Future Surface Combatants Research Articles

MARINE REQUIREMENTS ELUCIDATION AND THE NATURE OF PRELIMINARY SHIP DESIGN

In 2003 the author produced a paper, entitled “Marine Design – Requirements Elucidation rather than Requirements Engineering”, for the 8th International Marine Design Conference. This was intended to follow on from van Griethuysen’s 2000 IMDC paper “Marine Design – Can Systems Engineering Cope?”, while drawing on the author’s recent experience in, firstly, directing and then being the MoD Future Surface Combatant (FSC) IPT Team Leader in the concept phase for that programme, where the intentions of Smart Procurement were applied. Since leaving the MoD in 2000, the author’s academic endeavours, at UCL, have both refined the ideas in the 2003 paper and, through a diverse range of ship design studies, provided further substantial evidence in favour of that paper’s argument. The current paper was originally presented to the first Institution conference on systems engineering. This is a revised version in the light of the discussion at that conference on the applicability of systems engineering practice to initial ship design and presents the arguments of both papers to a wider audience.
 The current paper looks at the origins of the concept of Requirements Engineering, within systems engineering, when specifically applied to naval engineering acquisition practice. This is contrasted with consideration of the actual nature of the initial design of physically large and complex systems, typified by modern naval vessels. This is followed by drawing specific insights from a series of design studies undertaken by the UCL Design Research Centre, under the direction of the author. These diverse and wide ranging initial design studies can be seen as examples of the sophistication of Requirements Elucidation, exemplifying how systems engineering practice can be applied to the critical early stages of naval ship design. The paper concludes by looking at the characteristics of the initial or concept design process by seeing Requirements Elucidation, as the strategy to tackle the inherently “wicked problem” of determining what is really wanted of a naval vessel and what can be afforded.

The Multi Role Combatant - Jack of All Trades, Master or None?

For naval vessels Modularity is essentially a design style choice adopted to achieve both aspects of multi-role capability, namely, Flexibility (in deployment) and Adaptability (through life). This paper largely focuses on the second of these, which has been seen to be an attractive objective in Western naval vessel acquisition since the end of the Cold War. A paper to one of this series of warship conferences produced by the author a decade after the collapse of the Warsaw Pact was entitled “Adaptability – the Key to Modern Warship Design”. It particularly drew on the difficulties the author had experienced in establishing the case for the Future Surface Combatant (the precursor of the Type 26 Frigate), where the primary capability of this first post-Cold War combatant as a globally deployable class of warship was to demonstrate that Adaptability would be good value for money in an uncertain geopolitical environment. The current paper commences by revisiting the case for Adaptability nearly two decades on from that first consideration and whether the same drivers for Adaptability and advances in Modularity have made the case for multi-role combatants more convincing or whether they are still prone, if they are not truly “First Rate” designs, to be “Jacks of all trades, yet Masters of none?” Next the paper reviews past warship designs that have been inherently adaptable, leading on to consideration of "margins", the traditional way naval ship designers have been able to incorporate a measure of adaptability. However, non-ship design aware procurement authorities, have continued to squeeze seemingly generous margins as a short sighted means of achieving "savings" in the procurement element of defence budgets. There are of course other features, necessary to achieve Adaptability. Thus the paper explores how an adequate consideration of the ship architecture might provide an adaptable design and, specifically, how adopting Modularity to achieve this, can be explored early in ship design. Finally, leading on from the exploration of Adaptability, the paper concludes by a considering the Trimaran configuration. This configuration remains a highly attractive overall Style and ship configuration choice for future warships, precisely because it readily provides so many of the features that are seen to be appropriate in an Adaptable Multi-role Warship, which can be configured to avoid the Second-Rate “master of none” trap.

A Sliding-Mode Duty-Ratio Controller for DC/DC Buck Converters With Constant Power Loads

Incorporating a medium-voltage dc (MVDC) integrated power system is a goal for future surface combatants and submarines. In an MVDC shipboard power system, dc/dc converters are commonly employed to supply constant power to electric loads. These constant power loads have a characteristic of negative incremental impedance, which may cause system instability during disturbances if the system is not properly controlled. This paper proposes a sliding-mode duty-ratio controller (SMDC) for dc/dc buck converters with constant power loads. The proposed SMDC is able to stabilize the dc power systems over the entire operating range in the presence of significant variations in the load power and input voltage. The proposed SMDC is validated by both simulation studies in MATLAB/Simulink and experiments for stabilizing a dc/dc buck converter with constant power loads. Simulation studies for an MVDC shipboard power system with constant power loads for different operating conditions with significant variations in the load power and supply voltage are also provided to further demonstrate the effectiveness of the proposed SMDC.

Stretching the Future Surface Combatant: Examining the affordability benefits of a twin-variant ship

A ship concept design is presented that utilises a single common hullform across two distinct variants to meet the perceived needs of the Royal Navy's Future Surface Combatant, while satisfying the wide separation in target cost between the variants. This concept emerged from commonalities between the requirements of the Force Anti-Submarine Warfare Combatant (C1) and Stabilisation Combatant (C2) vessels. Both share some requisite capabilities, leading to specific areas where common systems can be adopted. However, other capabilities lead to major differences in the technical solutions that must be employed. While a single base hullform has significant cost advantages, to successfully fulfil both roles while maintaining commonality a number of design innovations are necessary. This paper also estimates the cost savings that could be achieved to adopt the design features proposed. These savings and the flexibility inherent to the design make the vessel well suited to the export market. A final discussion highlights the beneficial role of the twin variant concept in providing part of the affordable future fleet.

Challenge — Naval Force Development

Challenge — Naval Force Development

Integrated Liquid Discharge System for Waste Disposal on Future Surface Combatants

AbstractNational and international regulations restrict the overboard discharge of ship‐generated liquid waste. During the twenty‐first century, discharges of untreated sewage, graywater, and oily wastes will be further restricted in many littoral areas throughout the world. Future surface combatants will operate primarily in these littoral areas. Consequently, the Naval Sea Systems Command (NAV‐SEA) SEA 03R24 initiated a research and development (RDT&E) program to provide future United States (U.S.) Navy surface combatants with the capability to destroy liquid wastes aboard ship, maximizing shore independence and minimizing waste off‐load costs in foreign and domestic ports. Under this R&D program, the Carderock Division of the Naval Surface Warfare Center (NSWCCD) developed a liquid waste abatement strategy called the integrated liquid discharge system (ILDS).The ILDS contains three distinct elements; non‐oily liquid waste treatment, oily waste treatment, and thermal destruction. The basis of the ILDS is to minimize each of the waste streams so that a shipboard thermal destruction system can be used to process the remaining volume of waste.

Integrated Liquid Discharge System for Waste Disposal on Future Surface Combatants

ABSTRACT National and international regulations restrict the overboard discharge of ship‐generated liquid waste. During the twenty‐first century, discharges of untreated sewage, gray‐water, and oily wastes will be further restricted in many littoral areas throughout the world. Future surface combatants will operate primarily in these littoral areas. Consequently, the Naval Sea Systems Command (NAVSEA) SEA 03R24 initiated a research and development (RDT&E) program to provide future United States (U.S.) Navy surface combatants with the capability to destroy liquid wastes aboard ship, maximizing shore independence, and minimizing waste off‐load costs in foreign and domestic ports. Under this R&D program, the Carderock Division of the Naval Surface Warfare Center (NSWCCD) developed a liquid waste abatement strategy called the integrated liquid discharge system (ILDS).The ILDS contains three distinct elements; non‐oily liquid waste treatment, oily waste treatment, and thermal destruction. The basis of the ILDS is to minimize each of the waste streams so that a shipboard thermal destruction system can be used to process the remaining volume of waste.

Combat System Engineering for the DDG—51 Class and Future Surface Combatants

ABSTRACTConstraints imposed on future surface combatant acquisition will demand both design‐to‐capability and design‐to‐cost. The future Navy must be affordable and, to go in harm's way, must be combat capable. The quality of future ships depends on establishing an acquisition process that ensures capability independent of the rate of ship construction or the missions of the fleet.This paper explores surface combatant acquisition strategy and the engineering process that supports it. Events that shaped the combat system portion of the DDG‐51 shipbuilding program are reviewed as a basis to propose a modification to the process of future acquisitions. A historical perspective is established by outlining the shipbuilding program as it evolved from about 1978 to 1989. Factors that shaped the eventual upgrade program are presented in terms of the acquisition strategy and system engineering, which led to definition of the combat system configurations.Conclusions based on the information presented suggest that a more efficient system engineering process is needed to execute future preplanned upgrades and to support long‐term plans. This process is described in terms of a single research and development funding line for configuration definition, design, and development. This approach differs from the traditional ship design, acquisition, and construction process in terms of continuity of system development and emphasis on interdependencies of the combat system and ship.