NYK Line and Japan Marine United Corporation (JMU) have worked together to create a new type of shipbuilding contract that guarantees propulsion performance in actual sea conditions, based on collection and analysis of operational data after vessel delivery.
The new contract is an enhancement of typical current arrangements where ship speed is calculated from the relationship between ship speed and horsepower in calm sea conditions without waves, and agreed upon based on the sea trials that are conducted during construction.
However, these test conditions bear little resemblance to the range of actual environmental conditions that will be experienced by the ship during commercial voyages, so the propulsion performance of the vessel in actual weather conditions remains unknown. NYK and JMU are looking to change this by taking advantage of modern improvements in satellite communications and IoT technologies that allow modern ships to efficiently collect a variety of useful data.
Applying these advancements to the shipbuilding contract, once a ship enters service it will collect data relevant to propulsion performance for a specific period of time, which will then be verified and confirmed by both parties to provide proof that the vessel is indeed performing as stated in the contract during voyages in actual sea conditions.
“Ships sailing in waves, which is an irregular phenomenon, require more horsepower to achieve the same speed than when sailing in calm waters due to hull shaking and increased resistance due to reflected waves,” NYK said.
“This is affected by various factors such as wind direction, wind speed, wave height, wave direction, wave period, tidal current, ship speed, ship type, displacement, and loading condition. Advanced technical capabilities are required for verification.”
In addition to this contractual performance guarantee, NYK and JMU say that they intend to implement a continuous improvement process and jointly work on the construction of other ship types in the future, building on the companies’ existing joint research relationship in areas like data processing, storage and analysis methods to establish a performance feedback cycle.
“We plan to further develop this guarantee for verification of propulsion performance for many ship types, which is difficult to do in sea trials at the time of construction,” NYK said.
“We will conduct discussions with our partner shipyards on the performance of vessels in the actual sea conditions and make further improvements. By providing customers with well-performing vessels, we will also contribute to improving environmental consciousness throughout the supply chain.”