The traditional ‘spiral’ method of ship design, used successfully since the 1950s, consisted of several phases – concept, preliminary, contract and detail – each running a spiral of its own, including powering, arrangements, stability, and costing. However, the complexities of modern ships, together with relatively new concepts such as stricter emission reduction targets, mean that today’s ship designers need a more holistic, integrated digital design system.
The move away from using separate siloed design teams towards working off a single comprehensive virtual master model – or ‘digital twin’ simulation – allows fuller collaboration and connected working. This is essential in a world where team-members can be located anywhere.
From prow to stern, designs can be quickly updated or altered on the digital twin, ensuring that every part, whether an electrical cable or a section of bulkhead, can be examined in detail in 3D, and integrated seamlessly into the larger design. Customizable ‘out-of-the-box’ ship structures and the ability to quickly bring up and re-use whole systems from previous projects can mean huge savings in time and costs.
Further, teams can perform optimization studies, hydrostatic draft calculations, computational fluid dynamics (CFD) and finite element analyses (FEA). By making assessments of the ship’s performance at the early design stage, downstream workload and risk of error is reduced. For example, steel weight calculations and power are all part of the same simulation analysis, with results applied to the ship as a system (optimal performance of every subsystem is included in the simulation).
Ensuring everyone is using the same tools alongside optimal design systems enables designers to manage all the mechanical, electrical and software features of ship design in one collaborative environment. This is known as multidisciplinary design.
A multi-disciplinary approach to design
Rodrigo Perez Fernandez is Global Portfolio Development Director at Siemens Digital Industries Software. He sees multidisciplinary design as essential for the development of highly sophisticated systems like those found in modern ships.
“Multiple subsystems continuously interact with each other,” he points out, “and a large number of variables that impact the design, such as security aspects, technical requirements, budget constraints, market evolution, and optimization of production facilities require the concurrent engagement of a significant number of disciplines and different skill sets. This makes the traditional design methods, like the design spiral, highly inefficient.”
Fernandez says that naval architects should be moving away from the design spiral process, as a combination of both the complexity of modern ships and the economic stress in vessel development is already driving the market towards new technologies. “The market is already demanding faster development cycles with a lower total development cost,” he says. “We must respond to that need from our customers.”
Multidisciplinary design offers radically improved efficiency compared with traditional naval architecture techniques, helping naval architects look at a design holistically. Incompatibilities in specifications can be quickly identified and resolved at the early design stage, minimising costly reworkings.
“The multidisciplinary approach allows all the different disciplines to start working concurrently from the beginning, facilitating their online interactions among all subsystems,” explains Fernandez. “One example would be the development of the hull forms in collaboration with the team leading the propulsion system development. This team can specify the power plant requirements and the procurement department can quickly confirm the economic feasibility and availability of the selected equipment.”
Designing next generation vessels
Ship designers are under pressure to reduce the carbon footprint of modern vessels, and digital transformation is seen as key. The International Maritime Organisation is setting targets to reduce carbon emissions by 50% by 2050, and already some bigger shipping companies are setting their own targets, some aiming for carbon neutrality.
Meeting these targets will require new fuels, ship designs, and propulsion systems, with fossil fuels replaced by green hydrogen, electric batteries or other eco-friendly energy sources. Such radical re-designs of ship systems, with ever-increasing complexity, means using a digital twin will be essential to ensure all the parts work together.
Simulations will be essential for designing more efficient ships. The IMO Energy Efficiency Design Index regulations mandate that ships built before 2022 must be 20% more energy efficient compared with 2012 levels, growing to 70% by 2050. For naval architects, it means the ships they are designing now must be compatible with the low-carbon technologies and fuels of the future.
For shipbuilders to remain competitive, digitalisation is essential. For naval architects new to multidisciplinary design, implementation can take place in phases, says Fernandez: “One approach could be to start integrating the procurement team with the initial design team. Or a more typical approach is to integrate initial design teams with detail design teams.”
The use of digital twins will be crucial for designing key attributes of future vessels, says Fernandez: “Probably one of the most exciting attributes of the next generation vessel will be the continuous digitalization and development of its digital twin.
“We can imagine a near-term future where designers will have available a large amount of information in real-time. That will allow important and ongoing safety and efficiency improvements and optimization to both current and next generation vessels, improving security and efficiency.”
Siemens Integrated Ship Design and Engineering is part of the Xcelerator portfolio and offers as-a-service capabilities, helping shipyards scale their design, simulation, manufacturing, and IoT (Internet of Things) capabilities by offering full flexibility, accessibility, and scalability with minimised deployment efforts and costs, and maximised security. Download the whitepaper on this page for more information about Siemens Digital Industries Software.