Vessel Design and Performance: A Transparent Approach to Vessel Performance

Han Wensink, Managing Director, BMT ARGOSS

In October 2011, BMT ARGOSS and International Paint announced the formation of a partnership which can deliver demonstrable and transparent improvements in performance, efficiency and environmental emissions for the global shipping fleet.

By deploying International Paint's world class, fouling control coatings in conjunction with the BMT SMARTSERVICES system, ship owners and operators will be able to benefit from a measurable reduction in energy use and CO2 emissions. The system developed by BMT ARGOSS will independently monitor and report to stakeholders the performance of their vessels. 

Han Wensink, Managing Director of BMT ARGOSS, a subsidiary of BMT Group and Trevor Solomon, Project Manager at International Paint, discuss the significance of this partnership and explain why they are confident the new, independent monitoring system will silence the critics.

Understanding hull roughness is an important factor in understanding ship performance. Any increase in hull roughness will increase the hull frictional resistance which will either require additional power and fuel to maintain vessel speed or, if maintaining constant power, will result in speed loss and longer voyage times. 

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Based on evidence gathered from over 5,000 vessel dry-docking and inspections for fouling rating, combined with AHR (Average Hull Roughness) measurements, International Paint claims fuel and emissions savings for its Intersmooth®SPC coating. Behind this evidence, the International Paint 'Dataplan' system has coating details of over 1.7 billion deadweight tonnage (DWT), representing almost 200,000 dry-dockings that allow antifouling performance to be predicted and assessed. Results are derived from analysing the in-docking condition of a vessel, its coating performance and assessing the type, severity and extent of any fouling, if present. In conjunction with the vessel's trading pattern, operational profile and dry-docking interval, an antifouling performance rating can be calculated. Dataplan also records the vessel's coating condition, including the type, severity and extent of any corrosion, cracking, blistering, detachment and mechanical damage, all of which contribute to, and are included in hull roughness measurement.  

InternationalPaint1International Paint also cites the 2010 report, 'Energy and GHG Emissions Savings Analysis of Fluoropolymer Foul Release Hull Coating' by Professor James Corbett's Energy & Environmental Research Associates. The report analysed the latest fuel consumption data of three vessel types coated with Intersleek®900; Prem Divya, a single engine 21,126 horsepower (HP) tanker, Ikuna, a twin engine 3,400 HP bulker and five identical post panama container vessels, three of which were coated with SPC antifoulings and two with Intersleek®900. The results presented a reduction in fuel consumption of 10% on the Prem Divya, 22% on the Ikunaand 5% in five container vessels (based on all five ships carrying a comparable load). The report further stated that if similar fuel efficiency results were realised by all tanker and bulk cargo vessels within the commercial fleet that: 'annual fuel oil consumption could be reduced by roughly 16 million metric tons (MMT) per year, fuel expenditures could be reduced by $4.4 to $8.8 billion per year and nearly 49 million tonnes of CO2 emissions could be avoided annually'.

For some these claims are always open to debate. Critics argue that, no matter which coating is applied, a ship will naturally move through the water more smoothly if it has been blast cleaned during dry-docking. Furthermore they argue the linkage between hull smoothness and reduced emissions is tenuous in that, traditionally, extra smoothness was more likely to lead to some ships being driven faster, not to fuel savings.

On the surface, such seemingly persuasive arguments could be readily countered by observing the growing propensity for owners to operate slow steaming policies specifically in pursuit of fuel (and consequently, emissions) savings. Again while no one would dispute that, depending upon the fouling control system employed, a newly grit blasted or hydroblasted, freshly coated hull will perform better than a hull at the end of its docking cycle. The point is surely to measure how quickly hull performance deteriorates over time in the context of the coating systems applied.

For this reason, International Paint has been explicit in detailing the alternative methods that have been used as the means of establishing a linkage between the fouling control system selected and potential fuel savings which include:

  • Directly comparing the in-service vessel performance when using one fouling control system over its full lifetime to that of another
  • Comparing a period of time in-service prior to dry-docking with one fouling control system to the same period after the dry-docking and application of a new fouling control system
  • Directly measuring the same fouling control system over a given time period. This method uses an 'industry view' that a vessel, on average, will lose 5% speed over a 60 month period. This 5% speed loss would translate to roughly a maximum average of 15% increase in fuel in order to maintain speed.

Despite these various methods, International Paint has recognised the importance of providing owners with as much information as possible, on the performance of its products. The collaboration with BMT ARGOSS, a subsidiary of BMT Group aims to do just that - providing independent monitoring which will make both the evidence and methodology cited above incontrovertible. 

InternationalPaint2The BMT SMARTSERVICES system, developed by BMT ARGOSS, will capture and compile real vessel data and independently monitor and report on vessel performance. It will record data automatically from ships' sensors to monitor engine torque, the speed log, navigational signals (heading and speed over ground) and provide performance information to the crew and to shore-based management for analysis. The system which can be installed at the newbuilding stage or as a retro-fit, automatically records thousands of readings per day, providing unparalleled, accurate analysis of vessel performance.

Clearly and transparently measuring the in-service performance of International Paint's hull coatings, the system will draw on BMT's 24/7 in-house, high quality and validated MetOcean data which plays a critical role. Whilst it is clearly essential to monitor information on board, such as the relationship between hull roughness and fuel consumption, the same information must be integrated with the environmental conditions being experienced by the ship. This MetOcean data includes factors such as wind speed and direction, currents (speed and direction), as well as wave height and direction.

The system has been modelled using weighted coefficients to provide the basis for measurement of vessel performance against the condition of the propeller, hull, engine and fuel consumption. In depth analysis can be used to monitor the propulsive performance of a ship and to indicate how much additional power, or fuel would be required as a consequence of the combined effects of weather and fouling, or of the isolated effects of fouling on the hull or propeller. This analysis enables data trending which can then be used to optimise any scheduling of hull and propeller cleaning events and can be subsequently used to quantify the effectiveness of any such events.

To ensure complete data integrity, all the information that is collected will be sent straight to BMT. The client and International Paint will be able to view vessel data in a graphical or tabular format to develop trend analysis via a secure web interface, but cannot change or manipulate the data. Accurate monitoring of this nature provides the ship operator with a number of benefits including:

  1. Proof of compliance in line with charter agreements
  2. Ability to determine the energy efficiency of the vessel within the EEOI (Energy Efficiency Operational Index) encompassed in the SEEMP (Ship Energy Efficiency Management Plan) guidelines
  3. Provides the ability to act immediately on anything adversely affecting the optimum running of the vessel. For instance hull or propeller fouling and hull damage.

It is the consortium's mission to provide ship owners and operators with robust information in a completely open and transparent way to provide clarity to those using the information. We want owners to secure fuel saving benefits based on fact, whilst ensuring that there is a complete understanding of the actual savings possible, rather than just accepting unfounded claims. It is from many years of proven in-service performance with data from owners/operators, from Dataplan and from independent testimony that we know exactly what benefits each of these technology types can deliver. We strongly believe that this partnership will allow that knowledge to be completely transparent.

This article was first featured in The Naval Architect. To read similar features, visit their website.

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Contact Information

Han Wensink

Voorsterweg 28
8316 PT
The Netherlands

Tel: +31 (0)527 242 299

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