Naval Architect Apr 08

Embed Size (px)

Citation preview

  • 8/8/2019 Naval Architect Apr 08

    1/3

    Feature 2 I RO-RO TECHNOLOGY

    Building to IMPROVE standardsAn innovative concept of a large ro-pax vessel is one of three new shipdesigns emerging from the EC-backed IMPROVE project.

    S upported by the EuropeanCommission, the three year`IMPROVE' ship design researchproject is approaching the half-waystage in its bid to deliver a rationale formaking decisions pertaining to the design,production, and operation of three newship generations.

    Coordinated by ANAST, University ofLiege, IMPROVE involves 17 partners,including Aker Yards of France, Uljanikshipyard of Croatia, Szczecin NewShipyard of Poland, owners Grimaldi,Exmar, and Tankerska PlovidbaZadar, Bureau Veritas, two ship designcompanies, two engineering companies,and two software companies, as well asWEGEMT (European Association ofUniversities in Marine Technology andRelated Sciences).

    The team hopes that the project's resultswill help the European shipbuildingindustry to claw back market share it haslost to yards operating on a lower labourcost base, such as those in China.

    IMPROVE aims to use advancedsynthesis and analysis techniques atthe earliest stage of the design process,considering structure, production,operational performance, and safetycriteria on a concurrent basis. The shiptypes are new generations of LNG gascarriers and chemical tankers and, as thefocus of this article, an innovative conceptfor a large ro-pax vessel.

    Over recent years, Uljanik Shipyard hasdesigned several car-carriers, con-ro, andro-pax vessels for different shipowners.Its enduring association with Grimaldiprovides the bedrock for the developmentof the new ro-pax vessel, whose evolutionhas already gone through general andstructural analysis. The shipbuilder hasperformed extensive multi-objectivestructural optimisation of a ro-paxstructure using OCTOPUS-MAESTROsoftware, with a view to developinga ship design promising minimumcost, minimum weight, and maximumsafety measures, while also satisfyingstructural constraints: yielding, buckling,displacements, and ultimate strength ofhull girder and ship panels. Meanwhile,large operational savings are predicteddue to a novel propulsion concept.

    The main dimension criteria envisagea ship with a maximum length of slipway230m, and maximum breadth given as

    30.40m.From the owner's point of view,

    the new vessel will be developed forMediterranean Sea operations andgeneral design requirements including:load carrying flexibility; a perceptibleimprovement in operational performanceand efficiency when compared to existingships; design for the redundancy andsimplicity of systems; an increase in ship'smanoeuvrability; optimised sea-keepingperformance; maximised comfort and

    minimised vibrations.There is also a specific requirement for

    an 8% increase in carrying capacity (lanemetres) on the tank top, to be achieved bydecreasing the length of the engineroom.This involves developing a 'pre-formed'new design for the stern part of the ship.

    Uljanik's design objectives are todevelop a ro-pax ship taking into accountlarge variations in seasonal trade (summer3000pax, winter 100pax). The monohullship is to feature a superstructureconstructed of steel or composite (noaluminium).

    Ultimate vessel dimensions are to beoptimised to improve the hydrodynamics,while a slow-speed main engine has beenpre-selected to improve maintenance andconsumption. The criteria also dictate:minimum height of deck transverses; animprovement in design using existing andimproved tools for early design phase; rulecalculation - simplified CAD modelling,leading to simplified FEM and LBR5modelling; minimum weight of freeboarddeck transverses; minimum height of deckNo3 and deck No4 transverses; accuratecalculation at the early design stage ofbuilding tolerances and deformationconstraints; superstructure deckseffectiveness in the longitudinal strengthto be considered; web frame spacing andlongitudinal spacing to be optimised,while there are to be no pillars in cargospace.

    `Standard Ship',the existing ship oryard prototype.

    ft,

    28he Naval Architect April 2008

  • 8/8/2019 Naval Architect Apr 08

    2/3

    ... *.:le...................Further objectives include theminimising of maintenance costs over a25 year lifetime, while the design mustalso take account of the probability of apotential conversion after 10 years due tonew Rules or comfort standards (that isthe ship's design must be flexible enoughfor easy conversion). Cargo handling willbe of the traditional type - stern doorand internal ramps. One aspect of sea-keeping will be defined by the fact that nofin stabiliser is envisaged, instead therewill be internal active stabiliser tanks.With these parameters in mind,

    Uljanik also has other expectations forIMPROVE. Among its goals are: reducingproduction costs by 10%; reducing fueloil consumption by 12%; and reducingmaintenance costs by 10%.

    Uljanik is committed to simplifyingthe production process, throughstandardisation and an increase insubassembly activities, and to cuttinghull erection time on berth from 18to nine weeks (plus three weeks forfinishing). It also envisages reducing thenumber of erection blocks from 330 to13 0 blocks, with all parts to be paintedbefore erection.

    For the new design, extensivestructural analysis (global and detail FEanalysis) are being performed to evaluatestructural feasibility and eliminate hardspots regarding stress concentrationproblems.Sophisticated solutionsThe arrangement of cargo space withoutpillars requires sophisticated structuralsolutions. Reducing the height of the deckstructure is also a very demanding task,but can result in many benefits regardinggeneral ship design, eg: Lower VCG (better stability) Reduced light ship weight (increased

    deadweight) Smaller gross tonnage

    The challenge is to improve Rulestructural design at the early stage ofdesign (concept stage), to find optimaldesign solutions using IMPROVE tools,and continue the design process in thepreliminary stage (where more detailedFEM calculations are performed) withthe better starting point/design.

    Body lines of 'New Ship'.

    Regarding the general ship design theother targets are: Selection of resistance-friendly

    hullform Smaller propulsion engine for same

    speed Reduced fuel oil consumption Selection of hullform in order to reduce

    length of engineroom (increasedlength of cargo space)The design methodology in the

    IMPROVE project defines three designlevels as the project unfolds: STANDARD SHIP is the existing ship

    or yard prototype NEW SHIP, which has been designed

    during the first period of the project.The design has been realised mainlyusing existing methodology andincludes improvements to the maindimensions, general arrangement,hydrodynamics, and propulsion

    IMPROVE PROJECT SHIP, whichwill be obtained from the Level 2design using multi-criteria structuraloptimisation including the productionand maintenance modelsThe main characteristics of the

    `standard' ship are: length overall - 193m+ 4m; breadth - 29.8m; draught design- 7.5m; trial speed - 24.5knots; cargocapacities - trailers 3000 lane metres +300 cars; capacities: HFO - 1400m3 , DO -250tonnnes, FW - 1200m 3 , SW - 600m 3 ;passengers - 350 cabins + 200 aircraftseats; crew 200 persons. This design wasdeveloped in cooperation with SiemensSchottel and Sea Trade from Oslo. Sucha ship is propelled by two pods behindtwo skegs.

    The main dimensions of the second stage`new ship' have already been defined, withoptimisation achieved using TRIDENT/SEAKING software in order to obtainminimal main engine power and sufficientstability. A new application has beendeveloped, which finds a best combinationof main dimensions in order to achieveminimal resistance. After resistancecalculation, it was decided that this 'level 2'ro-pax would have a fixed pitch propeller(FPP) as m ain, and active rudder as auxiliarypropulsion. The auxiliary propeller is to bedriven by a direct electric drive of 5000kWusing bevel gears at the top and the bottomof the leg (inside circular torpedo body).Planetary gears for steering are driven byfrequency-controlled electric motors.

    Here, the original hullform was Uljanik'sbiggest PCTC, which was then transformedinto the new (level 2) form. In comparisonwith the standard ship, the new design wouldneed almost 7000kW less power, while theweight of machinery would be reduced by450tonnes, fuel oil consumption would be28% lower, and finally, the propulsion systemis characterised as more reliable. The indexof redundancy is 100% (two independentenginerooms, two engines, two independentpropulsion systems).

    The main characteristics of this level 2ship are: length overall - abt 193m; lengthbetween perpendiculars - 180m; breadth- 29.8m; design draught - 7.5m; blockcoefficient - 0.53; trial speed - 24.5knots;main engine power - 14,940kW; activerudder output - 5000kW

    With 18 months of the project to run, thefull 'stage 3 IMPRO VE project ship' has yetto emerge, although it is already known thatUljanik anticipates a 500tonne reduction insteel content over the forerunning design,

    The Naval Architect April 20089

  • 8/8/2019 Naval Architect Apr 08

    3/3

    "411;;113:1 Frame 1 48. PER 1 .( .

    tartr204H 1 1 . 1 1 1 1 1

    TDeo,

    H4H

    Ell 1 1 . 1-,-

    uti. ,.-- 1)ADVANCEDMARINE'SOLUTIONS:Access & Handling Systems,Cargo Access Equipment,Life Davits Systems,Swimming-pool TelescopicCovers, Valves RemoteControl System, TenderPlatforms and a lot more!

    TiThe Naval Architect April 2008 31

    0

    I

    Ure01;, - ;

    Meet Our Representatives at RORO 2008

    BPBMSTANDIIM\,.J

    -Z

    c

    a

    General arrangement plan with markedspecific positions (characteristic sub-sections at Frs 74, 129, and 184) influencingship zones 1-3.

    and that the propulsion solution will featurea novel combination approach, using a singleskeg and single pod configuration, workingin combination with two-stroke engines.

    The project is currently in the modelintegration phase (IMPROVE WP5), sothe most important tasks and developmentof new products are forthcoming. Theexpected most important design goalsare: 4% less lightship mass, 8% morelane metres on tank top, 9.5% less powerrequirement, 3.5% less machinery mass,4.5% less fuel oil consumption, 5%-10%less cost of maintenance, 10%-15% moreoperational efficiency, 8% less productioncost, and 1 1% less lead time. NA