The recent launch of Miros and BW Group’s joint venture, Miros Mocean, promises to disrupt the performance inefficiencies of the global shipping industry. To find out what makes the technology tick, we spoke with Miros sensor development manager, Rune Gangeskar.
What is Miros Mocean?
Miros Mocean is a vessel performance optimisation platform that integrates real-time, in-service vessel data with local wave and weather parameters, providing a live overview of vessel performance.
What makes it different?
By measuring vessel speed through water with unprecedented accuracy we can finally measure the output (transport efficiency) of a vessel at a given input of fuel, load, weather, etc. – without accurate speed through water it is not possible to accurately describe the performance of a vessel, so this is a big break through.
What makes Miros Mocean’s approach to measuring speed through water more accurate than conventional speed logs?
Using underwater instrumentation on moving vessels involves several important uncertainty factors, and there are also expensive and time-consuming installation and maintenance procedures. The speed through water, typically measured by speed log or equivalent instrumentation, is associated with a set of particular challenges and is often unreliable. Underwater sensors, such as acoustic Doppler current profilers (ADCPs), for example, are vulnerable to disturbances due to the vessel motion.
Air bubbles, turbulence, and inhomogeneous hydrodynamics caused by vessel motion and propellers will result in data considerably inﬂuenced by noise. In addition, such sensors are frequently inadequately calibrated, giving systematic errors in certain speed ranges. Equipment immersed in water is also exposed to fouling.
Instead of using traditional underwater instrumentation, the speed through water can now be measured by the Miros Wavex, based on X-band radar images. Such a “dry-mounted current measurement solution” can provide measurements with high accuracy, with no need for any equipment to be installed or maintained underwater. The speed through water can be measured using radar images covering local areas of interest, at a reasonable distance from any disturbing structures, including the vessel hull. The instrumentation can be connected to an already existing X-band radar or to a dedicated one.
We have made considerable improvements within the hardware and algorithms of Wavex in recent years. This has resulted in improved measurement accuracy for ocean waves and currents. After verifying a high accuracy for current measurements, and taking the challenges associated with traditional speed logs into consideration, we chose to further develop Wavex to also provide accurate speed through water measurements.
So this was a natural progression from previous Wavex capability?
Yes, it was. Measuring the speed through water has much in common with measuring currents. The major difference being that which the measured water speed is referring to: the vessel (when measuring the speed through water) or a fixed position (when measuring currents).
To what degree is noise and inaccuracy reduced using this technology?
First of all, let us agree that it is the actual measurement accuracy in transit, when the vessel is moving, which is of interest. The accuracy of speed log data when the vessel is at rest is not that interesting. The accuracy of speed through water measurements using Wavex in transit is typically within 5 cm/s. The observed noise in measurements from traditional speed logs in transit varies a lot, typically from a few tens of cm/s and up to several m/s, depending on to what extent measurements are disturbed by the vessel motion and propellers. Still, traditional speed logs often provide very accurate measurements when the vessel is at rest.
What is the benefit of using a speed log at all if it’s not very accurate?
Until recently, the speed log has mainly been considered as a backup for the GPS. As a result, the accuracy and reliability has been secondary. These days, however, with increasingly focus on speed through water data as essential input for applications like vessel fuel optimisation and hull performance estimation, the accuracy of such measurements is becoming very important.
How is the data incorporated into the Miros Mocean platform?
The data is collected via the Miros Edge computer onboard the vessel and transferred securely to Miros Cloud. There the data is stored and archived with some of the it processed to gain further insight.
There are also a number of applications to help our customers in their decision making. These applications can be reached from a web browser and provide insight into both real-time and historical vessel performance. There is also an application specifically comparing actual performance with the warranties in a charter party. The data can be downloaded easily, or otherwise transferred to a third-party vessel performance system.
What does Miros Mocean’s unprecedented data accuracy really mean to the customers in terms of savings?
Considering vessel fuel optimisation, speed through water data input can be used to operate at the lowest total cost. Having data with an accuracy of a few cm/s rather than, for example, 1 m/s can make a big difference. It can mean a decreased daily fuel consumption of tens of tons for a single ship. We are continuously acquiring more knowledge within this field based on results from several pilot projects.
Download the technical whitepaper here.