Singapore Technologies Marine Ltd 7 Benoi Road, Singapore 629882

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(Regn. No.: 196800180M)

A NEW CLASS OF PATROL VESSEL

AUTHORS

Presented by Lead Author:

Yeow Xian Ching (BEng(Hons))

Manager, Engineering Design Centre (Marine System)

Singapore Technologies Marine Ltd

A Company of ST Engineering

Co-Authored by:

Tan Ching Eng, (Dipl.-Ing, EMBA), Senior Vice President, Engineering Design Centre

Mathai Pambrakaran Pathrose (BEng(Hons)), Vice President, Engineering Design Centre

Sim Chee Chong (BEng(Hons)), Assistant Director, Engineering Design Centre (Automation Electrical

System)

SYNOPSIS

Patrol vessels play a vital role in littoral maritime security, safety of international shipping, and protection of

a state’s Exclusive Economic Zone (EEZ). This paper shares recent key developments in the design of new

generation Patrol Vessels (PVs). Missions, performance, manning, combat system outfits, and the main

characteristics of ship systems are discussed. This paper is written based on ST Marine’s proprietary design

of the Fearless Class TM Patrol Vessel.

BIOGRAPHIES

Mr. Yeow Xian Ching was appointed Manager (Engineering Design Centre, Marine System) in Feb 2016.

He is also a member in the Intellectual Property Rights Committee of ST Engineering. He was awarded

Association of Singapore Marine Industries (ASMI), Marine & Offshore Undergraduate Scholarship and

pursued a Mechanical Engineering (Marine Engineering Specialization) degree in Nanyang Technological

University. Graduated in July 2009 with a First Class Honors bachelor’s degree, he joined ST Marine. He has

been involved in several major naval and commercial new building programs. To name a few: ROPAX for

LDA, Diving Support Vessel for DOF Subsea, Landing Platform Dock for Royal Thai Navy, Patrol Vessels

for Royal Navy of Oman, Littoral Mission Vessels for Republic Of Singapore Navy and Heavy Marine Fire

Vessel for the Singapore Civil Defence Force.

Mr. Tan Ching Eng was appointed Senior Vice President (Engineering Design Centre) in Jan 2003. He is

also member in the Technologies Management Committee of ST Engineering. He was awarded Singapore

Public Service Commission (PSC) scholarship in 1981 and pursued a Naval Architecture degree in Institute

of Shipbuilding, Hamburg University. Graduated in Oct 1985 with a German Degree of “Diplom-Ingenieur”

(Master’s Degree) and a Welding Engineer Degree, he joined ST Marine (previously called Singapore

Shipbuilding and Engineering) in 1986. In 1996, he obtained a company sponsorship to pursue a part-time

Executive MBA program from State University of New York at Buffalo (SUNY) conducted at Singapore

Institute of Management (SIM), and graduated in 1999 with a MBA degree.

Mr. Mathai P Pambrakaran was appointed Vice President (Engineering Design Centre) September 2012.

He attended the Cochin University of Science and Technology in India and graduated with a Bachelor’s

Degree in Naval Architecture and Shipbuilding in 1990 and undergone a specialized training programme on

ship design at TID, The Netherlands for a period of one year, 1991-92. He started his career with Sesa Goa

Ltd and assumed various important positions with other organizations such as India’s National Ship Design

and Research Centre (NSDRC), Bureau Veritas, Dubai Dry-docks World, Lloyds Register Asia, Singapore

before joining ST Marine in 2008. He is a member of the Royal Institution of Naval Architects (RINA, UK).

Mr. Sim Chee Chong was appointed Assistant Director (Engineering Design Centre, Automation and

Electrical System) in Feb 2016. He joined ST Marine as an Engineer in 2004 after graduating from National

University of Singapore (NUS) with a Bachelor’s Degree (2nd Class Hons) in Electrical & Computing

Engineering. In his 12 years with ST Marine, Chee Chong has worked on various naval shipbuilding projects

which include the Formidable Class Frigate, Submarine Support and Rescue Vessel (SSRV), and Littoral

Mission Vessels for the Republic of Singapore Navy, Landing Platform Dock for Royal Thai Navy and

Patrol Vessels for Royal Navy of Oman.

1. INTRODUCTION

Maritime threats, which include piracy and maritime terrorism, affect the stability of national and

international economies. PVs play an integral and significant role in mitigating these threats. In addition to

the role of protecting territorial water during wartime, PV peace time operations in accomplishing Military

Operations Other Than War (MOOTW) have become increasingly important. Forming the backbone of every

maritime security fleet, PVs are used for a wide range of tasks, including naval surveillance, anti-smuggling

duties, anti-illegal immigration, anti-piracy patrols, maritime interdiction, and search and rescue operations

(SAR). In recent years, the capability of the PV has been stretched beyond her traditional roles to include

operation such as humanitarian assistance and disaster relief (HADR).

As a medium size shipyard in Southeast Asia, ST Marine has specialized in the design, construction, upgrade

and maintenance of naval and specialized commercial ships. This paper shares primarily our recent

developments of PV. These developments are based on the recent design and construction of the FearlessTM

Class PVs for the Royal Navy of Oman, and product development done in-house. Innovation and

optimization for the multi-role operations are taken into consideration in design to achieve operational

functionality and effectiveness for this class of ships.

This paper shall discuss key design process, enhanced ship platform design and combat system design based

on the Fearless 80 Mk IIITM.

2. DESIGN PROCESS

2.1 PRODUCT LIFECYCLE MANAGEMENT

Product Life Cycle Management (PLM) system has become increasingly important to shipyards and end

users in managing ship configuration from design to service and eventually disposal. The PLM system is

used as an engineering tool for design review, approval, information exchange, reporting, tracking and

resolution of technical issues for the service life of the ship.

It acts as a single shared electronic database for: the latest drawings and technical documents for design

reviews, generation of production information, maintainability assessments and logistics support analysis. It

can also integrate with 3D model software to allow design review and approval based on 3D model.

After ship delivery, end users can also access to ship system drawings and engineering data residing in PLM

database for maintenance activities, information exchange and collaboration with shipyards for system

upgrade and modification studies. Sense-making system and Service Lifecycle Management (SLM) system,

which are to be discussed in a later section in this paper, can be integrated with PLM system to achieve a full

solution of Fleet Management System (FMS).

2.2 3D MODEL BASED DESIGN

Data-centric, multidisciplinary 3D model based design tool is used for accurate and clash-free detailed design

and the creation of production information for the outfitting data of naval ships. It allows design of

equipment, piping, HVAC, miscellaneous steel structures and cable trays. Modelling is carried out in context,

using end user-defined catalogue and specification. A full range of outfitting drawings and production

information can be produced automatically from the model.

3D visualization tool for complex naval ships such as PV with features such as walk-through, animation, and

high quality photo-realistic images is used to analyze designs and communicate complex ideas. These

features allow ease of operation, maintenance and upgrade to be taken into considerations during design

phase.

With 3D model based design, large numbers of equipment, pipes, ducts, cable trays, and foundations are able

to be installed during block erection stage. Considerable cost savings can be achieved by adopting the

concept of design for Ease of Construction and Reduced Maintenance, such as the use of thicker scantlings to

reduce structure members and complexity. Ease of Installation and Maintenance is another key consideration

which can be determined with the use of 3D model during design phase. Examples include allowing for

higher deck height or space and use of pre-outfitted machinery modules.

3D model based design leads to cost savings as a result of improved engineering efficiency and effectiveness.

3. DESIGN PHILOSOPHY

3.1 ADOPTING A MIXTURE OF COMMERCIAL AND MILITARY DESIGN STANDARDS

Cost effectiveness is crucial for a PV design, build and logistics support, resulting in commercial standards

and practices being adopted to replace naval standards to an ever-increasing degree nowadays. Commercial

standards have been applied in the design of PV to a large extent in hull construction, propulsion train,

auxiliary machinery, electrical system, and navigation and communication equipment. However, mission-

critical systems and features such as weapons and sensors, and damaged stability are typically maintained to

be military or naval standard.

3.2 LIFECYCLE COST CONSIDERATIONS

Contractors are generally motivated to offer the minimum price that meets the tender requirements. However,

lifecycle cost assessment rather than capital cost alone has become criteria for evaluation. As it is not so easy

to accurately quantify lifecycle cost, and too much emphasis of this could lead to increase in the capital cost,

cost options have often allowed contractors to propose alternative solutions which may reduce the lifecycle

cost. The contractor typically uses the lowest capital cost as the base line offer. However, the contractor may

then propose options involving additional costs with justifications of lower lifecycle cost benefits.

The Commercial-Off-The-Shelf (COTS) equipment and components are likely to provide savings both in the

initial purchase and lifecycle cost. COTS designs aim to use commercial/industrial equipment and technology

to replace military system wherever feasible. Such COTS equipment should also meet certain baseline

requirements, such as reliability, system functionality, compatibility and flexibility to operate with the

existing systems. In practice, the new class of PV tends to use commercial equipment while the use of naval

standards is justified, where necessary.

3.3 REDUCED VULNERABILITY AND SUSCEPTIBILITY

In simple words, to reduce vulnerability is to reduce the probability of functions being destroyed, and to

reduce susceptibility is to reduce the probability of being detected and engaged. Independent / redundant

systems and equipment that are arranged further apart are becoming evermore considered in the new PV

design.

The key systems considered are:

Independent propulsion trains separated by fire rated bulkhead and watertight bulkhead

Independent electrical power supply with associated Main Switchboard (MSB) such that vital

equipment could be fed from either MSB space

Redundant HVAC system especially one that has Chemical, Biological, Radioactive and

Nuclear (CBRN) protection

Redundant circuit for signal and control system i.e. Integrated Platform Management System

(IPMS)

Redundant piping network for critical propulsion systems

4. DESIGN OF THE SHIP PLATFORM

Among the many parameters and requirements, the followings are key considerations for designing the new

class of PV.

4.1 MULTI-MISSION CAPABLE

The offshore-capable PV is significantly more cost effective because she is capable of performing many

different roles that previously could only be carried out with other larger naval and coast guard assets. These

different roles are:

Patrol and surveillance of territorial waters as well as Exclusive Economic Zone (EEZ)

Search and rescue operations (SAR)

Maritime pollution control

Counter terrorism

Anti-piracy

Customs enforcement including anti-smuggling

Launch and extraction of special forces

Humanitarian assistance and disaster relief (HADR)

With standard container-sized mission module developed and made available off-the-shelf (and many

potential mission modules are being developed now), the PV platform design is trending towards modular

payload capability. The developed solutions aim to be flexible and configurable so that the PV is capable to

receive various standard mission modules that are connected with the multi-function console system to

perform a wide range of tasks by the embarked specialists.

The platform is therefore modified and adapted with delegated mission bay or mission deck space, interface

facilities such as power and signal cables and multi-function consoles, and accommodation facilities to

receive the embarked specialists. The PV is manned by core crew complements that are capable of multi-

tasking to perform the baseline operations. Multi-mission capable PV requirement is evident in a number of

recent projects. Examples are as follow:

Republic of Singapore Navy’s Littoral Mission Vessel,

Royal Australian Navy’s Project SEA 1180,

Brazilian Navy’s OPV PROSUPER program,

Venezuela Navy’s OPV POVZEE program.

4.2 SUPERIOR SHIP PERFORMANCE

PVs are often required to operate for extended periods either independently or as part of a deployed task

force, to operate in national or multi-national forces in littoral waters.

Their primary mission is to patrol and protect inshore and offshore facilities. To do so, they are designed to

operate away from base and stay longer at seas. Thus, longer range, greater endurance and replenishment at

sea are required. Activities in open seas will be often limited to transit. The PV performing this role need to

be capable of protecting herself against surface ships and gain superiority over smaller units, which may

come from sudden attacks from the shore. Their secondary missions encompass embargo control, UN

mission, humanitarian assistance and disaster relief, custom and coast guard activities.

The new class of PV may require conducting offensive strike missions. In this case, the goal is to be able to

project fire power in a short time. The PVs are part of a deterrent force in national and multi-national mission.

These PVs are designed with higher speed, greater endurance and fitted with combat system for ASuW

and/or ASW and capable of self-defense against air, surface and underwater threats.

4.2.1 Speed

Top speed is in fact tightly linked to the operational profile and determines the type of propulsion system

onboard. Depending on the priority of operational profile, the new class of PV should have top speed

between 20 knots to 30 knots, sustainable at sea states (usually SS3 or SS4) at the area of operations, and yet

with lowest possible installed engine power.

Operating Profile

(% of total installed engine power)

Loading Time

(% of total operating hours in a year)

>90% 10%

40-90% 80%

< 40% 10%

Table 1: Typical PV operating profile

Loiter speed is usually 4 to 10 knots. The installed engine power to achieve loiter speed is typically less than

40%. Hence, it is not fuel efficient to operate diesel engines at prolonged low load condition. Hybrid

propulsion system with electrical motor coupled to gearbox powered by diesel generators, Combined Diesel

or Electric (CODOE) or Combined Diesel and Diesel (CODAD) configuration could be a good solution that

is fuel-saving.

4.2.2 Endurance

Endurance is not only a matter of ship ration and fresh water capacity, but also related to human factors. To

increase endurance requires not only increased fresh water/ship spare/cold/cool/dry provision/store

capacities, but also larger crew operations and living quarters allowing rest and recreation, improved crew

working and living conditions (better food, comfortable HVAC, reduced sea sickness, reduced noise and

vibration), and conducive lifestyle (work, administration, recreation, maintenance activities). The endurance

of patrol vessel mission is usually 14 to 28 days depending on the needs of the navies and coast guards.

4.2.3 Range

Range is normally defined at economical cruise speed of 12 to 16 knots depending on the needs of the navies

and coast guards. For the new class of PV with length overall 75m and above, it is normally required to have

3000 nautical miles or more, while for smaller inshore patrol vessel, the requirement is 1000 - 2000 nautical

miles.

The fuel oil storage should be computed to meet this operating profile, with diesel generators running at

ship’s cruise speed electrical load condition. Such requirement could be demanding for long endurance. To

lower fuel consumption, optimization of design, including hull lines and propulsion configuration are to be

considered.

4.2.4 Ship Stability

The new class of PV is designed according to stringent naval stability criteria or classification society naval

rules to ensure good ship survivability (intact stability to survive 70-100 knots beam wind, high speed

turning, stability in wave, as well as damaged stability criteria of at least two compartments damaged).

4.2.5 Seakeeping Performance

At operational sea state, the criteria for patrol vessel are as follow:

Fulfill ship seaworthiness criteria (preferably have superior sea-keeping performance characteristic)

Fulfill crew comfort criteria for personnel onboard

Capability to meet the combat system criteria

Capable to take-off and land helicopter (if fitted with helideck)

Capable to launch and recover sea boats

Capable to sustain operational speed

At survival sea state, the key concern is the ship structural strength, particularly the longitudinal wave

bending stress, and localized structure (bow flare and bottom structure) subjected to slamming loads. Besides

careful hull lines design to reduce such load, global and localized hull structure strengthening is necessary for

the PV. In considering extreme weather conditions and heavy seas, the ship’s commanding officer should be

warned in the ship’s operation handbook to reduce speed and avoid heading towards any safety limitation.

Roll damping and stabilizing are essential for PV. Bilge keel and / or active fin stabilizer are necessary to

ensure good seakeeping at beam sea condition. Other sea keeping characteristics, including pitching, vertical

accelerations, deck wetness, bow height, etc. should also be carefully examined either through predictive

calculations or model testing to ensure crew’s operation effectiveness of combat system and ship system.

4.3 EFFICIENT HULL FORM

The hull form emphasizes on hydrodynamic performance to satisfy ship performance and operational

requirements. The hull geometry is expected to derive from a proven yet modern hull form, where the

hydrodynamic performance is predictable. In some cases, new hull forms are created through direct design or

with significant modification from an existing hull form, but model tested to validate the performance.

Through the use of Computational Fluid Dynamic (CFD) methodology, the designer could optimize the hull

form and appendages geometry. CFD could predict the characteristics of the flow around the hull. In

comparison to model tests, CFD is capable of performing full scale computations, and is useful in verifying

changes in wave resistance in different hull alterations in a relatively short time and with lower costs, and to

arrive at a confident level of optimization prior to model testing.

Nevertheless, model testing in the towing tank facility should be performed to validate the resistance, shaft

power, measure the wake at propeller, and may conduct paint tests for hull appendages (rudder, shaft strut,

bilge keel, bow thruster, etc.) arrangement. In some cases, it is also used to optimize certain parts of the hull

form design, such as the stern wedge configuration. Other kinds of model testing usually carried out are open

water efficiency tests and cavitation tests for design propeller, sea-keeping performance and maneuverability

(turning circle, zig-zag turning).

The overall technical aim is to develop a hull form capable of highest top speed, fuel economical at cruising

speed, with good sea-keeping and maneuvering performance.

1. Developed highly efficient hull form with good hydrodynamic performance and less fuel

consumption by CFD software

a. Optimized hull form and ship appendages (shaft strut, scallop of bow thrusters, bilge keel)

by using CFD simulation.

b. Propeller optimization, including incorporating a tunnel in the hull to enlarge propeller

diameter for better performance.

Figure 1: Fearless 80 Mk IIITM hull form

2. Optimized hull form and appendages by extensive model tests

a. Rudder angle optimization

b. Trim wedge optimization incorporated into hull form

c. Propeller rotation direction optimization

Figure 2: Appendages optimization test

Figure 3: Key improvements of the hull form

3. The hull form developed is superior in terms of speed, maneuvering and sea-keeping capabilities as

compared to hull designs of similar fast crafts. In order to validate the hull form design, extensive

model tests have been conducted.

a. Resistance & Propulsion Test

b. Manoeuvring Test

c. Sea-keeping Test

1. Hull form optimised using CFD

3. Stern wedge reduces ship resistance

4. Shaft strut and rudder orientation optimised

2. Bulbous bow reduces ship

resistance

(a) Propulsion test (b) Manoeuvring test (c) Sea-keeping test

Figure 4: Propulsion, maneuvering and sea-keeping model test

4. Optimal propeller and rudder design has been verified by propeller cavitation test in order to avoid

cavitation behavior and to obtain the best ship speed performance. Underwater noise signature has

been reduced as a result of reduced cavitation and pressure pulses.

Figure 5: Propeller design and cavitation test

4.4 HYBRID PROPULSION SYSTEM

Electric propulsion has been considered for the PV. One key advantage of a ship with electric propulsion is

the flexibility of use in the distribution of electrical power to the three main consumers: propulsion, ship

service system and combat system. Electric propulsion also enables better equipment layout (for example, by

locating the diesel generators elsewhere than the ship’s bottom deck) and by judiciously distributing the

diesel generators.

The PV is equipped with a hybrid propulsion system whereby the propulsion train is driven by one main

engine and one electric motor coupled to a gear unit known as Combined Diesel Or Electric (CODOE) in

short. The shafting system is completed with a controllable pitch propeller. The main engine is used for

cruising at 16 knots and in high speed operation of more than 25 knots. The electric motor is used during

loitering condition at low speed operation of 10 knots and below.

The Key Challenge was to perform major equipment selection and to ensure that the integration achieve

specified performance. The main engine, electric motor, gear unit, shaft line and associated auxiliary such as

cooling pumps, controllable pitch propeller and flexible couplings have to be integrated both mechanically

and electrically in order to achieve functional requirement. Software integration is another challenge whereby

the propulsion remote control system has to be integrated in order to provide the necessary sequence of

various modes of operations.

The approach to overcome these challenges was to perform systematic design and integration reviews and

workshops with the participation of experts, equipment manufacturers and designers.

The key benefit of having hybrid propulsion is to fulfill the operational profile of the vessel whereby the

propulsion and vessel service power demand has large variations. By using propulsion e-motor at slow speed,

it results into fuel efficiency and low noise operation at low speed.

Figure 6: Typical load operation profile of Hybrid Propulsion

4.5 TOPSIDE ARRANGEMENT

In general, the topside arrangement takes into considerations of the mast, funnel (if fitted), helideck (if fitted),

weapon suite, and sensors. Maximum weapon and sensor coverage, and distribution of combat system as far

apart as possible for enhanced survivability would allow the ship to retain degraded capability should she be

hit.

4.5.1 Modular Mast

The Modular Mast will house communication antennas, navigation, surveillance sensors and electronic

cabinets within the mast structure. The Modular Mast size and height is also shaped and streamlined for

optimal air flow.

The main challenge of Modular Mast is to achieve electromagnetic compatibility (EMC) with all the

transmitters and receivers installed close to each other due to the limited space on the mast and these systems

work across a wide frequency range. Detailed EMC studies and simulations were carried out with system

suppliers, with the outcome of an optimize sensors and antennas arrangement and structural design of the

Modular Mast.

Figure 7: 3D model of in-house designed Modular Mast

4.5.2 Optimal Superstructure Shaping

4.5.2.1 Wind Tunnel Test

Smoke recirculation to the working areas and the air intakes can be a challenge for ships, especially for Navy

vessels, where the requirements with regard to smoke on the decks will be higher than for other ships. Smoke

recirculation to the working areas must be minimized. Wind tunnel test was conducted to validate the

dispersion of the exhaust gases from the diesel engines’ exhaust pipes.

The study indicated that diesel engines’ exhausts gasses are re-circulating at helicopter deck at most of the

tested angles in all flow conditions.

The superstructure/mast is located in front of the (much smaller) funnel; this arrangement produces increased

turbulent wake at the location of the funnel. As long as the exhaust gasses are trapped inside the turbulent

wake of the vessel, they will not disperse away from the vessel.

Figure 8: The 1:60 scale model of Fearless 75TM Patrol Vessel in the wind tunnel

4.5.2.2 Funnel, Exhaust Pipe and Mast Design

As a result of the wind tunnel test, the exhaust pipe & funnel design was reviewed and improved by taking

into consideration the exhaust gas recirculation and impingement on the helicopter deck. This is critical to

ensure safe landing of helicopter and crew operation safety. Several designs of the exhaust pipe top piece

were simulated and tested again through CFD and wind tunnel test. After several extensive design iterations

and tests, the final design with an extension of the exhaust pipe outside the funnel top with a 45 degree bend

was conceived as the best design.

To further enhance the funnel design, an “extended lip” was added to the funnel top to prevent exhaust gas

flowing downward to the helicopter deck. The funnel bulkhead was added with more louver openings to

allow better air flow. Other improvements include change of geometry of the funnel to allow slimmer and

higher funnel. In addition to the funnel and exhaust pipe design, the mast shape was improved and slimmed

down to reduce the blockage of wind and turbulent wake.

Figure 9: CFD Simulations and Wind Tunnel Test

In order to reduce the infrared signature of the exhaust gasses, the extension pipe was innovatively designed

to have a double wall which captures the surrounding air as a layer of thermal insulation. The engine room

exhaust ventilation system is integrated with the funnel to allow exhaust air from engine room to cool down

the engines’ exhaust fume temperature.

4.6 INTELLIGENT POWER MANAGEMENT SYSTEM

A minimum of two independent, 100% redundant electrical switchboard shall be considered. There shall be

one additional diesel generator on standby at the worst possible operation scenario. Vital equipment shall

have dual power supply from either switchboard.

In addition, an Intelligent Power Management System (i-PMS) can be incorporated into the new class of PV

design, to perform diesel generator scheduling - a process to load the diesel generators differently rather than

equally when running parallel to optimize fuel consumption. The i-PMS system is particularly useful when

the PV is on electric motor propulsion mode (refer to 4.4 Hybrid Propulsion System) in which a third

generator is to cut in to support the existing two generators in electrical load needed for hotel and propulsion

services concurrently. Potential DC grid system with variable speed diesel generators can add on to the fuel

savings. However, implementation of DC grid system makes more sense only on vessel that operates fully on

diesel electric propulsion system.

4.7 DATA CENTRIC

Data analytics on marine applications has gained a lot of interest over the last few years. As a result of

technological advancement and cost reduction in both data storage and computing power, there are huge

amount of system data available where analytics may be applied to gain new system insights. Advance

analytics may even be applied to allow for predictive and prognostic analysis, pathing the way for a

predictive maintenance and condition based maintenance instead of the traditional preventive and corrective

maintenance regime.

New PVs should be designed and built for data. During the design process, areas where analytics are to be

applied should be established so that the required sensors are identified upfront, built into the platform

systems and catered for in the ship design.

The next step is data collection or data acquisition. PVs are typically equipped with Integrated Platform

Management System (IPMS) or Ship Management System (SMS) which is capable of collecting analogue

and digital data from all shipboard systems in a single platform for centralized monitoring and control.

The IPMS or SMS can be enhanced with a Sense-making module that performs real time analytics on

shipboard systems’ data to provide health monitoring and predictive or pre-emptive warning of imminent

equipment/system failure, which can be further supplemented with advisory actions from a Decision Support

function.

The Sense-making module can be extended to a shore-based center to form a Fleet Management System,

where data collected onboard ships are sent back to shore via the ship’s SATCOM facilities for fleet-wide

analytics. Advisory actions or deployment instructions can then be sent from shore back to the ships out at

sea. It should be noted that the choice of SATCOM and cyber security, which are not discussed in this paper,

are also important points that need to be considered in the ship design, in order to facilitate the Fleet

Management concept described above.

4.8 LEAN MANNING

Crew numbers have reduced significantly with each generation of warship, but still remain a significant space

driver in the ship design. While the watch and station bill is generally determined by manning scenarios

based on operational experience of the navy, with the recent advancement of technology in ship automation

and remote control weapon system, manning level could be reduced significantly.

In determining the complement level, platform and combat systems level of automation, and the cost

associated with it are generally the key considerations. The following systems’ design could drive down the

manning requirements:

Integrated Platform Management System (IPMS)

Integrated Bridge System

Unmanned machinery space

CCTV surveillance system

Damaged control system

It is also important to train crew to be proficient in operating highly automated systems in order to achieve

safe operation while low manning is being considered.

4.9 ENVIRONMENTAL FRIENDLY DESIGN

Recent international legislations by the International Maritime Organization (IMO) require more stringent

control of handling ship wastes for pollution prevention. Governments are increasingly obliged by the

regulations, whether in whole or part, in order to set good example.

Recent SOx and NOx emissions limits have seen not only the commercial sector complying with the new

regulations but the navies as well. Ship building specification by the navies has required engine with

minimum TIER II compliance and the use of clean Marine Diesel Oil (MDO) or Marine Gas Oil (MGO).

Table 2: MARPOL Annex VI, SOx emission limits

Figure 10: MARPOL Annex VI, NOx Tier I-II-III requirements

Another recent pollution prevention regulation is the enforcement of IMO Ballast Water Management

Convention starting 8th September 2017. Ballast water treatment system has been mandated or made

provision by most navies in ship building specification. Ballast water treatment system includes the use of

filter, hydro-cyclone and ultra violet light to abate marine microorganisms from entering the ship’s ballast

tanks and subsequently being discharge to another location and cause harmful effects to the local marine eco

system.

5. DESIGN OF THE SHIP COMBAT SYSTEM

5.1 COMBAT SYSTEM

PVs are mainly equipped with medium-caliber guns and machine guns. However PVs have the potential to increase the military payload and self-defense (CIWS or AAM) system with the increase of size. Heavily armed patrol vessels would look more attractive, but should avoid functionally overkill. PVs are typically equipped with remote control main gun of medium caliber 57 to 76mm and 12.7 to 30mm

secondary guns, as appropriate to the size of ship. These guns provide the PVs with 360 degree defensive and

offensive coverage. Wing guns are normally 0.5 inch caliber machine guns.

Surface-to-Surface Missile (SSM) launchers and Anti-Air Missiles (AAM) are integrated to the

superstructure and deck spaces. Soft-kill chaff and decoy systems are located on the superstructure deck or

forward of superstructure.

The procurement of the combat system could either be part of turnkey contract or be a separate program. The

procurement strategy for the vessel must address the precise way in which the overall integration of combat

system and platform is to be achieved and, in particular, the roles and responsibility for the various parties in

the program. This process will inevitably create an area of uncertainty and risk for possible schedule and cost

overrun. There is also risk of technical impact (weight, electrical load, heat load, etc.). Allocation of

responsibility within a commercial contract framework is therefore important to manage the program and

mitigate the risks involved.

5.2 COMMAND, CONTROL COMMUNICATION, COMPUTER AND INTELLIGENCE (C4I)

SYSTEM

The combined Joint Task Force is widely used as a model for peacekeeping and other comparable operations.

In the maritime field, to assemble an international task force for an agreed mission, and to deploy, support,

and conduct possible opposed operations with full coordination of all assets, sensors and weapons is a

complex operation. Interoperability of Command, Control, Communications and the exchange of Intelligence

is key to successful conduct of Alliance/Coalition operations which have accounted for the majority, if not all,

military operations. New class of PV configuration shall have a minimum C2 system with C4I system

capable design.

5.3 HELICOPTER AND UNMANNED ARIEL VEHICLE (UAV) CAPABILITY

Operating a helicopter from a PV has always been a tough design requirement. Military specifications related

to helicopter operations are demanding including sea-keeping characteristic of ship, landing area, clearance

distances, air flow around landing spot, landing aid, control and communication, fire safety, structure load

during normal landing and in the event of crash landing, storage and maintenance capability (for an

embarked helicopter), onboard training, operation procedure, etc. In the frame work of an UN mission task

force, the PV should be able to receive a helicopter of another navy, or be able to receive an army helicopter

when operate in coastal waters. It is therefore necessary to certify the landing deck for a range of helicopters

during design and commissioning.

However, a PV’s capability is significantly increased if she is able to accommodate a combat helicopter or a

UAV with significant operational roles. UAV capable PV has become almost a new and standard

requirement for the new class of PV. In view of this, it is important that the design considers incorporating

the capability to land and take-off of a medium size helicopter or a UAV, and to accommodate a fixed hangar

for a larger patrol vessel.

6. CONCLUSION

The recent development trend in PVs has been towards a new class of multi-mission vessel, designed and

built with efficient hull form, equipped with hybrid propulsion, intelligent power management system, with

higher level of automation coupled with Sense-making to aid the end users in their operations. The

superstructure design is optimized to reduce radar cross section signature, infrared signature and exhaust gas

recirculation. The mast design has to consider all the various antennas, sensors and radars EMI/EMC

requirements. With the above mentioned design considerations and features, a new class of PV will definitely

serve its multi role purpose and meet navies ever increasing expectation. These objectives can be achieved

with everyone in the program team, including operator, contractor and suppliers working closely to integrate

their efforts towards the same common objective.

7. ACKNOWLEDGEMENTS

The lead author and co-authors would like to express our sincere gratitude towards the Engineering Design

Centre teams who have contributed to the success of the Fearless Class™ Patrol Vessel program. In addition

to the engineering team, we would like to thank our colleagues from operations, quality assurance,

purchasing, commissioning, and other supporting functions for their effort in supporting and completing the

build program of Al-Ofouq Class Patrol Vessel. The Al-Ofouq Class Patrol Vessel program has contributed

significantly to the Fearless 80 Mk III™ design. Lastly, the authors would like to thank ST Marine top

management for their relentless support and guidance.

8. FIGURES

Figure 1: Fearless 80 Mk IIITM hull form .......................................................................................................... 7

Figure 2: Appendages optimization test ............................................................................................................ 7

Figure 3: Key improvements of the hull form .................................................................................................... 7

Figure 4: Propulsion, maneuvering and sea-keeping model test ...................................................................... 8

Figure 5: Propeller design and cavitation test .................................................................................................. 8

Figure 6: Typical load operation profile of Hybrid Propulsion ........................................................................ 9

Figure 7: 3D model of in-house designed Modular Mast.................................................................................. 9

Figure 8: The 1:60 scale model of Fearless 75TM Patrol Vessel in the wind tunnel ........................................ 10

Figure 9: CFD Simulations and Wind Tunnel Test ......................................................................................... 11

Figure 10: MARPOL Annex VI, NOx Tier I-II-III requirements ..................................................................... 13

9. TABLES

Table 1: Typical PV operating profile ............................................................................................................... 5

Table 2: MARPOL Annex VI, SOx emission limits .......................................................................................... 12