Saving fuel – saving the planet

Fisherman meanwhile are being hit hard by the rising cost of diesel and as a consequence are demanding a better choice of fuel efficient engines, but, at the same time, these engines must offer equivalent, if not better performance. After all, it is the vessel's power system that ensures the crew reaches the fishing grounds quickly and returns home safely, so reliability cannot be compromised.

So, how are today's equipment manufacturers addressing this dual requirement for emissions-compliant and high-performance engines and what benefits can they offer the end-user?

Here, David Bull, Commercial Marine Sales Manager for Finning Power Systems, the UK's sole distributor of Caterpillar® engines, discusses the benefits of modern electronically-controlled engines and how they can offer boat owners greater control and help lower operating costs, whilst being fully compliant with the latest environmental legislation.

Understanding the law

The MARPOL Annex VI sets limits on sulphur oxide and nitrogen oxide emissions from exhausts and prohibits deliberate emissions of greenhouse gases. In October 2006, the Marine Environment Protection Committee of the International Maritime Organisation agreed to a timetable to limit the carbon dioxide emissions from ships, noting that 'climate change caused by greenhouse gas emissions from the burning of fossil fuel is a steadily growing concern for most countries.' As one would expect, therefore, all engine manufacturers are under pressure both legislatively and commercially to manufacture fully-compliant engines.

Marine engineers, driven by the need to develop cleaner power systems that can respond to changes in emissions regulations soon recognised the benefits of electronics over mechanical control. An electronic controller will coordinate and enhance fuel delivery, air supply and other engine functions for improved performance and reduced emissions output. It is a fair assumption therefore, that any vessel owner considering purchasing an electronic engine for either a newbuild or as a repower has his pick of suppliers, all of whom will offer environmentally suitable options for the respective power range.

Where the owner can make real benefits, suggests David, is in choosing a supplier that has specified its engine design to respond to tighter emissions standards in the future, combined with best-in-class fuel efficiency and superior reliability.

Take, for example, the repowering of a stone-crabbing vessel in Florida with a Caterpillar C18 in-line, six-cylinder engine. The 1000-hp, electronically-controlled twin turbo used in this vessel allows the crabber to reach speeds of 20 knots quickly, even when fully loaded with 400 traps and to maintain a cruising speed of 30 knots. Most importantly for this customer, is the significant improvement in fuel efficiency, which has enabled the owner to halve his fuel costs.

Improving performance

Most vessels operate over a wide power range and do not perform at their most economic point continuously, so owners will want an engine that can offer the best efficiency for the longest periods of time.

Fuel consumption is the biggest component of a vessel's lifetime operating cost and owners that use fuel-saving technologies can often recoup the initial cost of the engine. For example, a 10 per cent reduction in fuel cost on a trawler using 1,500 litres of fuel a day, 250 days per year is equivalent to an annual saving of £10,500 based on current UK net diesel prices; sufficient for the engine to pay for itself within a few years.

An electronic engine optimises fuel use by calculating load levels and adjusting the amount of fuel supplied to the engine accordingly, meaning that fuel consumption can be lower than a comparable mechanical engine. Caterpillar, which has invested over $500 million in the development of groundbreaking ACERT® technology for its 11kW to 16,000kW engine range, makes a direct comparison between the performance of its mechanical and electronic engines. In one test, under part load conditions, it quotes a 13.2 per cent decrease in fuel consumption at 1200rpm on the propeller demand curve.

David concludes, “What makes such technology good for the environment also makes it good for performance. Efficient combustion reduces engine wear and, with no partially-burnt fuel, it delivers the maximum energy from each injection, for better performance with the added benefit of a lower environmental impact.

“Because the combustion process is managed with high precision, it helps meet emissions requirements, with less noise and less smoke, making today's electronic engines both a financially-attractive and environmentally-responsible option for the fishing industry.”