Title of Invention	MODULARIZED SHIP HULL FORM.
Abstract	TITLE: A METHOD FOR MANUFACTURNG OF MODULARIZED SHIP HULL. A method for manufacturing of modularized ship hull involving a sytem of databases dividing the ship length into three distinct zones comprising aft body extending from aft till forward of engine room forward bulk head, fore body extending from fore end of the ship till aft of fore peak bulk head and mid body consisting of the middle portion between the aft body and fore body; identifying the functional requirements of the defined zones, ascertaining the constructional parameters for the said three zones based on the available input database and the functional requirements of the three zones; generating the modular design; and merging the zones; generating the modular design; and merging the zones into a single continuous three dimensionally faired body to thereby obtain the modular ship. The above method of modularization would favour cost-effective, fast and user specific production of various forms of ship hull.

Title of Invention

MODULARIZED SHIP HULL FORM.

Abstract

TITLE: A METHOD FOR MANUFACTURNG OF MODULARIZED SHIP HULL. A method for manufacturing of modularized ship hull involving a sytem of databases dividing the ship length into three distinct zones comprising aft body extending from aft till forward of engine room forward bulk head, fore body extending from fore end of the ship till aft of fore peak bulk head and mid body consisting of the middle portion between the aft body and fore body; identifying the functional requirements of the defined zones, ascertaining the constructional parameters for the said three zones based on the available input database and the functional requirements of the three zones; generating the modular design; and merging the zones; generating the modular design; and merging the zones into a single continuous three dimensionally faired body to thereby obtain the modular ship. The above method of modularization would favour cost-effective, fast and user specific production of various forms of ship hull.

Full Text	Field of the invention The present invention relates to a method for manufacturing modularized ship hull form for its production and to the production of ship hull form involving modularization of three modular zones of the ship hull involving the aft body, mid body and fore body. The invention is also directed to a system for use in separate modularization of the three zones based on the desired functional and geometric requirements and finally provide a composite form of the ship hull depending upon the end user requirements. The process of manufacture of the ship hull of the invention is directed to serve in large scale production of varieties of ship hull forms at reduced time span and at cost effective rates thereby serving better the requirements and demands of the ship building industry. Description of the known art Ships are generally custom-built. Each ship is developed as per the owner"s requirements independent of previous developed/designed hulls except in case of sister ships in which the same ship is repeatedly produced. Considering the varied uses and cost factors involved in the developments of such ships, it is not convenient to generate ship hulls as per the customer"s requirement readily and often the development of such ship hulls is found to be time consuming and cost extensive process. Additionally, as and when any ship is required to be developed involving alterations in form in view of the complexities involved, the conventional ship manufacturing processes are found to be not well equipped to generate such altered forms as per the end user"s requirements. Therefore, it is usual after the ship is developed the customer may not be satisfied and the builder may be required to rework on the existing module to make it somewhat satisfactory for the customer. However, it would be apparent from such conventional processes of ship manufacture that such processes are not streamlined and are usually attended on an ad-hoc basis involving lot of time and cost to develop a particular form of the ship. More importantly due to lack of direction in obtaining the modules of defined characteristics to suit the end users requirement, the conventional processes of manufacture often lead to products which do not have the desired uniformity or compatibility between the three modular zones of the ship i.e. the aft body, mid body and fore body. This again results in a ship hull, which may not achieve the desired functionality and geometric requirements for effective use. Objects of the invention It is thus the basic object of the invention to provide for improvement in the in ship hull form development and its production and enable the manufacture of various forms of ship hull which would avoid the above discussed limitations and constraints of the conventional art of developing ship hull forms. Another object of the present invention is directed to a process for modularization of ship hull to favour industrial production of varied modular forms of ship hull which would match the requirements of the end user by way of a more confirmatory and composite developmental process steps leading to ship hull forms meeting customer"s requirements and avoiding the conventional forms of reworking to meet customer"s satisfaction. Yet further object of the present invention is directed to the development of ship hull taking into account the complexities of the three dimensional structure and in particular the specific requisite of the aft body, fore body and mid body of a ship hull and provide process steps which could not only provide variations in the forms of the respective zones of the ship hull depending upon the varied end uses but would also provide for a compatible relation of the three zones to provide a continuous surface of the hull form improving its functional and geometric characteristics. Yet further object of the present invention is directed to providing a method of development of ship hull forms which can be industrially applied to generate varied forms of ship hull at cost effective rates meeting consumer requirements. Summary of the invention Thus according to the basic aspect of the present invention there is provided a method for modularization of ship hull for its production comprising : providing a system of database concerning the usual technical and building specification for a number of such ships; identification of the desired specifications for such modular ships including their functional and other features ; analyzing the available database and generating the specifications for the aft region, fore region and mid body region for the range of identified ships; dividing the ship length into three distinct zones comprising a) aft body extending from aft till forward of engine room forward bulk head, b) fore body extending from fore end of the ship till aft of fore peak bulk head and c) mid body consisting of the middle portion between the aft body and fore body; identifying the functional requirements of the thus defined three zones comprising said aft body, mid body and fore body ; ascertaining the constructional parameters for the said three zones based on the available input database and the functional requirements of the three zones ; generating the modular design of the said three zones satisfying the separate functional requirement and the overall geometric constraints ; and merging the zones into a single continuous three dimensionally faired body to thereby obtain the modular ship. The above disclosed method of modularization of ship hull, involve conventional software packages to support the various database and input data, execute statistical analysis, economic analysis, technical calculation, surface modeling and CAD. The method effectively integrates the above to facilitate simple and cost-effective modularization of the ship hull. According to a preferred aspect of the present invention there is provided a method for modularization of ship hull comprising: providing database concerning the usual technical and building specification for a number of ships preferably having stored data concerning laws of flotation, cargo requirements of volume and weight, requirements on operating economics, requirements of building economics, technical constraints imposed by the ship building yard, statutory requirements and requirements of ship classification societies; identification of the desired specifications for the modular ship including its functional and other features such as the desired hydrodynamics, propulsion, steering and accommodation of the aft body, the cargo, cargo volume and production kindliness of the mid body and hydrodynamics, production kindliness of the fore body; analyzing the available database and generating the specifications for the aft region, fore region and mid body region for the range of identified ships; dividing the ship length into three distinct zones comprising a) aft body extending from aft till forward of engine room forward bulk head, b) fore body extending from fore end of the ship till aft of fore peak bulk head and c) mid body consisting of the middle portion between the aft body and fore body; identifying the functional requirements of the thus defined three zones comprising said aft body, mid body and fore body ; ascertaining the constructional parameters for the said three zones based on the available input database and the functional requirements of the three zones ; generating the modular design of the said three zones satisfying the separate functional requirement and the overall geometric constraints ; and merging the zones into a single continuous three dimensionally faired body to thereby obtain the modular ship. Importantly, in the above method of the invention the modularized design of the three zones should satisfy separate functional requirements which would meet overall geometric constraints as hereunder: a) The parallel mid body should be adapted to be changed (thereby changing length of ship) to suit the requirements of the product mix. The depth can be varied to a limited extent by change of the above water portion of the ship to suit the requirements of the product mix maintaining requisite freeboard. b) Block Coefficient and Longitudinal Centre of Buoyancy ; the three zones should be so designed that the final Cb and LCB confirm to the optimal values with regard to Froude number. c) Deck area : The overall deck area must be adequate with regard to cargo arrangements (e.g. container arrangement above deck). d) Merging of the Zones : The most stringent requirement of the modularization concept is merging of the zones shapes into a single continuous three - dimensionally faired body. This requires that slope and curvature must maintain continuity in the water line and buttock planes in the merged region: aft body and mid body, mid body and fore body. Also, the above steps of modularization in the process of invention is carried out by modeling the three regions so that slope and curvature continuity can be achieved across the merged lines ensuring geometric requirements such as main dimensions, deck area, Cb and LCB location and smooth merging of the three zones. According to another aspect of the present invention there is provided a system for modularization /designing and production of ship hull comprising : means for providing database concerning the usual technical and building specification for a number of such ships; means for identification of the desired specifications for the modular ship including its functional and other features; means for analyzing the available database and generating the specifications for the aft region, fore region and mid body region for the range of identified ships; means for dividing the ship length into three distinct zones comprising a) aft body extending from aft till forward of engine room forward bulk head, b) fore body extending from fore end of the ship till aft of fore peak bulk head and c) mid body consisting of the middle portion between the aft body and fore body; means for identifying the functional requirements of the thus defined three zones comprising said aft body, mid body and fore body ; means for ascertaining the constructional parameters for the said three zones based on the available input database and the functional requirements of the three zones; means for generating the modular design of the said three zones satisfying the separate functional requirement and the overall geometric constraints ; and merging the zones into a single continuous three dimensionally faired body to thereby obtain the modular ship. The above disclosed system for use in manufacture of modularized ship hull, involve conventional software packages to support the various database and input data, execute statistical analysis, economic analysis, technical calculation, surface modeling and CAD. The system used should integrate the above to facilitate simple and cost-effective modularization of the ship hull. According to a preferred aspect of the present invention there is provided a system for modularization and production of ship hull comprising: means for providing a system of database concerning the usual technical and building specification for a number of ships preferably having stored data concerning laws of floatation, cargo requirements of volume and weight, requirements on operating economics, requirements of building economics, technical constraints imposed by the ship building yard, statutory requirements and requirements of ship classification societies; means for identification of the desired specifications for the modular ship including its functional and other features such as the desired hydrodynamics, propulsion, steering and accommodation of the aft body, the cargo, cargo volume and production kindliness of the mid body and hydrodynamic, production kindliness of the fore body ; means for analyzing the available database and generating the specifications for the aft region, fore region and mid body region for the range of identified ship; means for dividing the ship length into three distinct zones comprising a) aft body extending from aft till forward of engine room forward bulk head, b) fore body extending from fore end of the ship till aft of fore peak bulk head and c) mid body consisting of the middle portion between the aft body and fore body; means for identifying the functional requirements of the thus defined three zones comprising said aft body, mid body and fore body ; means for ascertaining the constructional parameters for the said three zones based on the available input database and the functional requirements of the three zones ; means for generating the modular design of the said three zones satisfying the separate functional requirement and the overall geometric constraints ; and means for merging the zones into a single continuous three dimensionally faired body to thereby obtain the modular ship. Description of the invention To meet the above objectives of the invention a detailed study and analysis of the complexities involved in the manufacture of ship hull forms were studied. It was identified that the development of modular form of ship hull is basically subject to the following constrains: i. laws of flotation; ii. cargo requirements of volume and weight; iii. requirement of operating economics; iv. requirement of building economics; v. technical constraints generally imposed by the ship building yard; vi. statutory requirements of port state control authorities i.e. safety, stability, free board, maneuverability, noise, pollution etc.; vii. requirements of ship classification societies i.e. structural arrangements, standards, machinery and equipment, viii. Hydrodynamic design requirements of powering, flow characteristics, etc. To meet the above complex requirements of ship hull forms and possible variants thereof and to make the possible process of manufacturing of such ship hull forms industrially applicable and to have control over the manufacturing process to meet consumer demands and end user requirements keeping in view the above complexities, the complex three dimensional structure of the ship hull is categorized under the process of modularization of the invention into three longitudinal zones comprising the aft body (from aft and till forward of engine room forward bulkhead), fore body (from fore end of the ship till aft of fore peak bulk head) and mid body (middle portion between the aft body and the fore body). Lengthwise arrangement of the three selected zones is shown in accompanying Fig. 1 The aft body is found to be the most complex portion of the ship having maximum content in terms of construction and assembly of equipment. It is also most demanding in terms of cost and time. Thus there exists a need for development of process of modularization/standardization of the aft body which could suit a range of product mix of ships in combination with different fore body and mid body whereby the cost and time of construction could be brought down. Importantly, such process of manufacture involving modularized/standardized aft body would enable standardization of machinery, equipment and production process of the aft body. The basic functions and requisites of the aft body for such purpose are identified as hereunder: a. hydrodynamics - good flow characteristics around the stern, propeller disc and rudder; b. propulsion - adequate internal volume to house a range of main machinery of the propulsion system subject to various requirements of the product mix; c. steering - proper aft body shape with constant position of aft perpendicular and stern aperture; d. accommodation - standardize accommodation matching with after body shape to serve the varying requirements of the product mix. It is also identified the mid body of the ship constitutes the biggest portion in terms of volume and length and is provided as the freight earning portion of the ship. It is structurally simpler than the other two zones of the ship but contains the maximum steelwork in terms of weight. The variations in this area are identified to include length, bilge radius (mid ship area) and prismatic co-efficient. It is also found that this mid body construction is subject to constraints of function and requirements such as; a. cargo - different internal arrangements for varying product mix such as containers, liquid cargo (POL), bulk cargo and general cargo etc; b. cargo volume - cargo volume can be adjusted to suit product mix by adjusting the following geometric characteristic in this region- i. length (change in parallel middle body length), ii. block co-efficient (by changing sectional area curve), c. production kindliness - this can be introduced into the product mix by keeping the same internal volume but varying the bilge radius and thereby altering the length of parallel middle body. It is further identified that the fore body of a ship is highly three dimensional, structurally complex and difficult to fabricate. Therefore, the process of modularization was directed to achieve a standardized fore body which could reduce production cost and time substantially. The fundamental requirements of the fore body module which required consideration were identified as follows: a. hydrodynamics - to suit the varying requirements of the product mix particularly with regard to design draught (container ship design draught is lower than that of a tanker) and ballast draught (found to be important for tankers and bulk carriers). Hydrodynamic designs of the bulb is also required such that it takes into account the range of speeds of the varying product mix; b. production kindliness - it is important the fore body shape is developed such that it can be produced easily and is able to house standardized anchoring and mooring equipment for the production mix. Keeping in view the above identified requisites for producing varied ship hull forms depending upon end user requirement the process of development of such ship hulls involving modularization in accordance with the present invention basically involves the following steps: 1. identification of product mix required in terms of the dimensional and other requirements such as length, breadth, depth, draught, speed, block co- efficient and longitudinal centre of buoyancy. 2. Identifying the required division based on such dimensional characteristics of the three sections comprising the aft body, mid body and fore body; 3. selectively providing desired number of units of each of the three modular zones to satisfy the product mix requirements; 4. selectively developing each of said modular zones keeping in view the functional and geometric requirements detailed above based on end user requirements/applications. It is found that by following the above process steps and modularizing the ship hull form and its utilization in the process of manufacture of ship hull one would provide for a more convenient and cost effective manufacture of varied forms of ship hulls. Importantly, it is found that by way of following the above process of modularization and integrating the same in the manufacture of ship hulls the various geometrical constraints of development of ship hull forms could be satisfied including : a. the parallel middle body can be adapted to suit the requirements of product mix. The depth can be varied to a limited extent by change of the above water portion of the ship to suit the requirements of product mix maintaining requisite freeboard; b. block co-efficient and longitudinal centre of buoyancy values are optimized with regard to Froude number by way of modularization of the three zones; c. the overall deck area can be maximized depending upon cargo arrangements/requirements; and d. effective merging of the three zones into a continuous three dimensional faired body. The slope and curvature selected to ensure the continuity in the water line and buttock planes in the merged regions of the three sections. The invention is explained in further detail by way of the following non-limiting example and the accompanying figures thereunder: Reference is first invited to accompanying figure 1A which is a block diagram illustrating the method of manufacture of modularized ship hull in accordance with the present invention. As represented in said figure such modularization of ship hull basically comprises of database (1) concerning the usual technical and building specification for such ship hull; identification (2) of the desired specifications for the modular ship including its functional and other features ; Analyzing (3) the available database and generating the specifications for the aft region, fore region and mid body region for the range of identified ship ; dividing (4) the ship length into three distinct zones comprising a) aft body extending from aft till forward of engine room forward bulk head, b) fore body extending from fore end of the ship till aft of fore peak bulk head and c) mid body consisting of the middle portion between the aft body and fore body; identifying (5) the functional requirements of the thus defined three zones comprising said aft body, mid body and fore body ; ascertaining (6) the constructional parameters for the said three zones based on the available input database and the functional requirements of the three zones ; generating (7) the modular design of the said three zones satisfying the separate functional requirement and the overall geometric constraints ; and merging (8) the zones into a single continuous three dimensionally faired body to thereby obtain the modular ship. Reference is now invited to accompanying figure 1B which schematically illustrates by way of a block diagram and an embodiment of the system for use in the method of modularization of the ship hull in accordance with the present invention. As shown in said figure the system basically involves means for providing database (A) concerning the usual technical and building specification for such ship hull; means for identification (B) of the desired specifications for the modular ship including its functional and other features ; means for analyzing (C) the available database and generating the specifications for the aft region, fore region and mid body region for the range of identified ship ; means for dividing (D) the ship length into three distinct zones comprising a) aft body extending from aft till forward of engine room forward bulk head, b) fore body extending from fore end of the ship till aft of fore peak bulk head and c) mid body consisting of the middle portion between the aft body and fore body; means for identifying (E) the functional requirements of the thus defined three zones comprising said aft body, mid body and fore body ; means for ascertaining (F) the constructional parameters for the said three zones based on the available input database and the functional requirements of the three zones ; means for generating (G) the modular design of the said three zones satisfying the separate functional requirement and the overall geometric constraints ; and merging (H) the zones into a single continuous three dimensionally faired body to thereby obtain the modular ship. Example STEP 1: Using a conventional shipping market database covering current published literature and in-house economic analysis to generate technical specifications for identified product mix. The broad product mix identified was as follows : 550-650 TEU feeder container vessels 9000-12000 t DWT product tankers for short sea voyages 9000-12000 DWT bulk carriers and multipurpose cargo carriers Identifying specific vessel types suitable for production based on available resoucees: • 550 TEU Feeder Container vessel for 14.0 knots to 15.5 knots design speed • 600 TEU Feeder Container vessel for 14.0 knots to 15.5 knots design speed • 650 TEU Feeder Container vessel for 14.0 knots to 15.5 knots design speed • 9000 t DWT Product Tankers/Bulk Cariers/Multipurpose Cargo Carriers for 13.5 knots to 14.5 knots design speed • 10500 t DWT Product Tankers/Bulk Cariers/Multipurpose Cargo Carriers for 13.5 knots to 14.5 knots design speed • 12000 t DWT Product Tankers/Bulk Cariers/Multipurpose Cargo Carriers for 13.5 knots to 14.5 knots design speed STEP 2: Identification of desired features of the ship based on modular concept and by utilizing the client requirement database based on the available resources of shipbuilding and the feeder container and POL service trade patterns for defined sea routes . The variation in the following main dimensions and ship particulars were determined : • Length to vary between 113m and 127m • Breadth not to exceed : 19m • Depth to vary between 10.3m and 11 m • Draught - fully loaded: 6.6m for feeder container vessel and 7.8m for the other vessels • Draught ballast: No special requirement for container vessel, 5.5m aft and 4.0m forward for other vessels • Block coefficient to vary between 0.68 and 0.72 STEP 3: Identification of the functional specification of the aft region, mid body region andfore region by utilising the technical information and preliminary design calculations for the desired range of ships. The following manufacturing specifications were identified for the modular region i.e. aft region, midbody region and fore region . The vessel with length 113 m should have the smallest length of parallel middle body. The vessel length should be changed by steps of 7m to generate ships of length 120 and 127m. This length variation to be obtained only by changing the parallel middle body. The depth variation between 10.3 m to 11.0 m is to be obtained by extending the above water portion of the hull only without affecting hydrodynamic performance of the ship. For an optimum hydrodynamic performance of the entire range of products, it was found that the LCB should vary between 0 m and 1 m forward of midship. The fore end should be suitable for two draught operations; (1) suitable for container ships and (2) suitable for tankers, bulkers and multipurpose vessels. The stern required to be standardized for the given range of vessels. STEP 4 : The ship length for the entire product mix was divided into three distinct modular regions. Fig. 1 shows such selective division of ships into three regions, which are as follows: • Aft body was selected from aft end till forward bulkhead of aft engine room bulkhead. • Mid body was selected from the fore end of the aft body till the fore peak bulkhead • Fore body was selected from fore peak bulkhead till fore end. STEP 5 : The functional requirements of the three module regions of the ship hulls were identified by utilizing the conventional information data base and naval architectural calculation software. The following desired functional requirements were identified for the three separate regions. Aft region: (1) is to be suitable for providing a uniform distribution of wake in the propeller disc region for all vessels (2) is to have adequate volume to provide propulsion and auxiliary machinery for all vessels (3) is to have adequate area in the upper deck region to provide standardized accommodation. Midbody region: (1) to provide adequate volume based on the payload requirement of all vessels (2) the fore and aft ends of the midbody region should merge with the fore region and aft region respectively in such a manner that the fore shoulder and aft shoulder of the ship hull is smooth and does not create adverse wave making effects (3) the distribution of the area along the length of this region is to be such that the required LCB of the vessel is attained. Fore body: the functional requirement of the fore body is primarily hydrodynamic which is (1) to have a bulbous bow to operate at 6.6 m draught for the container vessels and (2) to have a bulbous bow to operate at a full load draught of 7.8 m and a ballast draught 5.5m aft and 4.0 m forward for all other vessels. STEP 6 : Identifying the possible constructional parameters of the three modular regions meeting the producibility requirements and consumers requirements:: Aft region : (1) one stern shape was identified as a standard stern for all products mentioned above (2) two standard accommodation suiting the stern have been designed for (a) the container ship having a 6-tire accommodation and (b) a 5-tier accommodation for all other vessels. Midbody region: (1) two midbodies with bilge radius 2.2 m and 3.5 m were identified during different parallel middle bodies which can be selected based on the producibility requirements. Fore body region: two fore body shapes are identified (a) one for container vessel and (b) another for all other vessels. The desired fore body shape was selected taking into account the manufacturing capabilities. STEP 7 : Providing various shapes of the three regions utilizing standard CAD- software packages for the three separate regions. The following figures demonstrate the producible shapes of three regions identified. • Fore body F1 (fig 2) with bulbous bow - corresponding to container ship having a design draught of 6.6m for entire speed range of 14 to 15.5 knots • Fore body F2 (fig 3) with bulbous bow - corresponding to bulk carrier/tanker/multipurpose ship for entire speed range of 13 to 14.5 knots • Stern S (fig 4) for entire product mix given above • Mid body M11 (fig 5), M12 (fig 6) and M13 (fig 7) corresponding to 3 lengths with 2.2m bilge radius corresponding to the overall Cb of 0.71. • Mid body M21 (fig 8), M22 (fig 9) and M23 (fig 10) corresponding to 3 lengths with 3.5m bilge radius giving a large parallel middle body corresponding to the overall CB of 0.71 • M3 corresponding to a length of 120m with 2.2m bilge radius and minimum parallel middle body giving an overall Cb of 0.68 for a speed of 16.0 knots STEP 8 : Selectively merging the three zones to form a selective number of continuous ship hulls with detailed specifications for manufacture by conventional surface fairing and modeling software. The thus generated selective specifications of the ship hull involving the above method of modularization in accordance with the invention can be advantageously used to manufacture cost-effectively user specific ship hull using conventionally available gadgets and by following known methods. The hull shapes were found to be successful and as further illustrated by integration of modules Stern S, Fore bodies F1 and F2, superstructure SS5 and SS6 (figs 11 & 12) and mid bodies M11, M12, M13, M21, M22, M23 to generate ships as per the product mix. Thirteen (13) different ship types developed using the modularization steps and are 12 of these are shown in figures 13 to 24. It is thus demonstrated by way of the above exemplary illustrations that the step of modularization in the manufacture of ship hull forms would enable generating varied form of ship hull at cost effective rates and involving less time and complexities than that of the present art of manufacture of such ship hulls. Importantly, the invention would provide for standardization in manufacture of ship hull forms of varied specifications depending upon the end users requirements at an industrial level thereby avoiding of non-uniform modules and/or required reworking on modules to meet consumer demands/specifications. WE CLAIM : 1. A method for manufacturing of modularized ship hull comprising: providing a system of database concerning the usual technical and building specification for such ship hull; identification of the desired specifications for the modular ship including its functional and other features; analyzing the available database and generating the specifications for the aft region, fore region and mid body region for the range of identified ship; dividing the ship length into three distinct zones comprising a) aft body extending from aft till forward of engine room forward bulk head, b) fore body extending from fore end of the ship till aft of fore peak bulk head and c) mid body consisting of the middle portion between the aft body and fore body; identifying the functional requirements of the thus defined three zones comprising said aft body, mid body and fore body ; ascertaining the constructional parameters for the said three zones based on the available input database and the functional requirements of the three zones ; generating the modular design of the said three zones satisfying the separate functional requirement and the overall geometric constraints ; and merging the zones into a single continuous three dimensionally faired body to thereby obtain the modular ship. 2. A method as claimed in claim 1 wherein the said database and input data are supported by conventional software packages which is used to execute statistical analysis, economic analysis, technical calculation, surface modeling and CAD application. 3. A method as claimed in anyone of claims 1 or 2 comprising : providing database concerning the usual technical and building specification for such ship hull preferably having stored data concerning laws of flotation, cargo requirements of volume and weight, requirements on operating economics, requirements of building economics, technical constraints imposed by the ship building yard, statutory requirements and requirements of ship classification societies; identification of the desired specifications for the modular ship including its functional and other features such as the desired hydrodynamics, propulsion, steering and accommodation of the aft body, the cargo, cargo volume and production kindliness of the mid body and hydrodynamic, production kindliness of the fore body ; analyzing the available database and generating the specifications for the aft region, fore region and mid body region for the range of identified ship; dividing the ship length into three distinct zones comprising a) aft body extending from aft till forward of engine room forward bulk head, b) fore body extending from fore end of the ship till aft of fore peak bulk head and c) mid body consisting of the middle portion between the aft body and fore body; identifying the functional requirements of the thus defined three zones comprising said aft body, mid body and fore body ; ascertaining the constructional parameters for the said three zones based on the available input database and the functional requirements of the three zones ; generating the modular design of the said three zones satisfying the separate functional requirement and the overall geometric constraints ; and merging the zones into a single continuous three dimensionally faired body to thereby obtain the modular ship. 4. A method as claimed in anyone of claims 1 to 3 wherein the modularized design of the three zones is carried out to satisfy separate functional requirements respective zones and meet overall geometric constraints including : i) the parallel mid body is adapted to be changed (thereby changing length of ship) to suit the requirements of the product mix, the depth is varied to a limited extent by change of the above water portion of the ship to suit the requirements of the product mix maintaining requisite freeboard. ii) Block Coefficient and Longitudinal Centre of Buoyancy of the three zones are selected such that the final Cb and Lcb confirm to the optimal values with regard to Froude number. iii) the overall deck area is selected to be adequate with regard to cargo arrangements : iv) selectively merging of the Zones. 5. A method as claimed in claim 4 wherein said merging of the three zones is carried out such that the zones shape into a single continuous three - dimensionally faired body. 6. A method as claimed in claim 5 wherein the merging of the zone is carried out such that the slope and curvature maintain continuity in the water line and buttock planes in the merged region : aft body, and mid body, mid body and fore body. 7. A method as claimed in anyone of claims 1 to 6 wherein the modeling of the three regions is carried out such that slope and curvature continuity is achieved across the merged lines ensuring geometric requirements including main dimensions, deck area, Cb and LCB location and smooth merging of the three zones. 8. A method as claimed in anyone of claims 1 to 7 comprising : i) identification of product mix required in terms of the dimensional and other requirements such as length, breadth, depth, draught, speed, block co- efficient and longitudinal centre of buoyancy. ii) Identifying the required division based on such dimensional characteristics of the three sections comprising the aft body, mid body and fore body; iii) selectively providing desired number of units constituting each of the three modular zones to satisfy the product mix requirements; iv) selectively constructing each of said modular zones keeping in view the functional and geometric requirements detailed above based on end user requirements/applications. 9. A method as claimed in anyone of claims 1 to 8 which modularizes and integrates the manufacture of ship hull with the various geometrical constrains of development of ship hull forms including : a) providing the parallel middle body adapted to suit the requirements of product mix wherein the depth is varied to a limited extent by change of the above water portion of the ship to suit the requirements of product mix maintaining requisite freeboard; b) optimizing the block co-efficient and longitudinal centre of buoyancy values with regard to Froude number by way of modularization of the three zones; c) maximizing the overall deck area depending upon cargo arrangements/requirements; and d) effective merging of the three zones into a continuous three dimensional faired body wherein the slope and curvature are selected to ensure the continuity in the water line and buttock planes in the merged regions of the three sections. 10. A system for manufacturing of modularized ship hull comprising : means for providing database concerning the usual technical and building specification for such ship hull; means for identification of the desired specifications for the modular ship including its functional and other features; means for analyzing the available database and generating the specifications for the aft region, fore region and mid body region for the range of identified ship ; means for dividing the ship length into three distinct zones comprising a) aft body extending from aft till forward of engine room forward bulk head, b) fore body extending from fore end of the ship till aft of fore peak bulk head and c) mid body consisting of the middle portion between the aft body and fore body; means for identifying the functional requirements of the thus defined three zones comprising said aft body, mid body and fore body ; means for ascertaining the constructional parameters for the said three zones based on the available input database and the functional requirements of the three zones ; means for generating the modular design of the said three zones satisfying the separate functional requirement and the overall geometric constraints ; and merging the zones into a single continuous three dimensionally faired body . (to thereby obtain the modular ship) and means of manufacturing the modular ship hull by convertional process 11. A system as claimed in claim 10 comprising conventional software packages to support the various database and input data, execute statistical analysis, economic analysis, technical calculation, surface modeling and CAD. 12. A system as claimed in 10 or 11 comprising : means for providing a system of database concerning the usual technical and building specification for such ship hull preferably having stored data concerning laws of flotation, cargo requirements of volume and weight, requirements on operating economics, requirements of building economics, technical constraints imposed by the ship building yard, statutory requirements and requirements of ship classification societies; means for identification of the desired specifications for the modular ship including its functional and other features such as the desired hydrodynamics, propulsion, steering and accommodation of the aft body, the cargo, cargo volume and production kindliness of the mid body and hydrodynamic, production kindliness of the fore body ; means for analyzing the available database and generating the specifications for the aft region, fore region and mid body region for the range of identified ship; means for dividing the ship length into three distinct zones comprising a) aft body extending from aft till forward of engine room forward bulk head, b) fore body extending from fore end of the ship till aft of fore peak bulk head and c) mid body consisting of the middle portion between the aft body and fore body; means for identifying the functional requirements of the thus defined three zones comprising said aft body, mid body and fore body; means for ascertaining the constructional parameters for the said three zones based on the available input database and the functional requirements of the three zones ; means for generating the modular design of the said three zones satisfying the separate functional requirement and the overall geometric constraints; and means for merging the zones into a single continuous three dimensionally faired body to thereby obtain the modular ship. 13. A system as claimed in anyone of claims 10 to 12 wherein the system includes database on the basic functions and requisites of the aft body for such purpose as identified as hereunder: a. hydrodynamics - good flow characteristics around the stern, propeller disc and rudder; b. propulsion - adequate internal volume to house a range of main machinery of the propulsion system subject to various requirements of the product mix; c. steering - proper aft body shape with constant position of aft perpendicular and stern aperture; d. accommodation - standardize accommodation matching with aft body shape to serve the varying requirements of the product mix. 14. A system as claimed in anyone of claims 10 to 13 wherein the system includes database on the basic functions and requisites of the mid body for such purpose as identified as hereunder: a. cargo - different internal arrangements for varying product mix including containers, liquid cargo (POL), bulk cargo and general cargo, etc; b. cargo volume - cargo volume adjustment to suit product mix by adjusting the following geometric characteristic in this region-length (change in parallel middle body length), c. production kindliness - providing selective product mix by keeping the same internal volume but varying the bilge radius and thereby altering the length of parallel middle body. 15. A system as claimed in anyone of claims 10 to 14 wherein the system includes database on the basic functions and requisites of the fore body for such purpose as identified as hereunder: i. hydrodynamics; ii. production kindliness 16. A method for manufacturing of modularized ship hull substantially as hereindescribed and illustrated with reference to the accompanying figures and examples. 17. A system for manufacturing modularized ship hull substantially as hereindescribed and illustrated with reference to the accompanying figures and examples. A method for manufacturing of modularized ship hull A method for manufacturing of modularized ship hull involving a system of databases dividing the ship length into three distinct zones comprising (a) aft body extending from aft till forward of engine room forward bulk head, (b) fore body extending from fore end of the ship till aft of fore peak bulk head and (c) mid body consisting of the middle portion between the aft body and fore body; identifying the functional requirements of the defined zones, ascertaining the constructional parameters for the said three zones based on the available input database and the functional requirements of the three zones; generating the modular design; and merging the zones into a single continuous three dimensionally faired body to thereby obtain the modular ship. The above method of modularization would favour cost-effective, fast and user specific production of various forms of ship hull.

Full Text

Field of the invention
The present invention relates to a method for manufacturing modularized ship hull form
for its production and to the production of ship hull form involving modularization of
three modular zones of the ship hull involving the aft body, mid body and fore body. The
invention is also directed to a system for use in separate modularization of the three
zones based on the desired functional and geometric requirements and finally provide a
composite form of the ship hull depending upon the end user requirements. The process
of manufacture of the ship hull of the invention is directed to serve in large scale
production of varieties of ship hull forms at reduced time span and at cost effective rates
thereby serving better the requirements and demands of the ship building industry.
Description of the known art
Ships are generally custom-built. Each ship is developed as per the owner"s
requirements independent of previous developed/designed hulls except in case of sister
ships in which the same ship is repeatedly produced. Considering the varied uses and
cost factors involved in the developments of such ships, it is not convenient to generate
ship hulls as per the customer"s requirement readily and often the development of such
ship hulls is found to be time consuming and cost extensive process.
Additionally, as and when any ship is required to be developed involving alterations in
form in view of the complexities involved, the conventional ship manufacturing processes
are found to be not well equipped to generate such altered forms as per the end user"s
requirements. Therefore, it is usual after the ship is developed the customer may not be
satisfied and the builder may be required to rework on the existing module to make it
somewhat satisfactory for the customer. However, it would be apparent from such
conventional processes of ship manufacture that such processes are not streamlined
and are usually attended on an ad-hoc basis involving lot of time and cost to develop a
particular form of the ship. More importantly due to lack of direction in obtaining the
modules of defined characteristics to suit the end users requirement, the conventional
processes of manufacture often lead to products which do not have the desired
uniformity or compatibility between the three modular zones of the
ship i.e. the aft body, mid body and fore body. This again results in a ship hull,
which may not achieve the desired functionality and geometric requirements for
effective use.
Objects of the invention
It is thus the basic object of the invention to provide for improvement in the in ship
hull form development and its production and enable the manufacture of various
forms of ship hull which would avoid the above discussed limitations and
constraints of the conventional art of developing ship hull forms.
Another object of the present invention is directed to a process for modularization
of ship hull to favour industrial production of varied modular forms of ship hull
which would match the requirements of the end user by way of a more
confirmatory and composite developmental process steps leading to ship hull
forms meeting customer"s requirements and avoiding the conventional forms of
reworking to meet customer"s satisfaction.
Yet further object of the present invention is directed to the development of ship
hull taking into account the complexities of the three dimensional structure and in
particular the specific requisite of the aft body, fore body and mid body of a ship
hull and provide process steps which could not only provide variations in the
forms of the respective zones of the ship hull depending upon the varied end
uses but would also provide for a compatible relation of the three zones to
provide a continuous surface of the hull form improving its functional and
geometric characteristics.
Yet further object of the present invention is directed to providing a method of
development of ship hull forms which can be industrially applied to generate
varied forms of ship hull at cost effective rates meeting consumer requirements.
Summary of the invention
Thus according to the basic aspect of the present invention there is provided a
method for modularization of ship hull for its production comprising :
providing a system of database concerning the usual technical and building
specification for a number of such ships;
identification of the desired specifications for such modular ships including their
functional and other features ;
analyzing the available database and generating the specifications for the aft
region, fore region and mid body region for the range of identified ships;
dividing the ship length into three distinct zones comprising a) aft body extending
from aft till forward of engine room forward bulk head, b) fore body extending
from fore end of the ship till aft of fore peak bulk head and c) mid body consisting
of the middle portion between the aft body and fore body;
identifying the functional requirements of the thus defined three zones comprising
said aft body, mid body and fore body ;
ascertaining the constructional parameters for the said three zones based on the
available input database and the functional requirements of the three zones ;
generating the modular design of the said three zones satisfying the separate
functional requirement and the overall geometric constraints ; and
merging the zones into a single continuous three dimensionally faired body to
thereby obtain the modular ship.
The above disclosed method of modularization of ship hull, involve conventional
software packages to support the various database and input data, execute
statistical analysis, economic analysis, technical calculation, surface modeling
and CAD. The method effectively integrates the above to facilitate simple and
cost-effective modularization of the ship hull.
According to a preferred aspect of the present invention there is provided a
method for modularization of ship hull comprising:
providing database concerning the usual technical and building specification for a
number of ships preferably having stored data concerning laws of flotation, cargo
requirements of volume and weight, requirements on operating economics,
requirements of building economics, technical constraints imposed by the ship
building yard, statutory requirements and requirements of ship classification
societies;
identification of the desired specifications for the modular ship including its
functional and other features such as the desired hydrodynamics, propulsion,
steering and accommodation of the aft body, the cargo, cargo volume and
production kindliness of the mid body and hydrodynamics, production kindliness
of the fore body;
analyzing the available database and generating the specifications for the aft
region, fore region and mid body region for the range of identified ships;
dividing the ship length into three distinct zones comprising a) aft body extending
from aft till forward of engine room forward bulk head, b) fore body extending
from fore end of the ship till aft of fore peak bulk head and c) mid body consisting
of the middle portion between the aft body and fore body;
identifying the functional requirements of the thus defined three zones comprising
said aft body, mid body and fore body ;
ascertaining the constructional parameters for the said three zones based on the
available input database and the functional requirements of the three zones ;
generating the modular design of the said three zones satisfying the separate
functional requirement and the overall geometric constraints ; and
merging the zones into a single continuous three dimensionally faired body to
thereby obtain the modular ship.
Importantly, in the above method of the invention the modularized design of the
three zones should satisfy separate functional requirements which would meet
overall geometric constraints as hereunder:
a) The parallel mid body should be adapted to be changed (thereby changing
length of ship) to suit the requirements of the product mix. The depth can be
varied to a limited extent by change of the above water portion of the ship to
suit the requirements of the product mix maintaining requisite freeboard.
b) Block Coefficient and Longitudinal Centre of Buoyancy ; the three zones
should be so designed that the final Cb and LCB confirm to the optimal values
with regard to Froude number.
c) Deck area : The overall deck area must be adequate with regard to cargo
arrangements (e.g. container arrangement above deck).
d) Merging of the Zones : The most stringent requirement of the modularization
concept is merging of the zones shapes into a single continuous three -
dimensionally faired body. This requires that slope and curvature must
maintain continuity in the water line and buttock planes in the merged region:
aft body and mid body, mid body and fore body.
Also, the above steps of modularization in the process of invention is carried out
by modeling the three regions so that slope and curvature continuity can be
achieved across the merged lines ensuring geometric requirements such as main
dimensions, deck area, Cb and LCB location and smooth merging of the three
zones.
According to another aspect of the present invention there is provided a system
for modularization /designing and production of ship hull comprising :
means for providing database concerning the usual technical and building
specification for a number of such ships;
means for identification of the desired specifications for the modular ship
including its functional and other features;
means for analyzing the available database and generating the specifications for
the aft region, fore region and mid body region for the range of identified ships;
means for dividing the ship length into three distinct zones comprising a) aft body
extending from aft till forward of engine room forward bulk head, b) fore body
extending from fore end of the ship till aft of fore peak bulk head and c) mid body
consisting of the middle portion between the aft body and fore body;
means for identifying the functional requirements of the thus defined three zones
comprising said aft body, mid body and fore body ;
means for ascertaining the constructional parameters for the said three zones
based on the available input database and the functional requirements of the
three zones;
means for generating the modular design of the said three zones satisfying the
separate functional requirement and the overall geometric constraints ; and
merging the zones into a single continuous three dimensionally faired body to
thereby obtain the modular ship.
The above disclosed system for use in manufacture of modularized ship hull,
involve conventional software packages to support the various database and
input data, execute statistical analysis, economic analysis, technical calculation,
surface modeling and CAD. The system used should integrate the above to
facilitate simple and cost-effective modularization of the ship hull.
According to a preferred aspect of the present invention there is provided a
system for modularization and production of ship hull comprising:
means for providing a system of database concerning the usual technical and
building specification for a number of ships preferably having stored data
concerning laws of floatation, cargo requirements of volume and weight,
requirements on operating economics, requirements of building economics,
technical constraints imposed by the ship building yard, statutory requirements
and requirements of ship classification societies;
means for identification of the desired specifications for the modular ship
including its functional and other features such as the desired hydrodynamics,
propulsion, steering and accommodation of the aft body, the cargo, cargo volume
and production kindliness of the mid body and hydrodynamic, production
kindliness of the fore body ;
means for analyzing the available database and generating the specifications for
the aft region, fore region and mid body region for the range of identified ship;
means for dividing the ship length into three distinct zones comprising a) aft body
extending from aft till forward of engine room forward bulk head, b) fore body
extending from fore end of the ship till aft of fore peak bulk head and c) mid body
consisting of the middle portion between the aft body and fore body;
means for identifying the functional requirements of the thus defined three zones
comprising said aft body, mid body and fore body ;
means for ascertaining the constructional parameters for the said three zones
based on the available input database and the functional requirements of the
three zones ;
means for generating the modular design of the said three zones satisfying the
separate functional requirement and the overall geometric constraints ; and
means for merging the zones into a single continuous three dimensionally faired
body to thereby obtain the modular ship.
Description of the invention
To meet the above objectives of the invention a detailed study and analysis of the
complexities involved in the manufacture of ship hull forms were studied. It was
identified that the development of modular form of ship hull is basically subject to
the following constrains:
i. laws of flotation;
ii. cargo requirements of volume and weight;
iii. requirement of operating economics;
iv. requirement of building economics;
v. technical constraints generally imposed by the ship building yard;
vi. statutory requirements of port state control authorities i.e. safety, stability,
free board, maneuverability, noise, pollution etc.;
vii. requirements of ship classification societies i.e. structural arrangements,
standards, machinery and equipment,
viii. Hydrodynamic design requirements of powering, flow characteristics, etc.
To meet the above complex requirements of ship hull forms and possible variants
thereof and to make the possible process of manufacturing of such ship hull
forms industrially applicable and to have control over the manufacturing process
to meet consumer demands and end user requirements keeping in view the
above complexities, the complex three dimensional structure of the ship hull is
categorized under the process of modularization of the invention into three
longitudinal zones comprising the aft body (from aft and till forward of engine
room forward bulkhead), fore body (from fore end of the ship till aft of fore peak
bulk head) and mid body (middle portion between the aft body and the fore body).
Lengthwise arrangement of the three selected zones is shown in accompanying
Fig. 1
The aft body is found to be the most complex portion of the ship having maximum
content in terms of construction and assembly of equipment. It is also most
demanding in terms of cost and time. Thus there exists a need for development
of process of modularization/standardization of the aft body which could suit a
range of product mix of ships in combination with different fore body and mid
body whereby the cost and time of construction could be brought down.
Importantly, such process of manufacture involving modularized/standardized aft
body would enable standardization of machinery, equipment and production
process of the aft body. The basic functions and requisites of the aft body for
such purpose are identified as hereunder:
a. hydrodynamics - good flow characteristics around the stern, propeller disc
and rudder;
b. propulsion - adequate internal volume to house a range of main machinery of
the propulsion system subject to various requirements of the product mix;
c. steering - proper aft body shape with constant position of aft perpendicular
and stern aperture;
d. accommodation - standardize accommodation matching with after body
shape to serve the varying requirements of the product mix.
It is also identified the mid body of the ship constitutes the biggest portion in
terms of volume and length and is provided as the freight earning portion of the
ship. It is structurally simpler than the other two zones of the ship but contains
the maximum steelwork in terms of weight. The variations in this area are
identified to include length, bilge radius (mid ship area) and prismatic co-efficient.
It is also found that this mid body construction is subject to constraints of function
and requirements such as;
a. cargo - different internal arrangements for varying product mix such as
containers, liquid cargo (POL), bulk cargo and general cargo etc;
b. cargo volume - cargo volume can be adjusted to suit product mix by adjusting
the following geometric characteristic in this region-
i. length (change in parallel middle body length),
ii. block co-efficient (by changing sectional area curve),
c. production kindliness - this can be introduced into the product mix by keeping
the same internal volume but varying the bilge radius and thereby altering the
length of parallel middle body.
It is further identified that the fore body of a ship is highly three dimensional,
structurally complex and difficult to fabricate. Therefore, the process of
modularization was directed to achieve a standardized fore body which could
reduce production cost and time substantially. The fundamental requirements of
the fore body module which required consideration were identified as follows:
a. hydrodynamics - to suit the varying requirements of the product mix
particularly with regard to design draught (container ship design draught is
lower than that of a tanker) and ballast draught (found to be important for
tankers and bulk carriers). Hydrodynamic designs of the bulb is also required
such that it takes into account the range of speeds of the varying product mix;
b. production kindliness - it is important the fore body shape is developed such
that it can be produced easily and is able to house standardized anchoring
and mooring equipment for the production mix.
Keeping in view the above identified requisites for producing varied ship hull
forms depending upon end user requirement the process of development of such
ship hulls involving modularization in accordance with the present invention
basically involves the following steps:
1. identification of product mix required in terms of the dimensional and other
requirements such as length, breadth, depth, draught, speed, block co-
efficient and longitudinal centre of buoyancy.
2. Identifying the required division based on such dimensional characteristics of
the three sections comprising the aft body, mid body and fore body;
3. selectively providing desired number of units of each of the three modular
zones to satisfy the product mix requirements;
4. selectively developing each of said modular zones keeping in view the
functional and geometric requirements detailed above based on end user
requirements/applications.
It is found that by following the above process steps and modularizing the ship
hull form and its utilization in the process of manufacture of ship hull one would
provide for a more convenient and cost effective manufacture of varied forms of
ship hulls.
Importantly, it is found that by way of following the above process of
modularization and integrating the same in the manufacture of ship hulls the
various geometrical constraints of development of ship hull forms could be
satisfied including :
a. the parallel middle body can be adapted to suit the requirements of product
mix. The depth can be varied to a limited extent by change of the above
water portion of the ship to suit the requirements of product mix maintaining
requisite freeboard;
b. block co-efficient and longitudinal centre of buoyancy values are optimized
with regard to Froude number by way of modularization of the three zones;
c. the overall deck area can be maximized depending upon cargo
arrangements/requirements; and
d. effective merging of the three zones into a continuous three dimensional
faired body. The slope and curvature selected to ensure the continuity in the
water line and buttock planes in the merged regions of the three sections.
The invention is explained in further detail by way of the following non-limiting
example and the accompanying figures thereunder:
Reference is first invited to accompanying figure 1A which is a block diagram
illustrating the method of manufacture of modularized ship hull in accordance with
the present invention. As represented in said figure such modularization of ship
hull basically comprises of database (1) concerning the usual technical and
building specification for such ship hull; identification (2) of the desired
specifications for the modular ship including its functional and other features ;
Analyzing (3) the available database and generating the specifications for the aft
region, fore region and mid body region for the range of identified ship ; dividing
(4) the ship length into three distinct zones comprising a) aft body extending from
aft till forward of engine room forward bulk head, b) fore body extending from fore
end of the ship till aft of fore peak bulk head and c) mid body consisting of the
middle portion between the aft body and fore body; identifying (5) the functional
requirements of the thus defined three zones comprising said aft body, mid body
and fore body ; ascertaining (6) the constructional parameters for the said three
zones based on the available input database and the functional requirements of
the three zones ; generating (7) the modular design of the said three zones
satisfying the separate functional requirement and the overall geometric
constraints ; and merging (8) the zones into a single continuous three
dimensionally faired body to thereby obtain the modular ship.
Reference is now invited to accompanying figure 1B which schematically
illustrates by way of a block diagram and an embodiment of the system for use in
the method of modularization of the ship hull in accordance with the present
invention. As shown in said figure the system basically involves means for
providing database (A) concerning the usual technical and building specification
for such ship hull; means for identification (B) of the desired specifications for the
modular ship including its functional and other features ; means for analyzing (C)
the available database and generating the specifications for the aft region, fore
region and mid body region for the range of identified ship ; means for dividing
(D) the ship length into three distinct zones comprising a) aft body extending from
aft till forward of engine room forward bulk head, b) fore body extending from fore
end of the ship till aft of fore peak bulk head and c) mid body consisting of the
middle portion between the aft body and fore body; means for identifying (E) the
functional requirements of the thus defined three zones comprising said aft body,
mid body and fore body ; means for ascertaining (F) the constructional
parameters for the said three zones based on the available input database and
the functional requirements of the three zones ; means for generating (G) the
modular design of the said three zones satisfying the separate functional
requirement and the overall geometric constraints ; and merging (H) the zones
into a single continuous three dimensionally faired body to thereby obtain the
modular ship.
Example
STEP 1: Using a conventional shipping market database covering current
published literature and in-house economic analysis to generate technical
specifications for identified product mix.
The broad product mix identified was as follows :
550-650 TEU feeder container vessels
9000-12000 t DWT product tankers for short sea voyages
9000-12000 DWT bulk carriers and multipurpose cargo carriers
Identifying specific vessel types suitable for production based on available
resoucees:
• 550 TEU Feeder Container vessel for 14.0 knots to 15.5 knots design speed
• 600 TEU Feeder Container vessel for 14.0 knots to 15.5 knots design speed
• 650 TEU Feeder Container vessel for 14.0 knots to 15.5 knots design speed
• 9000 t DWT Product Tankers/Bulk Cariers/Multipurpose Cargo Carriers for
13.5 knots to 14.5 knots design speed
• 10500 t DWT Product Tankers/Bulk Cariers/Multipurpose Cargo Carriers for
13.5 knots to 14.5 knots design speed
• 12000 t DWT Product Tankers/Bulk Cariers/Multipurpose Cargo Carriers for
13.5 knots to 14.5 knots design speed
STEP 2: Identification of desired features of the ship based on modular concept
and by utilizing the client requirement database based on the available
resources of shipbuilding and the feeder container and POL service trade
patterns for defined sea routes .
The variation in the following main dimensions and ship particulars were
determined :
• Length to vary between 113m and 127m
• Breadth not to exceed : 19m
• Depth to vary between 10.3m and 11 m
• Draught - fully loaded: 6.6m for feeder container vessel and 7.8m for the
other vessels
• Draught ballast: No special requirement for container vessel, 5.5m aft and
4.0m forward for other vessels
• Block coefficient to vary between 0.68 and 0.72
STEP 3: Identification of the functional specification of the aft region, mid body
region andfore region by utilising the technical information and preliminary design
calculations for the desired range of ships.
The following manufacturing specifications were identified for the modular region
i.e. aft region, midbody region and fore region .
The vessel with length 113 m should have the smallest length of parallel middle
body.
The vessel length should be changed by steps of 7m to generate ships of length
120 and 127m.
This length variation to be obtained only by changing the parallel middle body.
The depth variation between 10.3 m to 11.0 m is to be obtained by extending the
above water portion of the hull only without affecting hydrodynamic performance
of the ship.
For an optimum hydrodynamic performance of the entire range of products, it
was found that the LCB should vary between 0 m and 1 m forward of midship.
The fore end should be suitable for two draught operations; (1) suitable for
container ships and (2) suitable for tankers, bulkers and multipurpose vessels.
The stern required to be standardized for the given range of vessels.
STEP 4 : The ship length for the entire product mix was divided into three
distinct modular regions.
Fig. 1 shows such selective division of ships into three regions, which are as
follows:
• Aft body was selected from aft end till forward bulkhead of aft engine room
bulkhead.
• Mid body was selected from the fore end of the aft body till the fore peak
bulkhead
• Fore body was selected from fore peak bulkhead till fore end.
STEP 5 : The functional requirements of the three module regions of the ship
hulls were identified by utilizing the conventional information data base and naval
architectural calculation software.
The following desired functional requirements were identified for the three
separate regions.
Aft region: (1) is to be suitable for providing a uniform distribution of wake in the
propeller disc region for all vessels (2) is to have adequate volume to provide
propulsion and auxiliary machinery for all vessels (3) is to have adequate area in
the upper deck region to provide standardized accommodation.
Midbody region: (1) to provide adequate volume based on the payload
requirement of all vessels (2) the fore and aft ends of the midbody region should
merge with the fore region and aft region respectively in such a manner that the
fore shoulder and aft shoulder of the ship hull is smooth and does not create
adverse wave making effects (3) the distribution of the area along the length of
this region is to be such that the required LCB of the vessel is attained.
Fore body: the functional requirement of the fore body is primarily hydrodynamic
which is (1) to have a bulbous bow to operate at 6.6 m draught for the container
vessels and (2) to have a bulbous bow to operate at a full load draught of 7.8 m
and a ballast draught 5.5m aft and 4.0 m forward for all other vessels.
STEP 6 : Identifying the possible constructional parameters of the three modular
regions meeting the producibility requirements and consumers requirements::
Aft region : (1) one stern shape was identified as a standard stern for all products
mentioned above (2) two standard accommodation suiting the stern have been
designed for (a) the container ship having a 6-tire accommodation and (b) a 5-tier
accommodation for all other vessels.
Midbody region: (1) two midbodies with bilge radius 2.2 m and 3.5 m were
identified during different parallel middle bodies which can be selected based on
the producibility requirements.
Fore body region: two fore body shapes are identified (a) one for container
vessel and (b) another for all other vessels. The desired fore body shape was
selected taking into account the manufacturing capabilities.
STEP 7 : Providing various shapes of the three regions utilizing standard CAD-
software packages for the three separate regions. The following figures
demonstrate the producible shapes of three regions identified.
• Fore body F1 (fig 2) with bulbous bow - corresponding to container ship
having a design draught of 6.6m for entire speed range of 14 to 15.5 knots
• Fore body F2 (fig 3) with bulbous bow - corresponding to bulk
carrier/tanker/multipurpose ship for entire speed range of 13 to 14.5 knots
• Stern S (fig 4) for entire product mix given above
• Mid body M11 (fig 5), M12 (fig 6) and M13 (fig 7) corresponding to 3 lengths
with 2.2m bilge radius corresponding to the overall Cb of 0.71.
• Mid body M21 (fig 8), M22 (fig 9) and M23 (fig 10) corresponding to 3
lengths with 3.5m bilge radius giving a large parallel middle body
corresponding to the overall CB of 0.71
• M3 corresponding to a length of 120m with 2.2m bilge radius and minimum
parallel middle body giving an overall Cb of 0.68 for a speed of 16.0 knots
STEP 8 : Selectively merging the three zones to form a selective number of
continuous ship hulls with detailed specifications for manufacture by
conventional surface fairing and modeling software.
The thus generated selective specifications of the ship hull involving the above
method of modularization in accordance with the invention can be
advantageously used to manufacture cost-effectively user specific ship hull using
conventionally available gadgets and by following known methods.
The hull shapes were found to be successful and as further illustrated by
integration of modules Stern S, Fore bodies F1 and F2, superstructure SS5 and
SS6 (figs 11 & 12) and mid bodies M11, M12, M13, M21, M22, M23 to generate
ships as per the product mix. Thirteen (13) different ship types developed using
the modularization steps and are 12 of these are shown in figures 13 to 24.
It is thus demonstrated by way of the above exemplary illustrations that the step
of modularization in the manufacture of ship hull forms would enable generating
varied form of ship hull at cost effective rates and involving less time and
complexities than that of the present art of manufacture of such ship hulls.
Importantly, the invention would provide for standardization in manufacture of
ship hull forms of varied specifications depending upon the end users
requirements at an industrial level thereby avoiding of non-uniform modules
and/or required reworking on modules to meet consumer demands/specifications.
WE CLAIM :
1. A method for manufacturing of modularized ship hull comprising:
providing a system of database concerning the usual technical and building
specification for such ship hull;
identification of the desired specifications for the modular ship including its functional
and other features;
analyzing the available database and generating the specifications for the aft region,
fore region and mid body region for the range of identified ship;
dividing the ship length into three distinct zones comprising a) aft body extending
from aft till forward of engine room forward bulk head, b) fore body extending from
fore end of the ship till aft of fore peak bulk head and c) mid body consisting of the
middle portion between the aft body and fore body;
identifying the functional requirements of the thus defined three zones comprising
said aft body, mid body and fore body ;
ascertaining the constructional parameters for the said three zones based on the
available input database and the functional requirements of the three zones ;
generating the modular design of the said three zones satisfying the separate
functional requirement and the overall geometric constraints ; and
merging the zones into a single continuous three dimensionally faired body to
thereby obtain the modular ship.
2. A method as claimed in claim 1 wherein the said database and input data are
supported by conventional software packages which is used to execute statistical
analysis, economic analysis, technical calculation, surface modeling and CAD
application.
3. A method as claimed in anyone of claims 1 or 2 comprising :
providing database concerning the usual technical and building specification for such
ship hull preferably having stored data concerning laws of flotation, cargo
requirements of volume and weight, requirements on operating
economics, requirements of building economics, technical constraints
imposed by the ship building yard, statutory requirements and requirements of
ship classification societies;
identification of the desired specifications for the modular ship including its
functional and other features such as the desired hydrodynamics, propulsion,
steering and accommodation of the aft body, the cargo, cargo volume and
production kindliness of the mid body and hydrodynamic, production
kindliness of the fore body ;
analyzing the available database and generating the specifications for the aft
region, fore region and mid body region for the range of identified ship;
dividing the ship length into three distinct zones comprising a) aft body
extending from aft till forward of engine room forward bulk head, b) fore body
extending from fore end of the ship till aft of fore peak bulk head and c) mid
body consisting of the middle portion between the aft body and fore body;
identifying the functional requirements of the thus defined three zones
comprising said aft body, mid body and fore body ;
ascertaining the constructional parameters for the said three zones based on
the available input database and the functional requirements of the three
zones ;
generating the modular design of the said three zones satisfying the separate
functional requirement and the overall geometric constraints ; and
merging the zones into a single continuous three dimensionally faired body to
thereby obtain the modular ship.
4. A method as claimed in anyone of claims 1 to 3 wherein the modularized
design of the three zones is carried out to satisfy separate functional
requirements respective zones and meet overall geometric constraints
including :
i) the parallel mid body is adapted to be changed (thereby changing
length of ship) to suit the requirements of the product mix, the depth is
varied to a limited extent by change of the above water portion of the
ship to suit the requirements of the product mix maintaining requisite
freeboard.
ii) Block Coefficient and Longitudinal Centre of Buoyancy of the three
zones are selected such that the final Cb and Lcb confirm to the optimal
values with regard to Froude number.
iii) the overall deck area is selected to be adequate with regard to cargo
arrangements :
iv) selectively merging of the Zones.
5. A method as claimed in claim 4 wherein said merging of the three zones is
carried out such that the zones shape into a single continuous three -
dimensionally faired body.
6. A method as claimed in claim 5 wherein the merging of the zone is carried out
such that the slope and curvature maintain continuity in the water line and
buttock planes in the merged region : aft body, and mid body, mid body and
fore body.
7. A method as claimed in anyone of claims 1 to 6 wherein the modeling of the
three regions is carried out such that slope and curvature continuity is
achieved across the merged lines ensuring geometric requirements including
main dimensions, deck area, Cb and LCB location and smooth merging of the
three zones.
8. A method as claimed in anyone of claims 1 to 7 comprising :
i) identification of product mix required in terms of the dimensional and other
requirements such as length, breadth, depth, draught, speed, block co-
efficient and longitudinal centre of buoyancy.
ii) Identifying the required division based on such dimensional characteristics
of the three sections comprising the aft body, mid body and fore body;
iii) selectively providing desired number of units constituting each of the three
modular zones to satisfy the product mix requirements;
iv) selectively constructing each of said modular zones keeping in view the
functional and geometric requirements detailed above based on end user
requirements/applications.
9. A method as claimed in anyone of claims 1 to 8 which modularizes and integrates
the manufacture of ship hull with the various geometrical constrains of development of
ship hull forms including :
a) providing the parallel middle body adapted to suit the requirements of product
mix wherein the depth is varied to a limited extent by change of the above water
portion of the ship to suit the requirements of product mix maintaining requisite
freeboard;
b) optimizing the block co-efficient and longitudinal centre of buoyancy values with
regard to Froude number by way of modularization of the three zones;
c) maximizing the overall deck area depending upon cargo
arrangements/requirements; and
d) effective merging of the three zones into a continuous three dimensional faired
body wherein the slope and curvature are selected to ensure the continuity in
the water line and buttock planes in the merged regions of the three sections.
10. A system for manufacturing of modularized ship hull comprising :
means for providing database concerning the usual technical and building
specification for such ship hull;
means for identification of the desired specifications for the modular ship including its
functional and other features;
means for analyzing the available database and generating the specifications for the
aft region, fore region and mid body region for the range of identified ship ;
means for dividing the ship length into three distinct zones comprising a) aft body
extending from aft till forward of engine room forward bulk head, b) fore body
extending from fore end of the ship till aft of fore peak bulk head and c) mid body
consisting of the middle portion between the aft body and fore body;
means for identifying the functional requirements of the thus defined three
zones comprising said aft body, mid body and fore body ;
means for ascertaining the constructional parameters for the said three zones
based on the available input database and the functional requirements of the
three zones ;
means for generating the modular design of the said three zones satisfying
the separate functional requirement and the overall geometric constraints ;
and
merging the zones into a single continuous three dimensionally faired body .
(to thereby obtain the modular ship) and means of manufacturing the modular
ship hull by convertional process
11. A system as claimed in claim 10 comprising conventional software packages
to support the various database and input data, execute statistical analysis,
economic analysis, technical calculation, surface modeling and CAD.
12. A system as claimed in 10 or 11 comprising :
means for providing a system of database concerning the usual technical and
building specification for such ship hull preferably having stored data
concerning laws of flotation, cargo requirements of volume and weight,
requirements on operating economics, requirements of building economics,
technical constraints imposed by the ship building yard, statutory
requirements and requirements of ship classification societies;
means for identification of the desired specifications for the modular ship
including its functional and other features such as the desired
hydrodynamics, propulsion, steering and accommodation of the aft body, the
cargo, cargo volume and production kindliness of the mid body and
hydrodynamic, production kindliness of the fore body ;
means for analyzing the available database and generating the specifications
for the aft region, fore region and mid body region for the range of identified
ship;
means for dividing the ship length into three distinct zones comprising a) aft
body extending from aft till forward of engine room forward bulk head, b) fore
body extending from fore end of the ship till aft of fore peak bulk head and c)
mid body consisting of the middle portion between the aft body and fore body;
means for identifying the functional requirements of the thus defined three zones
comprising said aft body, mid body and fore body;
means for ascertaining the constructional parameters for the said three zones based
on the available input database and the functional requirements of the three zones ;
means for generating the modular design of the said three zones satisfying the
separate functional requirement and the overall geometric constraints; and
means for merging the zones into a single continuous three dimensionally faired
body to thereby obtain the modular ship.
13. A system as claimed in anyone of claims 10 to 12 wherein the system includes
database on the basic functions and requisites of the aft body for such purpose
as identified as hereunder:
a. hydrodynamics - good flow characteristics around the stern, propeller disc and
rudder;
b. propulsion - adequate internal volume to house a range of main machinery of the
propulsion system subject to various requirements of the product mix;
c. steering - proper aft body shape with constant position of aft perpendicular and
stern aperture;
d. accommodation - standardize accommodation matching with aft body shape to
serve the varying requirements of the product mix.
14. A system as claimed in anyone of claims 10 to 13 wherein the system includes
database on the basic functions and requisites of the mid body for such purpose
as identified as hereunder:
a. cargo - different internal arrangements for varying product mix including
containers, liquid cargo (POL), bulk cargo and general cargo, etc;
b. cargo volume - cargo volume adjustment to suit product mix by adjusting the
following geometric characteristic in this region-length (change in parallel
middle body length),
c. production kindliness - providing selective product mix by keeping the same
internal volume but varying the bilge radius and thereby altering the length of
parallel middle body.
15. A system as claimed in anyone of claims 10 to 14 wherein the system includes
database on the basic functions and requisites of the fore body for such purpose as
identified as hereunder:
i. hydrodynamics;
ii. production kindliness
16. A method for manufacturing of modularized ship hull substantially as
hereindescribed and illustrated with reference to the accompanying figures and
examples.
17. A system for manufacturing modularized ship hull substantially as
hereindescribed and illustrated with reference to the accompanying figures and
examples.
A method for manufacturing of modularized ship hull
A method for manufacturing of modularized ship hull involving a system of
databases dividing the ship length into three distinct zones comprising (a) aft
body extending from aft till forward of engine room forward bulk head, (b) fore
body extending from fore end of the ship till aft of fore peak bulk head and (c) mid
body consisting of the middle portion between the aft body and fore body;
identifying the functional requirements of the defined zones, ascertaining the
constructional parameters for the said three zones based on the available input
database and the functional requirements of the three zones; generating the
modular design; and merging the zones into a single continuous three
dimensionally faired body to thereby obtain the modular ship. The above method
of modularization would favour cost-effective, fast and user specific production of
various forms of ship hull.

Documents:

561-CAL-2002-FORM-27.pdf

561-cal-2002-granted-abstract.pdf

561-cal-2002-granted-claims.pdf

561-cal-2002-granted-correspondence.pdf

561-cal-2002-granted-description (complete).pdf

561-cal-2002-granted-drawings.pdf

561-cal-2002-granted-examination report.pdf

561-cal-2002-granted-form 1.pdf

561-cal-2002-granted-form 18.pdf

561-cal-2002-granted-form 2.pdf

561-cal-2002-granted-form 3.pdf

561-cal-2002-granted-form 5.pdf

561-cal-2002-granted-letter patent.pdf

561-cal-2002-granted-pa.pdf

561-cal-2002-granted-reply to examination report.pdf

561-cal-2002-granted-specification.pdf

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Patent Number

214274

Indian Patent Application Number

561/CAL/2002

PG Journal Number

06/2008

Publication Date

08-Feb-2008

Grant Date

07-Feb-2008

Date of Filing

25-Sep-2002

Name of Patentee

INDIAN INSTITUTE OF TECHNOLOGY

Applicant Address

KHARAGPUR, PIN-721 302, WEST BENGAL, INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	PROF. S.C.MISRA	DEPT. OF OCEAN ENGG & NAVAL ARCHITECTURE, INDIAN INSTITUTE OF TECHNOLOGY, KHARAGPUR 721 302 WEST BENGAL, INDIA.
2	DR. OM PRAKASH SHA.	DEPT. OF OCEAN ENGG & NAVAL ARCHITECTURE, INDIAN INSTITUTE OF TECHNOLOGY, KHARAGPUR 721 302, WEST BENGAL, INDIA.

PCT International Classification Number

G06F17/50,B63B3/02

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA