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OCR for page 59
4
Establishing Safe Crew Levels
The U.S. Coast Guard relies on a combination of laws, regulations,
tradition, and informal policy guidance to set crew levels. This piecemeal
approach was effective in the past when technological change was slow and
manning scales generous. However, it is not a sound basis for decisions
that must accommodate changing technology and minimal manning.
Systems engineering techniques are beginning to be used in manning
decisions by shipping companies. These techniques include the construction
of computer models of vessel operations, so that shipboard functions and
tasks can be precisely specified and evaluated for a ship of a given design,
trade, and level of technology under normal and emergency conditions.
Manning scales can be established accordingly.
This chapter reviews current regulatory procedures for Coast Guard
manning determinations and discusses the advantages of systems engineer-
ing as an alternative. It also presents a functional task analysis model
developed and tested by the committee. With appropriate extension and
refinement, such a model could offer regulators, owners, and operators the
tools for making manning decisions on a sound analytical basis. As ship
operating technology and crewcut grow more complex, such an approach
will become increasingly necessary.
U.S. COAST GUARD CERTIFICATION PROCEDURES
The U.S. government controls vessel manning through statutes, which
are implemented in regulations and interpreted by judicial rulings. The
59
OCR for page 60
60
CREW SIZE AND MARITIME SAFETY
regulations are promulgated and enforced by the U.S. Coast Guard. In
addition, the Coast Guard specifies the minimum complement of licensed
and unlicensed persons necessary for safe operation of each vessel; these
requirements are set out by each vessel's Certificate of Inspection (COI),
as required by the International Convention on the Safety of Life at Sea
(SOLAS).
Until the late 1970s, most U.S.-flag vessels sailed with crew com-
plements well above the levels specified in Coast Guard-issued COIs as
necessary for safe navigation. Recent attempts to cut costs have brought
dramatic crew reductions, however, with some ships operating at or near
their COI minimum.
The Coast Guard anticipates that future technical and organizational
innovations will result in ships with crews of a dozen or fewer highly trained
specialists to operate the vessel and conduct emergency maintenance, and
that routine maintenance and cargo operations will be the responsibilities
of shore-based personnel (Connaughton, 1987~. Current statutes and reg-
ulatory procedures will be inadequate to accommodate these innovations
(see Chapter 5~.
Regulatory Procedures
The owner or operator of any ship that requires a COI must submit
an application for inspection to a Coast Guard Officer-in-Charge, Marine
Inspection (OCMI). The owner also must submit descriptions of the vessel
and the kind of trade in which it will be used. On the basis of these
descriptions, the vessel is placed in a particular class or inspection category
(e.g., freight vessel, tank vessel, or offshore supply vessel). Depending on
its class and intended service, the vessel's design and construction plans
are reviewed by either the Coast Guard's Marine Safety Center or the
American Bureau of Shipping, acting on behalf of the Coast Guard.
Once the vessel's class is determined, the owner or operator can
develop a manning plan according to standards set out in the Coast Guard
Mann e Safely Manual. The plan is submitted to the OCMI in the region
where the vessel is being built. The OCMI then sets a conditional manning
level, which is subject to revision if an OCMI later decides a change is
necessary for safety reasons.
The OCMI, in establishing manning levels, considers applicable statutes
(especially Part G. Title 46, of the U.S. Code [U.S.C.~), regulations (46 CFR
Part 15), and Coast Guard policies set out in the Mann e Safer Manual and
Navigation and Inspection Circulars (NVICs). Special conditions such as
shipboard automation and monitoring equipment, route and trade char-
OCR for page 61
ESTABLISHING SAFE CREW LEVELS
61
acteristics, maintenance and support facilities, and self-imposed operating
limitations can also be considered, along with the documented history of
any vessel being modified or reflagged.
Ordinarily, the OCMI's manning determination is a routine matter.
However, if the manning request involves innovation (the first ship of
a series, reduced manning on an existing ship, or a ship whose class is
not covered in policy guidelines) the OCMI forwards the request to the
Merchant Vessel Personnel Division at Coast Guard Headquarters.
When the OCMI and headquarters reviews are complete and the vessel
has completed sea trials, its manning complement is placed on the COI.
The complement specified on the COI represents the minimum number of
personnel considered necessary for safe operation, along with the license
and document grades and endorsements those personnel must hold. (The
COI will also specify the maximum numbers of "other persons in the
crew" and "persons in addition to the crew," according to the available
accommodations and lifeboat capacity.)
The Coast Guard normally does not specify manning levels outside
the deck and engineering departments (such as stewards), except for radio
officers, which are required by law and international agreement aboard
most ocean-going commercial vessels.
In 1983, a significant change in the manning statutes was made, partly
to accommodate increased number of requests for reduced manning. Pre-
viously, the law required manning levels to be determined as the minimum
necessary for safe navigation. In that year, a recodification of 46 U.S.C.
resulted in a requirement to set manning levels as the minimum "necessary
for safe operation" (46 U.S.C. § 8101(a); emphasis added). As a result
of this change, the agency pays more attention to maintenance plans in
manning determinations today than it did in the past. (Well maintained
equipment is especially vital with smaller crews.) In most cases, the agency
requires a strong preventive maintenance program.
Owners or operators wishing to reduce manning on existing ships
through automation must submit an application, together with required
documentation showing how the vessel may be operated safely at the
reduced level. Often the Coast Guard grants conceptual approval of such
plans before investments in vessel modifications are made. After the
modifications are made, the systems must undergo a trial period to prove
their reliability and safety. During this period, which may last for 6 months
or more, the owner must keep detailed records of the vessel's operating
history, crew overtime, equipment casualties, and other information. A
Coast Guard inspector sails aboard the vessel, observing routine operations
and emergency drills to assess the adequacy of the reduced manning.
OCR for page 62
62
Deck Department
CREW SIZE AND MARITIME SAFETY
Manning Reductions to Date
Deck department reductions to date have been the simplest crew
reductions to evaluate and have generally been processed in the field by
the cognizant OCMIs. The most common reduction at present involves the
addition of devices such as constant-tension winches, a watch call system,
and sanitary and coffee facilities on the bridge. If these additions are
approved, up to three ordinary seamen (OSs) may be removed from the
vessel's COI. If they are removed, the COI may be further amended to allow
two of the required six able-bodied seamen (ABs) to be "specially trained"
OSs (with the physical and training qualifications of able seamen, but
holding ordinary seaman endorsements). Some day-working maintenance
workers may be required in lieu of the removed ordinary seamen.
Engine Department
Engine department reductions are more complex and are usually re-
ferred to Coast Guard Headquarters for approval. Technical standards are
set out in 46 CFEt Part 62 (Vital System Automation, § 62.5~Manning).
Such reductions are of three types: (1) elimination of the requirement for
fire/watertenders on steam-powered vessels; (2) minimally attended engine
room operation (with the addition of a central engine room monitoring and
control station) to eliminate the need for several or all unlicensed watch
standing personnel; and (3) periodically unattended engine room operation,
with a variety of labor saving devices and monitoring and control systems
so that the engine room can be left unattended for prolonged periods.
Maintenance Departments
Use of a maintenance department (see Chapter 1) increases oper-
ational flexibility and permits reduced manning through reassignment of
personnel. Maintenance departments are subject to the approval of Coast
Guard Headquarters.
Future Manning Reductions
In the relatively near future, more complex manning reductions are
likely to be requested. For example, the Coast Guard may receive requests
to implement the dual-qualified, watch officer concept on the Japanese
model. In the long run, the advance of technology will generally tend to
erode the departmental distinctions aboard ships.
OCR for page 63
ESTABLISHING SAFE CREW LEVELS
A FUNCTIONAL MODEL FOR ASSESSING CREW LEVlELS
63
The committee developed a functional model for task analysis and
evaluated it by applying it to data from two actual ships. The model proved
easy to use, comprehensive, and accurate. With further development, it
could be used by the U.S. Coast Guard and by ship owners and operators
to determine, systematically and reliably, the minimum manning levels for
a variety of ship types and operating conditions. Additional work, for
example, would make it more robust and flexible and would add risk or
hazard analysis information.
The thorough assessment of shipboard functions and tasks permitted
by the model would be particularly useful to the Coast Guard in setting
manning levels. An initial determination of crew requirements could be
made using the model with data from expert opinions, and then confirmed
during sea trials by entering actual voyage data into the model.
Certification for smaller crews, using the model, could be based on
actual performance, rather than on judgment alone. Such a process might
have two steps. First, the owner or operator would submit for Coast
Guard conditional approval a functional analysis of crew activities (with
specified crew numbers and structure, skills and training, voyage profile,
and operation and maintenance plans). Upon conditional approval, the
vessel would be subjected to sea trials of up to six months, with logs of
crew activities. The data from the trials would be used to validate the
results obtained from the model.
Such a procedure would give the Coast Guard a sound basis for
decisions, explicitly taking account of the vessel's type, voyage profile, level
of technology, and operating conditions. It would replace the current
system of reliance on a patchwork of manning statutes, informal policy,
and tradition. It would thus permit the U.S. shipping industry to take
advantage of new technology without sacrificing the safety of vessels or
shipboard personnel.
Shipboard Task Analysis
Over the last decade, the maritime community has combined concerns
about the safety of navigation in an increasingly complex environment
with concerns about more efficient operations. One trend toward reducing
operational costs and increasing operational safety focuses on applying
systems engineering.
Systems engineering normally begins with a requirements analysis to
determine the mission and functional requirements of present and future
systems to help identify the tasks that must be supported (Figure 4-1~.
Next, a task analysis identifies the tasks presently performed and those
OCR for page 64
64
Tasks
Requirements Analysis
Task Analysis
Man-machine
tradeoff studies
Organizational Analysis
Software Analysis
l
Hardware Analysis
CREW SIZE AND MARITIME SAFETY
Results
System requirements
Tasks to be supported
l ~ · Present
· Future
Man-machine
tradeoff matrix
Organizational constraints
Software Breakdown
· Information Systems
· Decision Support Systems
· Expert Systems
Hardware Design and
Specifications
FIGURE 4-1 Systems Engineenng Approaches to Shipboard Manning.
to be performed In the future. During the task analysis, a man-machine
tradeoff study is performed to determine which tasks will be performed by
people and which by machines.
The next step is an organizational analysis to determine how the human
and machine tasks of the future will be supported in the organization. A
software analysis then focuses on the information processing requirements
of the tasks allocated to machines to determine, for example, which of the
machine tasks can be supported with conventional software, and which are
more amenable to decision support systems or expert systems implementa-
tion. Finally, a hardware analysis is performed to identify the appropriate
hardware.
The Committee's Functional Model
The committee's model is a task analysis tool applicable to all ship
types, classes, and trades. It permits the assessment of manning over an
entire voyage and in emergencies such as shipboard fires. Appendix E
describes earlier shipboard task analyses.
OCR for page 65
ESTABLISHING SAFE CREW LEVELS
65
The model uses a taxonomy of 10 general functions, broken down into
subfunctions, and sub-subfunctions that describe all aspects of shipboard
operations across a broad spectrum of cargo, ship, and voyage types (dibble
4-1~. The general skills and time required to perform these functions are
then determined to yield qualitative and quantitative minimum manning
requirements.
The model was applied to two actual ships. First, the taxonomy of
functions was used to code two sets of data from American President
Lines (APL): 30 months of actual maintenance data and summary deck
operations data developed by a panel of APL ship's officers (described later
in this chapter). Later, the taxonomy was used to code engineering and
deck operations data developed by a panel of Exxon ship's officers for a
specific Exxon ship and voyage profile (also described below). This coding
demonstrated the comprehensiveness of the initial taxonomy and resulted
in some refinements.
Descr~pi~on of the Model
Ten major shipboard functions identified in Table 4-1 are: cargo,
ballast, navigation, main engine operations, auxiliary equipment operations,
long-range radio operations, deck operations, general operations, general
administration, and hotel functions. Data were collected from APL and
Exxon for each function, subfunction, and sub-subfunction, and for each of
three voyage phases- at dock, transiting restricted waters, and at sea. The
time it took to perform any specific function was recorded for the range
(i.e. the minimum and maximum times) and for the average time required.
The maximum number of people required to perform the function at
any specific time was recorded, along with the number of persons of any
given skill level required. For example, if the average time for a given
function (such as loading cargo) was four hours, and one person of a
given skill classification (a licensed deck officer, for example) worked on
the function full-time, while another of the same skill classification was
required for two hours, 1.5 would be entered as the number of people
of that skill classification required to perform that function. Five general
skill classifications were used: licensed (N1) and unlicensed (N2) deck
personnel; licensed (E1) and unlicensed (E2) engineering personnel; and
steward's department personnel (G).
Any tasks that must be done in conjunction with the specific task were
also noted. Where the manning requirements for a specific function under
restricted visibility were greater than those in good visibility (for example,
while transiting restricted waters), the restricted visibility requirements were
recorded. Above the function coding portion of the form, spaces were
provided for indicating whether tasks were mandatory or discretionary for
OCR for page 66
66
CREW SIZE AND MARITIME SAFETY
TABLE 4-1 Shipboard Functions Identified in Committee's Functional Model
TASKS TO BE EVALUATED
1.0 CARGO
1.1 On-load
1.2 Off-load
1.3 Maintenance of cargo
equip~nent/deck stores/wares and
ballast tank cleaning and repairs
of cargo, desk equipment, stores
and wares
1.4 Record keeping (port logs)
1.5 Repair
1.5.1 Reefer-maintenance
1.5.2 Inspection
2.0 BALLAST
2. 1 On-load
2.2 Off-load
3.0 NAVIGATION
3.1 Track keeping
3.1.1 Day—good visibility
3.1.2 Night~ood visibility
3.1.3 Restricted visibility
3.2 Maneuvering
3.2.1 Chart correction
3.3 Collision avoidance
3.4 Voyage/passage planning
3.5 Record/chart keeping and
update/bridge logs/charts and
navigation information
3.6 Maintenance
3.6. 1 PMS
3.6.2 Unscheduled
3.7 Test vital systems
3.7.1 Prior to leaving port
3.7.2 Prior to entering port
3.8 Bridge housekeeping
3.9 Weather monitoring
3.9.1 Reporting
3.9.2 Planning
3.10 Hull Performance
3.10. 1 Monitoring
3.10.2 Maneuvering
3.10.3 Planning
Training (equipment operations,
procedure review, standard
operations)
4.0 ENGINE OPERATIONS
4.1 Operations routine and watch
standing
4.2 Maintenance
4.2. 1 Unscheduled
4.2.2 PMS
4.3 Record keeping
4.3.1 Records and record
keeping
4.3.2 Soundings
5.0 AUXILIARY EQUIPMENT
OPERATIONS (all non-main engine
propulsion equipment)
5.1 Generators
5.1.1 Operations
5.1.2 Unscheduled
maintenance
5.1.3 PMS
5.2 Fuel oil systems
5.2.1 Operations
5.2.2 Unscheduled
maintenance
5.2.3 PMS
5.3 Boilers
5.3.1
5.3.2
Operations
Unscheduled
maintenance
5.2.3 PMS
Evaporators
5.4. 1 Operations
5.4.2 Unscheduled
maintenance
5.4.3 PMS
~ ~ . . .
5.5.1
5.5.2
Refrieerator/air conditioning
Operations
Unscheduled
maintenance
5.5.3 PMS
Sewage systems
5.6.1 Operations
5.6.2 Unscheduled
maintenance
5.6.3 PMS
Inert gas systems
5.7.1 Operations
5.7.2 Unscheduled
maintenance
5.7.3 PMS
5.8 Electrical/electrical control
systems
5.8. 1 Operations
5.8.2 Unscheduled
maintenance
5.8.3 PMS
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ESTABLISHING SAFE CREW LEVELS
TABLE 4-1, Continued
67
5.9 Tools and test equipment
5.9.1 Operations
5.9.2 Unscheduled maintenance
5.9.3 PMS
5.10 Pumps
5.10.1 Operations
5.10.2 Unscheduled maintenance
5.10.3 PMS
5.11 Fuel transfer
5.12 Record keeping
6.0 LONG RANGE RADIO
OPERATIONS
7.0 DECK OPERATIONS
7.1 Dockinglundocking
7.2 Mooring/unmooring (offshore) 8.15
7.3 Anchoring/heaving-in 8.16
7.4 Helicopter operations
7.5 Underwater lighting
7.6 Tugs/crane using
7.7 Preparation for going into
yard/drydock
8.0 GENERAL OPERATIONS
8.1 Drills Lifeboat, firefighting, etc.) 9~4
8.2 Maintenance (lifeboats) 9~5
8.3 Safety tours
8.4 Vessel fabric maintenance
(paint, chip. grease, coat)
Deck equipment maintenance
Qights, structure, mooring
equipment, anchor, bow transfer,
gangway, capstans, windlass)
8.6 Line and wire maintenance
8.7 Stores and supplies
8.7.1 Handling
8.7.2 Storage
8.7.3 Ordering
8.8 Other training
8.9 Medical
8.10 Bunkering
8.11 Safety equipment maintenance,
gas test meters, and gauging
equipment
8.12 Vessel structure
. , .
mamtenance/repalr
8.13 Steering gear maintenance
8.14 Cleaning/wash down
8.14.1 Deck
8.14.2 Engine room
housekeeping
Supervise shore personnel/gangs
Stability and cargo planning
9.0 GENERAL ADMINISTRATION
9.1 Financial
9.2 Labor relations
9.3 Meetings
9.3.1 Shipboard management
9.3.2 Safety
Payroll
Regulatory requirement
. . .. . .
mon~tonng/lnspecuans/
walkarounds with inspection
regulatory authonues
9.6 Special projects
10.0 HOTEL FUNCTIONS
10.1 Catenng
10.2 Accanrnodai~on and space
clearing
10.3 Management
10.4 Provisioning
10.5 Maintenance
the given time periods, and whether they were intended to be performed
by the ship's crew or by a riding crew.
To determine the manning requirements, the ship voyage profile and
operating conditions were first specified. For each shipboard function,
the average time required was recorded, then multiplied by its frequency
of occurrence per voyage. This data was then multiplied by the number
of persons of a given skill classification needed to perform the function.
This gave the total amount of time required by persons of a given skill
classification to perform that specific function during the voyage. Dividing
this figure by the total number of voyage days yielded the average time per
day required for that function; dividing this number by the average number
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68
CREW SIZE AND MARITIME SAFETY
of true working hours per day per person in that skill classification gave the
number of persons required per day. In the validation studies, described
below under the heading "Evaluation of the Model," a 10-hour working
day was used as a baseline, reflecting experience at the two companies.
This procedure was repeated for each function and skill classification.
For each skill classification, the total number of persons per day required
across all functions yielded the total number of persons of that skill required
to operate the vessel safely and to support the requisite shipboard work
load. Summing these totals across all five skill classifications (N1, N2, E1,
E2, and G) yielded the total manning requirement for that ship, that voyage
profile, and that set of given operating conditions.
Based on the two validation studies described below, it appears that
simply adding the data across all phases provides an accurate estimate of the
minimum manning requirements for a particular ship. The data can also be
calculated for different phases of the voyage (at dock, transiting restricted
waters, at sea) to determine if different voyage phases require different
manning levels. Similarly, if some functions are routinely performed by
a riding crew, separate calculations can be performed to determine the
appropriate manning tradeoffs between the ship's crew and the riding crew.
Emergency Conditions
The procedures described apply to normal operating conditions only.
New state-of-the-art ships may be able to operate under normal operating
conditions with crews that are too small to handle emergency conditions.
Based on expert opinions of the persons who participated in the develop-
ment and two initial validation studies of the model, the ability to fight
shipboard fires will require larger crews than normal operations on some
highly automated ships. As a result, manning requirements for emergency
conditions particularly fighting shipboard fires were analyzed. This anal-
ysis required estimating both the manning requirements for operating the
ship while the fire is being fought and those for actually fighting the fire.
Two types of fire (an engine room fire from a broken high-pressure fuel
line and a container fire on deck) were analyzed.
Operating Conditions Affecting Manning
In developing and validating the model, the committee identified a
number of operating conditions bearing on manning:
.
Operating procedures i.e., will certain maintenance functions be
performed by the ship's crew, a riding crew, or a shore gang when the ship
is in port?
· Maintenance concept employed i.e., is a maintenance department
in use?
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ESTABWSHING SAFE CREW LEVELS
69
· Crew/role 17e~ability--i.e., to what extent can persons perform both
deck and engineering functions, or possess dual certification?
· Crew coniinuity--i.e., to what extent do crew members stay together,
or train as a crew?
Ship familianty--i.e., to what extent do crew members sail on the
same ship or same class of ship?
· Regulatory and union contract requirements and restnci'ons i.e.,
interdepartmental flexibility, employment continuity aboard the same ship
or class of ship, familiarity with the specific ship.
· Personnel selection procedures/cntena i.e., skills, physical condition,
personality factors, expectation levels.
· Job design—e.g., chief mate's responsibilities.
· 7?ainingJproficiency i.e., to what extent do crew members receive
training/education to upgrade skills, or cross-train to broaden their skills?
Evaluation of the Model
To test the model's utility, it was used to determine manning re-
quirements for two different ships, operated by different companies, with
different voyage profiles. Both shipping organizations had already under-
taken extensive manning studies and both had high confidence in their
manning requirements. The first ship used was an American President
Lines C-9 container ship operating between the west coast of the United
States and the Far East. The second ship was an Exxon product tanker on a
14-day coastwise run between Houston, Texas, and a variety of southeastern
U.S. ports.
The committee's first objective was to determine whether the functional
model was adequate to accommodate all functions performed on both
ships during routine voyages. As noted above, the model was found to be
comprehensive and required only minor refinement, mainly the addition
of some sub-subfunctions (primarily in Function 5, Auxiliary Equipment
Operations).
The second objective was to determine whether the model would
produce results that accurately reflected manning requirements. This de-
termination was made somewhat differently for the two ships, as described
below.
American President Lines C-9 Container Ship Study
American President Lines (APL) had conducted an extensive study of
one of its C-9 container ships by carefully collecting actual maintenance
data over a Month period, during 25 voyages. In addition, a panel of
C-9 ship's officers had classified and developed consensus expert opinions
on the functions and manning requirements for all bridge operations. With
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70
CREW SIZE AND MARITIME SAFETY
assistance from APL personnel who had worked on the computerization
and coding of the C-9 data, the data were recoded using the committee's
functional model codes. These data were compiled and used to determine
manning requirements for the subject C-9 ship. These calculated require-
ments matched its actual manning scale, both in number (21 people) and
crew organization. They also suggested that under different operating con-
ditions (i.e., those that would provide crew continuity or familiarity with
the C-9), manning requirements could be reduced.
Four major types of fires were identified to be of concern: (1) high-
pressure fuel line break in the engine room, (2) generator fire, (3) stores fire,
and (4) container fires (from internal combustion or stack exhaust sparks).
Of these, the engine room fire from a high-pressure fuel line break was
judged to be the most labor-intensive. ~ operate the ship while fighting
the fire, two persons the master and a helmsman would be required for
machinery operations. To fight the fire, an emergency coordinator and two
three-man hose teams, each with a squad leader, would be required. This
estimate results in a total of 11 people, well below present manning.
Environ Mated Product Tanker Study
Through careful observation and study of many of their voyages, the
officers of an Exxon mixed product tanker had developed expert opinions
about the time and skill requirements for the various ship operating func-
tions. Several of the ship's officers and several senior ship captains from
other Exxon tankers helped the committee complete the function analysis
forms for the model. The data thus gathered were used to determine the
vessel's minimum manning requirements.
The vessel's present manning is 18 people: 4 N1 (1 master, 3 mates),
6 N2 (6 ABs), 4 E1 (1 chief engineer, 3 assistant engineers), 2 E2 (1
engine unlicensed, 1 pumpman), and 2 G (2 stewards).] The Exxon group
believed that two of the ABs were not actually needed, and that with
some policy modification it would be possible to operate with only one
steward. The vessel's COI authorizes a crew of 14, based on the use of a
maintenance department and only 1 steward (the maintenance department
having eliminated the need for one AB).
The manning requirements determined by the model are 4 N1, 3 N2,
4.5 E1, 2 E2, and 1.5 G. for a total crew of 15. Rounding up to the nearest
whole person in each skill classification brings the total number to 16. In
summary, the model supported the Exxon team's belief that the number of
N2s (ABs) could be reduced by at least two. By requiring the crew to do
1 Shipboard positions were classed as N1 (licensed deck), N2 (unlicensed deck), E1 (licensed
engine), E2 (unlicensed engine), and G (stewards).
OCR for page 71
ESTABLISHING SAFE CREW LEVELS
71
more of their own housekeeping, the number of stewards could be reduced
to 1, for a total of 15.
After reviewing the model's output, the Exxon team agreed that, with
minor changes in task distribution, the ideal minimum crew would be a
crew of 15: 4 N1 (1 master, 3 mates), 4 N2 (4 ABs), 4 E1 (chief engineer,
3 assistant engineers), and 2 E2 (1 engine unlicensed, 1 pumpman).
By changing maintenance procedures and assigning painting and chip-
ping to shore-based personnel, manning could be reduced by an additional
N2 (1 AB), for a total of 14.
The vessel's manning requirements for an engine room fire resulting
from a high-pressure fuel line break were analyzed and found to be the
same as the those of the APL C-9, or a total of 11 people, which is below
the minimum manning level of 14 for normal operations.
The tanker study not only validated the model's utility in determining
minimum manning requirements, it also demonstrated how the model could
be used as a management tool to make manning adjustments for greater
operating efficiency.
It should be remembered that the data used in the tanker validation
study were based mainly on expert opinion, backed up by some recorded
data and considerable deliberate observation by the team of experts and
their colleagues aboard the vessel. A next logical step would be to conduct
a validation study of the model, based on systematically recorded voyage
data for the same vessel.
The Model's Utility
The validation studies show that the model provides an accurate esti-
mate of minimum manning levels. Manning by phase (at dock, transiting
restricted waters, or at sea) can be calculated, and tradeoffs (e.g., ship crew
tasks versus riding crew tasks) can be analyzed.
Once the data for a given voyage profile and set of operating conditions
have been collected and analyzed, the model can be used to estimate the
effect of new technology (i.e., unattended engine room, decision support
systems), alternative voyage profiles, or revised operating conditions. The
model can thus be used as a management tool to assess the impact of
changes (or proposed changes) on safe manning requirements.
The model also would allow the U.S. Coast Guard, ship owners, and
operators to identify manning-sensitive tasks, manning-rich areas (can-
didates for manning reductions), simultaneous tasks (time-substitutable
tasks), tasks performed by similarly skilled personnel (skill-substitutable
tasks), and tasks requiring similar time to perform (duration-substitutable
tasks). Such tradeoff studies could assess the manning impact of new
technology; of new ship designs, layouts, facilities configurations; or new
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72
CREW SIZE AND MARITIME SAFETY
shipboard procedures, processes, and controls. Safety concerns could be
highlighted, or safety issues addressed, by maintaining minimum hourly
performance requirements in the data.
Limitations of the Model
The work to date supports the notion that the functional model devel-
oped can be used by the U.S. Coast Guard, ship owners, and operators in
determining minimum manning levels for a variety of ship types. However,
there are a number of limitations to the model as it exists:
· The model has been validated with two sets of shipping data: one
from a product tanker in the domestic trade, one from a container ship
trading between the U.S. West Coast and the Far East. Before the model
is accepted for general use, it needs to be validated against actual voyage
data for a wider variety of ship types, trades, designs, and under varying
operating conditions.
· A more thorough empirical analysis of emergency and restricted
visibility conditions needs to be conducted with the model; only anecdotal
emergency and restricted visibility information were used during the initial
validation studies.
The model is not at present tied to risk or hazards analysis data (or
a risk or hazards analysis model). If it were, model-recommended manning
estimates could be compared with preferred manning structures (from a
risk or hazards analysis perspective) to produce qualitative comparisons
and rankings between alternative manning structures.
· There is no formal mechanism within the model for ranking and
comparing alternative manning structures. This decision support capabil-
ity could be incorporated into the model, so that ranked recommended
manning alternatives, with explanations, would be the model's output.
· At present, the model does not accommodate uncertain or incom-
plete information. Neither does it accommodate decision making under
time pressure. Both capabilities could be incorporated.
· The model does not offer a graphical representation of shipboard
tasks over time, which would be helpful in visualizing those performed
at different times, at the same time, or by similarly skilled personnel. In
addition, beneath the graphic representation, a link between the model and
cost-benefit analysis data would be helpful, so that recommendations for
time- and personnel-substitutable tasks could be linked to cost data for a
quantitative and qualitative comparison.
These limitations do not suggest that the model as it presently exists
is not a useful preliminary tool in arriving at minimum manning estimates.
However, additional validation studies need to be conducted before it
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ESTABLISHING SAFE CREW LEVELS
73
is adopted for general use. The added enhancements may improve its
robustness, decision support capabilities, and ease of use.
FINDINGS
In establishing safe crew levels, the government and industry need to
consider demands on the crew: each vessel's technology, type of service,
crew skills, and quality of management and management programs. Systems
engineering methods, including functional task analysis, offer an objective
basis for such determinations. The model developed Is one approach to
implementing systems engineering approaches to determining safe ship
manning levels.
REFERENCES
Connaughton, Sean. 1987. Coast guard merchant vessel manning. Paper presented at
1987 Ship Operations, Management and Economics International Symposium, U.S.
Merchant Marine Academy, Kings Point, New York. September 17-18.
Denny, M. 1987. Shipboard productivity methods. U.S. Department of Transportation,
Maritime Administration, Washington, D.C. Volumes 1-3. February.
Liverpool Polytechnic and Collaborating Colleges. 1986. Technology and Manning for Safe
Ship Operations, Volumes 1 and 2. Department of Transport. London. November.
Schuffel, H., J. P. A. Boer, and L" van Breda, 1989. The ship's wheelhouse of the nineties:
The navigation performance and mental workload of the officer of the watch. Journal
of Navigation 42~1~:60-72.
Williams, V. E. 1983. Crew Rationalization Study: ODS Liner Vessels. U.S. Department
of Transportation, Maritime Administration, Office of Research and Development,
Washington, D.C. April
Yamanaka, K., and M. Gaffney. 1988. Effective manning in the Orient. U.S. Department
of Transportation, Maritime Administration, Washington, D.C. Report Number MA-
RD-770-87052. March 15.
Representative terms from entire chapter:
manning requirements
