HANSA 05-2022

SCHIFFSTECHNIK | SHIP

SCHIFFSTECHNIK | SHIP TECHNOLOGY Smooth Transition into 2023? IMO is set to cut the carbon footprint of shipping. The upcoming 7th HullPIC conference gives better insights into the industry’s psyche in seeing the EEXI and CII writing on the wall. By organizer Volker Bertram The Big Zero is the long-term goal for the second half of the century, but as in football, the next opponent is always the hardest. And next one up is EEXI and CII, mandatory as of 1st January 2023. The EEXI is the Energy Efficiency Existing Ship (Design) Index, akin to the EEDI for newbuildings, expressing the theoretically achievable energy efficiency for the ship as designed, in prime condition as in initial sea trials. The CII is the Carbon Intensity Indicator, calculated based on IMO’s fuel oil DCS (Data Collection Scheme), where the requirement to just monitor is now enhanced by grading the performance each year from A to E. Poor operational performance (E once or three consecutive years D) will entail mandatory action to improve performance, planned, documented, tracked, and audited in a SEEMP. So far, this summarizes the plan in a nutshell, where the big picture is known to most in the shipping community, but the devil lurks in the details, as always. EEXI and CII cast their shadows ahead already. There is a certain tension in the air, reminiscent of pre-exam stress. What if the verdict – for some of the ships in a fleet – is »you have been measured and found wanting«? Not everyone was a straight-A student in university days, and not every fleet manager will have straight-A scores for his ships. Best to take a mock exam first to see how much we have to worry. But that at best gives only an indication, and we don’t just want to pass, we want to be best of class. Can we get some extra credit doing this or that? Rumors float around the corridors how you might argue for special status and pass that way. And most students play it safe, work hard and actually improve to pass the exams. But analogies carry you only so far. The upcoming 7th HullPIC conference gives better insights into the industry’s psyche in seeing the EEXI and CII writing on the wall. It’s the speed, stupid Suppose your energy efficiency is not good enough. What can you do to improve it? IMO gives some first pointers with its GHG studies and its GloMEEP website. To modify Bill Clinton’s campaign slogan slightly: »It’s the speed, stupid«. Older ships were often designed for much higher speeds than used in current operation. Engine power limitation (EPL) is then expected to be a measure adopted by many ships to achieve EEXI targets. EPL may come in various forms, e.g. through fuel index limiters or deactivating cylinders. Alternatively, one may consider Sha- PoLi, a more recent entry to our acronym list. Shaft Power Limitation uses torque monitoring and an additional control unit to ensure the power limitation. In emergencies, this can be overridden. Another advantage is that the required sensor and monitoring equipment adds valuable data for performance monitoring insight. »[We] explore the possibilities of ShaPoLi as an accelerator of telemetry installations within the maritime industry«, says Hauke Hendricks, Head of Sales at Hoppe Marine, in this context. The second-biggest lever after speed reduction (with associated power reduction) is better hull management, where a standard reference is given by the Clean Shipping Coalition which estimates that 10 % of the world fleet’s fuel consumption may be saved through better hull management, i.e. better coatings and cleaning strategies. Ships typically gain on average 7 %–10 % per year in resistance and thus fuel consumption at given speed due to progressive fouling and hull roughness. Cleaning, in drydock every 5 years or in between in water, restores the performance at least partially again, resulting in characteristic zig-zag curves in performance over time. Coating and the CII EEXI, EEDI, CII – The energy efficiency of ships, whether new or already in-service, will be one of the central topics next year Better hull management aims at smaller slopes of the zig-zag curves through better antifouling solutions with less degradation in performance, and overall lower peaks through shorter cleaning intervals. One of the problems here is that currently most popular selfpolishing copolymer (SPC) antifouling coatings degrade rapidly with conventional cleaning, reducing the lifespan of coatings with increased cleaning frequencies. As a consequence, premature drydocking for recoating to avoid dramatic performance loss with largely eroded antifouling protection may be needed. The potential 62 HANSA – International Maritime Journal 05 | 2022

SCHIFFSTECHNIK | SHIP TECHNOLOGY for energy efficiency improvements is there, but cleaning strategies need to be adapted to different (and for some operators new) coating systems. »Hull coatings can have a significant impact on CII, as proven in performance monitoring, but operators need to be aware of implications of different coating technologies,« points out Stein Kjolberg, Global Category Director Hull Performance at Jotun. The key word here is »proven«. Much of the discussion in the community is around reducing uncertainties for better decision making. How can we more accurately predict energy savings for assorted technologies? And how can we track and verify these savings, both for future decisions and for performance-based contracts, e.g. between charterers and owners? Richard Marioth, founder of Idealship, brings it to the point: »Monitoring per se does not improve energy efficiency, but insight gained from it leads to better decisions.« Hapag-Lloyd on board Better decisions in how to operate ships, for example. It has long been suspected that performance monitoring feedback to crews also has an indirect training effect changing crew behaviour towards better energy efficiency. One of the highlights of HullPIC 2022 is a paper by Martin Köpke, Manager Fleet Analytics & Technical Optimization at Hapag-Lloyd, with a detailed confirmation of the effect of sharing operational insights with the crew: »In order to achieve a higher level of transparency and mutual understanding, Hapag-Lloyd introduced automated feedback to vessel crews for all 250 operated ships. Each reported value is compared to an expected value which is based on a virtual model of each individual ship. This way the crew is immediately aware of reporting errors, measurement errors and possible excess consumptions.« The contribution is all the more valuable, as it also reveals unsuspected hurdles encountered during the initial implementation. Better decisions through performance monitoring applies also to the assessment of energy saving devices, which enjoy increasing interest in the context of the EEXI and options to improve it. For energy saving devices, the best way to assess their effectiveness is long-term monitoring. But often ship owners don’t have the luxury of such experience with proven savings for their type of ships and operational profiles. In many cases, »it’s complicated.« CFD application For propulsion improving devices (PIDs), i.e. assorted nozzles and fins intended to improve the propulsive efficiency of the propeller, traditional model basin tests suffer from large scale-effects, as neither boundary layer near the propeller nor propeller rpm can be similar in model tests. Instead, CFD simulations for fullscale conditions have become state of the art in the industry. »The new [EEXI] regulations and trends in shipping pressure ship owners to quantify the effect of these devices, giving rise to an uptake in CFD application for this purpose,« reports Inno Gatin of In Silico, whose »Cloud Towing Tank« has been busy with such investigations for the past 12 months. He will share his findings in an attempt to draw general observations on the effectiveness of different PIDs. While the CFD methods as such may be very mature by now, the actual assessment of PIDs is not yet. The industry still focusses on design conditions, in the simulations and in the sea trials for verification. Off-design conditions This may be understandable in view of achieving a certain EEXI value, but for the larger picture, for reducing the long-term carbon footprint, we should look at performance in off-design conditions. How does a given PID perform at lower speeds that are much more frequently found in the operational spectrum? And how do changing boundary layers due to increasingly fouled hulls impact a PID’s effect on the propulsive efficiency? At least, these questions are discussed at HullPIC. Raised awareness is already a step in the right direction. © Amasus Wind assisted propulsion is coming, but guidelines and standards on how to assess performance improvement and fuel savings have yet to develop HANSA – International Maritime Journal 05 | 2022 63