Waterjet propulsion solutions

Propulsion solutions with waterjetsWaterjets propulsion is the most successful and efficient method

of propulsion for high-speed applications. The advantages are

not only higher efficiency, but also lower vessel resistance due to

the absence of underwater appendages like shafts, rudders and

shaftstruts. The absence of any parts below the waterline also

makes waterjets an ideal solution for shallow water operation.

The unique design features of the Lips jet will ensure access to

even the smallest ports.

Hybrid propulsion systems - the use of two fixed or

controllable pitch propellers in combination with a centre

waterjet - combine the best of both worlds. The propellers are

used for normal cruising while the combination of the propellers

with the centre waterjet is used to achieve the top speed. Hybrid

systems allow optimization of the propellers for the normal

cruising condition, resulting in improved efficiency, low noise

and vibrations and a smaller propeller diameter.

Looking for excellent manoeuvrability at all vessel speeds and

fast turn-around times? Waterjets outperform almost every

propulsion alternative. With catamarans it is usually possible to

achieve pure sideways movement and 360 degree turning

without a bow thruster.

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Wärtsilä designs waterjet propulsion systems

for the commercial, military and superyacht

market. A unique welded modular jet

construction is used that makes it possible

to offer competitive solutions in stainless

steel as well as custom solutions in every

power range and in every form and

execution. In close co-operation with a

limited number of partners, experienced in

building welded constructions in stainless

steel and titanium for the marine and nuclear

power industries, we are developing the

future of waterjet propulsion.

The waterjet range starts at around 500 kW.

Every LIPS® jet is optimized using

Computational Fluid Dynamics (CFD)

calculations based on the design details and

operating profile of the vessel. The result is

the standard of excellence in performance

and reliability that our markets expect.

Thruster DT-type jet with 360 degree revolving nozzle.

Designing the solutionWith the largest type and size range of waterjets available, we

can offer an optimized configuration for every propulsion

solution based on the required operating profile of the subject

vessel. We use Computational Fluid Dynamics to design the

optimum inlet characteristics based on the hull designed by the

naval architect. We can also contribute know-how during tank

tests. Several waterjet/stern mounting and installation options

are available and if required we can take responsibility for

complete solutions with intermediate shaftlines up to the

gearbox flange.

We aim to be more than just a supplier - we actively

co-operate with all parties involved. The result is a waterjet

propulsion installation with the lowest possible weight, lowest

maintenance costs, and optimized efficiency and cavitation

characteristics for all main operating conditions of the vessel. In

all cases the solution is competitive with standard solutions,

especially when considering the true lifecycle costs of the

customized propulsion system.

On request we can also deliver designs fulfilling very specific

demands for the use of advanced materials, special steering

layouts, control systems, resistance to shock loads or whatever

may be required. Examples of our special designs successfully in

operation are a 20 MW jet built according to NATO shock

requirements with a special, high-speed, full power crash-stop

installation, and a waterjet that supplies thrust in all directions

through a 360 degree revolving nozzle.

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Custom-designed reversible unit for the military market.Feadship with hybrid propulsion system.

Key benefits of the Lips jetThe design of our jets has evolved since the first units were

delivered in the 1970s. The design is unique and focused on

reliability and ease of maintenance. The main distinguishing

technical features are listed below.

Reliability: the inboard thrust bearing

A waterjet thrust bearing can be placed in two positions: on the

shaft end outboard of the ship in the waterjet stator bowl, or

inboard in the engine room. Only one solution makes sense -

inboard in the engine room - for three clear reasons: the hostile

sea environment is avoided, the risk of failure is reduced and

maintenance, if required, is far easier. The inboard thrust

bearing, accessible with the ship afloat and without dry-docking

or disassembly of the jet stator bowl, minimizes downtime and

maintenance costs. Furthermore, the additional space available

inside the ship makes it easier to install large bearings for

increased lifetime. Every Lips jet has the thrust bearing inside

the ship and operators who have experience with both inboard

and outboard thrust bearings praise this unique feature of the

Lips jet.

Its advantage is reinforced by the solution we have designed

for the outboard shaft end. The sea environment, unsuitable for

a thrust bearing, is ideal for a water-lubricated bearing due to

the high pressure and flow aft of the impeller. This makes a

water-lubricated bearing a highly reliable, high-tech and

low-cost solution. The tip clearance between the impeller and

the impeller seat ring is accurately tuned by a specially designed

interface between the impeller and the stator bowl, which

balances the impeller and makes the pump efficiency

independent of bearing wear.

Reliability: few moving parts

The design of our jets, and especially the design of the steering

assembly, is based on the philosophy that the greatest possible

reliability and lowest maintenance requirement is achieved by

limiting the total number of moving parts.

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Meko A-200 corvette with LJ210E reversible waterjet. The inboard thrust bearing and advanced hydraulic systems put safety and

reliability in first place.

Reliability: inboard hydraulics

As an option the hydraulic system can even be brought entirely

inside the vessel if required by the operating conditions. This

removes all hydraulic hoses and feedback cables from outside the

vessel, which increases the system availability.

Flexibility: welded jet construction

Since the only cast piece is the impeller, we have almost

unlimited flexibility to design the waterjet based on what is

required. This is demonstrated by the many special designs we

have produced over the years, our customized waterjet/stern

mounting options, and the wide range of types and sizes

available. We can offer the exact jet size required with the

weight optimized for the engine power and ship speed.

Flexibility: Lipstronic/j 7000jet control systems

Various control system layouts can be realized including

intelligent joystick control systems that integrate the control of

the waterjet and the bow thruster. As a result, pure sideways

movement of the vessel and 360 degree turning around the

ship’s axis is possible, enabling fast docking and fast

turn-around times. We have optional solutions for a number of

different ship types and operating challenges, such as portable

panels for luxury yachts.

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Main bridge panel of the Lipstronic/j 7000 Joystick control system.

HSV-XI with 4 x LJ150D waterjets. Military vessel operating in hostile waters.

OCEA fast patrol boat with 2 x LJ65E waterjets. LJ120E waterjets with inboard hydraulic system.

Optimized efficiency: CFD calculations

Computational Fluid Dynamics (CFD) calculations

revolutionize the hydrodynamic optimization process of the

waterjet. With CFD we can optimize every waterjet installation

we supply for the specific design requirements defined by the

naval architect. We have developed a highly advanced CFD

model of our waterjets that is capable of analyzing every

operating condition fast and at low cost. Our CFD model has

been validated in hydrodynamic research centres around the

world.

Safety: reduced risk of clogging

The Lips jet has only 7 stator blades in the jet bowl after the

impeller compared to 11 or more in other designs - another

positive spin-off of our inboard thrust bearing. In our design,

the "crash-stop" forces acting on the thrust bearing are not

transferred to the stator section of the jet, which allows fewer

stator blades. The low number of stator blades in Lips jets

substantially reduces the risk of clogging

Safety: manoeuvrability,acceleration and crash stop

Waterjets offer excellent manoeuvrability from zero to full ship

speed, good acceleration and excellent crash-stop capabilities.

Special reversing designs can enhance these features even

further.

Comfort: low noise and vibrations

Noise and vibrations and hydro-acoustic noise are far lower for

waterjets than for propellers. This improves passenger comfort

and reduces the signature of a naval vessel.

Easy maintenance and service

Key factors in successful operation include low maintenance

costs and reliable service without downtime and delay due to

mechanical problems. To achieve this we have designed our jets

to avoid complex oil-lubricated mechanical components outside

the vessel and with a philosophy focused on limiting the total

number of moving parts.

To reduce the maintenance costs even further we have

introduced standard maintenance sets for all main mechanical

maintenance jobs. To find what is needed to overhaul a

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Rodriquez TMV84 with 4 x LJ91E waterjets.

hydraulic cylinder, for instance, you no longer need to browse

through parts lists. The maintenance appendix of our electronic

manual lists all the necessary parts for the job. Simply print the

sheet, add notes as you please and fax it to our offices. The

maintenance set you receive includes all parts and a drawing

showing the replacement. The maintenance sets will reduce your

costs by saving time during both preparation and overhaul.

Furthermore, since the maintenance sets are standardized,

logistics costs are reduced on our side and the value of the sets is

far higher compared to the individual ordered parts.

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Rodriquez TMV115 with 4 x LJ114E waterjets. InCat hull 051 with 4 x LJ150D waterjets.

InCat hull 050 with 4 x LJ150D waterjets. Austal Autoexpress 86 with 4 x LJ120E waterjets.

Example of maintenance set for a

rubber bearing. One maintenance

set includes all the numbered

parts, a drawing showing the

replacement, and the consumables

required for mounting.

Standard scope of supplyWaterjets are standard delivered with:

� Hydraulic powerpacks

� Load-sensing PTO-driven variable displacement pumps

� Inboard thrust bearing complete with oil lubrication set

� Feedback frame for position indication of the steering

assembly

� Bridge control system including engine room control cabinets

� Design of inlet duct hydraulic profile.

This scope of supply can be extended, if required, with

intermediate shaftlines in steel or composite materials, shaft

couplings in steel or aluminium, and (partial) waterjet inlet

ducts.

Waterjet inlet duct

The hydraulic profile of the waterjet inlet duct is always

designed by us based on the design and operating parameters of

the ship. We employ the most modern CFD tools in

combination with the deep knowledge we have gained from

cavitation and wind tunnel tests to match the pump and inlet

duct characteristics. The structural design and construction is

normally made by the shipyard. The inlet duct can then be built

as an integrated part of the ship. If required we can also include

the (partial) inlet duct in our scope of supply.

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Townsend Bay Marine 21m sportsyacht with 2 x LJ51E.

Hydraulic system

The main components of the hydraulic system are the variable

displacement pump and the powerpack on which the

proportional valves and the normal safety and indication devices

are mounted. The proportional valves operate the steering and

reversing functions via double pressure lines. The variable

displacement pump controls the flow so that both functions can

be used simultaneously. A load sensing control system, supplied

as standard with the variable displacement pump, optimizes the

efficiency of the system by minimizing the heat losses.

The variable displacement pump is typically driven by a

power take-off on an engine or gearbox. A small separate

electric-driven pump including motor is mounted on the

powerpack for start-up and back-up. A three-way valve enables

the replacement of the filter cartridge in the return line of the

system during operation. The hydraulic system can be supplied

in various executions and with several optional functions.

Oil lubrication system

The oil lubrication system dissipates the heat generated in the

bearings and seals of the thrust bearing and provides lubrication.

The oil is pumped from the reservoir into the pressure line

through a filter and a cooler.

In the thrust bearing housing the flow is divided over the

radial and the axial bearings. Since the thrust bearing is inside

the vessel, lubrication under pressure is not required. An

electric-driven gear or vane pump feeds the oil into the housing

from where it leaves via natural flow through the return line

back to the reservoir.

To minimize losses and weight the thrust bearing housing is

only partly filled. A minimum oil level is maintained at all times,

to ensure that the bearings are always running through an oil

bath. In the event of a power failure onboard the ship the waterjet

can stay in operation at approx. 30% of its normal capacity.

Systems independent of electric power are available as an option.

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CFD optimisation of waterjet propulsion system. Hydraulic powerpack and oil lubrication set.

LJ65E waterjet.Six-bladed impeller and thrust bearing block.

Lips jet E-series, 6-bladed waterjetsRelation between power and vessel speed for the most often used waterjet sizes

Waterjet selectionThe above graphs indicate the jet size required based on the relationbetween the engine power and the design speed of the vessel. Forinstance a ship with four 4000 kW engines and a correspondingdesign speed of 35 knots will need four LJ91E jets. A ship with three9000 kW engines and 37 knots will need three LJ135E jets. Thecorrect jet size is thus indicated by the line above the intersection ofthe power and the design speed (see examples in above graphs).

The above size range is not complete but represents the most

often-used waterjet sizes up to 50 knots. We are available from theearliest design stages of the vessel to work with you on an optimizedpropulsion system. Please contact us for an accurate jet selectionbased on the specific vessel design parameters, or for details ofwaterjets for speeds above 50 knots and 40,000 kW. DXF / DWGformat general arrangement drawings of the most often used sizesare available.

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Lips jet E-series, 6-bladed waterjetsGeneric weights and dimensions for the most often used waterjet sizes

Notes:1. The waterjets defined in the above table are the mostoften used waterjet sizes. Intermediate sizes for the aboverange like a LJ160E or LJ175E size and the data for therange up to the LJ400E size are available on request.

2. The data in brackets is the maximum outboard length infull reverse and steering.

3. Inboard length may vary depending on the optimizedshape of the inlet duct.

4. Transom flange connections can be custom designed. Smaller transom flangediameters are possible if the requirements for the interface with the hull are met.

5. Weights are calculated based on jet power density. Please contact us for theweights of the jet sizes above the LJ99E based on the power density of yourdesign. Weights include an inboard bearing, but exclude hydraulic powerpacksand oil lubrication sets.

6. Water in the inlet duct is calculated to the transom and based on the standardshaft height.

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outboard length inboard length

Waterjetsize1

Outboard length[mm]2

Inboard length[mm]3

Transom flange�

4Weight steering

[kg]5Weight booster

[kg]5Entrained water

[ltr]6

LJ43E 1175 (1260) 1870 725 475 330 250

LJ47E 1275 (1370) 2040 795 615 435 330

LJ51E 1395 (1490) 2210 860 780 545 420

LJ55E 1505 (1620) 2380 930 995 695 530

LJ60E 1635 (1760) 2600 1015 1290 910 690

LJ65E 1780 (1910) 2810 1100 1635 1155 880

LJ71E 1935 (2070) 3070 1200 2070 1465 1150

LJ77E 2110 (2250) 3330 1300 2690 1890 1460

LJ84E 2290 (2450) 3630 1420 3400 2420 1900

LJ91E 2490 (2660) 3940 1535 4470 3160 2410

LJ99E 2705 (2890) 4280 1670 5510 3915 3100

LJ108E 2945 (3140) 4670 1825 5730 ~ 6860 4085 ~ 4730 4030

LJ114E 3100 (3320) 4930 1925 6720 ~ 8100 4755 ~ 5535 4740

LJ120E 3270 (3500) 5190 2025 7805 ~ 9635 5605 ~ 6570 5530

LJ127E 3465 (3700) 5490 2145 9415 ~ 11170 6625 ~ 7630 6550

LJ135E 3685 (3930) 5830 2280 11160 ~ 13160 7925 ~ 9065 7870

LJ142E 3880 (4140) 6140 2400 13100 ~ 15390 9395 ~ 10725 9160

LJ150E 4095 (4370) 6480 2535 15630 ~ 18560 11195 ~ 12765 10800

LJ157E 4285 (4570) 6780 2650 18120 ~ 21170 12985 ~ 14755 12380

LJ164E 4475 (4770) 7090 2770 20505 ~ 23815 14715 ~ 16635 14120

LJ171E 4665 (4980) 7390 2890 23205 ~ 27815 16745 ~ 19255 16000

LJ179E 4880 (5210) 7730 3025 26410 ~ 31605 19320 ~ 21940 18350

LJ190E 5185 (5530) 8210 3210 32805 ~ 37240 23671 ~ 26075 21950

LJ200E 5460 (5830) 8640 3380 38100 ~ 43870 27900 ~ 30255 25600

Wärtsilä is The Ship Power Supplier for builders, owners and operators

of vessels and offshore installations. We are the only company with a

global service network to take complete care of customers' ship

machinery at every lifecycle stage.

Wärtsilä is a leading provider of power plants, operation and lifetime

care services in decentralized power generation.

The Wärtsilä Group includes Imatra Steel, which specializes in special

engineering steels.

For more information visit www.wartsila.com

WÄRTSILÄ® and LIPS® are registered trademarks. Copyright © 2004 Wärtsilä Corporation.

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Wärtsilä Propulsion Netherlands B.V.Lipsstraat 52, P.O. Box 65150 BB DrunenThe Netherlands

Tel: +31 416 388115Fax: +31 416 373162www.wartsila.com