Ship Repairs, Underwater Works, Oil Tanker Cleaning & Cargo Holds Cleaning

Performance monitoring – a process of optimisation

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Republished by kind permission of: A&A Thorpe, 131a Furtherwick Canvey Island, Essex SS8 7AT Tel: +44 (0) 1268 511300 Fax: +44 (0) 1268 510467 shipaat@aol.com

 

Accurate performance monitoring is an increasingly key component in effective ship operation and SEEMP plans on board. And for owners who have opted to retrofit their vessels with fuel-saving devices, accurate before and after figures are important both for their own analyses and in negotiations with potential charterers. There are many systems on the market but some are more useful than others.

There are two main types of systems. Some measure real-time data including wind, waves, speed and fuel consumption and provide a basis for ship operators to fine-tune certain variables to improve performance. However, these systems only provide guidance based on the prevailing conditions and they rely on shipboard sensors which are prone to error, as well as the ability of ships’ crews to interpret data and respond correctly.

The systems themselves are responsive and cannot predict the likely outcome of a particular course of action.  Furthermore, some systems merely record the data and then send it ashore for subsequent analysis. This may be relevant for the gauging of long-term trends such as the build-up of marine fouling, for example, but are of little help in optimising immediate ship operation.

For this, ship operators need to know what-if’s – the result of a certain action – as well as the actual performance of a certain parameter, such as fuel consumption, in real-time. The second set of performance monitoring systems predict the results of changing a parameter before the move is made. Such a system, many operators believe, is significantly more useful for seafarers and it has been noted that certain “rules of thumb” believed to be virtual certainties by some ship masters have been shown to be invalid in certain circumstances.

The launch this week of FutureShip’s latest Eco-Assistant, with a range of enhanced features, falls into the second set of systems and therefore provides a prediction relating to a certain course of action. The Germanischer Lloyd subsidiary has already sold more than 600 Eco-Assistant systems over the last three years and, it claims, payback periods in terms of fuel saved can typically be measured in months.

The trim optimisation system is based on a matrix comprising a range of variables based on up to a week of computational fluid dynamics (CFD) analysis. The resulting software relates to a specific ship, therefore, or a series of sisterships, and is predictive. Now, new features including a fuel consumption calculator, system usage monitoring, benefit reporting and an E-learning to assist with training, significantly add to the functionality of the system.

“Trim optimisation is one of the most effective tools for enhancing ship fuel efficiency as it offers benefits which have been verified in sea trials, can be easily implemented on existing tonnage and has a payback time which can be measure in months,” FutureShip claims. And it points out that managing energy more efficiently has become a key area in shipping with new Ship Energy Efficiency Management Plan (SEEMP) regulations which themselves require greater monitoring of shipboard performance.

According to Dr Karsten Hochkirch, FutureShip’s Head of Fluid Engineering, Eco-Assistant has demonstrated energy efficiency improvements of up to 6%. And now, the system can be integrated with a ship’s cargo-planning system to minimise ballast, optimise its location and maximise fuel saving potential. Meanwhile, the new fuel-calculating feature, developed in partnership with Hamburg-based ship operator NSC, provides the fuel consumption for a particular sailing condition at a single click. This function uses the hydrodynamic knowledge derived from the CFD analysis while performance data and “semi-empirical corrections” are used to provide fuel consumption curves that reflect individual hull fouling, ambient conditions, fuel quality and engine characteristics.