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There are many sides to the single or twin-engine rig debate, and pros and cons for each. Integrity Motor Yachts has taken a stance since establishing its brand in 2008, favouring the single-engine shaft drive installation for their displacement and semi-displacement, shaft drive vessels, with the firmly held belief that this set up is “the future of affordable boating”.
Not only is a single engine cheaper to run, service, maintain and generally look after, most of single-engine installations in today’s boats are quieter and the reliability of the modern premium engine is second to none.
Single engines generally offer easier access with more room around the engine, allowing ease of service which results in further cost savings.
The notion that you install twin for safety is no longer true across the board – proven by the track record of the 99 Integrity motor yachts sold to date, all of which have travelled under the single engine set up the coastline of Australia, from Tasmania to PNG with never an issue.
Company founder, Brett Flanagan points to the international commercial fishing fleet for insight; 90 percent of which would be single engine craft, varying in size from small to massive. “One engine is less costly to run and service than two, which is the reason professional who rely on boats for their livelihood believe in single engine installations,” asserts Brett.
Many leading manufacturers recommend single engine for displacement and semi displacement vessels. A single centre line propeller is protected by the keel and rudder which offers more protection that unprotected twin engine propellers.
The addition of both Bow and Stern Thrusters, which makes docking simple and reduces the pressure on the skipper, means stress-free boating for Integrity owners.
Richard and Sue Croall are loyal Integrity owners whose latest vessel is the Integrity 530 Grand Sedan, named ‘Impetuous’, the largest Integrity built to date.
Fresh from his first Sydney to Gold Coast voyage sharing the helm and the 38-hour run with Adam Workman, Integrity’s Sydney dealer, Richard was impressed with the performance of his boat’s single Scania 700 hp engine.
“We made the journey in one hit – 38 hours straight – which is something I have always wanted to do, but never had the confidence to attempt. The engine didn’t miss a beat on the entire trip, and we got about 18 knots out of her at top speed.”
Despite the logic that may say two engines are better than one, Richard states the configuration of the boat lends itself to a single engine. “And when you consider that every Sydney ferry, commercial craft and trawlers the world over all rely on single engines, that’s pretty convincing.”
After a New Year raft-up at Mushroom Bay near Akuna Bay in Pittwater with a group of about 12 boats that call themselves “Team Integrity”, Richard and Sue are planning to head to Jervis Bay and then further afield to The Whitsundays and Tasmania. “Impetuous could take us anywhere, I know that for certain.”
From Integrity’s home base of Sanctuary Cove, prawn trawler Captain David Patane explains that single engines are the norm for commercial vessels up to about 80ft. “The majority of trawlers use single engines,” he says, adding there is less complication and risk of things going wrong. “They are great for fuel economy and modern engines are so efficient, there’s no need for two. If something does go wrong, it gets fixed. As farmers of the ocean, we are Marine Engine Drivers Grade 3, net makers, do the paperwork, market our product, be charming to customers and cook a good barbeque. With all that on our plates, we have to have simple, reliable engines.”