GAS TURBINE POWER AND PROPULSION OPTIONS FOR THE MODERN … · 2013-09-17 · Proceedings of GT2007 ASME TURBO EXPO 2007 14 – 17 May 2007: Montreal, Canada GT2007-27470 GAS TURBINE

Proceedings of GT2007

ASME TURBO EXPO 2007

14 – 17 May 2007: Montreal, Canada

GT2007-27470

GAS TURBINE POWER AND PROPULSION OPTIONS FOR THE MODERN WARSHIP

David J. Bricknell Director, Systems and Product Strategy - Naval

Richard Partridge Senior-Principal Marine Engineer - Naval

Rolls-Royce plc Bristol United Kingdom

ABSTRACT

Modern naval combatants appear to be dividing into three

distinct ship types: ocean capable patrol-craft, globally deployable combatants, and the developing new class of fast littoral combatant. Each ship type places different and significant demands on the power and propulsion system. This paper describes the technical and operational issues driving the demands on the power and propulsion system including ship speed, un-refuelled endurance, fuel type, on-board maintenance and the new electric mission-systems. Gas turbine powered mechanical-geared systems, gas turbine alternator powered integrated full-electric systems and hybrid mechanical/electrical systems are all examined and their contribution to the success of the system is discussed.

INTRODUCTION

The globally deployable combatant is a ‘blue-water’

capable ship operating throughout the world’s oceans. It provides area air defence with large numbers of Vertically Launched (VL) missiles, a large multi-function radar, gunfire support (which in future could be an electric rail gun). It carries special-forces, one or two medium/large helicopters, and deploys Anti-Submarine Warfare ASW assets through unmanned vehicles. The role of the ship requires it to have a long unrefuelled endurance together with a good sustained speed for accompanying battle/carrier groups. This requires the capability to loiter for prolonged periods and benefits from a good sprint speed. The modern ship still has a substantial complement (about 200 reduced from the more usual 350 or so from a generation ago) and spends a considerable time away from base port, requiring systems and equipment to be reliable and maintainable with or without an accompanying infrastructure. Current and future ships fulfilling this

requirement are around 8,000t/150m (in a conventional displacement-type hull) with an all gas turbine power and propulsion system driving twin propellers for a ship speed in excess of 30 knots. Examples of ships in this class are the US DDG51, Japan’s Kongo and South Korea’s KDXIII. European ships offering lower overall capability in terms of speed and endurance as well as missiles and helicopter capability are the Royal Navy’s Type 45, Franco-Italian Horizon and FREMM, the Dutch LCF, Spanish F100 and German F124. It is no surprise, perhaps, that many of the designs arose from the nine-nation NATO NFR90 programme.

The Ocean Capable Patrol Craft is a ‘green-water’ vessel

patrolling near to the base country with capability to operate off the continental shelf out to say 1000nm or so from the shoreline. Current and future ships fulfilling this role are around 2,000t/90m Offshore Patrol Vessel OPV (or Corvette) with minimal crew number (~60 complement) and a shorter un-refuelled endurance of about 2,500nm at 12-15 knots. The OCPC is generally a more complex and capable ship than an Exclusive Economic Zone (EEZ) protection vessel and its role is more than just fisheries and minerals protection. The ships tend to be faster (25 –27 knots) than the typical 20-knot OPV but slower than the Global Combatant. This class of vessel has tended to be all diesel powered, primarily for initial cost reasons but also because speed aspirations are limited. Time away from base is less, permitting ease of maintenance of the diesels at the homebase.

The developing new class of fast combatant currently

focuses around broadly two types of craft: the first is the Swedish Visby-type own-country littoral combatant and the second is the trans-oceanic littoral combatant like the US Littoral Combat Ship. Both types of vessel are designed to operate close to shore either in one’s own littorals or in those of another country. The vessel characteristics are high-speed,

1 Copyright © Rolls-Royce plc 2007

shallow draft and waterjets. Propulsion is by gas turbine/diesel combinations. Both ship types have a reduced crew complement with the Visby class able to return to base frequently and LCS being supported by an extensive transportable infrastructure.

This paper speculates on the power and propulsion

characteristics for two new classes of fast combatant: the green-water fast combatant delivering OCPC capability at higher speeds and the blue-water fast combatant delivering self deployable capability throughout the world’s oceans but still being able to travel at high-speeds.

GLOBAL COMBATANT

The globally deployable combatant is a blue-water power-projection vessel. The vessel provides area air defence and is normally equipped with a large numbers of vertically launched missiles with the launcher silos (48 to 64) demanding a deep girder ship structure. It is required to provide shore gunfire support and will fit a large (greater than 5”) gun that may, in the future, be changed for a rapid-fire electric-rail gun. The ship embarks special-forces including their means of deployment and recovery; addresses asymmetric threats and mines through the deployment of unmanned air and surface vehicles; and includes one or two medium/large helicopters and their maintenance and flight crews. The vessel needs long un-refuelled endurance and a good sprint speed both for coastline dominance and keeping up with large battle or carrier group [1].

Figure 1 –Propulsion system options: The current

standard COGAG system - four medium size gas

turbines sharing the duty equally and combining for a

high maximum speed (A); an alternative all gas

turbine COGOG - two large and two small gas turbine,

each optimised for the sprint and endurance speed

ranges (B); the very fuel efficient twin large GT and

twin cruise high-speed diesel CODOG system (C);

and the hybrid electrical- mechanical COGLOG

system (D).

The ship has a requirement for ‘minimum crew’ but this is still likely to be some 200 or so driven in part by the aviation capability, more capable combat system and the requirement to deliver more at-sea maintenance and upkeep. The ship will spend time throughout the speed range. This Global Combatant’s operational requirement will demand of the power and propulsion system a fuel-efficient, high-power, low at-sea maintenance/upkeep system and supporting equipments, and the capability to deliver electrical growth for future electric mission systems. Current and near-future designs for this class of ship are over 8,000t with sprint speeds of 32 knots or more. The ships are twin propeller-driven and require installed propulsive power of in excess of 60MW. Older designs have an un-refuelled range of about 4,500nm at 18 knots whilst future requirements are for 6000nm or more at a similar or greater speed. A ship’s service and mission system electrical load of about 4 to 6MWe is demanded once the ship is at sea and combat ready. Today’s most commonly installed system adopts four medium power marine gas turbines coupled in a COGAG arrangement (total propulsion of 72MW) supported by three small gas turbine alternators to provide electrical load (3x2.5MW). The system delivers low-at-sea maintenance by virtue of its all gas turbine prime-mover selection but it falls short in delivering long un-refuelled endurance or in providing any electrical power headroom for any future adoption of electric mission systems. Figure 2 – Un-refuelled endurance comparison for the

Global Combatant’s potential power and propulsion

systems showing the significant endurance

improvements that can be achieved by moving to an

optimised cruise/boost propulsion system

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D Delivering improved un-refuelled endurance with such a system is relatively straightforward now that more powerful marine gas turbines are available. Figure 2 shows the nautical miles per tonne of fuel throughout the ship’s operational speed range for four systems. The first is the current quad 18MW GT and three 2.5MW ship service generators; the next three replace the four 18MW GTs with two 36MW GTs thereby maintaining the ship’s maximum speed but releasing the space available for dedicated cruise engine system. The choice of cruise system is then between smaller GTs, high-speed diesels or hybrid electric drive (either powered by diesel generators or by gas turbine alternators); the aim for each system being to deliver a cruise speed of at least 18 knots. Figure 3 shows comparative initial costs and weights.

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Figure 3 – Initial Cost and weight comparison for the

Global Combatant’s Power and Propulsion Systems.

There is no doubt that the combined diesel and gas

turbine system delivers lowest weight and initial cost

but this must be balanced against higher at-sea

maintenance. The innovative hybrid electric system

incurs a higher system weight but this is largely

offset by lower overall fuel load.

An all-electric power and propulsion is not included here as the power density required for the Global Combatant’s 32 knots is more than one and a half times that currently being achieved by today’s technology [2]. The inclusion of an electric-rail gun delivering a projectile every 15 seconds or so is likely to demand around 15MW of

further installed electrical generating capacity together with a substantial and bulky energy storage device [3]. Ship displacement is likely to increase to accommodate this adding maybe a further 1,000t or more to the ship weight. With a ship and mission system electrical load now being around 17.5MW and a ship’s propulsion power requirement of 72MW (but not at the same time), integration of the power and propulsion systems becomes attractive in order to reduce initial cost and installed power. Figure 4 – Hybrid Power and Propulsion System for a

Global Combatant with Electric Rail Gun. The system

includes direct geared drive from the gas turbines

and, with a suitable clutching arrangement, the

electric motors can direct-drive the propellers up to

18 or 20 knots without the gear operating. Power for

such a system is derived from a combination of two

small and two medium size gas turbine alternators.

In theory such a requirement would be ideally met by an all-electric power and propulsion system diverting propulsion power to the rail-gun when necessary. As discussed earlier in order to achieve this either the ship size needs to be substantially increased or the ship speed compromised in order to include the necessary electrical power and propulsion equipments. Instead, to limit the increase in ship displacement and to ensure ship maximum speed is maintained, a hybrid electrical/mechanical system is proposed. This system is shown in Figure 4.

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For the hybrid system, and in order to gain sufficient benefit from integrating the power and propulsions systems, selecting the ship speed at which one transitions from electric drive to mechanical drive is important. At 10 knots the Global Combatant requires about 1.5MW whilst at 18 knots this is around 10MW, after allowing for system losses. To arrange the ship for efficient operation without the rail gun or hybrid electric drive would require two x 2.5MW GTAs for ship power. Add a rail gun and the system might look more like two x 2.5MW GTAs plus two 10MW GTAs. With all GTAs operating a ship speed of 18 knots would then be achievable with two 5MW shaft mounted electric motors. Failure of one 10MW GTA would reduce ship speed to 12 knots with all other systems powered up - alternatively the ship could turn to all GT mechanical propulsion. Figure 5 illustrates a hybrid-electric Global Combatant Gas Turbines are currently available for the small GTA and for the main propulsion GTs but no marinised 10MW GTA is currently available. Electric Motor

Electric Motor

‘mid-size’ GTA’s

‘small’ GTA

‘small’ GTA GT

GT

Electric Motor

Electric Motor

‘mid-size’ GTA’s

‘small’ GTA

‘small’ GTA GT

GT .

Figure 5 – An artists impression of a hybrid-electric

Global Combatant. One main propulsion gas turbine

and one electric motor and one of the two mid-size

GTAs are each mounted in a common compartment

with two main machinery spaces adopted port and

starboard. The smaller GTAs are situated in a

common compartment but remote from the main

machinery rooms.


OCEAN CAPABLE PATROL CRAFT

The Ocean Capable Patrol Craft OCPC extends littoral capability into ‘local’ green-water. Good sea-keeping and a powerful combat system are required but within a relatively compact and inexpensive platform with a limited complement. This has tended to lead to a new and very populous class of ship sometimes described as Corvettes (or even Frigates) but just as often described as Offshore Patrol Craft (OPVs) although they clearly have a role above and beyond protection of a country’s Exclusive Economic Zone (EEZ). Currently this class of ship are designed at around 90m with a displacement of a little less than 2,000t and a ship’s maximum speed from 25knots to a sprint speed of 28 or maybe 30knots. This ship length hits the main resistance ‘trough’ at about 22 knots and the main resistance ‘hump’ at about 30 knots (Froude number of 0.31 to 0.54) and generally these ships are designed for service speeds nearer to 25 knots. Achieving 25 knots will require a propulsion power of about 18MW whereas achieving 30knots will require around 30 MW.

Figure 6 – Power and Propulsion Options for Ocean

CO

s

ith a maximum ship speed below 35 knots, propellers are

ost and fuel-efficient very compact high-speed diesels (@

Figure 7 – Un-refuelled range comparison for an

Oc

igure 8 – Initial System Weight and Cost comparison

capable Patrol Craft showing the ‘standard’ CODAD

system 17 or 32MW (upper), an all gas turbine

GAG 18MW (middle) and a ‘new’ CODAG 32MW

system utilising the new 20V high-power higher

peed diesels and a mid-power gas turbine with a

combining gearbox (lower).

Wnormally adopted thereby locating the engine room near amidships due to shaft rake. High-speed diesel (HSD) CODAD configurations are normal and are adopted due to the power density and the low overall power required. Increased on-board maintenance effort of HSDs is acceptable due to the proximity to the ship’s permanent shore-base. Replacing HSDs on a like-

for-like basis with gas turbines, i.e. four medium size GTs at, say, 4.5MW whilst reducing on-board maintenance effort will increase ship’s first cost and significantly impact on un-refuelled endurance: few benefits can be gained from the characteristics of modern marine gas turbines in this configuration. However it may be that the latest improvements to smaller high-speed diesels will once again open up the possibility of gas turbines in this ship type. C1800 - 2100rpm) are now available up to 4.3MW and at this power the OCPC is able to achieve an endurance speed of around 20 knots. More general acceptance of multi-speed combining gears allows twin gas turbines at 12 MW each to be added to the small high-speed diesels thereby delivering maximum powers of around 30MW. Such a system delivers very low installation impact with high un-refuelled endurance at a competitive cost albeit it still is situated near amidships. System options are shown in Figure 6, fuel usage at Figure 7 and initial weight and cost comparisons at Figure 8.

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As can be seen from the above graphs, for a 30 knot plus OCPC, excellent endurance and low fuel burn can be achieved by both the CODAD and CODAG systems but the CODAG system shows a significant improvement in system weight and an improvement in combined fuel and system weight with a lower initial cost. As with the Global Combatant the mid-size gas turbine at about 12MW would be required to deliver good sprint-speed fuel consumption within a compact and cost effective package. However in addition to the growth of the OCPC class of ship there is a also a trend toward faster vessels more attuned to operating in near-to home littorals whilst growing toward the size necessary for green-water operation and an aviation capability. Both Visby and the Omani Baynunnah class at about 70m and capable of speeds greater than 35 knots are demonstrating the characteristics required for 21st Century warfare: both are waterjet powered and Visby is gas-turbine powered.

FAST COMBATANTS

Fast Combatants are a rapidly developing class of ships. In

many respects the first of this new breed was the Swedish ‘Visby’ class. This is a relatively small vessel (approx 70m), designed to be deployed in a country’s own littorals. High sprint speed, shallow draft, extended low-speed running, and low noise and low magnetic signature are key characteristics but green-water capability, organic aviation and very high un-refuelled endurance are not attainable in a ship of this size.

The US Littoral Combat Ship has been developed in order to operate in other countries’ littorals. It is shallow draft, fast and agile but it is also designed to be deployable trans-ocean (from one green-water area to another). It has multi-mission capability due to the modular payload and requires transportable infrastructure to deploy and support it.

This section examines the type of vessel necessary to

dominate a country’s own littorals but coupled with an ocean going capability for domination of the ‘green-water’. Defence of one’s own country whilst providing significant force-projection in near waters, particularly to deploy in key shipping choke-points, requires vessels with similar characteristics as Visby but in this case these must be coupled to higher un-refuelled endurance and the capability to deploy in the green-water battle-space. These additional characteristics, coupled with the ability to deploy an aviation capability (including helicopter and unmanned vehicles) as well as special forces deployment, demanding manoeuvring at high-speeds, will require a minimum hull size of around 100m.

Power and Propulsion system options for a fast green-

water combatant have a considerable impact on the ship’s size and general arrangements when high maximum speed is coupled with long endurance.

For the purposes of power and propulsion system options

comparison a target green-water ship displacement of 2,500t has been used and the fuel load and mission systems were kept common. The fast littoral craft design developed is illustrated in Figure 9.

Figure 9 – Illustrative Fast Littoral Combatant developed to enable the comparison of Power and

Propulsion options for a green-water fast combatant.


Propulsion options considered are shown in the following four figures. Figures 10 shows a single Gas Turbine and Twin Diesel CODAG configuration, Figure 11 shows a twin Gas Turbine CODOG arrangement, Figure 12 an innovative Visby-style quad mid-size Gas Turbine and twin small Diesel configuration and Figure 13 illustrates some of the difficulties of achieving an all-electric Power and Propulsion System in a ship of this required power density, speed and size:

Figure 10 - Single 40MW Gas Turbine CODAG and

T

Figure 11 - Twin 25MW Gas Turbine CODAG

producing 61MW. Twin GTs are mounted in different

Figure 12 - ‘Visby-style’ CODOG system with four

12.75MW cold-end drive gas turbines delivering

51MW in a CODOG arrangement with two 5.5MW

high-speed diesels. This arrangement leads to the

smallest and lightest ship design with excellent

maximum speed and endurance.

Figure 13 - Integrated Full-Electric Power and

Propulsion arrangement with 80MW propulsion

power. All-electric propulsion has a significant

impact on the ship’s general arrangement, structural

and machinery weight and on unrefuelled endurance.

Gas

Turbines

High-speed

Diesels

Waterjets

Gas

Turbines

High-speed

Diesels

Waterjets

Gas Turbine

High-speed

Diesels

Waterjets

Gas Turbine

High-speed

Diesels

Waterjets

twin 5.5MW high-speed diesels producing 51MW.

he single gas turbine arrangement and twin diesels

can be mounted in the same compartment thereby

reducing the impact on the size of the ship.

Gas Turbine

High-speed

Diesels

Waterjets

Gas Turbine

High-speed

Diesels

Waterjets

Gas Turbine

Alternators

mid-size

GTAs

Direct-drive

motors

Convertors

Switchboards

Waterjets

Gas Turbine

Alternators

mid-size

GTAs

Direct-drive

motors

Convertors

Switchboards

Waterjets

compartments from the diesels.


A ship and system weight comparison is shown in figure 14. The Visby-Style propulsion system can be seen as the ligh st in weight and also has the lightest ship structural wei . The all-electric power and propulsion system is the heav st by quite some margin as well as incurring the heaviest stru ural weight. The choice and availability of a particular pow d size of gas turbine can have a significant impact in ove l ship size and displacement.

Figure 14 Ship and system weight comparison.

Accompanying the substantial IFEP electrical system

weight is also an increase in ship’s structural weight.

by trading off the poorer el consumption of a smaller Gas Turbine against the smaller d lighter ship and its lower power requirement..

The IFEP ship with Gas Turbine Alternators demands a nsiderably larger ship to cope with the size of the electrical otors and the size and weight of the generation and ansmission systems. Range is significantly curtailed due to e poor overall transmission efficiency.

Between the more conventional single and twin GT

arrangements the single GT gains benefit from the narrower beam of the ship allowing for a higher maximum speed.

teghtie

cter an

ral

A scale comparison of the three fast ship types can be seen in Figure 15 showing the 10m increase in ship length when going from Visby-style to conventional GT to IFEP. The Visby-style arrangement gains considerable benefit from the cold-end drive arrangements and exhausting over the stern allowing a smaller ship overall andfuan

0

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Visby-Style Single Gt Twin GT IFEP0

200

400

600

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1000

Weig

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Visby-Style Single Gt Twin GT IFEP

comtrth

8080

1200

1400

1600

Ship Weight Comparison

ElectricalPropulsion SystemSteelweight

1200

1400

1600

Ship Weight Comparison



Figure 15 – Comparison of the ‘same mission’ fast littoral ship when comparing different power and

propulsion options. The quad lightweight, cold-end drive Gas Turbine/Diesel combination delivers an

overall smaller and lighter ship with long unrefuelled endurance and high maximum speed

IFEP

Twin and

Single GT

CODAG

Visby-Style

CODAG

IFEP

Twin and

Single GT

CODAG

Visby-Style

CODAG


Twin GT Single GT Visby-Style IFEP

Table 1 shows the power and propulsion system comparison at a ship level.

Length OA m 116.3

116.3 105.6 126.4

Beam m 15.5

15.0 15.0 16.5

Displ deep t 2865 2722 2508

3776

Displ light t 2261

2240 1942 2786

Speed knts 46.8

44.4 48 48

Mission length days

20.6 20.6 24.8 14

Tab

as un-packaged as on Visby and othe imilar ships. Power density is very igh with a unit weight less than 2 tonnes. No such engine is currently available for such a system, but the basis exists for a marine version of a current regional jet aero-gas turbine.

The

ship speed range as is illustrated in figu 16.

adoption in an IFEP version of the green-water fast combatant are dominated by the space available in a ship of this size: a key driver for such a GTA is its overall length which must not be much over 10m including package and alternator if it is to fit between an acceptable damage compartment length. [3]

le 1 Power and Propulsion system analysis for the

Fast Corvette.

The small’ cold-end drive gas turbine is assumed fitted‘

r s h

Visby-Style arrangement also benefits from excellent fuel consumption throughout the

re

3000

4000

6000

Ran

ge (

nm

)

7000

8000

T

G Quad Cold-end d OGrive COD

Single-GT CODAG

Figure 16 Endurance calculations for the different

power and propulsion options

Characteristics of the gas turbine alternator suitable for

2000

5000

9000

0 10 20 30 40 50

IFEP

Twin-G

CODA

Speed (knots)

Figure 17 A 140m Globally Deployable Frigate with electric rail gun capability


resented here is blue-water deployable and has creased mission independence which increases displacement

and hence installed power. Designs of this type may well be introduced at the same time as electric rail guns are developed and whilst no such system capable of being fitted in a combatant of this size currently exists the power required for such a system can be included in the analysis. This is illustrated in the ship shown in figure 17:

It is envisaged that the ship will be used in a number of roles:

x� a Task Group Escort providing rapid response to asymmetric threats,

x� a land attack and unmanned surface/air vehicle deployer by fast dash into the gun-line

x� as a force multiplier through rapid manoeuvre and deployment of unmanned vehicles and special

The ship will need to be able to manoeuvre at high-speed

in s

l top speeds. Their impact on st combatants is likely to be considerably more demanding.

Sucpower station with the necessary rating: (gas turbine

alternato wand combini A sets into one system will influence thedesign to pro

Extending the green-water fast combatant to a genuine blue water role requires a minimum ship length of 140m. The design repin

forces

hallow water, carry sufficient fuel to deploy blue-water (say 7000nm @ 18 knots), carry sufficient armament to be a deterrent without mission module change-out and to be future upgrade proofed for future electric mission systems.

Power and Propulsion for this ship is a 110MW hybrid electro-mechanical system providing high maximum speed (>40 knots) and power for the weapons within a reasonable ship displacement: Full Electric Power and Propulsion in a blue-water fast combatant would incur too high an impact on ship size and initial ship cost.

However, there is currently considerable uncertainty about

the optimal energy storage solution for warships with electric mission systems at conventionafa

cessfully integrating propulsion motors, power converters and a

rs ill be required on the grounds of power density). ng waterjets and GT ship’s range capability, and will need careful

vide an acceptable capability..

Figure 18 – Globally deployable fast frigate power & pra hybrid electric/mechanical arrangement maximising capability for ships power, propulsion power and electrhigh-power gas turbines combined with twin electric mservices, propulsion and rail gun is provided by a mix alternators.

opulsion system schematic including the installed electrical generation ic-gun system. The ship uses two otors for propulsion, Power for ship of small and medium size gas turbine


Skarda working with the Rolls-Royce team.

GT Gas Turbine GTA Gas Turbine Alternator HSD High-Speed Diesel IEP Integrated Electric Propulsion IFEP Integrated Full Electric Propulsion LCS Littoral Combat Ship MW Mega-Watt MSD Medium-Speed Diesel nm nautical mile OCPC Ocean Capable Patrol Craft OPV Offshore Patrol Vessel VL Vertical Launch WJ Waterjet

CONCLUSIONS

Whether future naval combatants follow the conventional

speed route or turn to faster designs, gas turbines would appear to have a secure future. High-power and high-power density are the distinguishing features for the selection of the power system once ship speeds increase and the ship arrangements should be adapted to maximise the Gas Turbine’s benefits.

Modern propulsion systems for large global combatants are

likely to adopt a twin-gas turbine system, in conjunction with propulsion diesels or an electric drive system designed specifically for cruise operation. Whilst retaining the same top ship speed as the legacy quad Gas Turbine arrangement, these modern systems offer a greatly enhanced range or endurance capability and potentially lower initial and operational cost.

Modern naval programmes need to consider whether they

wish to implement electric rail gun technology, as it becomes available for retro-fit. Whilst offering significant operational benefits, the requirements for electrical power generation and energy storage is a serious challenge to the designer. Integrated electric propulsion systems using present-day technology do not provide the prerequisite power density for these high performance ships, but hybrid electro-mechanical arrangements are worthy of serious consideration.

xisting high-speed diesels are perfectly acceptable for OCP us operandi means that multiple-GT arrangements are unsuitable. However, new and very com

ost as well as improving vessel sprint speed.

Fast combatants with agility and shallow draft are a rapidly ip. Power and propulsion arrangements

r these green-water combatants have a considerable impact on s significantly larg ntially curt to n effic we ngement, usin ay offer sign progra ts.

at is fitted ‘for t with presents an interesting chal to t engineering com does not lend to fast rid electro-mechanical arra However, successfully integrating the ele e propulsion train and the ble ship with acceptable range capa ccessful resu be ach

REFERENCES

[1] Bricknell, David J and Skarda, Robert - Power Growth in

DTA Asia Feb 2005 CE Preston – Power for the Fleet ISBN 0 9508076 0 5 [2]

Acknowledgements The extensive ship design and propulsion system

considerations shown for the fast combatants are acknowledged as largely the work of Robert

NOMENCLATURE

ASW Anti-Submarine Warfare COGOG COmbined Gas turbine Or Gas turbine COGAG COmbined Gas turbine And Gas turbine CODOG COmbined Diesel Or Gas turbine CODAG COmbined Diesel And Gas turbine EEZ Exclusive Economic Zone

EC-type vessels; their mod

pact high-speed diesels, in combination with a modern circa 12MW GT, may offer an attractive alternative, in terms of combining low installation impact and high endurance at competitive c

developing class of shfo

hip size. IEP systems with GTA sets demand a er ship to accommodate the plant and range is substaailed due the relatively poor overall transmissioiency. Ho ver, a ‘Visby-style’ CODAG arrag a new small cold-end drive marine gas turbine, mificant mme and operational benefi A blue-water fast combatant, particularly one thbut no ’ an electric rail gun relenge he naval architecture/marinemunity. Given that present-day IEP technology itself ship applications, hybngements are again attractive.

ctric weapon system, thpower station into an affordability will require considerable attention if a sult is to ieved.

Naval Combatants,

Bricknell, David J and Partridge, Richard – Power and Propulsion for the Modern Global Combatant; Pacific 2006 [3] Casson, Wood, Bricknell, Daffey, Partridge – Power and Propulsion for the new global combatant; RINA Warship 2006


Documents

GAS TURBINE POWER AND PROPULSION OPTIONS FOR THE MODERN … · 2013-09-17 · Proceedings of GT2007 ASME TURBO EXPO 2007 14 – 17 May 2007: Montreal, Canada GT2007-27470 GAS TURBINE