A complex system of complex systems
Warship Design
ALAIN BOVIS
© 2015 FrontLine Defence (Vol 12, No 2)

The debate is heating up around the multi-billion-dollar Canadian Surface Combatant (CSC) procurement. The government has chosen Irving Shipyards as the shipbuilder and is close to selecting both a Combat System Integrator (CSI) and a platform designer – selections they intend make, based purely on notional proposals (choosing a ‘Most Qualified Team’ option over a ‘Most Capable Design’ approach). The real game – the trade-off studies, the preliminary and detailed design, the negotiation and implementation of the contracts – will start later.

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French Ship Chevalier Paul (D621), the second of France’s new Horizon Class ­multirole area air defence destroyers, is shown here undergoing sea trials. This 7,000 tonne ship was commissioned in late 2009. DCNS was the warship designer, builder and combat system integrator. (Photos provided by DCNS)

Much has been said about the fairness and transparency of this acquisition process (and the lack thereof), but little about the technical challenges associated with combining multiple, sophisticated, and cutting-edge technologies and then turning them into an integrated, state-of-the-art warship.

A modern warship is one of the most complex man-engineered systems on Earth, far more complex than any other single air or land vehicle. A warship is much more than a simple collection of systems, and a warship provider is anything but an equipment retailer.
 
A Complex System of Complex Systems
A few decades ago, a warship (like Canadian Iroquois Class Destroyer Algonquin shown at left) could still be described as a naval platform – carrying a military payload and composed of different suites of gunnery, communication and detection equipment. The platform was designed according to nautical and structural requirements, with each operational system selected separately. The ship was built the way a house is constructed, first raising the hull, then installing the propulsion and auxiliary systems and eventually setting onboard the above deck systems.

To some extent, this is still the philosophy governing ship modernization. However, with the introduction of naval anti-ship missile proliferation, naval combat changed dramatically, leaving naval architects to cope with new requirements like real-time data processing, multi-target engagement and stealth technology. Further, asymmetrical littoral warfare imposed new rules of engagement, resulting in evolved concepts in ship mobility, situation awareness, multi-platform cooperation and combat versatility.

Alas, the role of Combat System Integrator emerged in the 90s out of the need to coordinate operations of an increasing number of sensors and weapons and to process an exponentially large amount of data. Today, the functional integration of various sensors and weapons is performed through the Combat Management System (CMS) – the architecture of which evolves from year to year.

A clear departure from the fully proprietary architecture dedicated to a specific set of equipment, the latest generation CMS has an open component-based architecture that allows for integration and evolution of a combination of equipment of different brands. This architecture opens the operational modularity of the ship, widens the choice of equipment for the customer, and gives the possibility of incremental modernization during the ship’s life cycle.

Design to Build
Military shipbuilding has made a quantum leap in productivity by adopting the aerospace building practice of modular construction. Modular construction means that the ship frame is divided into blocks, built (pre-equipped) individually in shops and later assembled and interconnected on the dry dock.

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On 2 March 2015, HMS Duncan, the sixth and final of the UK’s sophisticated, new class of Type 45 destroyers, was formally handed over to the Royal Navy. BAE Systems Prime Contractor, Shipbuilder, Platform System Integrator and Combat System Integrator. (MOD Photo RN: LA(Phot) Guy Pool)

Reduced construction time and higher production quality result from parallel work on the different blocks. However, modular construction requires that the detailed design of every sub-system, includ­ing the weapon systems, be incorporated into the structural design of the blocks before the building begins. A detailed numerical mock-up of the complete warship is required to effectively monitor any change in the configuration of a system and to detect the side effects of this change on other systems.

Today, an up-to-date warship must be a highly integrated system of systems – with no individual function disconnected from another. Radar’s performance, despite what the manufacturer catalogue says, is dependent on ship stability as well as on its electromagnetic compatibility with other electronic equipment. As a result, installing the heavy antennae of sophisticated multi-function radars becomes one of the most constraining tasks of naval architects.

The overall electromagnetic signature of the vessel – which determines the ship’s vulnerability against adverse weapons – must be minimized. The designer’s goal, therefore, is to reach the best compromise between a low radar cross section and an efficient detection capability. The same goes for infrared and acoustic signatures. Warship integration within a budget means solving the problem of global optimization between competing and sometimes contradictory performance. Any complex system designer knows that a global optimum under constraints is rarely the addition of single-view optima. Though ­crucial in the context of crew reduction, global optimization is even more challenging on multi-mission frigates and destroyers, as they must combine capabilities in anti-submarine warfare, air defence, and aircraft operations.

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Operator ­console in FREMM Class frigate’s combat information center. DCNS is the overall warship integrator for this programme. (Photo provided by DCNS)

Warship Design Authority
The military superiority of a ship comes from the consistent combination of its nautical performance (stabilization, speed, navigation and manœuvrability); power production and distribution (integrated powering system); signatures management; and weapon system efficiency. And so, the future trend in warship design is clearly to extend the integration frontier to integrated topsides in which multifunction structures will replace walls, masts and antennae and perform simultaneously active functions (detection, communication, electronic warfare) and structural properties (strength and durability, RCS reduction, fire resistance, NBC protection…).

The warship integrator is a complex system designer able to optimize, at the global warship level, the architecture, the functional definition and detailed design of all the components together.

The Warship Design Authority role answers the need to manage, validate and communicate the configuration of the entire ship to all users at any time of the design, production and in-service life cycle. The warship integrator has the design authority on the platform, the platform systems, and the combat system. It can anticipate future changes in demands of the actual customer or those of future markets. It is in the position to develop a versatile design that can be adapted to different requirements and operational contexts, in order to limit the re-design effort (and cost, time and risk) at the time of each new contract.

Trying to match an existing combat system with a ship platform when both have been developed separately (and have been proven valuable in their own context), is close to developing a new warship. However, due to the lack of a global engineering vision, this “patchwork” will most definitely not give the full reward of the advanced technology provided by each system. More to the point, such a process will put most of the integration burden on the assembling yard, which will be drawn into endless design modifications to reconfigure mismatching interfaces.

Securing the Acquisition Process
It is not rare that a naval shipbuilding program faces challenges related to schedule, cost or quality. Beyond the obvious fault of a contractor or supplier, the most inextricable cause of program failure is the inconsistency of the design in ‘blurred zones,’ where none of the contractors or sub-contractors are clearly responsible. Considering its impact on the overall ship military value, the overlap between the platform and the combat system has proven to be one of the most risky grey zones. Experience has shown that, in such a case, the customer has no guarantee for reparation or damages unless a warship integrator is clearly made liable for any such inconsistency.

In conclusion, a naval construction program draws a major advantage of a clear chart of technical and contractual responsibility. The overall warship design governs the final operational capabilities. None of these capabilities can be any longer allocated to a single sub-system, whatever its importance, but is unavoidably impacted by decisions and trade-offs made on any part of the ship.

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USS Zumwalt (DDG-1000), the lead ship of her class, is a guided ­missile destroyer of the United States Navy. The Zumwalt Class was designed as multi-mission stealth ships with a focus on land attack. Raytheon is the systems integrator for these ships, the first of which is expected to be commissioned in 2016. (U.S. Navy photo)
 
It is critical that a global designer be in charge of the compliance of the warship design with the customer’s functional expectation and of the relevance of the design specification to the production process. From the contractual point of view, the respective technical responsibilities of the customer, of the prime contractor, of the warship designer, of the CSI and of the shipbuilder have to be clearly and completely allotted, knowing that at each contractual level, the buyer is held responsible for any ill-defined interface between its own sub-contractors.

An experienced warship designer, empowered with full design authority, is undoubtedly the most secured guarantee of performance for the final customer.

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Alain Bovis retired at the rank of Rear-Admiral after 27 years as a Naval Constructor within the French Ministry of Defense. In industry, he has held a number of high level positions including Science and Technology Director for DCNS. He is a Professor of Naval Architecture in several academic institutions and is currently President of Innovis, a consulting company in naval shipbuilding.
© 2015 FrontLine Defence

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