Your SlideShare is downloading. ×
  • Like
Design of a Pleasure Craft with Catamaran Hull
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×

Now you can save presentations on your phone or tablet

Available for both IPhone and Android

Text the download link to your phone

Standard text messaging rates apply

Design of a Pleasure Craft with Catamaran Hull

  • 1,168 views
Published

Final Year Graduation Project Presentation for Bachelor's Degree (Naval Architecture) in Myanmar Maritime University. November 2012.

Final Year Graduation Project Presentation for Bachelor's Degree (Naval Architecture) in Myanmar Maritime University. November 2012.

Published in Education
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
No Downloads

Views

Total Views
1,168
On SlideShare
0
From Embeds
0
Number of Embeds
1

Actions

Shares
Downloads
76
Comments
0
Likes
1

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide

Transcript

  • 1. Design of a Pleasure Craft with Catamaran Hull NA 18 NA 32 NA 38 NA 42 Htike Aung Kyaw Kaung Zaw Htet Paing Hein Htet Tin Htaik Thu Aung Supervised by Daw Khin Khin Moe
  • 2. We chose this project title because there are no former projects from our university which relates to this field of study. • This type of craft has better stability and faster speed than the other conventional types of ship. • It can give one’s pleasure or comfort, luxury, attract most people. •
  • 3.  Chapter-1 Chapter-2  Chapter-3  Chapter-4  Chapter-5  Chapter-6 Chapter-7   Introduction Types of Pleasure Crafts, Yachts and Catamarans Designing Concepts and Detail Design of Pleasure Craft with Catamaran Hull Rules and Regulations which this Pleasure Craft Complies Design Calculations for Pleasure Craft Model Making Conclusions and Recommendations
  • 4.    This project concentrates on the concept on an easy to handle pleasure motorboat constructed as a catamaran. Seeking the current market situations, there aren’t any places for catamarans here in Myanmar. Catamarans are used as luxury crafts mostly in Australia and New Zealand, can also be found in America.
  • 5. General Definition  Multihulls Crafts with more than one structural body  Usually of two, three or five hulls, namely Catamaran, Trimaran and Pentamaran   Pleasure Crafts Vessels that are used for sports, fishing or recreational purposes only  Do not operate for any financial gain to the owner 
  • 6.      Yachts Motor Yachts Pleasure Crafts/Luxury Crafts Catamarans Types of Catamaran Hull Forms
  • 7. A recreational boat.  Maybe of sail- or power- boats.  Yachts are different from working ships mainly by their leisure purpose.   Motor yachts generally fit into the following categories:  Day cruiser yacht (no cabin, sparse amenities such as refrigerator and plumbing)  Weekender yacht (one or two basic cabins, basic galley appliances and plumbing)  Cruising yacht (sufficient amenities to allow for living aboard for extended periods)  Sport fishing yacht (yacht with living amenities and sporting fishing equipment)  Luxury yacht (similar to the last three types of yachts, with more luxurious finishing/amenities)
  • 8. • Pleasure craft includes motor yachts, sailing yachts generally owned by private individuals; few are large enough to be regarded as ships. • They provide the maximum safety, comfort and entertainment for the passengers. • Maintaining stability of the hull is important. • No extreme of luxury can offset a simple case of sea sickness. • A ship consisting of two hulls, joined by some structure, the most basic being a frame. • Catamarans can be of sail- or engine-powered. • The twin-hulled sailing or motor boat has since become a popular pleasure craft, largely because of its speed and stability.
  • 9. • When talking about catamarans, we are not speaking of just one type of hull, but merely a whole hull category with many different types of constructions and optimization for different purposes. • Variations of hull forms exist.   BASIC CATAMARAN PONTOON OR HYDROAIRY TYPE SWATH (SMALL WATERPLANE AREA TWIN HULL)
  • 10. Type-A Type-G Type-B Type-H Type-C Type-I Type-D Type-E Type-F Type-J  A. Australian type with symmetrical sponsons*, fine entry, medium-square tunnel, low dead rise. B. Sailing-boat type symmetrical, round-bilge and tunnel, deep forefoot, no strakes. C. Asymmetrical sponsons with low dead-rise bottoms and no-trip chine, medium height square tunnel. D. Split monohull with narrow, low square tunnel with high attack angle at bows. E. Super-slim sponsons with medium-to-high tunnel, fine entry, designed to be used on protected waters. F. SES (solid side skirt) hovercraft with low tunnel and skirts at bow and stern. G. Kenton cat type with low round tunnel and round bottoms, tunnel lifting at bow. H. HySuCat with one main foil and two trim foils, high dead-rise bottoms and medium-high tunnel. I. Bobkat with round, asymmetrical sponsons, high tunnel with tunnel-chines and bow steps. J. Bobkat with HySuCat foils.
  • 11. Aspects A B C D E F G H I J 1. Low Vertical Acceleration – Sponsons 2 7 5 4 9 9 5 6 7 8 2. Low Vertical Acceleration – Tunnel 3 3 3 1 5 9 1 6 7 9 3. Inward banking in Turns 1 1 9 7 6 4 5 7 9 9 4. Non-broaching in Following Seas 2 3 6 7 4 6 7 5 8 8 5. Non-weaving in Quartering Seas 8 8 2 3 4 7 7 3 8 8 6. Resistance to Barrel-Rolling 1 5 9 3 7 7 7 5 9 9 7. Load Carrying Ability 5 5 6 7 2 3 8 5 6 7 8. Transverse Stability 6 6 7 3 4 3 4 7 7 7 9. Pitching Stability 4 5 6 7 4 3 6 7 7 8 10. Dry Ride in Small Chop 6 6 6 3 7 2 2 7 7 7 11. Economy at Planing Speeds 8 4 7 4 2 9 7 9 6 8 12. Economy of Construction 8 9 8 7 5 1 6 7 9 7 Total Score 54 62 74 56 59 57 65 74 90 95
  • 12.              Length overall – Length in waterline – Breadth (maximum) – Depth – Draught, at design waterline – Block Coefficient – Speed – Displacement – Classification – No. of Passengers – Propulsion – Power – Fuel & Fresh Water Capacity – 15 m 13.904 m 6.75 m 2.1 m 0.7 m 0.516 15 knots 20.42 tonnes Lloyd’s Register of Shipping 6 2xVolvo Penta IPS 600 2x320kW (2x435hp) 3387.131 liters, 680.045 liters
  • 13.   The principle dimensions of this design ship are derived from Thidar Catamaran (a 23.837m Catamaran, the only two catamarans built in Myanmar as Thidar I & Thidar II). The General Arrangement Plans is adopted from a graduation project by Juri Karinen, Lahti University of Applied Sciences, Finland, named as eCAT hybrid. Lines Plan of Thidar Catamaran
  • 14. 1. 2. 3. 4. From the Lines Plan of Thidar catamaran, we collect data to create the offset table. (Note that there may be errors up to 20 millimeters in full scale). From this offset table, we use Geo-Sim method to create an offset table for a 15m Catamaran. Notice that Thidar catamaran is a round bilge hull and our design is a chine hull catamaran. We create the chine hull using the values of the offset table for the 15m GeoSim catamaran as the limits. In creating a chine hull, first we draw it by hand, adjusting the limits. Again, we collect offset data from the hand drawing and create a 3D marker data which will later be imported to Maxsurf Pro software.
  • 15. 5. 6. 7. 8. 9. Marker data is created using Microsoft Excel Spread Sheet and saved in a “.txt” format. On markers window in Maxsurf Pro, Open the saved “.txt” marker data. Prefit software is not used as it will give and undesirable result while importing catamaran hull marker data. Create multiple surfaces, bond them, trim them as necessary. Transverse stiffness is set to 2 as we are creating a chine hull form. After quite enough fairing is done, the required hull form is obtained in a “.msd” format.
  • 16. Markers from Offset Table seen in Perspective View in Maxsurf
  • 17. 10. 11. 12. 13. To create Lines Plan and GA Plan, we used AutoCAD software. It is easy to bridge Maxsurf and AutoCAD software. The hull form that we created in Maxsurf can be exported as a “.dxf” format. This is a data exchange format that most CAD modeling software know. The export file can now be opened in AutoCAD. Unnecessary lines are deleted and the lines from each view is arranged in a new file after which it is saved. A Line Plan in “.dwg” format is achieved. GA Plan is drawn similar to eCAT hybrid.
  • 18. 14. 15. For Calculations, we will calculate with aid of software and verify by hand calculation wherever possible. For the first step of powering prediction, we use the resistance data obtained from NavCad. Lines Plan
  • 19.   It can be used both in Protected Waters and Sea-going. As it has a low draft, it has no problems in going shallow water, but it is designed mainly to go offshore, coastal area around Myanmar.
  • 20. 3D Rendering Video
  • 21. 4 View Windows in Maxsurf
  • 22. NavCad Prediction Results using Gronslett (Catamaran) Prediction Method
  • 23.          Propulsion is by twin installation of Volvo Penta IPS 600. Much improved efficiency, higher top speed, reduced fuel consumption/extended range, and great acceleration Low-speed maneuvering is easy, and high speed handling is a really fine Onboard comfort is greatly enhanced thanks to much lower levels of sound and vibrations Installation is greatly simplified More space available for accommodation Improved safety and quality Ease of service, and a complete system supported by one supplier Improved overall
  • 24. • Increased blade area vs. output, smaller propeller diameter and large gear ratio • No side force • Half propeller loading, means half tip losses and minimized cavitations • Horizontal shaft and thrust • Counter-rotating creates no rotational losses
  • 25.     There is another interesting fact in our designed ship. It is no other than the sewage system. There are two toilet bowls in our designed ship but there is neither retention tank nor a sewage treatment plant. This is because we use INCINOLET, the electric incinerating toilets. INCINOLET uses electric heat to reduce human waste (urine, solids, paper) to a small amount of clean ash, which is dumped periodically into the garbage.
  • 26.   SOLAS Rules and Regulations for the Classification of Yachts and Small Craft (Lloyd’s Register of Shipping)
  • 27.   Our design ship will go in Sea Area A1 only. Below, we will define basic ship requirements (equipments required to be fitted onboard) by SOLAS. Chapter IV, Part C &  Chapter V    Sea Area A1 is between 30~40 nautical miles from land, i.e, an area within the radiotelephone coverage of at least one VHF coast station in which continuous DSC alerting is available. DSC (Digital Selective Calling) is a technique using digital codes which enables a radio station to establish contact with and transfer information to another station.
  • 28. Equipments No. Required VHF with DSC x1 VHF with DSC receiver x1 NAVTEX receiver x1 Float-free satellite EPIRB x1 Radar Transponder (SART) x2 Hand-Held GMDSS VHF Transceiver x1 VHF NAVTEX EPIRB SART GMDSS - Very High Frequency Navigational Telex Emergency Position-Indicating Radio Beacon Search and Rescue ( Radar ) Transponder Global Maritime Distress and Safety System
  • 29.     On 1st July 2002, some new regulations came into force, which directly affect the pleasure boat users. These regulations are part of Chapter V of the International Convention for the Safety of Life at Sea, otherwise known as SOLAS V. Most of the SOLAS convention only applies to large commercial ships, but parts of Chapter V apply to small, privately owned pleasure craft. If a boating accident is involved and it is subsequently shown that the users have not applied the basic principles outlined here, they could be prosecuted.
  • 30.       Many large ships rely on radar for navigation and for spotting other vessels in their vicinity. So, whatever size of the boat is, it’s important to make sure that it can be seen by radar. Regulation V/19 requires all small craft to fit a radar reflector ‘if practicable’. If the boat is more than 15m in length, it should be able to fit a radar reflector that meets the IMO requirements of 10m2. If the boat is less than 15m in length, it should be fitted with the largest radar reflector possible. Whatever size of the boat is, the radar reflector should be fitted according to the manufacturer’s instructions and as high as possible to maximize its effectiveness.
  • 31.    Regulation V/29 requires the pleasure boat users to have access to an illustrated table of the recognized life saving signals, so that they can communicate with the search and rescue services or the other boats if they get into trouble. If the boat is not suitable for carrying a copy of the table on-board (because it’s small or very exposed), they must make sure that they have studied the table before they go boating. Larger boats should keep a copy on-board.
  • 32.    If the yachts and small crafts are to be registered under the Lloyd’s Register of Shipping class, the rules and regulations must be applicable. Some of the main important factors to consider are listed below. For constructional safety arrangements,         Bulkheads Hatches and Doors Portlights and Windows Guard Rails Ventilations Fire Protection Chains, Anchors and Mooring are to be considered. For machinery and electrical installations,      Engine Seatings Pumps and Piping Systems Electrical Installations Electrical Distribution Systems Batteries
  • 33.    Stability Calculations Resistance and Powering Calculations Strength Calculations
  • 34.  Hydrostatic Curve Calculation  The density of water used is 1.0252 tonnes/m3  The hydrostatic particulars at the draft of 0.7 m are:  Displacement – 20.42 tonnes  LCB – 1.105 m (aft of midship)  VCB – 0.451 m  WPA – 45.362 m2  LCF – 1.344 m (aft of midship) 26.071 m  KML –  KMT – 10.564 m  WSA – 67.691 m2 0.458 tonne/cm 0.409 tonne-m/cm  TPC –  MTC –
  • 35.  Displacement vs. KN Values
  • 36.    As our design ship is small, every single loads acting on it can cause serious stability issues. Thus, even small loads like chairs and accessories aren’t neglected. The following load case is used to determine large angle stability.
  • 37.     For most vessels, the GZ Curve must satisfy the criteria stating that the angle where maximum GZ occurs must be above 30 degrees. But for multi-hulls which have only small heel angles, maximum GZ might occur on angles less than 30. For our design ship, Max GZ of 2.127m occurs at the angle of 21.9 degree. HSC Code states that multi-hulled vessels must have Max GZ at the angles greater than 10 degree.
  • 38.        In still water condition, we can see that the boat is trimming by aft. The draft at AP is 0.06m more than the average draft. Both LCB and LCF are located aft of the midship. The immersion is 0.468 LT/cm. This is because the boat is relatively small. The deck has a maximum inclination of 0.6 degree. This isn’t much. This deck inclination is cause by the trim of the boat, having the same trim angle of 0.6 degree. Trim is by stern.
  • 39. Sectional area curve for still water condition
  • 40.    Resistance Calculation/Prediction in catamaran is more difficult and complicated than most conventional mono-hull. Generally saying, catamaran resistance is twice the individual hull resistance, plus an added drag due to the interference of the hulls with each other. Solutions cannot be generalized by one simple formula but varied in accordance with specific configurations of catamaran hull forms and their separation.
  • 41. Viscous interference  Due to asymmetric water flow around each hull. Wave interference  Due to interaction of the two separate wave systems in the tunnel between the hulls.
  • 42.  Insel and Molland (1992) proposed that the total resistance of a catamaran should be expressed as: CT CAT = (1+ ϕk) σCF + τCw  They also state that for the practical purposes, σ and ϕ can be combined into a viscous resistance interference factor β, where (1+ ϕk) σ = (1+ βk).  Thus, total Resistance Coefficient; CT = CF + CR = (1 + βk)CF + τCw
  • 43. Where, CF = Frictional Resistance Coefficient can be calculated by 0.075 the formula of C F = (log R − 2)2 n CR = CW = β = Viscous Resistance Interference Factor τ  Residuary Resistance Coefficient (Residuary resistance coefficient is found by using Froude – CR diagrams) Wave Resistance Coefficient Wave Resistance Interference Factor = It may be noted that for demi-hull in isolation, β = 1 and τ = 1, and for a catamaran, τ can CWCAT [CT − (1 + βk )as:]CAT be calculated CF τ=  C WDEMI = [C − (1 + k )C ] T F DEMI Form factor (1+k) is obtained using regression method, plotting Fn4/CF vs. CT/CF, using an index of m=4.
  • 44. Myanmar Maritime University Marine Hydrodynamics Centre Lm Ls Length Ratio Corresponding Speed 1.364 15 11       Vm=Vs*(Lm/Ls)^0.5   (Lm/Ls)^0.5   0.301551543 Ship Speed Ship Speed Corresponding Speed Corresponding Speed (knots) (m/sec) of Model (knots) of Model (m/sec) 6 7 8 9 10 11 12 13 14 15 3.09 3.6 4.12 4.63 5.15 5.66 6.18 6.69 7.21 7.72 1.81 2.11 2.41 2.71 3.02 3.32 3.62 3.92 4.22 4.52 0.93 1.09 1.24 1.4 1.55 1.71 1.86 2.02 2.17 2.33 Rt m 1.42292 2.79462 5.095257 7.71465 13.15901 19.839 30.51165 39.18444 39.22122 39.55348
  • 45. Finding Form Factor (1+k) using Regression Method v (m/s) RT (N) Rn = vL/ν CT=RT/(0.5ρSv2) CF=0.075/(log Rn -2)2 Fn=v/(gL)0.5 CT/CF Fn4/CF 0.931395 1.42292 1406099.799 0.005603246 0.004358935 0.263591832 1.285462 1.107509 1.086628 2.79462 1640449.765 0.008085155 0.004221568 0.307523805 1.915202 2.118562 1.241861 5.095257 1874799.731 0.011286201 0.004107756 0.351455777 2.747534 3.71431 1.397093 7.71465 2109149.698 0.013501838 0.004011145 0.395387749 3.366081 6.092907 1.552326 13.15901 2343499.664 0.018654555 0.003927582 0.439319721 4.749629 9.484131 1.707558 19.839 2577849.631 0.023243209 0.003854219 0.483251693 6.030588 14.15002 1.862791 30.51165 2812199.597 0.030037575 0.003789025 0.527183665 7.927522 20.38545 2.018024 39.18444 3046549.564 0.03286916 0.003730501 0.571115637 8.810923 28.51865 2.173256 39.22122 3280899.53 0.028367868 0.003677518 0.615047609 7.713863 38.9117 2.328489 39.55348 3515249.497 0.024920907 0.003629199 0.658979581 6.866779 51.96095
  • 46. Compare principle particulars of our model to the models tested by Molland A.F. Length (m) 1.273 L/  1/3 5.110 L/B 6.816 B/T 2.935 CB 0.5108  WSA (m2) 0.588 S/L 0.16  The model 4b shows the most nearest values, thus the related values of 4b will be chosen.
  • 47.   Calculation can now be done using the 8 procedures shown in the book. The results are as follows: vS (knots) vS (m/s) RTS (N) PES (kW) 6 3.0887 1148.3 3.55 7 8 3.6035 4.1182 2780.78 5655.08 10.02 23.29 9 4.633 13006.32 60.26 10 11 5.1478 5.6626 16057.18 24839.44 82.66 140.66 12 6.1774 39054.01 241.25 13 14 6.6921 7.2069 50877.41 50140.95 340.48 361.36 15 7.7217 50151.29 387.25
  • 48.       Effective power for the ship speed of 15 knots is 387.25 kW. Assume QPC = 65% or more QPC = PE/PD Delivered Power Required = 595 kW. One Volvo Penta IPS 600 engine could deliver a power of 307 kW. Since two units are installed, Delivered Power Installed = 614 kW.
  • 49.      Other way of saying, Volvo Penta IPS 600 gives out a total of 614 kW delivered power. QPC = 65% Thus the effective power of 399.1 kW can be achieved. Effective Power for 15 knots = 387.25 kW. Power Installed > Power Required.
  • 50.  Longitudinal Strength Calculation Load Case (Weight Distribution with Forward and Aft Limits)
  • 51.      Materials used for fiber boat building, polyester resin, catalyst, accelerator, color pigments, gelcoat, wood and plywood, are to be of approved type by the Society for marine construction purposes. Production of the craft can be either by hand lay-up or spray lay-up contact moulding techniques, and either of single-skin or sandwich construction or the combination of both. Recommended that the sandwich construction for hull and singleskin construction for deck and other structures. Moulds are constructed of suitable material and adequately stiffened to maintain their overall shape and fairness of form. The scantlings are to be determined by interpolation of the values given in tables in the Rule Book with respect to the dimensions of the craft.
  • 52.   The mechanical properties of a laminate, at a glass content by weight per layer of reinforcement of 0.3 are: Ultimate tensile strength = 85N/mm2, Tensile modulus = 6350 N/mm2, Ultimate flexural strength = 152 N/mm2, Flexural modulus = 5206 N/mm2, Ultimate compressive strength = 117.2 N/mm2, Compressive modulus = 6000 N/mm2, Ultimate shear strength = 62.0 N/mm2, Shear modulus = 2750 N/mm2, Interlaminar shear strength = 17.25 N/mm2 and Nominal laminate thickness per weight of reinforcement = 0.7mm per 300 g/m2. The reinforcements are to be thoroughly impregnated with resin, and consolidated to give a maximum glass content by weight of reinforcement as follows: Chopped strand mat or sprayed fibres = 0.34, Woven rovings = 0.5, Unidirectional rovings = 0.54 and Cloth fabrics = 0.5
  • 53.       The scantling of hull laminate is to be determined by the type of the craft, length and stiffener spacing. The values required are interpolated with respect to Length and Speed to Length ratio. Basic Stiffener Spacing = 422.5 mm Bottom Shell Weight = 4988.7 g/m2 Side Shell Weight = 3756.9 g/m2 Keel Width = 662.5 mm Keel Shell Weight = 7483.05 g/m2
  • 54.      LOA LWL B T vM In order to test resistance in towing tank, we need a fiber model. Fiberglass making is managed mostly by a couple dozens of companies. Rare for individuals to make their own fiberglass products as there is a difficulty to buy material required. For this project, a fiber model of approximately 1.5m in length is required. We chose a scale ratio of 11. Model dimensions are shown below. = 1.364 m = 1.268 m = = = 0.614 m 0.064 m 2.33 m/sec for 15 knots of ship speed
  • 55.                3-plywood sheets x4 2”x1” timber blocks x7’ Silicone sealants x2 Masking tape x1 No.3, P:36 Sandpapers x2 No.0, P:120 Sandpapers x3 Paper print-outs ½” Nails ¾” Nails 1” Screws Printer Hacksaw, Handsaw Pliers, Screw drivers Caulking gun Scissors, Knife, Rulers, Pen, Pencils, Permanent Markers, Tee and Set-
  • 56. Tools used in making wooden mould Stations cut out using hacksaw Assembling stations and plating shells
  • 57. View from aft (Transom) of wooden mould View from below (Fish view) Profile view of wooden mould
  • 58.       Cost of Timber mould is about 35,000 kyats. The usual way of fiber model making requires the female fiber mould to be made first out of wooden primary mould. Usually made with 6 laminates of chopped strand mat. Primary mould (Wooden) must first be sanded, applied with poly putty and again sanded starting from the sandpaper no. of 40 to 1800. For sandpapers of no. 400 and above, mould surface must be first sprayed with water before rubbing. Gelcoat is painted or sprayed on this finished surface, lamination starting about an hour after.
  • 59.         Chopped strand mat and polyester resin is used for lamination. Mat laid, Resin applied, Rollers coated, avoided air gaps, released excessive resin. 6 layers of laminate, Female mould is ready. Final male model is made similarly using the female mould as base, of 4 layers of laminate. This usual way can cost extra money if we make only one model, leaving the female mould an exces. For a 4.5’x2’x7” model, could cost 250,000 Kyats or more. As one model is only needed and best if final male model can be obtained without making a female fiber mould. Possible?
  • 60.       We want the cost to be minimum as we only want one model for our project. The company named Fusion Fiberglass agreed to make a final male model, costing only around 140,000 Kyats, where we won’t be able to get back the wooden primary mould. The way they make isn’t usual. Although we couldn’t see the making of it with our eyes, they explained us how they made. First, they put a tape fully around the primary mould. Then applied a really thick putty around it and let it dry. They destroyed the wooden mould which is lying inside the putty, taking care not to harm the putty. After peeling the tapes off, the putty now forms a female mould. Care must be taken in all stages afterwards. The male model is made just the same as the steps mentioned above.
  • 61.       The required fiber model will be shown below. When Fusion Fiberglass delivered the model, they said they have tested that the model is watertight. But we need to verify it. No lake or tank to test the model immediately. So, filled the model with water and see if there were leaks. None. Finally, we got our model for just around 18000 Kyats. Fit wooden pieces for seating of dynamometer and guiding arms, to test in towing tank. Dynamo must be fitted at CG both longitudinally and transversely. LCG position calculated by Maxsurf and verified by putting the model subjected to a tripping point, most likely to be edge of chair and seen balanced and stabled.
  • 62. Carriage Moving at a Speed of 2.33 m/sec, Related Ship Speed = 15 knots
  • 63.  Conclusion      In our project, detail definition relating to catamaran hull forms and pleasure crafts, designed hull drawn with Maxsurf and its calculations, rules and regulations required and model making are included. This project will help the development of using catamaran hull forms in ship industry in our country. Chine hull form is used, intended to design a semi-displacement/semiplaning craft. Displacement hull forms, useful for load carrying but slow speed. Planing hulls, designed for speed but power requirements are too high. Thus semi-displacement/semi-planing craft is selected for our design, pleasure craft. Maxsurf, easy to use and fast calculation. Required catamaran hull form is created by bonding and trimming surfaces in Maxsurf. GA plan and Lines plan are drawn in AutoCAD.
  • 64. Stability calculations by Hydromax. Freeboard and Tonnage calculations are not necessary for this type of craft.  Resistance test in towing tank of MMU. Calculation by Insel and Molland Theory. Viscous and Wave Interferences present for catamaran resistance calculation.  Strength and Section Modulus by Lloyd’s Rules, interpolated linearly from given tables w.r.t length and speed to length ratio.  Model making chapter help understand basic model making and fiberglass technology.  FRP boat building, not widely used here.  Locally manufactured boats are cheaper than imported ones. 
  • 65. In mass production of same design, fiber boat building is more beneficial and less costly compared to conventional boat building but if built only a few, the cost of making fiber mould is expensive and unprofitable.  Project points out superior facts of catamarans compared to monohull.  Further developments necessary.  Fast ferries should be designed as catamarans.  In depth study in this field would give stable, fast and more profitable catamaran design. 
  • 66.  Recommendations      No mother ship. Best if there is one. Calm water wave resistance, estimated by using theories and previous test data by others. Preferred if all separation to length ratio of specific type of hull form is tested. Resistance due to appendages neglected. Strength calculation incomplete. More rules and theories to study for strength calculation of FRP crafts. Projects that can be derived using this as a base:     Change GA Plan to design a ferry boat of same size with a capacity of 35 to 50 passengers, more rules and regulations required. Study resistance. Verify wave resistance w.r.t hull separation. Fit hydrofoils to form HySuCat arrangement. Install solar panels to form either electric only or diesel-electric hybrid system or hydrogen fuel hybrid system.
  • 67.  “Design of a Pleasure Craft with Catamaran Hull” is just a graduation project, which we approached design aspects with the availability of data and resources all we could get. Took a lot of hard work to gather data as there is no former project to rely on and most data from the internet are incomplete and costly. We really hope this project could be the start or foundation of many projects relating this field of study for students in our country.