Stena Elektra

Dynamic design of ships

There is a big potential in optimising the construction of ships by reducing weight and steel. Transports can become more energy efficient and reduce the environmental impact at sea. To find out more, a pre-study was conducted in 2016 and now a collaboration is established. SSPA (project manager) together with Chalmers University of Technology, KTH Royal Institute of Technology and Stena Teknik will conduct research on methods for dynamic ship dimensioning and the understanding of dynamic loads on ships will be able to enhance. During the project, a vessel model will be equipped to measure structural loads, model wave tests, and numerical calculations will be validated against model trials. Stena's concept vessel Stena Elektra is chosen as a model vessel.

The merchant vessels tends to grow, but what if the ship's weight and steel consumption can be reduced? There is a big potential to optimise the construction to reduce weight and steel to lower the cost for building and operate the ship. Transports can become more energy efficient and reduce the environmental impact at sea and for the shipowners it can also lead to reduced costs for building the ship. More research is needed to ensure that lighter hulls meet the requirements of strength, sea characteristics, environmental requirements and maritime safety.

Pre-study

A pre-study, completed in December 2016, defined the project “Dynamic design of ships”. The goal was to establish a joint collaboration with participants from the academia and the industry with representation from the hydrodynamic and structural community in Sweden. The pre-study showed that, today, dimensional regulations do not fully take into account the interaction between wave loads and ship's dynamic response and there is uncertainty as to whether the safety margins have been sufficiently large or unnecessarily conservative, which can lead to the vessels being oversized and having a higher energy consumption and environmental impact.

Joint research

Now, a collaboration is established between SSPA, Chalmers University of Technology, KTH Royal Institute of Technology and Stena Teknik. The project is financed by the Swedish Transport Administration with 3.2 million SEK and joint research on methods for dynamic ship dimensioning will be conducted and the understanding of dynamic loads on ships will be enhanced (i.e. how wind and wave loads affect the structural response.). The first results from the project will be presented in 2018. Joint research will be conducted on experimental and numerical methods for dynamic ship dimensioning and increasing understanding of how winds and waves affect the ship. The overall goal is to increase understanding and develop new knowledge about dynamic loads on ship structures, and their response to these loads, for increased energy efficiency in the maritime sector. 

Elektra as model vessel

During the project, a vessel model will be manufactured and equipped to measure structural loads, model wave tests will be performed and numerical calculations will be validated against the model wave tests. A literature study to define the requirements for creating a model is made. Stena's concept vessel Stena Elektra has been chosen as a model vessel, a RoPax vessel thought to be powered by lightweight material.

-“Stena Teknik started to look into a hybrid solution vessel but then got the idea to design an all-electric system”, says Henrik Nordhammar at Stena Teknik. -“You realize by removing the fuel engines, you can also remove the fuel tanks, the piping, purifiers, heaters and exhaust gas systems. You basically don’t need an engine room, just space for the batteries”, he continues.

-"Elektra has no ordinary engine room so the layout will be different and therefore the need to measure structural loads and how the vessel moves in waves will become important and interesting", says Jonny Nisbet from SSPA and project manager for this joint project.

Illustration

The concept vessel Stena Elektra has been chosen as a ship model. Illustration: Stena Teknik

Read more at Lighthouse.nu: New methods shall provide lighter and more energy efficient hulls

Read the pre-study: Dynamic design of ships

Read more at Stenateknik.com about Stena Elektra