Ship Design and System Integration Dipl.-Ing. Christina Vossen (Senior Engineer), Robert Kleppe (Principle Engineer, Electrical Systems), M.Sc. Siv Randi Hjørungnes (Principle Engineer, R&DT), Rolls-Royce Marine AS, Ship Technology Offshore Systems Abstract Ship design is a complex, iterative and multifaceted process, influenced by a number of factors. Based on the vision of a customer, the ship designer has to develop the most cost efficient ship for a designated task, within the boundaries of international and national rules and regulations. Finding the best compromise within the given boundaries is the challenge for the ship designer and system integrator. In the offshore sector, ship design is getting more and more diverse, with more stringent rules and regulations ensuring safe and secure operation, as well as more advanced operational requirements. Furthermore, the physical and functional integration of systems and equipment on board is getting more complex. 2D and 3D design, modeling, simulation and calculation software is playing an important part in making the design process more efficient and successful. A successfully designed ship is the result of close and good cooperation between the designer, the customer, the yard and the equipment suppliers. None of these players can be left out in the process of designing the ships of the future. 1. Introduction In a historical perspective, new ship designs have been based on existing vessel designs and on minor breakthrough innovations, bringing the industry a few steps forward. Ship designs have been developed further to meet new customer requirements, new regulations and the needs of the market. Positive experience as well as lessons-learned from accidents and incidents leads to improved and better designs. New ship designs can be divided into two groups. They either evolve from research and development projects (R&D) of the ship designers, or from a sustained development together with the customer. R&D projects are independent of contract projects and are based on long-term strategies. The ship designers start an innovative process, based on market studies and new ideas and concepts. After a successful design process, the new ship design will be introduced to the market. In comparison, a sustained development is a customer driven process. Requests from the customers, requirements from authorities and regulatory bodies and the technical available solutions have to get aligned to design the customized ships of the future. A successful ship design lies in the close cooperation of ship designers (naval architects and marine engineers), ship owners, shipyards, charterers, as well as internal and external equipment suppliers.
This paper will focus on the ship design process in the offshore industry, as a sustained development (Chapter 2 and Chapter 3). System integration, physical and functional, will be discussed in Chapter 4, including its possibilities and challenges. Chapter 5 gives an insight into the special role Rolls-Royce Marine has, as an equipment supplier and integrator as well as ship designer. 2. Ship Design Design Requirements and Factors A ship design is influenced by a number of market players. A ship owner, a charterer and a ship broker can be involved in the tender processes, as illustrated in Figure 1. These three parties have to align their requirements whilst approaching a ship design company and/or ship yard. Figure 1: Involved parties in a tender process In such a tender process, a number of requirements and aspects have to be taken into account. These can be grouped in four categories, as illustrated in Figure 2 and can be seen as a starting point for the whole design process. Operational Requirements External Requirements Available Technology Vessel Specification/Ship Design Commercial Aspects Figure 2: Requirements and aspects influencing a ship design
Commercial Aspects relate to the current market situation and the market perspective. The key market drivers for the offshore shipping industry are the international oil and gas prices in addition to the national and international economical situation. The availability of the different types of bunker fuel in operational areas (ref. Operational Requirements), as for example the availability and infrastructure of LNG terminals, can be a decisive and limiting factor for the design itself. The supply and demand of offshore vessels on the world market is highly dependent on the national and international oil prices. Available building capacity at the ship yards, together with the availability and cost of materials (mainly steel) and equipment, regulates building costs and the time frame for the build. Operational Requirements cover all the requirements related to the operational tasks of the vessel. These are related to the cargo capacity, such as deck area and tank capacities, crane capacity and special systems and equipment needed for the operational task of the vessel. The special equipment and systems include for example: helicopter deck, moon pool, remote operated vehicles (ROV), towers, diving equipment, winches, etc. These are the main driving factors for the main dimensions such as length (L), breadth (B) and draught (D). Additional operational requirements are the maximum speed, transit speed and dynamic positioning (DP) capability. The geographical area where the vessel is going to operate in is another important requirement. The operational area has to be considered with respect to water depth, wave heights and periods and climatic conditions such as temperature and humidity (water and air). Especially harsh environments in arctic latitudes will influence the vessel structure, the arrangement and systems and equipment to great extend, due to ice loads, climatic conditions and environmental awareness. Operational Requirements are also often referred to as the Design Parameters. External requirements describe all the requirements related to international and national rules and regulations. All vessels have to be built according to prevailing international rules, ensuring safe and secure shipping. The International Maritime Organization (IMO) is a specialized UN agency manifesting these international regulations. Hundreds of codes and guidelines cover the design, the construction, the equipment, maintenance and the crew, following the slogan of IMO Safe, secure and efficient shipping on clean oceans. In addition to the international regulations, the ship design and construction has to apply to the rules of the respective flag administrations. On top of that, certain specific restrictions might apply due to the operational area of the ship (see for example MARPOL Annex VI: Prevention of air pollution by ships). Emission Control Areas (ECA) limit emissions to air, introducing solutions such as gas-fueled engines, exhaust gas cleaning and low sulfur fuels. A classification society, listed accordingly to IMO and authorized by the flag administration, is an independent organization verifying the compliance with its own classification rules during construction and the service life of a vessel.
Increasing environmental concerns and a higher focus for safety at sea lead to more stringent rules. Especially after major incidents/accidents, new rules are put into place. Developments in ship design are often closely linked to these new rules and regulations. Additionally, special requirements and standards of the industry (e.g. oil companies) might have to be followed. The Available Technology is the fourth aspect influencing a ship design. This includes on the one hand the available building materials and building technology on the market. The available equipment on the market, either off-the-shelve products, custom made equipment or newly developed equipment is an important factor. Custom made or newly developed equipment is often triggered by changed market needs. On the other hand it includes the available design software, such as 3D modeling, CFD calculations and simulation software. In addition to the aspects and requirements mentioned above, the design is to great extent adapted to the requirements set by the ship yard or the owner, such as: Available building facilities at the ship yard, Building standards and procedures at the ship yard, Implemented and used design software (2D and 3D) at the ship yard, Preferred equipment of the ship yard and ship owner or charterer (makers list), setting requirements for the integration into the vessel, Owner requirements with regards to interior and comfort standards (e.g. special comfort class or minimum cabin size).
3. Ship Design The Design Process J. Evans visualized the process of ship design in a spiral in 1959 (Figure 3). Figure 3: Ship Design Spiral (Evans, 1959) The design spiral is a conceptual model of a process for effecting ship design (Mistree, Smith, Bras, & Allen, 1990). Mission (tender) requirements are the starting point for the concept design phase, leading to preliminary power estimations, a propulsion system, a hull shape, a general arrangement, preliminary hydrostatic and hydrodynamic calculations and preliminary cost estimations. The above is evaluated and lessons are drawn for the following preliminary design phase. The evaluated solutions are discussed in close cooperation with the customer to find the most efficient overall design. Solutions are getting more and more specific and options are narrowed down. In a successful tender process a final proposal and a contract proposal lead to a signed design contract and the detailed design and actual building process starts. In the process of designing a vessel a number of tools are used. These include for example 3D modeling, CFD calculations, simulations and tank tests. The availability and utilization of calculation and simulation software has increased, as computer utility got cheaper and requires less process time. The results help to verify predictions and to optimize the design. Modern tools such as these help speed up iterations of the design spiral. However, the tasks remain unchanged since the design spiral was drawn in 1959. Besides verifying assumptions and predictions in the design process by calculations, computer based modeling and tank tests, it is important to incorporate the feedback and experience of the customers/users. This feedback is essential to constantly improve vessel designs and to stay ahead of the competition. A really important feedback in this context is the logging of the operation modes on board of a vessel. An example for such an onboard measurement is given in Figure 4 shown in comparison to an estimated operational profile by the Ship Owner or Ship Designer.
Harbou r 17 % Transit 1 10 % Transit 2 15 % Harbou r 5 % Standb y 12 % Transit 2 17 % Transit 1 7 % DP 30 % Transit 3 28 % DP 30 % Transit 3 29 % Figure 4: 1 Year actual operation, logged on board of a UT design (left), Estimation by the Ship Owner or Ship Designer (right) The actual logged profile provides important information for optimizing propulsion systems. Based on the operational profile and calculations of Life-Cycle-Costs (LCC) a propulsion system is chosen. However, it has to be kept in mind that a vessel might change its operational tasks during its life-cycle. Therefore flexibility in the system can be very important. A hybrid propulsion system, combining direct diesel mechanic propulsion with diesel electric propulsion, is an example for a flexible, state of the art power system as shown in Figure 5. Figure 5: Rolls-Royce Marine Hybrid System with Hybrid Shaft Generator (HSG) It is essential to integrate the power system into a hull, designing a ship with a high overall efficiency. The hull form has to be optimized with respect to hydrostatic and hydrodynamic
aspects. The arrangement of the vessel has to be the most practical one with regards to the working procedures on board and the utilization of the space. This process of finding the optimum is an iterative process, narrowing down the variables (s. Figure 3) and leading to the best compromise. Optimizing one system or subsystem might impair the functionality of other systems. One example is the implementation of a Roll- Reduction Tank at a high position in the vessel. This tank will increase the comfort on board, by increasing the vertical centre of gravity (VCG) and therefore the roll period. On the downside, a higher VCG has got a negative impact on the stability of the ship. With regards to the arrangement, a roll-reduction tank might be a challenge to place in the arrangement (as it stretches over the complete breadth of the ship) due to required staircases, escape routes and emergency exits. 4. System Integration System integration is a discipline that combines processes and procedures from systems engineering, systems management, and product development for the purpose of developing large-scale complex systems that involve hardware and software and may be based on existing or legacy systems coupled with totally new requirements to add significant functionality (McGraw-Hill, 2003). Successful system integration requires good cooperation between the different disciplines of a design company. The designer or naval architect has to work together with the engineers from the Structure, the Machinery, the Electrical and the Hydro Departments. For example, the piping system, the electrical system, the HVAC system and all equipment on board has to be coordinated, so that no system interferes with another system in a negative way. Nowadays, 3D modeling is an inevitable tool in ship design and system integration. Figure 6 illustrates this, using the 3D models of the piping system, the equipment and the electric system on board as an example.
Equipment Piping System Electric system Figure 6: 3D modeling as a tool in system integration Integrating equipment and connecting their subsystems to the main system of the ship requires sufficient information by the sub supplier. This includes details about the scope of supply, system drawings and information of all necessary specific values. Therefore, the right information is needed at the right time for a successful integration of the equipment into the main system, the ship. Integrating a system into a ship is not only the physical integration; it is also the functional integration. With today s technology, more and more information becomes available everywhere on board, at any time. Power Management Systems (PMS), Dynamic Positioning Systems (DP) and Integrated Automation Systems (IAS) are examples of important parts of the complex information system on board. Their information needs to be routed in the correct way to the correct recipient(s). Besides routing information in the correct way and making it available everywhere on board at any time, it is getting more and more important to limit the visible and audible information. The user should not be overloaded by information he does not need for a certain operation. Otherwise, the operator will not be able to process all the available information, limiting his working efficiency and maybe bringing others into danger by overlooking essential warnings.
5. The role of Rolls-Royce Marine, Ship Technology - Offshore Systems Rolls-Royce Marine is an equipment supplier as well as a ship design company. Three large market segments are covered by Rolls-Royce Marine: offshore, merchant and naval. Currently, more than 30.000 vessels are sailing worldwide with a Rolls-Royce design and/or equipment on board. The customer can choose between single pieces of equipment, a ship design with an integrated equipment package or an equipment package without a ship design. These different choices for the degree of scope of supply are illustrated in Figure 7. Figure 7: Degree of the scope of supply by Rolls-Royce Marine Rolls-Royce s approach to integration enables delivery of complete system solutions from concept and feasibility studies to ship design, equipment selection, procurement, systems engineering and integration. System integration at Rolls-Royce Marine implies one contact, one supplier and just one deal. This entails a more reliable and more cost-effective solution. Figure 8 shows some examples of the wide product range of Rolls-Royce Marine.
Figure 8: System integration by Rolls-Royce Marine with a wide product range of in-house equipment In an international market, like the offshore industry, this market strategy enables Rolls- Royce Marine to adapt more easily to the needs of its customers and the market. System integration at Rolls-Royce is taken even further, by offering tailored training courses and programs for the customers, ensuring safe and secure operation. Besides that, products are developed to meet the needs and requirements of the customer, with the aim to be as user-friendly as possible. A common control philosophy, common hardware (controllers, monitors, I/O units, switches, etc.) and common software create recognizability for all Rolls- Royce products. An example of successful ship design and system integration at Rolls-Royce is the new unified bridge (Figure 9). It is a human-centered design with focus on safety, performance, simplicity and proximity.
Figure 9: Rolls-Royce unified bridge Functions include operation planning, execution and monitoring, based on clearly presented information. The human-machine interface is based on an extensive study of requirements. Crews differ in height, arm reach and other parameters, so the system allows the operator to find a comfortable position, sitting or standing as needed, with controls ergonomically placed and necessary information presented on touch screens. Consistency in command transfer, system operation and alarm handling enhances operational safety. (Rolls-Royce, Integrated Bridge Systems, 2013)
6. Conclusion/Outlook The shipping world is a constantly changing industry. Especially in the offshore segment, operating areas are getting more diverse with vessels entering deeper waters and colder areas. Hull designs and the equipment and systems on board have to be adapted accordingly. International Rules and Regulations are getting more stringent in respect to environmental issues and safety aspects. Competitiveness between vessel operators requires more work- and cost-efficient vessels. All these factors play an important part in designing the ships of the future, requiring an even closer cooperation of ship designers, ship owners, charterers and equipment suppliers. As stated above, Rolls-Royce Marine has an advantage in keeping and strengthening its market position due to the large variety of in-house products in the market segments. However, the research and development has to continue, within the Rolls-Royce system as well as in cooperation with business partners, leading to even better ship designs and improved system integration. 7. Bibliography Bruinessen, T., Hopman, J., & Smulders, F. (2012). Improved Models in the Design of Complex Specials: Success or failure? IMDC 2012: 11th International Marine Design Conference. Glasgow. Evans, J. (1959). Basic Design Concepts. Naval Engineers Journal, 671-678. IACS. (2011). www.iacs.org.uk. Retrieved from http://iacs.org.uk/document/public/explained/class_whatwhy&how.pdf. McGraw-Hill. (2003). Dictionary of Scientific & Technical Termans. The McFraw-Hill Companies. Mistree, F., Smith, W., Bras, B., & Allen, J. (1990). Decision-Based Design: A Contemoporary Paradigm for Ship Design. Annual Meeting. San Francisco: The Society of Naval Architects and Marine Engineers. Rolls-Royce. (2013). Integrated Bridge Systems. Retrieved August 18th, 2013, from Rolls- Royce Marine - Products: http://www.rolls-royce.com/images/110750-05%20mission%20control%20a4%204s%20unified%20bridge%20brochure_tcm92-36688.pdf Rolls-Royce. (2013). Ship Technology Offshore. Rolls-Royce Marine AS.