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DESIGNING SHIP DECK FOR MISSION FLEXIBILITY
Foong Xin Yu1, Quah Yan Hsien
2, Martin Wibawa
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1Dunman High School, 10 Tanjong Rhu Road, Singapore 436895 2River Valley High School, 6 Boon Lay Ave, Singapore 649961
3Defence Science and Technology Agency (DSTA), 1 Depot Road, Singapore 109679
BACKGROUND OF RESEARCH
The navies around the world have been actively contributing to key missions, namely,
Humanitarian Assistance and Disaster Relief (HADR), search-and-rescue (SAR) and anti-
piracy operations as seen in the aftermath of the 2004 Aceh tsunami, 2013 typhoon Haiyan in
Philippines, the search for the missing MH370, and the anti-piracy effort in the Gulf of Aden.
Due to the unique demands and objectives of each operation, the set of operational
requirements, such as the inventory of equipment and vehicles to be loaded on board the ship,
is likewise specific to the operation. Presently, naval ships are designed for specific mission
sets; consequently, they are only able to respond to a limited range of scenarios and cannot be
reconfigured quickly for a uniquely different operation. In his keynote address at the
International Naval Engineering Conference (INEC) 2015, Major-General (NS) Ng Chee
Khern, Permanent Secretary (Defence Development) and Second Permanent Secretary
(Health), noted that the future environment is uncertain, with unpredictable and evolving
threats [1]. As a result, it is essential for modern ships to be versatile and prepared to respond
to unforeseen operational scenarios, which is a key aspect that the current generation of ships
were not designed for. Therefore, there is growing demand for an entirely reconfigurable ship
deck that allows for mission flexibility, so as to develop a next generation of ships that can be
rapidly reconfigured for different operations.
Recognising this importance, the Republic of Singapore Navy (RSN) has developed the
Littoral Mission Vessels (LMVs) with mission modules that resultantly enable the LMVs to
tackle a wider spectrum of operations. For example, they can be configured with medical
modules to support HADR and SAR missions [2]. In this paper, possible adaptations of the
mission flexibility concepts on future ships are explored.
PURPOSE OF RESEARCH AND ENGINEERING AIMS
In the present study, the engineering aim is to firstly design a ship deck that has the capability
to accommodate the full set of equipment and vehicles required for HADR, SAR and anti-
piracy operations. These three operations were focused on as they are most common in
peacetime [3].
Secondly, the design of the ship deck has to maximise mission flexibility. As such, the ship
deck would be fully self-sufficient in all procedures of loading and unloading, as well as
launch and recovery. Also, the entire reconfiguration process would be designed to minimise
the time, manpower and effort needed to reconfigure the ship between any two missions, out
of the three selected ones.
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METHOD AND MATERIALS
3D Models
The project begins with the modelling of a generic Landing Ship Tank (LST) type ship that
would serve as the platform for the design of a reconfigurable ship deck that maximises
mission flexibility. With reference to Figure 1, the ship model consists of a ship deck and a
flight deck. The specific dimensions of both decks are tabulated in Annex A.
Figure 1: Cross section of the ship model, as designed on SolidWorks.
Thereafter, the possible set of equipment and vehicles for each of the three missions
identified earlier were designed on SolidWorks with the correct dimensions. In doing so, a
database of accurately-scaled models was constructed, which would help to contribute
towards future 3D modelling and design studies. The inventory of these models has been
included in Annex B.
SHIP DECK DESIGNS AND RECONFIGURATION
Gantry Crane
In order to ensure that the ship deck is designed to be fully self-sufficient in the
reconfiguration process, the integration of a gantry crane was proposed, as illustrated in
Figure 2.
Figure 2: SolidWorks model of the proposed gantry crane that was designed to be fully
integrated to the ship deck infrastructure.
The gantry crane system was proposed as it occupies minimal floor area of the ship deck, as
demonstrated in Figure 2. Moreover, the gantry crane system is an existing technology and
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infrastructure [4]. Therefore, its application to the ship deck would be feasible and of low
risks. The gantry crane would cover the inner mission bay and the well dock, thus effectively
enabling both containers and surface vessels to be loaded and reconfigured.
In addition, the arm of the crane has also been redesigned. With reference to Figure 3, the
arm is designed to be fully extendable, thus enabling the crane to reach its target area much
more efficiently. Furthermore, this compact design allows for two cranes to be installed on a
single ship deck, where they would be able to fully function simultaneously. These in turn
would minimise the loading and unloading durations, hence reducing the reconfiguration
time, manpower and effort. The design of the integrated gantry crane system would enable
the ship deck to be self-sufficient and reconfigurable even when the ship is out at sea. This is
in contrast to the LMVs, which rely fully on shore cranes for loading and unloading of
equipment and vehicles.
Figure 3: Illustration of the proposed design of a fully extendable crane arm.
Reconfiguration Checklist
In addition to the gantry crane, the following reconfiguration checklist was designed to
identify the key aspects that have to be fulfilled in order to minimise the reconfiguration time,
manpower and effort:
1. Equipment and vehicles that are of greater importance and would be required more
urgently, such as water supplies, should be positioned near the exits of the ship deck;
likewise, those that are of least importance should be located furthest from the exits.
2. Equipment and vehicles that are repeated between missions should be positioned at areas
such that they would not obstruct or hinder any loading or unloading of other equipment
or vehicles.
3. All vehicles that are loaded onto the ship deck should be positioned such that they have a
clear path to exit.
4. Shore facilities should be able to access all equipment and vehicles on the ship deck.
5. Standardisation of payload interface should be implemented, where equipment, supplies
and control centres are housed in standardised ISO containers.
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HADR Mission Modules
The complete missions set of equipment and vehicles to be loaded on board the ship for the
HADR operation has been listed in Table 1.
S/N Quantity Equipment/Vehicle
1 2 All Terrain Lifter Forklift
2 2 Medium Bulldozer
3 6 Rover
4 4 Relief Supplies International Organization for Standardization (ISO)
Container
5 4 Food ISO Container
6 4 Medical ISO Container
7 4 Accommodation ISO Container
8 2 Fast Craft
9 2 Helicopter
Table 1: Set of equipment and vehicles to be loaded on board the ship for HADR operation.
In order to achieve the aspects of the reconfiguration checklist, a symmetrical layout was
proposed for the configuration of the HADR mission modules on the ship deck, as depicted in
Figure 4a where the red dotted line represents the line of symmetry.
This symmetrical configuration divides the HADR mission modules into two identical
groups, where the half that is closer to the side ramp exit contains all the primary mission
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equipment and vehicles, while the other half further from the side ramp contains the reserve
mission modules. As a result, even with the HADR’s tight configuration, the half that is
further from the side ramp would still be able to fulfil the reconfiguration checklist
requirements, particularly Checklists 3 and 4, by taking into account that the other half closer
to the ramp would be unloaded first. Additionally, the ISO containers that contain the primary
supplies have been positioned beside the side ramp exit, while keeping the exit clear and
unobstructed. This allows the more essential primary supplies to be unloaded quickly (fulfils
Checklist 1); and if the need to reconfigure the ship deck from a HADR to SAR operation
arises, the ISO containers, which contain supplies relevant to the SAR operation, can remain
on the ship deck without hindering the loading or unloading of other equipment or vehicles
(fulfils Checklist 2).
SAR Mission Modules
S/N Quantity Equipment/Vehicle
1 1 Unmanned Aerial Vehicle (UAV)
2 1 UAV Launcher System
3 1 UAV Recovery System
4 2 Unmanned Underwater Vehicle (UUV)
5 2 Unmanned Surface Vehicle (USV) with Cradle
6 2 Rigid-Hulled Inflatable Boat (RHIB) with Cradle
7 4 Medical ISO Container
8 4 Diving Equipment ISO Container
9 3 Control Centre ISO Container for UAV, UUV and USV
10 2 Helicopter
Table 2: Set of equipment and vehicles to be loaded on board the ship for SAR operation.
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Anti-piracy Mission Modules
S/N Quantity Equipment/Vehicle
1 2 RHIB with Cradle
2 1 UAV
3 1 UAV Launcher System
4 1 UAV Recovery System
5 1 Control Centre ISO Container for UAV
6 2 Helicopter
Table 3: Set of equipment and vehicles to be loaded on board the ship for anti-piracy
operation.
It is evident from Figures 5a and 6a that there is an excess of floor area of the ship deck for
the configurations of both the SAR and anti-piracy mission modules; as a result, for these
scenarios, the design of the ship deck may seem flawed due to the overestimation of floor
area. However, the ship deck has been designed to be mission-flexible; and as such, it is
essential for the ship deck to be capable of meeting the most stringent operational
requirements. The HADR operation had the greatest operational demands as shown in Figure
4a, which the ship deck design was able to fulfil, hence demonstrating its capability of being
mission-flexible.
CONCLUSIONS AND RECOMMENDATIONS FOR FUTURE WORK
In conclusion, the mission flexibility concept has been successfully adopted onto a generic
ship deck design for future ship applications. The first unique feature of the ship deck is that
it has the capability to accommodate the possible set of equipment and vehicles required for
HADR, SAR and anti-piracy operations. Secondly, a gantry crane system with a fully
extendable arm has been specially designed to be integrated into the ship deck. This is
essential in enabling the ship deck to be fully self-sufficient in all of its reconfiguration
processes. Thirdly, a reconfiguration checklist and the symmetrical configuration have been
designed to minimise the time, manpower and effort needed to reconfigure the ship deck
from one mission to another. All these would pave the way in developing a ship deck that is
fully mission-flexible to effectively respond to future uncertainties and emerging threats.
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It is important to consider that mission flexibility is not only maximised through the
configuration of the ship deck, but also the system design. Therefore, for future work, an
investigation into the enhancement of the system design can be conducted, where the
engineering aim would be to minimise the number of moving components in order to further
reduce the reconfiguration time and effort. One possible approach to achieve this aim would
be to study the integration of multifunctional equipment into the system design.
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REFERENCES
1. Ministry of Defence (MINDEF) Singapore. (2015, May 20). Keynote Address by
Major-General (NS) Ng Chee Khern, Permanent Secretary (Defence Development) and
Second Permanent Secretary (Health) at the International Naval Engineering
Conference. Retrieved November 30, 2015, from:
http://www.mindef.gov.sg/imindef/press_room/official_releases/sp/2015/20may15_spe
ech2.html#.VpJr1BV97IV
2. Ministry of Defence (MINDEF) Singapore. (2015, July 3). Littoral Mission Vessel.
Retrieved November 30, 2015, from:
http://www.news.gov.sg/public/sgpc/en/media_releases/agencies/mindef/press_release/
P-20150703-2/AttachmentPar/01/file/[Final]%20FS%20-%20LMV.pdf
3. Ministry of Defence (MINDEF) Singapore. (2014, November 6). News Releases.
Retrieved November 30, 2015, from:
http://www.mindef.gov.sg/content/imindef/mindef_websites/atozlistings/navy/news/20
14.html
4. K.v. Dokkum. Ship Knowledge: Covering Ship Designs, Construction and Operation.
DOKMAR, P.O.Box 360, 1600 AJ Enkhuizen, Netherlands, Second Edition, 2005.
5. K. L. Butler, M. Ehsani. Flexible Ship Electric Power System Design. Proc of the
Symposium of Engineering the Total Ship, 1998.
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APPENDICES
Annex A: Dimensions of Ship Model
The dimensions of the LST Model that was constructed in this project are shown in Table 4.
Component Dimensions
Well Dock 40m x 20m
Ramp Base Length: 8m
Height: 2m
Inner Mission Bay 40m x 20m
Flight Deck 88m x 20m
Table 4: Specific dimensions of the LST Model used in the project.
Annex B: Inventory of accurately-scaled, three-dimensional SolidWorks models of the
possible set of equipment and vehicles for HADR, SAR and anti-piracy missions.
HADR Mission Modules
S/
N Equipment/Vehicle Figure
1 All Terrain Lifter Forklift
Figure 7: SolidWorks model of the Forklift.
2 Medium Bulldozer
Figure 8: SolidWorks model of the
Medium Bulldozer.
3 Rover
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Figure 9: SolidWorks model of the Rover.
4 Relief Supplies ISO Container
Figure 10: SolidWorks model of the ISO
Container.
5 Food ISO Container
6 Medical ISO Container
7 Accommodation ISO Container
8 Fast Craft
Figure 11: SolidWorks model of the Fast Craft.
9 Helicopter
Figure 12: SolidWorks model of the Helicopter.
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SAR Mission Modules
S/
N Equipment/Vehicle Figure
1 UAV
Figure 13: SolidWorks model of the UAV housed
on its Launcher System.
2 UAV Launcher System
3 UAV Recovery System
Figure 14: SolidWorks model of the
UAV Recovery System.
4 UUV
Figure 15: SolidWorks model of the UUV.
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SAR Mission Modules
S/
N Equipment/Vehicle Figure
5 USV with Cradle
Figure 16: SolidWorks model of the USV.
6 RHIB with Cradle
Figure 17: SolidWorks model of the RHIB.
7 Medical ISO Container Refer to Figure 10 of the HADR Mission
Modules. 8 Diving Equipment ISO
Container
9 Control Centre ISO Container
for UAV, UUV and USV
10 Helicopter Refer to Figure 12 of the HADR Mission
Modules.
Anti-piracy Mission Modules
S/
N Equipment/Vehicle Figure
1 RHIB with Cradle Refer to Figure 17 of the SAR Mission Modules.
2 UAV Refer to Figure 13 of the SAR Mission Modules.
3 UAV Launcher System
4 UAV Recovery System Refer to Figure 14 of the SAR Mission Modules.
5 Control Centre ISO Container
for UAV
Refer to Figure 10 of the HADR Mission
Modules.
6 Helicopter Refer to Figure 12 of the HADR Mission
Modules.