The Full Story
Testing an innovative life-saving system
VIKING Life-Saving Equipment A/S developed an innovative lifesaving system – LifeCraft™. The LifeCraft™ combines all of the advantages of modern lifeboats – such as self-propelled manoeuvrability – with the flexibility, comfort and smaller footprint of today’s life rafts.
Manufacturers of lifesaving crafts like the Viking LifeCraft™ have to rent a ship with characteristics similar to those of the ship on which the equipment will be installed. The equipment must then undergo a sea trial – during which the significant wave height is higher than 3 m throughout the entire test – to prove that the equipment works.
Illustration showing operation of new LifeCraft™ system © VIKING Life-Saving Equipment A/S
This process is very expensive, so manufacturers want to be sure that the equipment can pass the sea trial the first time. Scaled physical model tests offer an inexpensive and easy way to assess the equipment in conditions similar to those experienced at sea. Before undergoing sea trials, VIKING came to us to utilise our knowledge and experience testing offshore floating structures. From an early stage in the development process, they used our wave tank to test their LifeCraft™ system.
Utilising our knowledge and offshore wave tank
During the development of the new LifeCraft™, Viking visited our testing facilities in Denmark several times to conduct physical model tests. They examined different aspects of their new concept, focusing mainly on:
- the stability and general behaviour of the LifeCraft™ system when moored to the mother ship (the ship from which people evacuate) under different wind, current and sea state conditions
- the forces on the bowsing lines (responsible for holding the LifeCraft™ system together as well as ensuring that they can only move a small distance away and alongside the mother ship during evacuation)
The latter is especially important because the LifeCraft™ has a chute system (a tube in which people slide down from the mother ship). If LifeCraft™ moves too much along the side of the ship, evacuation could become unsafe or even impossible. The tests conducted in our offshore wave tank helped VIKING gain confidence that their development process was going in the right direction from an early stage. Over a three-year period, VIKING used our offshore wave tank numerous times to conduct several test campaigns.
Test of the LifeCraft™system with free floating mother ship (1:30 scale). We tested the deployment of the system (the neon yellow box-es) towards the bow (front) of the ship and movements and forces at the mooring lines at midship (portion between the front and back). © DHI
For each visit, VIKING brought their own engineers, who worked in close cooperation with our engineers and technicians. We helped VIKING analyse the data from the wave tank tests and recommended improvements to their system. This enabled VIKING’s engineers to obtain the most information possible from the tests, giving them valuable insight into whether their system worked as intended – within a short timeframe.
Passing official sea trials
The physical model tests pinpointed issues that VIKING had not considered before they tested the LifeCraft™ system in our wave tank. This ultimately helped VIKING understand how the LifeCraft™ system would react in rough seas and what forces were needed to keep the LifeCraft™ system in position. This information enabled them to easily and rapidly test their design improvements. Because of our ability to promptly implement and assess modifications, they quickly progressed towards a design that worked and allowed for safe evacuation. The system was subsequently tested a number of times at sea.
Our model tests helped VIKING develop a lifesaving system that passed the mandatory sea trial under rough conditions the first time, saving them time and money.
Deployment and testing of the Viking LifeCraft™ during the mandatory sea trial tests, in which significant wave height is larger than 3 m. © VIKING Life-Saving Equipment A/S