ISO 19030 points way to reducing world energy fleet costs and GHG emissions
Practical methods for measuring changes in ship-specific hull and propeller performance are included in the forthcoming ISO 19030 standard developed to enable the shipping industry to operate with enhanced efficiency and environmental performance.
Hull performance monitoring solutions offer significant fuel and emission saving potential, a fact that is prompting growing interest from the maritime industry – especially in light of the forthcoming ISO 19030 standard. However, hull performance monitoring is difficult due to several rapidly changing factors that influence fuel consumption including draft, trim, ship speed, and wind. Also, while the different monitoring systems all have a similar approach, the available approaches are difficult to measure.
The standard, which prescribes practical methods for measuring changes in ship-specific hull and propeller performance, has now been approved by the ISO Draft International Standard (DIS) ballot, with 93% of country representatives voting in its favour. This resounding approval rate paves the way for final publication, with ISO 19030 expected to be publicly available at the end of Q3 this year.
Geir Axel Oftedahl, Jotun’s Business Development Director – Hull Performance Solutions, managed the project on behalf of the International Organization of Standardization (ISO) and is clear about its importance.
“Poor hull and propeller performance is estimated to account for around 10 per cent of the world fleet’s energy costs (USD 20 billion),” he notes. “There are very effective solutions for improving performance but, until now, no globally recognised and standardised way for measuring this and providing return on investment for ship owners. ISO 19030 satisfies that demand, prescribing measurement methodology and defining performance indicators for hull and propeller maintenance, repair and retrofit activities.
We believe this will provide much needed transparency for both buyers and sellers of fuel saving technologies and solutions, and in doing so, enable the industry to operate with genuinely enhanced efficiency and environmental performance.”
Oftedahl has, since 2013, managed a project involving 53 experts in an ISO working group convened by Svend Søyland of Nordic Energy Research in a bid to develop a standard that is comprehensive, accurate and workable worldwide.
Oftedahl and Søyland are keen to emphasise that performance monitoring is entering a mature phase and that the new voluntary standard represents a “good starting point to offering a level playing field and the adoption of industry-wide best practices and transparency”.
Here is an outline of the initial motivation, purpose and implementation of the standard (extract from their paper entitled ISO 19030 - the motivation, scope and development) followed by Oftedahl’s views on advances in measurements of hull performance and the implications for buyers and sellers of performance enhancing technologies and solutions.
Today hull and propeller performance is a ship efficiency killer. According to the Clean Shipping Coalition in MEPC 63-4-8, poor hull and propeller performance accounts for around 1/10 of world fleet energy cost and GHG emissions. This points to a considerable improvement potential; 1/10 of world fleet energy costs and GHG emissions translates into billions of dollars in extra cost per year and around a 0.3% increase in man-made GHG emissions. The culprits are a combination of biofouling and mechanical damages. Most vessels leave the new build yard or subsequent dry-docking with their hull and propeller in a fairly good condition. Then on account of a combination of biofouling and mechanical damage, hull and propeller performance begins to deteriorate.
There are technologies and solutions on the market that can protect the hull and maintain good performance over the full duration of the docking interval - why then is hull and propeller performance still so poor?
In the past the problem has been a lack of measurability. If one cannot measure it, one cannot manage it. Now a multitude of measurement methods are being introduced in the market; some quite good, some really bad, most of them proprietary (black box) and many using their own yardsticks. It is becoming challenging, however, even for the most resourceful to determine which of these methods can be relied upon and which cannot. Moreover, the measurement methods have different and incompatible yard sticks resulting in the measurement output serving to confuse rather than inform.
This standard is intended for all stakeholders that are striving to apply a rigorous, yet practical way of measuring the changes in hull and propeller performance. It could be shipowners and operators, companies offering performance monitoring, shipbuilders and companies offering hull and propeller maintenance and coatings. ISO 19030 will make it easier for decision makers to learn from the past and thereby make better informed decisions for tomorrow. It will also provide much needed transparency for buyers and sellers of technologies and services intended to improve hull and propeller performance. Finally, it will make it easier for the same buyers and sellers to enter into performance-based contracts and thereby better align incentives.
What ISO 19030 covers
ISO 19030 outlines general principles of, and defines both a default as well as alternative methods for, measurement of changes in hull and propeller performance. The standard defines sensor requirements, measurement procedures, including various filters and corrections, as well as how to calculate a set of four performance indicators for hull and propeller related maintenance, repair and retrofit activities.
One of the performance indicators is “in-service performance”. In-service performance refers to the average change in hull and propeller performance over the dry-docking interval. Performance over the first year following the docking is compared with performance over whatever remains of the docking interval – typically two to four years. This performance indicator is useful for determining the effectiveness of the underwater hull and propeller solution – for example the hull coating system used.
The three additional performance indicators are “Dry docking performance”, “Maintenance trigger” and “Maintenance effect”.
*Dry docking performance: Hull and propeller following the present out-docking is compared with the average performance from previous out-dockings. This provides useful information on the effectiveness of the docking.
*Maintenance trigger: Hull and propeller performance at the start of the dry-docking interval is compared with a moving average at a point in time. Useful for determining when hull and propeller maintenance is needed – including propeller polishing or hull cleanings.
*Maintenance effect: Hull and propeller performance in the period preceding the maintenance event is compared with performance after. This provides useful information for determining the effectiveness of the event.
ISO 19030 is fairly all-encompassing. It covers what sensors are required, how these are to be maintained, step-by-step procedures for filtering and correcting the data, and finally how the individual performance calculators are to be calculated.
- ISO 19030-1 outlines general principles for how to measure changes in hull and propeller performance and defines the 4 performance indicators for hull and propeller maintenance, repair and retrofit activities.
- ISO 19030-2 defines the default method for measuring changes in hull and propeller performance. It also provides guidance on the expected accuracy of each performance indicator.
- ISO 19030-3 outlines alternatives to the default method. Some will result in lower overall accuracy but increase applicability of the standard. Others may result in same or higher overall accuracy but include elements which are not fully validated in commercial shipping.
The figure shows actual hull and propeller performance over three separate five-year dry-docking intervals on the same vessel in the same trade, but with different hull coating solutions.
In the middle dry-docking interval, the development in hull performance is very similar to what was found to be market average in MEPC 63-4-8. In this interval there is a 6.4% speed loss or an 19% increase in power needed to maintain the same speed - on average over the four years following the benchmark period. Note that the ship needs 38% more power at the end of the period to maintain the same speed.
In the first of the three dry-docking intervals, the development in hull performance is somewhat better. In this interval there is a 2.7% speed loss or an 8% increase in power needed - on average over the four years following the benchmark period.
In the last of the three dry-docking intervals, the development in hull performance is indicative of what is possible with today’s hull antifouling technologies: virtually no performance loss over the full period. On this particular vessel the hull coating in question is Jotun’s SeaQuantum X200.
The difference between market average and best performance is around 18% in the power required to maintain the same speed over the past 4 years of the dry-docking interval. On the 54k dwt bulk carrier in question, at a bunker price of $350 per ton, this difference would translate into a $1.8 million difference in fuel cost and a 16,000 ton difference in CO2 emissions.
Oftedahl further argues the point that “for decision makers, reliable and comparable measurement output will, when delivered in a timely fashion, also allow for quicker decisions on unplanned maintenance and repair of the underwater hull. Such a capability can prove very valuable.”
Consider again the middle interval from the real life example provided above.
After about 3.5 years into the dry-docking interval, the underwater hull on the vessel was cleaned. This resulted in an immediate improvement in speed of around 6% or conversely an 18% reduction in the power needed to maintain speed. Note that the hull was cleaned a second time after around 4.5 years into the dry-docking interva.
On this vessel, at the time, performance data was collected and stored but changes in hull performance were not monitored continuously. As can be seen from the data, if changes in hull performance had been continuously monitored it would have been possible to identify a negative trend at a much earlier stage. 2.5 years into the dry-docking interval, this negative trend would have been impossible to miss.
Regular cleaning of the underwater hull from about 2.5 years and onwards would not have eliminated the problem but would have served to improve hull performance over the remainder of the dry-docking interval considerably. A reasonable estimate is that the vessel, given cleaning every 6 months or so (for a total of 5 cleanings), would have been able to end up with an average over the period speed loss of around 4% rather than 6.4% (based on 2 cleanings).
On the 54k dwt bulk carrier in question, and at a bunker price of $350 per ton, this difference would translate into a $0.7 million difference in fuel cost and a 6,000 ton difference in CO₂ emissions. The direct cost of the 3 additional underwater hull cleanings would typically be around $0.1 million – leaving a $0.6 million net gain.
“In summary, advances in measurements will make it possible for buyers and sellers of technologies and solutions that promise improvements in hull performance to make better and quicker decisions. It will also make it easier for both to better align interests with 3rd parties,” says Oftedahl and concludes, “the advances in measurements as reflected in the new ISO 19030 standard should therefore contribute to the realisation of the great improvement potential within hull and propeller performance and as such to have a measurable impact on world fleet energy cost and GHG emissions.”