options (Cooke, 1991; Harrald et al., 19921.
RISK IN MARINE TRANSPORTATION
Considerations in Reducing the Probability of Accidents
The increased cost of accidents causing pollution provides a strong incen-
tive to improve safety performance. Increased economic risks often motivate
businesses to raise insurance coverage, change operating procedures, add or en-
hance training of operating and maintenance personnel, update technologies to
reduce the probability of a loss, or implement a combination of these options.
For example, some shipping and towing companies have invested in improved
vessel design, construction, navigation equipment, training, and operating prac-
tices. In this regard, the quality of tankers chartered for service to U.S. ports
appears to have improved (Arthur McKenzie, Tanker Advisory Center, personal
communication, January 15, 19931. Another option raising insurance cover-
age may be a satisfactory response to economic risk, but it is neither a means
to reduce the occurrence of accidents nor necessarily an incentive to do so.
Improvements in organizational structure, professional development, oper-
ating practices, and technology are the principal methods for reducing the proba-
bility of accidents. Major advances to achieve such a reduction may require
fundamental changes in navigation and piloting practices, administration and
technologies, operational procedures employed aboard vessels, marine traffic
regulation (including the setting of limits on vessels or operations in certain
areas), and training to use new or updated technologies and techniques. Long-
term action may be required to effect some changes, particularly those that re-
quire the introduction of new technology, changes in organizational culture or
structure, or establishment of support infrastructures.
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MINDING THE HELM
Traditional Risk Management by Mariners
Mariners are pragmatic with respect to their operating environment and op-
erational risks. They think in terms of threats to vessel safety from physical
dangers (such as shoals, rocks, obstructions), other vessel traffic, and environ-
mental conditions. Mariners, their vessels, and cargoes are the immediate recipi-
ents of the physical consequences of accidents, regardless of the economic costs,
so operational risk is emphasized over economic risk in terms of perceived phys-
ical threats and abilities to avoid or counter these threats. To protect themselves,
mariners must constantly identify, assess, and respond to actual or potential
threats and conduct operations to reduce exposure, insofar as is practical. Their
performance reflects the planning and risk reduction measures of their operating
companies and the adequacy of their own professional development. Their esti-
mates and procedures are based on experience and may or may not be effective
as measures of probability and cost.
Mariners have two basic tools to manage risk: the practice of good seaman-
ship and the effective use of informed judgment derived from accumulated expe-
rience and expertise. The general rules of good seamanship are based on a long
history of experience developed through trial and error and reasoned response to
maritime operating conditions. For example, methods of voyage preparation,
including identification of physical threats to vessel safety (from charts and nav-
igation publications) and passage planning to reduce exposure to them, are well
established (MacElrevey, 1988; Maloney, 1985; Meurn, 19903. Practical appli-
cation of these methods varies greatly in form and precision (Cahill, 1983, 19851.
Sometimes chances are taken based on professional judgment and a vague sense
of the probability of success based on experience. Statistics and methods for
formal analysis to determine the probability for success are not available at sea,
nor do mariners have the means to develop such measures. But ample evidence
exists demonstrating that sometimes informal decisions are in error (Cahill, 1983,
1985; NTSB, 1980, 1986, 1988a,b,c, 1989a, 199 la,b, 1992, 1993; USCG,
1993b,d).
Shippers, port authorities, marine and public safety authorities, and environ-
mental protection agencies also must be concerned with risk insofar as there are
threats to human life, the environment, and property. Economic costs must be
considered. Too often, the full costs only become apparent after an accident has
occurred. Except for companies with much to lose and a sufficient base to fund
scientific analysis, there is little evidence that more than cursory attempts are
made to systematically assess risk and to manage it in ways that could improve
the safety of operations. Thus, the well-intended efforts of many operating com-
panies to improve training, operational procedures, and navigation technology
may or may not be directed toward underlying causes of shortcomings or failure
in human performance.
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RISK, THE OPERATING ENVIRONMENT, AND SAFETY
~ . ~
167
~.~.~. ~. ~, ~i ~,., ~. ~. ~i.,
. , ~ i., .,. ~,,~. ~ ,, ~ If, , ~.q
Containership outbound crossing the Columbia River bar in common Pacific Northwest
weather and sea conditions. (Columbia River Bar Pilots)
Assessing Risk in Marine Transportation
Although there are two primary approaches to assessing risk and human
error, there is no widely applied methodology for assessing risk or accepted
approach for assessing safety performance in marine transportation. Likewise,
there is no accepted method for normalizing data to accommodate vast differenc-
es among port, waterway, and river systems so that comparative safety perfor-
mance can be assessed. Furthermore, there is no systematic performance moni-
toring program to aid in a holistic examination of the risk variables identified in
Chapter 1 that affect development and implementation of safety improvement
measures. Major safety studies are conducted infrequently, providing a limited
basis for determining trends that affect safety. Safety trends are generally de-
rived from analysis of casualty data, but the data are weak with regard to human
causes of marine accidents (Fuji) et al., 1984; Gates, 1989; Glansdorp, 1987,
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68
MINDING THE HELM
1988; Johnson and Katcharian, 1991; Maio et al., 1991; NAS, 1973; NRC, 1983,
1990a, l991b, 1993; Ponce, 1990; USCG, 1973; Yamaguchi, 1991; Young,
19921. The performance of the marine navigation and piloting system is not
routinely monitored through systematic analysis of safety data, nor are existing
data adequate for this purpose. Analyses using historical casualty records are not
timely enough for near-term adjustment of safety programs. Even if analysis
were timely, marine casualty data do not provide a complete basis for consider-
ing new or revised safety strategies, policies, and programs.
Existing casualty data are not a complete reflection of the overall nature of
safety problems in any port area (Maio et al., 1991; Young, 19921. Systemwide
problems may or may not be apparent from single marine accidents. Further,
there is no proven way to screen out local causal factors from those of a systemic
nature. Comprehensive cause-and-effect analyses are possible but difficult to
perform within the scope of available safety and performance data: For example,
marine casualty data for specific ports and waterways are often too limited to
establish statistical validity for important causal factors. The use of data cover-
ing several decades does not fully solve this problem; additional error can be
introduced because of changes in shipping practices and technologies during the
period. The use of global casualty data provides a sufficient sample but screens
out locally significant safety considerations that are important in planning local
improvements.
Examinations of casualty records, accident investigations (where detailed
reports are available for all casualties), and anecdotal information have proven
useful in determining relationships between tasks and error. However, inspection
of each case record is required, an intensive effort that is usually beyond the
resources available for such research. A few reliable reports and assessments are
available (NAS, 1976; NRC, 1983, 1990a; Paramore et al., 19795. Most assess-
ments have been limited to a few performance factors and focus on vessel-
specific casualty data rather than human causal factors. Yet, human error is the
predominant cause of collisions, rammings, and groundings (Cahill, 1983, 1985;
Gates, 1989; NAS, 1976; NRC, 1983, 1990a; NTSB, 1980, 1986, 1988a,b,c,
1989a, l991a,b, 1992, 1993~.
Approaches to risk and safety assessment are receiving renewed attention.
For example, Det norske Veritas (DNV), the Norwegian classification society,
believes that 95 percent of human errors associated with marine accidents are
caused by laclc of knowledge, skill, instruction, or motivation. Thus, DNV does
not see human error as the real cause of accidents, but the symptom of failure in
the management system (Mackenbach, 1992), including the waterways manage-
ment system and management aboard each vessel (Cahill, 1983, 19851. Further,
causal analyses of human error and risk analyses, and quantitative as well as
qualitative approaches to assessing risk, are also receiving increased attention.
These causal and qualitative approaches focus on identifying causal factors in
accidents and risk analyses, as well as latent or potential errors, in an effort to
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RISK, THE OPERATING ENVIRONMENT, AND SAFETY
169
anticipate difficulties in a system, or "to break the error chain" (Grabowski and
Roberts, 1993; Harrald et al., 1994; Reason, 19903.
The Exxon Valdez grounding and subsequent tanker groundings with oil
spillage off Newport, Rhode Island; in New York and New Jersey's Kill Van
Kull; and in the Houston Ship Channel were watershed events in renewing atten-
tion to the system in which operations occur (Davidson, 1990; NTSB, 1990,
l991a,b; Roberts and Moore, 1993; USCG, 1990a; U.S. Congress, 19911. The
Coast Guard, in executing congressionally mandated examination of the need for
improved marine traffic control, included risk and exposure variables in the
resulting Port Needs Study (Maio et al., 19913. The agency is also continuing to
develop an exposure data base to provide the resources needed to support a
broader examination of risk and safety performance (Abkowitz et al., 1985;
Hantzes and Ponce, 1991~. Despite these advances, the prevailing approach to
safety analysis remains narrowly focused. One subsystem, marine pilotage, is
the locus of considerable attention. When vessels ground or collide, close exam-
ination of pilot actions are sure to follow.
Consequences of Risk
Risk becomes a matter of direct public concern when major accidents occur.
Accidents can pose severe threats not only to the vessels, crews, and cargoes but
also to the public, environment, property, and local and regional economies.
Short- and long-term consequences have been demonstrated by the stranding and
loss of the Amoco Cadiz and resulting environmental damage to the Brittany
coast (Cahill, 1985), the pollution caused by the Exxon Valdez grounding (Alas-
ka Oil Spill Commission, 1990; Davidson, 1990; National Response Team, 1989;
NTSB, 1990), and a host of other marine accidents. While the aftermath of
accidents has led to public outcry, little public attention has been paid to preven-
tative measures. The movement of hazardous or dangerous cargoes is not re-
viewed until a major marine accident occurs, especially when accompanied by a
major oil spill. Notable exceptions include the movement of dangerous cargoes
in bulk (such as liquefied natural gas) and bulk movement of crude oil and
petroleum products in Alaska's Prince William Sound and in Washington State's
Puget Sound and the San Juan Islands. But some coastal states are becoming
more active in addressing local and regional interests in marine safety. For ex-
ample, both Washington and California have created state offices responsible for
addressing marine safety. In Washington, activities of this office include moni-
toring federal marine safety activities insofar as they pertain to state interests.
The safety measures that have been implemented so far typically address the
proximate causes of accidents, not the underlying or systemic factors that con-
tribute to the causal chain of events. Substantial tradeoffs have been made be-
tween risk, economics, and safety (Week, 1986~. The Port Needs Study provides
some insight on potential consequences of accidents by developing cost esti
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174
MINDING THE HELM
handling skills increases substantially when vessels are in narrow channels or
have small under-keel clearances (Armstrong, 1980; Ferreiro, 1992; Gates, 1989;
Hooyer, 1983; MacElrevey, 1988; NRC, 1985, 1992a; NTSB, 1991a; Plummer,
1966~. Vessel behavior in confined and shallow waters poses significant chal-
lenges to the individual piloting the vessel, whether a marine pilot, the master, or
another qualified member of the crew. The challenge is especially great for the
marine pilot, who is expected to provide expert shiphandling regardless of prior
experience with the vessel or even the category of vessel being piloted (Cahill,
1985; Hooyer, 1983; NRC, 1985~. If pilot response to the various forces affect-
ing vessel behavior is not correct, then casualties can quickly follow (Gates,
1989; NTSB, 1991a). These forces, and the shiphandling theory, local knowl-
edge, and practical skills needed to respond effectively to them, are not evident
in casual observation.
Forces Acting on a Ship
As a ship moves from deep into shallow water and into constricted channels,
the effects of hydrodynamic forces acting on the ship change dramatically, and
maneuvering characteristics are greatly affected (Ferreiro, 1992; NRC, 19855.
Graff (1993), prepared for this report, discusses the various forces that shiphan-
dlers must understand in order to maneuver their vessels effectively while in
pilotage waters. These forces include wind, current, and wave effects in open sea
and shallow water conditions; shallow water effects on inertia, maneuverability,
heading stability, resistance to headway, stopping distance, and squat and sink-
age; and narrow channel effects on vessel control and vessel interactions. A1-
though there many texts and professional papers that discuss these forces, their
effects, and responses to these effects, there is no "cookbook" solution to pilot-
ing. The study of hydrodynamics has advanced considerably, but there is still
much to be learned about hydrodynamic effects on vessel maneuvering in re-
stricted shallow water, especially where there are small under-keel clearances.
Therefore, considerable observation and practical experience is necessary for
shiphandlers to develop an appreciation for the forces and to develop the capa-
bilities to appropriately respond to their effects.
Controlled Hydrodynamic Interactions
Unlike the situation in aviation, where maintaining separation between air-
craft is paramount to safe navigation (Chapter 5), marine navigation in confined
channels routinely involves and sometimes requires direct interactions between
vessels. Indeed, this is a major distinguishing factor between the marine and
aviation operating environments. In some cases, safe passage cannot be accom-
plished without controlled hydrodynamic interactions between passing vessels
(Box 4-31. Hence, what might appear to be a reckless maneuver between two
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RISK, THE OPERATING ENVIRONMENT, AND SAFETY
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175
opposing ships may in fact be the only safe way for two vessels to meet and pass.
It may be possible, however, to reduce the number of such evolutions through
such measures as regulation of marine traffic, although this could cause signifi-
cant economic effects (Box 4-41.
Transit Considerations
Risk is significantly affected in piloting waters by the nature of marine
commerce and the vessels engaged in it, as well as cargoes carried, length of
exposure, and navigation support available both on and off the vessel. The Port
Needs Study provides a wealth of information on the type and scope of vessel
traffic and the nature and quantities of cargoes carried. The study also identified
geographic areas where accidents occurred (but did not examine underlying caus-
es). These factors and their interactions are part of the risk equation. However,
there is no evidence that they are systematically considered by marine safety
authorities in the effort to improve risk management in ports and waterways.
Navigation aids also are a factor in risk assessment. While these aids are
intended to reduce risk, they sometimes can have the opposite effect. For exam
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RISK, THE OPERATING ENVIRONMENT, AND SAFETY
Maneuvering during meeting situations in restricted shallow waters with small under-keel
clearances, such as is common in the Houston ship channel, necessitate use of hydrody-
namic interactions to effect a safe passage. Also required are highly-developed shiphan-
dling skills and precise timing of conning commands by the marine pilots. (U.S. Coast
Guard)
Simulation training using manned-models enables mariners to practice "hands-on" use of
hydrodynamic forces during maneuvering. (SOGREAH Port Revel Centre)
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MINDING THE HELM
pie, radar is widely credited for reducing strandings and collisions. However,
there are also numerous cases where "radar assisted" collisions occurred because
mariners focused too much attention on the radar picture or incorrectly interpret-
ed radar information (Aranow, 1984; Cahill, 1983; CAORF Research Staff, 1978;
Hayes and Wald, 1980; NTSB, 19721. The implication is that technological ad-
vances can ameliorate some risks while introducing others.
ISSUES TO BE ADDRESSED BY
QUANTITATIVE RISK MANAGEMENT
Data Limitations
Considerable marine safety data are collected under protocols established by
the Coast Guard. Although these data are useful, they do not provide the resourc-
es necessary to assess trends related to vessel construction, outfitting, manning,
technical systems, and maintenance, or to develop a full understanding of all
safety needs (NRC, 1990a). Also, a large number of small-scale, localized inci-
dents occur that, with few exceptions, are not tracked by marine safety authori-
ties. The potential for small-scale incidents to develop into marine casualties is
neither well understood nor addressed in most waterways management activities,
except where VTS systems have been established (Young, 1992, 19943. Until
data designed to support quantitative assessment are available that could help
guide safety initiatives intended to reduce operational risk, such assessments will
remain difficult to conduct and will be based on historical data.
Causal Factors in Marine Accidents
A few reports are available that examine task performance problems and
situational factors in marine accidents. Some found that different task perfor-
mance problems are associated with different types of marine accidents (Cahill,
1983, 1985; Gates, 1989; NAS, 1976; Paramore et al., 1979; Smith et al., 1976~.
Although vessel and navigation technologies have changed since most of these
reports were prepared, many aspects of navigation and piloting remain much the
same, partly because of reliance on traditional operating practices while in pilot-
age waters. Therefore, some of the earlier findings remain relevant today. The
committee examined key findings from these studies for relevance to the current
operating environment. The results are presented in the following sections. Also
available were a number of important safety studies; marine accident reports;
and other analyses, testimony, correspondence, and anecdotal information per-
taining to navigation and piloting practices. A summary of these studies pertain-
ing to pilotage and what can be learned from them is provided in Appendix D.
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RISK, THE OPERATING ENVIRONMENT, AND SAFETY
Communications
179
Stoehr (1977) concluded that the bridge-to-bridge radiotelephone was a very
effective anti-collision device on inland waterways. Paramore et al. (1979' con-
cluded that a parallel degree of success was not evident in harbor areas. Since
then, VIIF bridge-to-bridge voice radio communications has become universal
for domestic and foreign-trade commercial vessels. Marine pilots report that
harbor safety has improved substantially as a result. However, bridge-to-bridge
communications are not without problems. For example, use of separate VTS
frequencies (in ports having a VTS) to provide navigation information increases
the communications load on the bridge team and pilot, even if the VTS assumes
or reduces radio guards (monitoring' on other government-required frequencies.
Voice-radio use increases during periods of reduced visibility. This phe-
nomenon can quickly lead to overloading of the bridge-to-bridge radio channel,
especially in harbors and congested waterways at the time when radio communi-
cations are most urgently needed (Ives et al., 1992; Walsh, 1993; Young, 1994~.
The network is further pressured by the widespread availability of VIIF radio-
telephones to the commercial fishing industry and recreational boaters, and oc-
casional unauthorized use of frequencies reserved for bridge-to-bridge commu-
nications. Thus, although communications can be said to have improved, they
are overloaded at times. Development of alternative means of communications,
such as electronic data transfer of traffic and position information, would seem
to offer a viable means of sustaining, and perhaps improving, the safety benefits
achieved through vessel-to-vessel and vessel-to-VTS communications (Ives et
al., 1992; Martin, 1992b; Young, 1994~.
Navigation Technology
Building and maintaining shiphandling skills is a never-ending training re-
quirement. To the degree that interpretation of vessel response is a problem, real-
time precision positioning systems, real-time environmental information, and
automated decision aids potentially can be applied to reduce the potential for
human error. Electronic charting systems and Electronic Chart Display Informa-
tion Systems (ECDIS), in particular, hold tremendous promise for improving
vessel navigation and piloting. But with the introduction of new technology
come new validation requirements and training needs (Chapters 6 and 7~. If
history is any guide, there will also be a proliferation of different equipment
configurations, inhibiting the ability of marine pilots to maintain familiarity with
all of them. Thus, risk could be increased if the introduction of new technology
is not planned and implemented carefully, particularly with regard to implica-
tions for training needs and operating practices.
The widespread introduction of radar is instructive in this regard. Paramore
et al. (1979) identified radar-related problems, including limits in design capabil
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MINDING THE HELM
ities of equipment, poor equipment-operating condition, inadequate operator rec-
ognition of when to use available equipment, and inadequate operator skills for
using equipment effectively. Radar technology has improved substantially since
1979, including development of reliable ARPA systems (for coastwise and ocean
transits) and daylight radar presentations. Nevertheless, marine pilots report that
the substantial variation in equipment configurations and capabilities, particular-
ly with the availability of advanced digital features, sometimes makes radar
operation difficult. There are simply too many configurations for individual pi-
lots to remain familiar with all of them despite the availability of courses in radar
plotting (a manual radar-plotting course is required for renewal of mariners'
licenses and for pilots' licenses or endorsements). ARPA systems are especially
varied and not suitable for manual plotting. Furthermore, marine pilots and dock-
ing masters in some operating areas have limited incentive to acquire familiarity
with ARPA systems because of the limitations of such systems noted earlier.
The difficulty of maintaining familiarity with all forms of technology can be
expected to grow as automatic dependent surveillance (ADS), electronic chart-
ing systems, including ECDIS; integrated bridges; and other high-technology
systems begin to proliferate aboard ships and as bridge teams become smaller.
At the same time, training requirements for bridge teams will change, probably
becoming more stringent, and most likely requiring individuals comfortable with
high-technology systems. This change may necessitate recruitment of individu-
als with advanced education at the same time that seafaring careers are losing
popularity because of the work demands placed on merchant crews and the lack
of opportunity to relax while a vessel is in port.
Shore- and Waterway-based Navigation Support Services
An alternative to onboard systems for addressing causal factors in piloting
accidents is the use of traditional off-ship aids to navigation and shore-based
traffic support. Traditional aids to navigation such as buoys continue to be im-
portant (Ramaswamy and Grabowski, 1992J. They can be improved to facilitate
visual acquisition and use. Use of shore-based navigation support systems such
as VTS is growing slowly but cannot replace effective performance by masters,
bridge personnel, and marine pilots. The effectiveness of shore-based systems in
offsetting human errors such as those found in collisions, rammings, and ground-
ings is an open question. VTS can make a positive contribution, but there is also
the potential for "VTS assisted" accidents (CCG, 1984, 1988, 1991c; EC, 1987;
Herberger et al., 199 1; Ives et al., 1992; Maio et al., 199 1; Young, 1992, 19941.
Data on Potage Risk
Pilotage is a response to risk that, if effective, reduces the probability of an
accident. As pilotage is already an expert service, only incremental improve
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RISK, THE OPERATING ENVIRONMENT, AND SAFETY
181
meets may be possible through improved training, such as preparation for using
emerging navigation technology. Regardless of how good pilotage may be or
where fault may lie, pilotage often takes center stage when an accident occurs;
the effectiveness of shiphandling and position keeping are the first targets of
efforts to determine why an accident occurred. The person piloting the vessel,
whether a marine pilot, master, or vessel officer, is a discrete, recognizable entity
upon which to focus. Technical or mechanical problems such as steering gear
failure also may be readily identifiable. But underlying causal factors, particular-
ly deficiencies in professional development and human performance, are diffi-
cult to discern, even to trained marine accident investigators. Casualty data have
not been adequate to support this task (NAS, 1973, 1976, 1981; NRC, 199Oa,
1991a). Most examinations of the safety records of marine pilots have relied on
these data and have employed narrow analytical methodologies to establish points
of view (Appendix D). Lacking convincing research, discussions of pilotage
usually devolve into philosophical debates rather than rigorous analysis of risk,
task performance, and technological factors. Analysis of these issues could help
identify actions that might improve proficiency and performance of pilots, vessel
navigation and maneuvering, and related waterways management.
Controversy Over Pilot Safety Performance
The controversy over pilotage was introduced in Chapter 1; safety aspects of
the controversy are summarized here. Specific issues pertaining to safety are
pilot safety records (Booz, Allen and Hamilton, 1991; Journal of Commerce,
1989, 1992a; Leis, 1989, 1992; Neely, 1992; USCG, 1993c), oversight (princi-
pally pilot discipline; Ashe, 1984; Crowley, 1991; Journal of Commerce, 1992a;
Nadeau, 1992; NTSB, 1988a; Parker, 1988; Quick, 1992), and economics (in-
cluding pilotage rates and competition for pilotage business; Journal of Com-
merce, 1992a,b; Wastler, 1992a). When pilot safety records are discussed, eco-
nomic interests usually are lurking below the surface. Some observers argue that
where pilot groups compete, all pilotage business should be handled by the safer
group, and governance should be modified to effect this change. This concept
has fomented considerable controversy (Abrams, 1992a,b; Journal of Commerce,
1992a,b,c,d; Wastler, 1992a,c). Economic arguments seem to coincide with the
presence of larger ships and a lessening number of port calls (reducing pilotage
business). Also at issue are actual or potential shifts in shipping business be-
tween competing ports. Such shifts affect pilotage business (Abrams, 1992b);
the nature of port-specific pilotage provides virtually no flexibility for mobility
between pilotage districts. There is also very strong and continuing debate over
how much pilots should be paid for their services (Journal of Commerce, 1992a;
Wastler, 1992a). The committee, in the present report, did not address the fair-
ness of pilotage rates other than to observe that pilots are experts deserving of
suitable compensation for their services and that rates need to accomrrlodate the
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MINDING THE HELM
pilotage infrastructures insofar as they are required to support essential pilot
services (Abrams, 1992b; DOT, 1988; Sherwood, 1992~. Fairness of rates is a
matter for local determination based on circumstances peculiar to each pilotage
route. Considerations normally include infrastructure requirements, hazards pe-
culiar to the profession (especially boarding at sea), and recognition of the expert
services that are provided.
IMPROVING RISK ASSESSMENT, MANAGEMENT, AND
COMMUNICATION
The need for improved safety data and systematic performance assessment
has been identified in previous National Research Council reports (NRC, 1990a,
1991a). "Fully effective administration of safety programs depends on adequate
data resources. Without reliable and statistically valid data, safety shortcomings
cannot be identified with clarity, and once safety programs are in place, they
cannot be evaluated to determine if they are effective and whether resources
committed to safety are being used wisely" (NRC, 1991a). In addition, reliable
data on the range of identified risk factors is needed to support complete risk
assessments. Alternatives for development of data on risk and exposure that are
identified in the following sections are intended to supplement recommendations
of prior NRC reports.
Establish a Near-Miss Reporting System
Valuable early insight on actual or potential trends or problems can-be ob-
tained through routine recording and analysis of data on:
· marine accidents;
· unusual events (such as loss of propulsion, steering system failures, and
near misses that do not qualify as reportable casualties);
· marine events (such as regattas);
· fires (including fires ashore detected through VTS surveillance equip-
ment); and
· other incidents of interest to waterway administrators (Young, 19923.
Although administration of a system data base is best handled by a single
organization in order to maintain data integrity, cooperative near-miss reporting
is nevertheless a possibility. New technologies offer the potential for collecting
key data as part of existing government and commercial operations. Information
could be recorded and maintained by a VTS, a harbormaster, Coast Guard Cap-
tain of the Port office, marine exchange, pilot dispatch office, or port authority
operations office, if such offices were equipped and staffed for this purpose.
Improvements in collection and analysis appear feasible using advances in inte-
grated electronic display technologies and software (such as automated tracking
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RISK, THE OPERATING ENVIRONMENT, AND SAFETY
183
capabilities) to automate collection of key data as it is processed during opera-
tions. Once data sets are automated, pre-formatted reports and options for sup-
plemental sorting and presentation (including graphics) could offer a very con-
venient means to support program assessment and administration. Analysis of
acquired safety-performance data and application to program analysis, planning,
administration, and implementation are also feasible at the port level using auto-
mated relational data bases and computer graphics. These activities could either
be integrated with VTS computer-based operating systems or accomplished off
line using desktop computers and software.
Implementation plans would need to address such factors as information
sharing between the port community and the Coast Guard, potential liabilities,
and fairness in characterizing the performance of individual vessels or vessel
classes. An earlier attempt at developing and implementing such a maritime
near-miss reporting system failed when participants were wary of attribution
difficulties. Surmounting these difficulties would be important in implementing
an effective near-miss reporting system.
Establish an Exposure Data Base
Limited information is available on traffic flows, seasonal variations, daily
variations, trouble spots, trouble conditions (such as problems in an anchorages,
problem vessels, commodity flows, effectiveness and utility of navigation sup-
port systems such as NITS and onboard electronic equipment, casual factors, and
other information essential to refinement of operations and system planning.
Some of this information already is collected in varying degree but is not widely
used to plan or guide traffic regulation operations or safety programs. This infor-
mation could be combined in a reliable data base, such as the Coast Guard's
prototype exposure data base, which would facilitate identification and analysis
of risk and exposure across a wide range of variables. Risk and exposure data
could be consolidated to facilitate their use in risk analysis.
Establish a Comprehensive Risk-Assessment Program
Information is of no practical value unless it is effectively used. A continu-
ing risk-assessment program could be established at the national level. The pro-
gram would draw on information from near-miss reporting; national and world-
wide exposure databases; and relevant quantitative risk-assessment studies,
including those based on modeling performed as part of permit applications and
other activities requiring risk assessment and other appropriate safety informa-
tion. The purpose would be to provide near-term capability to detect trends in
shipping that affect marine, public, and environmental safety and U.S. economic
interests. The program also would provide essential data for planning improve-
ments to the marine traffic safety system, setting priorities for regulatory initia
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MINDING THE HELM
fives, and determining benefit-cost relationships for possible regulatory require-
ments and government programs.
Databases would need to be constructed to support quantitative risk assess-
ments, including valuation of consequences, comparisons of alternative strate-
gies, and provision of absolute risk values. Such an effort would require coordi-
nation among worldwide regulatory, classification, and insurance interests to
ensure that the data base was large enough to provide statistically significant
results. Implementation would require long-term commitment of resources by
the Congress, the Department of Transportation, and the agency designated to
conduct the program.
Representative terms from entire chapter:
marine accidents
