Framework for Designing Reliable Propulsion Systems ofFramework for Designing Reliable Propulsion Systems ofManned-autonomous Vessels ＊Manned-autonomous Vessels *Putu Hangga Nan Prayoga ＊＊Shinichi Inoue ＊＊＊＊ **, Takumi Nakamura**
Putu Hangga Nan Prayoga**, Shinichi Inoue**, Hideaki
NomuraTakumi Nakamura ＊＊Hideaki
Nomura1. Introduction
The propulsion system of autonomous ships plays a pivotal
role in their functionality, efficiency, and environmental
impact. As the shipping industry shifts towards increased
autonomy, a better understanding of current technologies,
challenges, and potential future developments is crucial.
Nakashima et al. [1] proposed a model-based systematic
design methodology and a safety evaluation method forautonomous ships. This was applied to the Designing the
Future of Full Autonomous Ship (DFFAS) Project in Japanas a part of MEGURI2040 Fully Autonomous Ship Program
launched by The Japan Foundation in 2020 to support thedevelopment of autonomous technologies [2]. The authorsemphasized the importance of the Concept of Operation(ConOps) elements, which guide numerous stages fromdevelopment and validation to the implementation ofautonomous vessel systems.
Designing propulsion systems for autonomous ships is acomplex task that requires a balance of efficiency, reliability,
safety, and environmental impact. Many scholars highlightthe importance of designing systems with built-in
redundancy to mitigate the risk of system failure. Moreover,there is a consensus on the need for advanced monitoring
and control systems, allowing remote diagnosis and fault
prediction.
Further research is necessary to enhance the efficiency andreliability of both current and emerging propulsion
technologies applicable to autonomous vessels. While manystudies advocate for innovative propulsion systems andautomation, fewer studies deal with overcoming thepractical implementation challenges of incorporating anautonomous framework into a conventional vessel, a step
often overlooked in the creation of full autonomy.
*Received June, 19th , 2023**Monohakobi Technology Institute (Trade name MTI.Co.Ltd)（Yusen Building, 2-3-2 Marunouchi, Chiyoda-ku, Tokyo）

Journal of the JIME

Vol.00,No.0(20XX)

Journal of the JIME Vol. 58, No. 5（2023）

It is also crucial to note that autonomous does not mean
unmanned. Even highly autonomous ships are likely torequire some human crew for the foreseeable future. The
transition to more autonomous shipping is expected to be
gradual, and the impact on manning levels will depend on
how the technology develops.
In the context of manned-autonomous vessels, the role of thehuman element stationed onshore becomes critical, yet
under-explored, particularly in terms of controlling
autonomous ships and supervising onboard personnel. A
review by Veitch & Alsos [3] highlighted System-Theoretic
Process Analysis (STPA) and Bayesian Networks (BNs) as
the most suitable tools for goal-based design of safetycontrols. In the DFFAS project, the conceptual design of anautonomous navigation and operation system has been
conducted using the Model-Based Systems Engineering
MBSE approach.
However, to the best of the authors knowledge, theseapproaches are primarily used for high-level safety
constraints and are mostly implemented for design ofautonomous navigation systems, while the use of theseapproach for the design for propulsion system were lessmentioned.
This study aims to introduce novel framework to beincorporated into design of propulsion system formanned-autonomous vessel. This includes considerations ofmarine engineers' work, functional risk assessment ofmachinery systems, and the role of the onshore fleet
operation center, including its interaction with the vessel.

2. Safe manning for autonomous vessel
The Principles of Minimum Safe Manning [4], adopted in2011, note that safe manning is a function of the number ofqualified and experienced seafarers necessary for the safety
and security of the ship, crew, passengers, cargo, andproperty, as well as for the protection of the marine－1－
日本マリンエンジニアリング学会誌 第 00 巻 第 00 号 (20XX)― 46 ―
日本マリンエンジニアリング学会誌 第58巻 第 5 号（2023）

Design Reliability
Frameworkfor Propulsion
Frameworkfor Designing
Reliable
PropulsionSystems
SystemsinofManned-Autonomous
Manned-autonomous Vessels
Vessels

environment. While this study is not dedicated to defining
safe manning requirements for manned-autonomous vessels,
the authors strongly believe that the evaluation of engine
department work by Duration, Frequency, Competence, andImportance should always be the first step to consider and toembed into the design of the propulsion system formanned-autonomous vessels. This includes analyzing cases
where work requires multiple people and where workoverlaps. It then should become a reference for consideringand maximizing the use of automation, remote control
monitoring technology to be incorporated into ConOps.
In addition to IMO resolution A.1047(27), which
recommends safe manning requirements for amanned-autonomous ship, a variety of other factors mustalso be considered. While the specifics may vary dependingon the type and size of the vessel, its operational area, andthe level of autonomy, the following points generally need tobe addressed:
1. Level of Autonomy: The degree of autonomy or remotecontrol applied on the different ship functions will be amajor determinant of the crew size. Increased use of
autonomy and remote control may require fewer crew
members but also different competencies and more
highly specialized personnel, on the ship as well as
remote control/monitoring centers.
2. Transformation of Engineer’s Role: There may be aneed for crew members with new skills, such as remotemonitoring, cybersecurity, and system troubleshooting.
As the nature of human roles onboard changes, this willaffect how an engineer's competency and training
should be planned.
3. Risk and Safety Analysis: Thorough risk assessment isnecessary to understand how the autonomous systems
might fail and what safety risks this could create.
4. System Redundancy: Level of redundancy built into theautonomous system affecting the need for human
backup and shore supervision.
5. Regulations and Standards: Compliance and awarenessof emerging and evolving regulations, such as the IMOMASS Code, as well as flag-state requirements.
6. Operational envelope: Factors such as routes, voyage
duration, and the complexity of operations within theoperational design domain.
7. Maintenance and Repair: Autonomous ships will stillrequire maintenance and repair, and considerations
should be made regarding how this should be
performed.

Journal of the JIME

Vol.00,No.00(20XX)

Journal of the JIME Vol. 58, No. 5（2023）

652

Fig.1 Process and Technology Guidance to the design andarrangements of systems supporting autonomous vessels(Image courtesy of DNV [5])8.

Technology Trustworthiness: It's crucial to ensure thatthe new technology employed in autonomous vessels isrobust, reliable, including the incorporation of fail-safe
mechanisms. One such mechanism is the concept
qualification process proposed by DNV [5], as
exemplified in Figure 1. This process ensures that theapplication of such innovative concepts andtechnologies results in a safety level equivalent to, or
better than, that of conventional vessel operations.

3. Propulsion system specification and design flow
Evans [6] visualized the process of ship design as a spiral,
representing a conceptual model of a process for effective
ship design that has been widely adopted by shipyards
worldwide. Similarly, the design of the propulsion systemfollows this iterative process from basic design to production,
primarily consisting of three stages. The flow begins withdefining functional requirements, which organize theoperations and work of the engine department necessary forship operation. In the basic design stage, the ship designer
will design the equipment configuration required for
operation, automation, remote control, and remotemonitoring targets and specifications according to thespecifications. Subsequently, a risk assessment will be
performed to ensure that minimum safety equivalency is
met in the event of various assumed anomalies with these
specifications and workflows. Finally, these processes will
be iterated several times until all the safety requirements canbe satisfied.
On the other hand, the authors argue that a propulsion
system for a manned-autonomous vessel requires additional
design considerations. These include the incorporation ofautonomous functions, remote control/monitoring systems(operable either from the engine control room or a shore
operation center), and design interactions of new entities
involved in the operation of the vessel.

－2－
日本マリンエンジニアリング学会誌 第 00 巻 第 00 号 (20XX)― 47 ―
日本マリンエンジニアリング学会誌 第58巻 第 5 号（2023）

653

日本マリンエンジニアリング学会執筆要項
Framework for Designing
Reliable Propulsion Systems of Manned-autonomous Vessels

consortium, made up of approximately 60 cooperatingcompanies and organizations, including 30 companies fromdiverse fields with the organization structure as shown by
Figure 2. These include various original equipment
manufacturers (OEMs), shipyards, and ship owners.
Through the social implementation of the DFFAS project(referred to as DFFAS+), consortium members assigned tothe propulsion working group conducted various workshops.
They discussed and exercised the framework to consider
overall requirements and functions based on the purpose andgoal of the propulsion system as well as supporting remotemonitoring functions and supervision at the FOC.
Through these workshops and discussions, a novel
framework has been proposed and exercised for designing
the propulsion system of a manned-autonomous vessel. In
addition to conventional design stages, additional design
flow depicted in Figure 3 were introduced in subsequent
sub-sections:Fig.2 Organization of DFFAS projectFig.3 Proposed system design flow for propulsion system

In the previous DFFAS project, a container vessel named
SUZAKU was retrofitted with an autonomous navigationand propulsion monitoring system to demonstrate theconcept. At that time, there wasn't much room for
introducing the novel concept of autonomy in propulsion,and emphasis was placed on the new role of shore engineers
stationed at the Fleet Operation Center (FOC) tasked withsupervising and supporting safe vessel operation with fewer
engineers stationed onboard. In the next phase, termed as
DFFAS+, a new container vessel will be designed and built.
It will have more flexibility to introduce novel technologies
or approaches in accordance with safe manningrequirements, aiming to reach better or equivalent levels ofsafety compared to conventional vessels, especially in casesof onboard crew reduction objective.
We leveraged the advantages of having the DFFAS
Journal of the JIME

Vo00， No． 00

Journal of the JIME Vol. 58, No. 5（2023）

3.1. Functional work decomposition
To better reflect user requirements, we have thoroughlyorganized the identification of the relationship diagram,which illustrates the work of marine engineers necessary tokeep the propulsion system operational. We specificallyreferred to one methodology, Human-Centered Design(HCD). According to Veitch et al. [7], HCD effectively
addresses safety-critical interactions between humans andmachines using principles from ISO 9241 Part 210:
Human-centered design for interactive systems. We concurthat understanding and specifying the context-of-use formajor functions in any shore control center should precede
the definition of user requirements. This naturally implies
that the context of use should be well-described in theConcept of Operations (ConOps). In this research, we
designed the interactions of actors utilizing procedures,schemes, systems, tools, and means of communication tomodel interactions, as well as redundancy for bothhuman-machine interaction onboard and sea-shore
engineer’s interaction. We identified several functional tasks
that need to be considered for manned-autonomous vessels,
which are as follows:
Troubleshooting operations

Scheduled maintenance workSpare parts and equipment inventory management
Lubricant inventory management
Fuel oil residual level management
Fuel oil replenishment
Engine plant preparation before departure－3－
日本マリンエンジニアリング学会誌 第 00 巻 第 00 号 (0000-00)― 48 ―
日本マリンエンジニアリング学会誌 第58巻 第 5 号（2023）

Design Reliability
Frameworkfor Propulsion
Frameworkfor Designing
Reliable
PropulsionSystems
SystemsinofManned-Autonomous
Manned-autonomous Vessels
Vessels
Thruster operations (starting and shutdown)
Auxiliary Engine (generator) operations

Main engine shutdownEngine room fire detection and mitigation
One example of how interactions are being considered isillustrated in Figure 4, which pertains to relationship activity
diagram for troubleshooting operations. A crucial point
identified in the process is the importance of including theship management company in the coordination loop, in
addition to facilitating interactions between the onboard
engineer and the shore engineer at the Fleet Operations
Center (FOC). When multiple chief engineers aremonitoring various vessels on duty at the FOC, it isadvisable to have the supervisor from the ship managementcompany responsible for a particular vessel, acting as thepoint of contact. This ensures efficient communication with
the Original Equipment Manufacturer (OEM) or the ship
operator/charterer regarding issues on each vessel.
3.2. Functional work/task classification
Understanding the interaction in each functional aspect of
the newbuild manned-autonomous vessel allows for a clear
perspective on user requirements, which can be linked to thedesign specifications of the propulsion system. Before
progressing to the hardware/software design stage, anothercrucial step in the design process is to clearly derive theserequirements from the decomposed functional work.

654

For each functional work, the required level of autonomy
and mandatory functions in the ConOps should beconsidered, allowing a more detailed work activity to be
drawn. Through relevant discussions, and by referring to themanning plan desired by the ship owner as well as minimum
safe manning principles, these activities were classified intofunctions requiring automation, onboard remote control,
land remote control, land remote monitoring and supervision,and functions that will be maintained by manual operation.
As mentioned in Section 2, here, we consider an in-depth
evaluation for the engine department's work usingparameters such as Duration, Frequency, Competence, andImportance. Our aim is to maximize the use of automation,
remote control, and land-based remote monitoring (andsupport) technologies for optimization. The top priority is toanalyze cases where work requires multiple people andwhere work overlaps. Each function can then be broken
down into a task list that includes the attributes listed below:A) Task Duration:
Refers to the time required to execute each task. Time in thiscase is a measurement of total man-hours versus the actual
duration taken for task completion. Since some tasks can bedone in a shorter time by using multiple individuals, thiswork duration should ideally be minimized or kept the same.
B) Task Frequency
Refers to how often a task is performed, and should also be
minimized or kept the same wherever possible.

Fig.4 Example of a functional work decomposition for troubleshooting operation in manned-autonomous vessel operation

Journal of the JIME

Vol.00,No.00(20XX)

Journal of the JIME Vol. 58, No. 5（2023）－4－
日本マリンエンジニアリング学会誌 第 00 巻 第 00 号 (20XX)― 49 ―
日本マリンエンジニアリング学会誌 第58巻 第 5 号（2023）

655

日本マリンエンジニアリング学会執筆要項
Framework for Designing
Reliable Propulsion Systems of Manned-autonomous Vessels

Fig.5 Example of a functional work classification of marine engineers onboard manned-autonomous vesselC) Personnel competency
This includes the skills, training, and qualifications needed
to consistently perform the task properly. At the very least, if
the ship's engineer's capacity is insufficient, it will be
supplemented by remote monitoring and technical support.
D) Task ImportanceThis involves the risk or consequence associated withimproper performance when executing a task. As a measure,work associated with the risk of causing serious accidents
should be closely monitored by onshore supervisors orcovered by new automation functions to reduce the risk oftrouble caused by improper operation as much as possible.

implementing novel technologies in autonomous vessel
functions.
We discuss and agree on high-level prevention measures foreach threat and mitigation barriers for each potential
consequence. As a result, three distinct risk categories areassociated with the manned-autonomous vessel propulsion
system when considering the use of novel technology. These
include risks associated with ship operation with only one
engineer onboard (as aimed by DFFAS+), work supervision
by a shore engineer, and the use of a remote control/monitoring system. Each bowtie diagram consists of ahazard, an unsafe condition described as a top event, and aset of threats and consequences related to the event.

Understanding the task classification is beneficial for
conveying user requirements more effectively during theprocess of defining functional requirements, especially inproviding guidance for shipyards and OEMs. In this project
we defined 224 tasks classified into 24 work classifications.
Figure 5 exemplified tasks necessary for M/E Operation.
3.3. Basic Hazard Identification:
By formulating task classifications, we can easily identify
tasks that require the introduction of novel or supporting
technologies/tools. This process results in a more focused
approach towards targeted tasks that necessitate a thoroughfunctional risk assessment. The aim is to identify hazards inpropulsion system operation that derive from the Concept ofOperations (ConOps) requirements. In DFFAS+, we utilize
the bow-tie methodology [8] to perform this stage, as
exemplified in Figure 6. During this process, we referred toClass guideline DNV-CG-0264 [5] for guidance on safely
Journal of the JIME

Vo00， No． 00

Journal of the JIME Vol. 58, No. 5（2023）(a)Bowtie showing threats for remote control/monitoring
system for manned-autonomous vessel－5－
日本マリンエンジニアリング学会誌 第 00 巻 第 00 号 (0000-00)― 50 ―
日本マリンエンジニアリング学会誌 第58巻 第 5 号（2023）

Framework for Designing Reliable Propulsion Systems of Manned-autonomous Vessels(b) Bowtie showing threats for operation with one engineer onboard

656(c) Bowtie showing threats for remote supervision by shore engineer

Fig.6 Example of basic hazard identification by bow-tie methodology

For each threat, we identify barriers that will be used toprevent the threats from leading to the top event. Similarly,
for each consequence, we identify barriers to recover fromthe occurrence of the top event, and to prevent major
consequences from happening. As experienced in the project,
identifying these barriers is central to the functional safetyassessment and has proven invaluable in allowing focusedand detailed safety analysis of each part of the system.
The DFFAS+ project has been contributing to a draft classguideline developed by DNV for the approval of REMC
(Remote Engineering Monitoring and Control) systems,
focuses on remote operations of machinery and otherengineering systems. The guidelines are based on practicalrisk analysis, as experienced in several projects, including
DFFAS+.
3.4. Functional safety assessment
This process involves identifying the failure modes of theequipment that comprises the engine system, performing
FMEA (Failure Mode and Effects Analysis) and FTA (Fault
Tree Analysis), selecting the measurement items necessary
for status diagnosis and anomaly detection, and developing
the equipment status diagnosis logic. Model-Based Safety
Assessment (MBSA) was selected as the methodology, andJournal of the JIME

Vol.00,No.0(20XX)

Journal of the JIME Vol. 58, No. 5（2023）

Ansys Medini™ Analyze [9], a model-based toolset forfunctional safety design and analysis, is being utilized. The
following systematic steps were undertaken:
A) Creation of the block diagram describing component,
system, and functions in engine plant (Figure 7(a)).
B) Define functions and the potential malfunctions foreach component, which configure the main systems.
C) FMEA to be done according to the defined
malfunctions (failure modes).
D) Evaluation of failure modes and identification ofdesign control detection as well as safeguards
In conducting FMEA, various failure modes with differing
causes and effects were outlined, and each failure mode was
evaluated using "Occurrence" and "Detection" for potential
failure causes, and "Severity" for potential failure effects.
There may be a close connection between tasks, andsubsequently between failure modes. Thus, connections
between failure modes of different systems can be made andvisually identified. Figure 7(b) exemplifies a functional
block diagram, showing the connections between different
failures in M/E operation that may share common causes
and effects. Finally, safeguards can be designed for eachsystem component.

－6－
日本マリンエンジニアリング学会誌 第 00 巻 第 00 号 (20XX)― 51 ―
日本マリンエンジニアリング学会誌 第58巻 第 5 号（2023）

657

Framework for Designing Reliable Propulsion Systems of Manned-autonomous Vessels(a) Relationship diagram of various systems in functional block diagram (emphasize on FO service system)(b) Failure propagation flowchart connecting different failure mode scenario and identification of safeguards
Fig.7 Functional safety assessment
Table 1 Additional sensor specification design following functional safety assessment

Note: text marked in red in column G represent required sensor to be placed for control detection to be performed

Journal of the JIME

Vol.00,No.0(20XX)

Journal of the JIME Vol. 58, No. 5（2023）－7－日本マリンエンジニアリング学会誌 第 00 巻 第 00 号 (20XX)― 52 ―
日本マリンエンジニアリング学会誌 第58巻 第 5 号（2023）

Design Reliability
Frameworkfor Propulsion
Frameworkfor Designing
Reliable
PropulsionSystems
SystemsinofManned-Autonomous
Manned-autonomous Vessels
Vessels658

Fig.8 Identification of unsafe condition (example of onboard fuel shift work)

Fig.9 New system requirement to support coordination between onboard and shore engineer

3.5. Additional specification for autonomous vessel
Following the basic design discussions with the shipyard
and OEMs regarding propulsion system specifications,control detection measures, and safeguard functions to
support the monitoring of critical machinery functions, we
utilized this information extensively to propose sensor
specifications for installation on the newbuild vessel.
Moreover, we delineated how telemetry data capture fromthese sensors should be linked to either the Integrated Alarm
System (IAS) or other systems designed for both onboard
and shore monitoring. Table 1 illustrates how the results offunctional safety assessments are used to determine theJournal of the JIME

Vol.00,No.00(20XX)

Journal of the JIME Vol. 58, No. 5（2023）

required sensors for monitoring functions
The sensor specifications devised are fundamental to theoperation of the monitoring scheme and safeguards.
However, they may not provide complete visibility for all
operations. In this context, we link the Failure Mode andEffects Analysis (FMEA) to the identification of unsafe
conditions in the hazard analysis. Figure 8 illustrates an
instance of an unsafe condition that could occur during
onboard fuel shift works. This iterative process, focused on
critical operations, enables us to determine whether thedesigned condition monitoring scheme can identify or
mitigate unsafe conditions.

－8－
日本マリンエンジニアリング学会誌 第 00 巻 第 00 号 (20XX)― 53 ―
日本マリンエンジニアリング学会誌 第58巻 第 5 号（2023）

659

日本マリンエンジニアリング学会執筆要項
Framework for Designing
Reliable Propulsion Systems of Manned-autonomous Vessels

3.6. Remote control and monitoring specification
Since the Fleet Operation Center (FOC) is a neworganization in the operation of manned-autonomous vessels,
we have also discussed and determined the design ofworkflows and systems for remote monitoring, operation,and management by a land-based supervisor (equivalent to achief engineer). This includes the nature of communication
between the ship's engineer and the shore engineer stationed
at the FOC, as well as interaction to automation system.
Figure 9 illustrates how the tasks should be performed andsupervised for specific operation in a mission phase. These
considerations subsequently dictate the new functions andsystems needed to support this operational design. To thisend, a Concept of Operations (ConOps) for Remote Engine
Monitoring and Control (REMC) of Autonomous Vessels
was specifically created as part of the ship-systems ConOps.
At the time of this manuscript's publication, the ConOps isbeing iteratively modified and reviewed by the classificationsociety for concept qualification.
In advancing this objective, we describe a general concept ofmanning, the remote engine monitoring center, and theoperational structure extracted from the DFFAS’s REMC
ConOps in the sections below:
Target of the REMC
The REMC aims to enable onshore monitoring of multiple
vessels to ensure their continued safe operation by a single
engineer aboard each vessel.
Key Success Factors
The remote control and monitoring system at the FOC
should empower shore engineers to effectively supervise theengine plant from ashore, thereby decreasing the workloadof the onboard engineer. While monitoring the condition of
the main engine is a crucial part of the engineer's duties, asystem that can lessen these responsibilities is also necessary
for maintaining vessel operation with fewer engineerscompared to existing conventional vessels.
General Operational Strategy
Team of shore engineers, working in shifts, will be assigned
the task of remote monitoring and supervision of the fleet
under their purview. For the DFFAS project, the FOC
intends to oversee the operation of five manned-autonomous
vessels operating domestically within Japanese waters.
We propose that the monitoring concept needs to be tested
before implementation. An advantage we seek to capitalize
on is for ship owners who already have remote monitoring
systems in place for health and performance propulsion
Journal of the JIME

Vo00， No． 00

Journal of the JIME Vol. 58, No. 5（2023）

systems for conventional vessels, such as [10]. This is acontext in which various assumptions and hypotheses can beverified. Specifically, the practical challenges associatedwith remote operation center personnel managing multiple
vessels effectively are a crucial factor that needs to be morethoroughly tested, rather than merely conceptualized.
3.7. Safe manning evaluation
In the final process, a qualitative and quantitative evaluation
shall be conducted to assess the volume of work and to
determine whether labor savings can be achieved in the
ship's engine department. This will constitute the final
assessment, carried out together with the flag state agency,
confirming whether the minimum safety equivalent can be
met with a reduced number of onboard personnel on amanned-autonomous vessel equipped with onboard
automation, supplemented by supervision and backup fromshore personnel.
While the DFFAS project is not designed to recommend a
generic safe manning requirement for a mannedautonomous vessel (a bottom-up approach), the proposed
framework serves as a valuable tool to be used for designing
the propulsion system of a manned-autonomous vessel. Thisis particularly true when considering how the propulsion
system should be designed to meet the user's manningrequirements (a top-down approach), identifying potential
challenges, and systematically proposing solutions to meetthese requirements.

4. Contribution of this research
Clear motivation underlying the introduction to the proposed
framework, are classified, and discussed below:
A) Response to Seafarer Shortage:
We aim to design an efficient propulsion system with fewer
engineers onboard for Japanese domestic vessels, in
response to the shortage of seafarers in Japan.
B) Improved Safety of Ship Operation
Due to concerns that fatigue and other factors may cause
humans to overlook dangerous conditions, leading to poor
judgment, the development of an automated system andremote-control supervision is essential. These will assist insafe operations and reduce human error.
C) Reduction of Workload on Onboard Seafarers
The use of an onboard automated control system, combinedwith the ability to perform remote control from a Fleet
Operations Center (FOC), can significantly reduce thewatchkeeping workload for onboard engineers.

－9－
日本マリンエンジニアリング学会誌 第 00 巻 第 00 号 (0000-00)― 54 ―
日本マリンエンジニアリング学会誌 第58巻 第 5 号（2023）

Design Reliability
Frameworkfor Propulsion
Frameworkfor Designing
Reliable
PropulsionSystems
SystemsinofManned-Autonomous
Manned-autonomous Vessels
VesselsD) Contribution to International Standardization
Active efforts are anticipated in the development of more
concrete rules for the societal implementation oftechnologies developed for autonomous vessels. This
operational concept will strengthen initiatives alreadyemerging in maritime industries and contribute to thedevelopment of international rules related to remote control
and engine room monitoring for autonomous vessels.
E) Contribution to the Legal System
By defining and implementing the framework, we canshowcase a proposal for the flag state and classificationsociety in a creating safe manning requirement for engine
room operations in accordance with the competence,
qualifications, and training required for the seafarers whowill man the autonomous vessels.

660

Manning, International Maritime Organization (2011)[5] “DNV-CG-0264 : Autonomous and remotely-operated ships”,
DNV, (2021)[6] ”Basic Design Concepts”, Evans, J., Naval Engineers Journal ,pp 671-678, (1959)[7] ”Design for Resilient Human-System Interaction in Autonomy:
The Case of a Shore Control Centre for Unmanned Ships”,
Veitch, E. A., Kaland, T., Alsos, O. A, Proceedings of the
Design Society. Cambridge University Press; 2021;1, pp
1023–32, (2021)[8] “A Challenge to Development of Technology on Autonomous
Navigation”, Morioka, T., Kuwahara, S., Keynote speech at
Asia Navigation Conference, Toyama, Japan (2022)[9] Ansys MediniTMAnalyze User Guide, Copyright © 2020
ANSYS Germany GmbH[10] “NYK Opens 24/7 Engine Plant Monitoring Center in Manila”,

5. Conclusion

https://www.nyk.com/english/news/2020/20200821_01.html

This paper introduces a novel framework to be incorporated
into the design of propulsion systems for mannedautonomous vessels, as experienced in the DFFAS project.
The proposed framework significantly incorporates user
requirements by defining the critical tasks of onboard
engineers. Moreover, the application of functional safety
analysis is highlighted, leading to comprehensive additional
specifications. These specifications are intended for bothonboard automation and remote control/monitoring systems,
ensuring safety levels equivalent to, or better than, those of
conventional vessel operations, especially in scenarios
where reduced crew members are desired to operate theautonomous vessel. The proposed method is believed to bescalable, offering insights on how the propulsion systemdesign should adapt to meet varying user manningrequirements at different levels of autonomy.

Authors

References‐ Prayoga, Putu Hangga Nan‐ Born in 1986
‐ Machinery System Solution Team Unit
Leader, MTI.Co.Ltd‐ Graduated from Kyushu University in 2015
‐ Research area: Marine Systems Design‐ Inoue, Shinichi‐ Born in 1978
‐ Machinery System Solution Team Manager,
MTI.Co.Ltd‐ Graduated

from

Kobe

UniversityofMercantile Marine in 2001
‐ Research area: Marine Engineering,‐ Nomura, Hideaki‐ Born in 1967

[1] “Model-Based Design and Safety Assessment for Crewless‐ Director, MTI.Co.Ltd

Autonomous Vessel”, Nakashima,T., Kutsuna, K., Kureta, R.,‐ Graduated from Tokyo University of

Nishiyama, H., Yanagihara, T., Nakamura, J., Ando, H.,

Marcantile Marine in 1992

Murayama, H., Kuwahara, S.,Journal of Physics: Conference
Series, (2022) doi:10.1088/1742-6596/2311/1/012024‐ Nakamura, Takumi[2] ”無人運航船プロジェクト「MEGURI2040」” (in Japanese),https://www.nippon-foundation.or.jp/what/projects/meguri2040[3] “A systematic review of human-AI interaction in autonomous‐ Born in 1993
‐ Machinery System Solution Team SeniorResearcher, MTI.Co.Ltd

ship systems”, Veitch, E., Alsos, O.A., Safety Science, Vol. 152,

‐ Graduated from Kyushu University in 2017(2022) https://doi.org/10.1016/j.ssci.2022.105778‐ Research area: Ship design process[4] IMO Resolution A.1047(27): Principle of Minimum Safe
Journal of the JIME

Vol.00,No.00(20XX)

Journal of the JIME Vol. 58, No. 5（2023）－10－
日本マリンエンジニアリング学会誌 第 00 巻 第 00 号 (20XX)― 55 ―
日本マリンエンジニアリング学会誌 第58巻 第 5 号（2023）