Further objectives include the
minimising of maintenance costs over a 25 year lifetime, while the design must also take account of the probability of a potential conversion aſter 10 years due to new Rules or comfort standards (that is the ship’s design must be flexible enough for easy conversion). Cargo handling will be of the traditional type – stern door and internal ramps. One aspect of sea- keeping will be defined by the fact that no fin stabiliser is envisaged, instead there will be internal active stabiliser tanks. With these parameters in mind,
Uljanik also has other expectations for IMPROVE. Among its goals are: reducing production costs by 10%; reducing fuel oil consumption by 12%; and reducing maintenance costs by 10%. Uljanik is committed to simplifying
the production process, through standardisation and an increase in subassembly activities, and to cutting hull erection time on berth from 18 to nine weeks (plus three weeks for finishing). It also envisages reducing the number of erection blocks from 330 to 130 blocks, with all parts to be painted before erection. For the new design, extensive
structural analysis (global and detail FE analysis) are being performed to evaluate structural feasibility and eliminate hard spots regarding stress concentration problems.
Sophisticated solutions Te arrangement of cargo space without pillars requires sophisticated structural solutions. Reducing the height of the deck structure is also a very demanding task, but can result in many benefits regarding general ship design, eg:
• Lower VCG (better stability)
• Reduced light ship weight (increased deadweight)
• Smaller gross tonnage The challenge is to improve Rule
structural design at the early stage of design (concept stage), to find optimal design solutions using IMPROVE tools, and continue the design process in the preliminary stage (where more detailed FEM calculations are performed) with the better starting point/design.
The Naval Architect April 2008 4
Body Lines of ‘New Ship’. Body lines of ‘New Ship’.
Regarding the general ship design the other targets are:
• Smaller propulsion engine for same speed
• Reduced fuel oil consumption Te main dimensions of the second stage
• Selection of resistance-friendly hullform
• Selection of hullform in order to reduce length of engineroom (increased
length of cargo space) The design methodology in the
IMPROVE project defines three design levels 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.
• IMPROVE PROJECT SHIP, which will be obtained from the Level 2
design using multi-criteria structural optimisation including the production and maintenance models
The main characteristics of the
‘standard’ ship are: length overall – 193m + 4m; breadth – 29.8m; draught design – 7.5m; trial speed – 24.5knots; cargo capacities – trailers 3000 lane metres + 300 cars; capacities: HFO – 1400m3 250tonnnes, FW – 1200m3
, SW – 600m3
, DO – ;
passengers - 350 cabins + 200 aircraſt seats; crew 200 persons. Tis design was developed in cooperation with Siemens Schottel and Sea Trade from Oslo. Such a ship is propelled by two pods behind two skegs.
Te design has been realised mainly using existing methodology and includes improvements to the main dimensions, general arrangement, hydrodynamics, and propulsion
‘new ship’ have already been defined, with optimisation achieved using TRIDENT/ SEAKING software in order to obtain minimal main engine power and sufficient stability. A new application has been developed, which finds a best combination of main dimensions in order to achieve minimal resistance. After resistance calculation, it was decided that this ‘level 2’ ro-pax would have a fixed pitch propeller (FPP) as main, and active rudder as auxiliary propulsion. Te auxiliary propeller is to be driven by a direct electric drive of 5000kW using bevel gears at the top and the bottom of the leg (inside circular torpedo body). Planetary gears for steering are driven by frequency-controlled electric motors. Here, the original hullform was Uljanik’s
biggest PCTC, which was then transformed into the new (level 2) form. In comparison with the standard ship, the new design would need almost 7000kW less power, while the weight of machinery would be reduced by 450tonnes, fuel oil consumption would be 28% lower, and finally, the propulsion system is characterised as more reliable. Te index of redundancy is 100% (two independent enginerooms, two engines, two independent propulsion systems). Te main characteristics of this level 2
ship are: length overall – abt 193m; length between perpendiculars – 180m; breadth – 29.8m; design draught – 7.5m; block coefficient – 0.53; trial speed – 24.5knots; main engine power – 14,940kW; active rudder output – 5000kW. With 18 months of the project to run, the
full ‘stage 3 IMPROVE project ship’ has yet to emerge, although it is already known that Uljanik anticipates a 500tonne reduction in steel content over the forerunning design,
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