*********** 041793B.ENG *********** Country: China From CHINA SCIENCE AND TECHNOLOGY JPRS-CST-93-005 22 March 1993 p. 23-27 Keywords: Ship design, modules, fleet modernization MODULAR CONCEPT FOR WARSHIP DESIGN ADVOCATED 93FE0296A Shanghai CHUANBO GONGCHENG [SHIP ENGINEERING] in Chinese No 6, Dec 92 pp 4-8 [Article by Wang Zhiguo [3769 1807 09481 of the Naval Engineering Academy: "Concept and Recommendation for Modular Warship Design"] [Text] ABSTRACT: The concept of initiating research on modular warship design in China is presented. The necessity of the work is discussed. Based on the present situation, the contents, key issues, approach and steps related to this effort are also presented. Modular ship design was developed in the late 1960's. Different from conventional ship design methods, the development of the platform is done separately from the study of its payload. This allows the parallel and independent development of ship platform and payload and drastically reduces the development cycle for new ships. Furthermore, it also significantly shortens the time and lowers the expense required to modernize ships. In addition, it effectively improves the usage rate of ships currently in service. Therefore, modular ship design is a major step in ship design, representing the trend in ship design technology worldwide. I. SIGNIFICANCE OF MODULAR SHIP DESIGN RESEARCH The Chinese Navy has accumulated considerable experience in the development and construction of warships over the past 30 years. Especially in the development of ship platforms, it is relatively mature and at a world class level. However, the development of onboard weapons and electronic equipment is still lagging behind major western nations by 10 to 20 years because of the technological level in China and the military technology blockade imposed by other countries. Consequently, the overall combat capability of the Chinese Navy is still trailing behind that of other major naval forces. To improve the overall combat capability of our naval vessels and to shorten the gap with the others is an urgent issue that ought to be dealt with as soon as possible. Modular ship design is an effective shortcut to accomplish this goal. The following is a discussion of this argument. 1. UTILIZE THE EXPERIENCE IN SHIP PLATFORM DEVELOPMENT AND CONSTRUCTION Modular ship design does not introduce any major changes in the design of ship platform. The experience accumulated in the development of ship platforms can be fully utilized. As far as construction is concerned, a modularly designed ship is more suited for construction by modules. Different sections and internal equipment can be built and tested in shops before final assembly. This can significantly reduce the work period on the platform and after it is launched in water can save cost. We have accumulated considerable experience in modular ship construction and it will not be very difficult to make improvements on this foundation. Therefore, in the area of ship platform design and construction, adopting modular design will not involve great technical risk and large capital investment. In addition, it can shorten the construction cycle. 2. INCREASE SHIP TYPE AND QUANTITY WITH LIMITED FUNDS One significant advantage of modular warship design is that it is easy to alter the mission of the vessel, such as changing from anti-aircraft to anti-submarine or anti-surface vessel. This is because different (onboard) weapons for various missions can be conveniently installed to arm the modular combat system while requiring very little or no changes to the platform. For instance, when the Navy needs an anti-aircraft ship, it can be built by modifying an anti-surface ship or anti-submarine vessel without any development work. This can save a substantial amount of money for development. The money saved can be used to build more ships to strengthen the Navy. Modern naval warfare is a long range high-tech affair. The technical level of the combat system plays an important role. If a great deal of capital is spent on the development of the platform, it will limit the resources available to the development of weapons and electronic equipment, which is detrimental to the overall combat capability of the Navy. 3. SHORTEN TIME PERIOD AND REDUCE COST FOR MODERNIZATION OR MAINTENANCE The biggest advantage of modular warship design is that it is extremely easy to modify the weapons on board. It usually takes a few weeks to install or remove modular weapons and electronic equipment. Usually, the ship does not have to be placed on a dry dock. Certain small-scale work can be done at the maintenance pier. The amount of time required at a shipyard is reduced and the ship is ready for sail sooner. Based on a report,[1] a ship designed and constructed by the MEKO/FE technique is ready for sail 90 percent of the time. It is much easier to modify the weapons and electronic equipment on modularly designed and built ships. It is relatively fast to upgrade or replace outdated or damaged weapons and electronic equipment. Therefore, the maintenance and upgrade cost is much less compared to that of a ship built by conventional design. Based on the analysis done by a research institute in the United States, compared to other conventional vessels, the moderniza- tion cost of the modularly designed DD963 class frigate is $9.3 million lower and the time required is only one-tenth.[3] 4. FACILITATE THE INTRODUCTION OF TECHNOLOGY TO KEEP THE WEAPONS UP TO DATE Major western naval surface vessels employ standardized modular weapons systems. Weapons and electronic equipment are interchangeable among NATO nations. If the Chinese Navy also adopts the same modular design and construction standard, it will facilitate the import of advanced western weapons and electronic equipment and allow us to put them into action very quickly. In addition, if series of weapons and electronic equipment are built modularly, then new weapons and electronic equipment can also be developed and produced based on the same standard. This enables us to rapidly modernize our existing vessels and keep our weapons systems up to date. 5. ENABLE US TO RAPIDLY ALTER THE MISSION OF WARSHIPS TO MEET DIFFERENT NEEDS The world situation is constantly changing. It is difficult to predetermine the enemy for our naval forces. The mission of a new warship may change after it is placed into service to meet new requirements. A modularly designed warship can quickly meet this demand. By altering the type of weapons on board, one can switch between anti-surface, anti-aircraft and anti-submarine mode. In future sea battles, anti-submarine warfare, convoy missions or landing campaigns, some warships need to be rapidly modified to meet the needs in the specific combat situation. In addition, modularly designed and constructed vessels are more competitive in the export market. Different weapons systems can be installed according to specifications requested by the buyers. The MEMO/FE design and construction method developed by the B+V [Blohm + Voss) Company of Germany was evolved along such a guideline. II. IMPLEMENTATION AND FEASIBILITY OF MODULAR WARSHIP DESIGN IN CHINA In the area of modular warship design, China is trailing by more than 20 years. We should follow the path of learning and digestion, partial construction, overall improvement and actual ship development to implement modular warship design. By referring to the method and experience of modular warship design in other countries, the steps for us to take to implement modular warship design are as follows: 1. INVESTIGATE FINE DETAILS OF MODULAR WARSHIP DESIGN IN OTHER COUNTRIES Specific techniques and technical details of modular ship design employed by other countries (especially B+V Company of Germany) must be investigated. If necessary, import some weapons and electronic modules as samples for research and duplication. 2. INITIATE RESEARCH TO PRODUCE MODULAR WEAPONS AND ELECTRONIC EQUIPMENT Key issues and technical hurdles that require breakthroughs must be selected at the onset of the effort to modularize weapons and electronic equipment. In the area of weapons, the key issues to be resolved are the vertical missile launcher, concentrated fast-loading mechanism and missile storage inside module for large missile modules, as well as the automatic tracking and control of large- and medium-caliber guns and storage of shells and a small flexible shell transport and loading mechanism. For small-caliber guns, the emphasis is on the standardization and serialization of the shape and size of the module. As for electronic equipment, the focus is on placing radar, sonar and communications equipment in boxes. After these problems are resolved, the next step is to study the standardization of the shape and size of the module and the interface. Our Navy has obtained considerable results in the study of weapons and electronic equipment used to arm civilian vessels for combat use. It would save a great deal of money and time if further study is carried out on this basis to develop weapons and electronic equipment for warships. 3. START RESEARCH FOR A DISTRIBUTED COMBAT COMMAND SYSTEM This study has two aspects. One is hardware for a modular combat command system which includes automatic data processing in various weapons and electronic equipment modules, and microcomputer-control systems for automatic control and data exchange. The other is the modular command control software. The difficulty is in research on the data bus-the central nerve of the combat command system employing multi-channel modulation and fiber-optic communications technology. In recent years, some institutions are involved in research on modular command systems and have built a solid foundation in this area. With more funding to expand the work, results can be obtained fairly rapidly. 4. MODIFY A MODULAR PLATFORM We have accumulated considerable experience in the study of ship platforms. A successful model of existing intermediate surface vessel should be selected as the basic model for modification based on the outcome of research on modular weapons and electronic equipment. The primary objective is to finish the division of functional modules (areas), internal layout of functional modules (areas), distribution and layout of various ship systems and auxiliary weapons systems, overall layout, weight and center-of-gravity balance, and division and construction of large-scale modules. In addition, structural strength of large module interface and overall vessel strength, independence of functional modules and overall coordination of the ship, and optimal locations for the installation of weapons and electronic equipment should also attract a high level of attention. The Chinese Navy has considerable experience in platform development and has designed and modified a variety of vessels. As far as the technical capability is concerned, it is completely feasible for us to implement modular design and construction of platforms. On the basis of the successful experience mentioned above, relevant regulations and standards should be formulated to meet the needs of the Navy. III. CLASSIFICATION OF WEAPONS AND ELECTRONIC MODULES AND MAJOR RESEARCH AREAS The Navy has a variety of weapons and electronic equipment, including attack weapons such as guided missiles, guns, torpedoes and depth charges; electronic detectors such as radars and sonars; and equipment associated with communications and missiles. They come in different shapes and sizes and have different installation requirements. To modularize weapons and electronic equipment, we must first classify them. The types of modules should be kept at a minimum in order to facilitate the standardization and retrofitting work. It is recommended that they be classified as follows: 1. LARGE AND MEDIUM WEAPONS Large and medium weapons define the mission of the warship. To make them into the same standard modules will facilitate the retrofit of a warship for different missions. These weapons include medium- and large caliber guns and reloadable missile launchers. The main area of research for this module is to concentrate most of the weapon system-including firing mechanism, ammunition storage, transport and loading mechanism-within a specific module size. This primarily involves the internal layout and the incorporation of maintenance space. Missile launchers and gun turrets are not included in the module; however, they must be positioned over the area defined by the length and width of the module. Furthermore, size-reduction studies must be done for a number of super-large weapons. Problems associated with ventilation, air conditioning, heating and hydraulics in the modules must also be resolved. 2. SMALL WEAPONS Small weapons are light-weight, compact and flexible to place. They are relatively easy to modularize. They include small- caliber guns, one-time-use missiles, antisubmarine torpedoes and electronic warfare equipment. The main area of research is in putting weapons control mechanisms, small ammunition boxes and shell-loading mechanisms in containers. If necessary, some size reduction may also be required. 3. RADAR, SONAR AND COMMUNICATIONS EQUIPMENT This kind of electronic equipment usually consists of two parts: transducer (sensor) and controller, and signal processing unit. The main effort is to put various display and control units in panels and to develop independent software to run them. The shapes, sizes, interfaces and standards should be classified in a uniform manner. It is best to refer to the modular standards adopted by the United States and western European countries in order to facilitate the import of equipment. IV. SPECIAL REQUIREMENTS RELATED TO PLATFORM DESIGN Modular design imposes a number of special requirements, compared to the conventional method, on the platform design. The major aspects are discussed in the following. 1. ZONE DIVISION The concept of "zone module" is introduced to the hull structure by adopting modular design. Based on the locations of major weapons on the warship, the hull is divided into several functional zones. Each zone has its own special function and is used by a specific piece of equipment (such as a launcher). Figure I (not transmitted) shows a classic diagram of zones. The hull is divided into zones for weapons and equipment, electronic command and control, engine room and living quarters. The weapons and equipment zone should have substantial margin in terms of both weight and volume. In addition, this zone should be equipped with supplies (such as power) anticipated for future modernization. The layout for these zones must be flexible to some extent so that it may be conveniently altered without major impact on other parts of the vessel. The zoning must be done by taking into consideration factors such as overall layout, vitality, stability resistance against destruction, command and control and system requirements. 2. SHIP LAYOUT Usually, the procedure for ship design is to determine the weapons and equipment to be installed and then to optimize the platform. The objective is to provide the most compact and desirable layout with the minimum displacement. Modular design, however, expects to obtain an interface between a standard effective payload and the platform. The interface specifies that certain areas of the platform are used to install weapons and equipment. The interface is determined independent of the optimal requirements of the weapons to be installed. Hence, the interface may be too "large" or "small." Therefore, a modularly designed platform may not be the optimal design in the conventional sense. The requirements for the interface between the platform and the effective payload include: installation site of the module, size of opening, installation gap, interface for supplies and location of passageway. The module installation site must be determined based on the layout of the combat system and the platform zoning design. It must meet the fire-power distribution requirements and the zoning needs. The following factors must also be considered in determining the vertical position of the modules. (1) Lower the center of gravity to the extent possible. (2) Minimize interference with supply and field of view as much as possible. (3) Meet installation and construction requirements. (4) Provide a base at a place of least impact. (5) Provide a passageway at the bottom of the module. Each module for weapons or equipment must have a passageway inside for emergency repair when it is flooded or inoperative and for installation. In addition, personnel assigned to the module may have a need to enter the passageway. The entrance of the passageway should be an integral part of the flow pattern of the entire vessel. The layout for each zone for weapons or equipment should be centered around weapons and electronic equipment modules. The supply of electricity, steam and water from the platform, as well as the connection of cables and pipes between weapon and electronic modules, must be taken into consideration. Under the premise that a suitable margin is reserved, the distribution of other cabin space is then to be considered. 3. STRUCTURAL STRENGTH The hull structure of a modularly designed warship must take into consideration the impact of the weight of future weapons modules. Structural analysis should be done for the worst case. In other words, the initial payload may not be the total payload and there is some strength reserve. The large opening on open deck for large weapon modules must be investigated in detail. A large opening must be structurally reinforced. The reinforcement can also serve the purpose of securing the weapons module in place and preventing water take-up from the deck. The base of the module must be capable of ensuring the stability of the module. However, one also needs to minimize the weight of the structure. This also requires some investigation. 4. SUPPLY SYSTEMS FOR WEAPONS MODULE Since the same weapons module site may be used to install different weapons and different weapons require different supplies from the platform, it is necessary to study the types and capacities of different weapons that might be installed during the lifetime of the ship. Based on a study done in the United States,, it is recommended that electric power be supplied centrally by the platform. This means that the power plant on the ship is designed to meet the maximum power requirement. The platform provides energy sources (such as sea water, compressed air, cooling water, etc.) for heating, ventilation and air conditioning, while each weapons module has its own blowers, heaters and pipes. The platform is designed to handle the maximum load. It is also adjustable at several different levels to meet the minimum payload requirement. All hydraulic systems are handled by weapons modules locally. There should be a 50- I 00 percent power reserve for systems that rely on the platform to provide power. V. PRELIMINARY RECOMMENDATIONS FOR IMPLEMENTING MODULAR WARSHIP DESIGN IN CHINA In view of future development of the Navy, the recom- mendations for the implementation of modular warship design are as follows: 1. SET UP PRELIMINARY STANDARDS FOR THE WEAPONS AND ELECTRONICS MODULE Based on a wide range of surveys and analyses of the main guns and small-caliber guns, surface-to-surface missiles, surface-to-air missiles, surface radars, air radars, gun radars, sonars, and radio equipment, prepare a plan to define the requirements for the shape, size and supply interface of the weapons and electronics module. 2. ACCELERATE STUDY OF A DISTRIBUTED COMMAND SYSTEM The distributed (modular) command system has been under investigation for years. No significant results have been obtained to date. We should speed up the pace by increasing funding to an appropriate level so that we can obtain some valuable results as soon as possible. 3. USE THE PRESENT FRIGATE MODEL AS THE PLATFORM FOR RETROFITTING The frigate is the major vessel of the Navy. The weapons and platform designs are more mature. Various technical information is also more complete. It is an ideal model. On the basis of the modules for weapons and electronic equipment prepared, specific schemes to retrofit the ship according to the requirements of modular design will be investigated. REFERENCES 1. Special Supplement on the Blohm + Voss MEK02000, NAVY FORCES, 1988. 2. Spero, J. R., Hicks, W. F. and Greene, A., "Philosophy of Naval Ship Design and Construction," NAVAL ENGINEERS JOURNAL, Vol 83, No 5,197 1, pp 45-52. 3. Abbott, J. W., "Modular Payload Ship in the U.S. Navy," SNAME TRANSACTIONS, Vol 85, 1977, pp 350-395. 4. James, C. D. R. and Jolliff, "Modular Ship Design Concepts," NAVAL ENGINEERS JOURNAL, Vol 86, No 5, 1974, pp 11-33. 5. Luo Jianming [5012 6015 24941, "Construction of Surface Ships Using Functional Modular Design," JIANCHUAN LUNZHENG CANKAO [WARSHIP REVIEW], No 3, 1983. ************** END Msg. B.ENG **************