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Human factors in ship design and operation: Experiential learning
Vincentius RumawasDoctoral thesis
2
Introduction
Background:
• Fatal accidents at sea
• Caused by human errors and/or human-related factors (mostly)
• Human factors were barely a consideration when designing a ship
3
(introductory) Questions:
Several preliminary questions were raised:
• Is «human factors» really neglected in (ship) design? or
• Is «human factors» actually considered?
• How is it implemented?
• Is there any effect of implementing human factors to reducing the probability of accident?
4
Some definitions
• “human factors”:
– “Ergonomics (or human factors) is the scientific discipline concerned with the understanding of interactions among humans and other elements of a system, and the profession that applies theory, principles, data, and other methods to design in order to optimize human well-being and overall system performance” (IEA, 2012)
– “human factors” is concerned with the task people perform and the environment they do it in – fitting the job to the person. The topic of human factors is divided into eight considerations: habitability, maintainability, workability, controllability, manoeuvrability, survivability, occupational health and safety (OHS) and system safety (LR, 2008).
NB: “human factors” ≠ “human element” (physiological, psychological), “human error”, “human performance”, “HSE”, “human reliability”.
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(formal) Research questions
1. How are HF and different aspects of HF taken into account in ship design?
2. Is there any significant effect of HF considerations to incidences on board?
a) Does ship design have any significant effect on HF evaluation?b) Does ship design have any significant effect on incidences on board?
3. Are the existing standards for HF in ship design effective?
4. What factors strongly influence crew performance at sea?
5. What are the underlying factors of HF in ship design?
6
Research design
• RQ 1:
How are HF and different aspects of HF taken into account in ship design?
– There are several ways to answer this Q:
• Ask the designer, the shipyard and/or the shipowner, or check the design specification/contract
Check and review the ship itself Ask the users Consult the existing rules, regulations and standards available
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Research design
RQ 1
RQ 2
RQ 3
RQ 5
RQ 4
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Study 1. Literature study
To check if human factors issues are taken into account in the existing standards, a survey of literature was performed.
Two questions are to be answered:
What /which publications contain HF?
Which aspects of HF are addressed/considered?
Results:
“A Content Analysis of Human Factors in the Design of Marine Systems”.The International Conference on Ship and Offshore Technology, 11-12 Nov 2010, Surabaya
“A Content Analysis of Human Factors in Ships Design”The International Journal of Maritime Engineering, RINA Transactions Part A3, Vol 156, Jul – Sep 2014
RQ1. How are human factors and different aspects of human factors taken into account in ship design?
Study 1. … Literature study
Results
• There are abundant documents cover HF. HF issues have been sufficiently addressed. The documents are optional.
• All HF DIMENSIONS are covered
• SYSTEM SAFETY is the most mentioned
• MAINTAINABILITY is covered the least
• HF issues is developing very fast
• HABITABILITY (COMFORT) and CONTROLLABILITY are covered the most extensively,
including:
– HAB: Noise, vibration, indoor climate & lighting/illumination
– CONT: Alarms, control centres, workstations, control & switches
RQ1. How are human factors and different aspects of human factors taken into account in ship design?
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Study 2. Exploratory field study
To check if the facts in reality is in accordance with the facts on paper
Exploratory field surveys were performed using qualitative approach, incl:
• Observation
• Interview & discussion
Results:
“Offshore supply vessel design and operation: A human factors exploration” European Safety Reliability Conference, 18-22 Sept 2011, Troyes France.
“Exploratory surveys of human factors on offshore supply vessels in the Norwegian Sea”Naval Engineers Journal, Vol 125, issue 2, June 2013.
RQ1. How are human factors and different aspects of human factors taken into account in ship design?
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Study 2. Exploratory …
Some issues on ship design in general were documented:
Illumination problems on the bridge Ergonomic issues; no leg space, incorrect
height/orientation Problem with access & personnel movement, etc.
Previous incidences & accidents on OSV were also documented:
• Person squeezed between moving containers• Poor autopilot interface system• Collision with offshore installations
Hansson 2006, PSA Norway 2011
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Study 3. Qualitative study
Human factors framework
derived from:Lloyd’s Register, 2008, 2009 and developed in Rumawas & Asjbjørnslett 2010
Study 2. Exploratory field study.
Represents one of the most advanced technologies in the maritime industry
The design changes rapidly and has leapt forward beyond most conventional vessels
Many improvements were made together with the ship
An OSV is a combination of a bulk, general cargo, container and a tanker, plus some extra functionalities
The object of the study:
OFFSHORE SUPPLY VESSEL
Study 2. Exploratory field study
OSVs in Norwegian Sea:
• Carry goods from base to offshore platforms (and back)• 12-16 crew on board• Make 2-3 trips per week, visiting 2-6 platforms per trip
Study 2. Exploratory …
Sensitive to motion, esp rolling Slamming is disturbing High pitch noise (bow thrusters, on DP
operations)
Relatively stable, but sensitive to pitching
No slamming effect Squeaking noise inside the cabin
Study 2. … Exploratory
• OSV A • OSV B
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Study 2. … Exploratory
Other issues were noted,
in terms of Controllability:
Illumination problem
Flooding of alarms
Abundant communication
Dangerous failures:
DP system failure
Blackout
Study 2. … Exploratory
Ergonomics issueLadder issue
Study 2. Exploratory field study
Lessons learned
Increased bulwark height, to avoid green water Modification of the autopilot system Defined 500 m safety zone to avoid collision
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Study 2. Qualitative study
Conclusions
In general, HF is already been considered in OSVs design; The crews in general are satisfied with their vessel There is no such thing as a perfect ship There is always room for improvement
Different problems are experienced by different vessels HF problems are unique (noise, motion, controllability, etc.) Some issues remain (illumination, layout, space, stairs, access)
Best satisfying: Habitability & Workability OHS & safety-related dimensions were addressed without compromise Lowest satisfying: Maintainability
RQ1. How are human factors and different aspects of human factors taken into account in ship design?
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Study 3. Quantitative study
To check if the qualitative findings are valid
An explanatory study using quantitative approach was conducted
Results:Human Factors on Offshore Supply Vessels in the Norwegian Sea – An Explanatory Survey
Accepted in the International Journal of Maritime Engineering, RINA Transactions
RQ1. How are HF and different aspects of HF taken into account in ship design?RQ2. Is there any significant effect of HF consideration to incidences on board?
Study 3. … Quantitative
• Human factors • Habitability are significantly
addressed• Workability• Dimensions of human factors are not rated
equally:• OHS is rated more highly than workability
and maintainability• Maintainability is rated lower than
habitability, workability and OHS
RQ1. How are human factors and different aspects of human factors taken into account in ship design?
Study 3. Quantitative
• There is an indication that human factors rating varies as a result of OSV design, but the finding is inconclusive (due to numerical correction)
• And, so are for the habitability and workability
RQ2a. Does ship design have any significant effect on HF evaluation?
Study 3. Quantitative
• There is a significant difference in water on deck incident as the result of OSV design
• There is a significant difference in moving cargo on deck incident as the result of OSV design
RQ2b. Does ship design have any significant effect on incidences on board?
Study 3. Quantitative
• Habitability has a positive effect on the frequency of personnel becoming seasick, fatigue and experiencing sleep disturbance.
• Maintainability has a negative effect on the frequency of fire or explosion on board.
RQ2. Is there any significant effect of HF consideration to incidences on board?
Study 3. Quantitative …
Yerkes-Dodson Law
Or known as the inverted U model
When there was little pressure, deadline was flexible, the work wasn’t challenging, performance is low
When people were given the right amount of pressure, they do their best (optimum)
Too much pressure, then performance can suffer
29
Study 4. Evaluation study
To check if the existing standards of human factors in ship design and operation are effective
An evaluation study was conducted, by performing physical measurements on board, combined with some observations and daily diaries filled in by the seafarers after every watch
RQ3. Are the existing standards of HF in ship design effective?
Study 4. Evaluation study
Methodology Data collection:
July 2011 (summer) October 2011 (winter)
Noise level measurement: Class 2 sound level meter
Bruel & Kjær type 2236 A-frequency weighting Average equivalent
continuous sound level (dB)
Ship motion measurement:
High-precision tri-axis inertial sensor: ADIS16364 from Analog Device
Report:Human Factors Evaluation in Ship Design: A Case Study on Offshore Supply Vessels in the Norwegian Sea, Part I: Theoretical Background and Technical Constructs
Naval Engineers Journal (accepted)
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Study 4. Evaluation studyResults of noise level measurements:
Study 4. Evaluation study
NORDFORSK 1987 (RMS):2.0° Cruise liner4.0° Heavy manual work6.0° Light manual work
ROLL MOTION
Criteria (RMS):
4° (NATO 2000) 6° (NORDFORSK 1987)
33
Study 4. Evaluation study
PITCH MOTION
Criteria (RMS): 1.5°
(NATO 2000)
Study 4. Evaluation study
MSI criteria (NATO 2000):– 20% of crew at 4 hours
MII criteria (NATO 2000):– 1/min (=1.0)
• MII risk level (Graham 1990):0.1 : ‘Possible’0.5 : ‘Probable’1.5 : ‘Serious’
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Study 4. Evaluation study
Conclusions:
The existing noise criteria do not reflect comfort Disturbing noises [impulsive noise, high pitch noise, squeaking noise
and hammering noise] are not covered nor captured
Motion criteria need to be revised for OSV operations They are not realistic; the criteria are too high (too lenient),
especially MII and roll motion.
The MSI (McCauley et al, 1976) is extremely conservative for seafarers population, needs to be adjusted
RQ3. Are the existing standards of HF in ship design effective?
36
Study 5. Multivariate analysis
• To find out which factor(s) influence seafarers’ performance at sea, a multivariate analysis was performed.
• Report: Human Factors Evaluation in Ship Design: A Case Study on Offshore Supply Vessels in the Norwegian Sea, Part II: Multivariate Analyses and Structural Modelling Naval Engineers Journal (accepted)
Daily diaries (questionnaires)• Anonymous• Based on NATO
questionnaires• Completed by the
seafarers after every watch
RQ4. What factors considerably influence crews’ performance at sea?
Study 5. Multivariate …
Study 5. Multivariate analyses …
Time of watch
Study 5. Multivariate …
40
Study 5. Multivariate …
RQ4. What factors considerably influence crews’ performance at sea?
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Study 6. Theoretical evaluation
Some issues were found when developing HF check lists and questionnaires, indicating that the concept of HF is still developing
A theoretical evaluation was performed to evaluate or to confirm the concept of HF in ship design & operation, using factor analysis
Report:Human Factors in Ship Design and Operations: A Preliminary Survey of the Theoretical ConstructThe International Journal of Maritime Engineering, RINA Transactions (accepted)
RQ5. What are the underlying factors of HF in ship design (and operation)?
42
Study 6. Theoretical evaluation
Controllability
Workability
Habitability
Cargo facilities
Reliability, Automation and Maintainability
RQ5. What are the underlying factors of HF in ship design (and operation)?
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Study 6. Theoretical evaluation
Reliability, operability and maintainability
Interfacing complexity
Ship handling and manoeuvrability
System & procedure
Deck working condition
ER & ECR
Habitability
RQ5. What are the underlying factors of HF in ship design (and operation)?
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Study 6. Theoretical evaluation
A model showing human factors considerations in ship design and operation is presented as a result of the theoretical study
RQ5. What are the underlying factors of HF in ship design (and operation)?
45
Conclusion
HF have been sufficiently addressed, developing very fast, optional. Hab & Contr covered the most, Maint the least
HF are considered in OSV design, lessons learnt, no perfect ship, room for improvement. HF problems are unique, some problems remain. Hab & Work best satisfying, OHS no compromise, Maint least
Noise ≠ comfort, disturbing noises not covered, motion criteria (incl. roll, pitch, MII, slamming) are not realistic, need to be revised, MSI is extremely conservative for OSV crew
HF are significantly addressed (incl Hab & Work), HF aspects are rated differently (OHS>Work>Maint). Deck incidences [grwater & cargo] = f(OSV design), Seasick, Sleep = f(Hab); Fire & expl = f(Maint)
Crews’ prfrmnc = f(roll, work shift, sleep amount, symptoms). Symptoms = f(sleep amount & quality, non-ship relt’d sleep problems). Sleep = f (ship-rlt’d sleep problem), Ship-rlt’d sleep problem = f(pitch)
CONTr, WORK, HAB, CARGO, RAM (reliability, automation & maintainability)A model of interconnectivity of HF
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Discussion
• Very limited data, generalisation is then limited:
– OSV, 93-94 m. LOA, relatively newly built (2-3 years old)– Qualified, well-trained personnel, characterised by Nordic population,
Norwegian shipbuilding and petroleum industries– Only one researcher, two OSVs, 42 crew members
• The scope of the study is very broad ⤇– the investigations seem too brief– lack of detailed analysis
• Shows that HF can be assessed and their effectiveness can be measured
47
Recommendations
Standards and criteria be re-examined within a reasonable period of time, especially in case an incident occurs
Human factors considerations should be inserted as one of the criteria in ship design spiral; that include: A human factors engineer/expert User opinions Design specification
For designers: Establish a direct and conducive communication with the users Understand the way the users operate the vessel in their natural environment Step-by-step improvement is advised, radical change of design should be avoided
48
Recommended Future Works
• Extend the study by involving designers and shipbuilders
• A fewer topic should be selected for human factors investigation– Controllability– Comfort
• More accurate methods should be used for quantitative and evaluation studies:– Continuous data recording on board– Incident record– Actiwatch
• Developing human factors standards which related to crews’ performance and comfort, not only health & safety
Thank you for your kind attention
The end of the presentation