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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.