A trio of IBEX propulsion standoutsPosted on Written by Chris Landry
I often turn to developments in propulsion when looking for innovation in the marine industry. IBEX always delivers. I found three interesting products this year that deserve some recognition.
The EP-1000 electric motor from Elco Motor Yachts becomes the company’s most powerful electric motor to date, generating giddy-up comparable to a 100-hp diesel. It takes two to three hours to charge, and operating time ranges from two to three hours cruising on batteries only. You have continuous cruising power with a genset.
The engine’s first job will be to power a 1941 Elco cabin cruiser. “We will have a very old boat with the latest in electric propulsion,” Elco East Coast representative Neil Satterly told me at the company’s display at IBEX.
The Elco suits slower, larger boats from about 50 to 85 feet, such as trawlers.
In contrast, the second product I’d highlight serves smaller, faster boats with high-horsepower outboard propulsion. Mercury Marine promises a 10 percent improvement in fuel economy with its Enertia Eco Prop.
The engine company’s proprietary X7 stainless steel enabled its engineers to design a prop with a large blade area and high, progressive rake, resulting in “reduced drag through increased bow lift,” Mercury propeller product brand manager Dirk Bjornstad explained to me at the show. “The primary customers will be those who have your typical center console fishing or cruising boat that spends a lot of time offshore and at cruise speeds. That’s who will realize the most fuel savings.”
The Enertia propeller enters the market in January, teaming with another fuel-efficiency product for Mercury. The Eco display identifies the engine’s most efficient speed, rpm and trim angle for the boat operator.
Next up: a product that comes from an electronics company, but falls into the propulsion category. Raymarine’s engine and drive-by-wire steering interface — called the ECI-100 — aims to help boatbuilders and installers of electronics bridge the gap between the latest engines and steering systems and Raymarine products.
“It’s a very small device that’s a solution for unifying Raymarine with NMEA-compatible and non-compatible engines, and bridging Raymarine systems with drive-by-wire steering systems, such as Volvo IPS,” Raymarine director of marketing Jim Hands says. “Today, we currently integrate with those systems, but it requires a ‘gateway’ from the manufacturer. So if we want to integrate with the steering we need a gateway, and [with] the engine we need another gateway.”
The gateways can cost thousands of dollars. The new ECI-100, which is priced at $299, gathers and connects engine information to deliver performance data, fuel consumption and alarm information through Raymarine multifunction displays.
The ECI-100, which hit the market in October, works with Volvo Penta, Yamaha Marine Command Link Plus, Caterpillar and Yanmar engines and interfaces with Volvo Penta IPS and Yamaha Helm Master autopilot systems. Compatibility will grow, so the company urges checking with www.raymarine.com for updates.
“We plan to add other engine manufacturers as time goes on,” Hands says. “Our goal is universal compatibility. It breaks down a lot of barriers for system integrators and boatbuilders.”
Naval architect Rob Kaidy, CEO of Ocean5 Naval Architects in Stuart, Fla., was at IBEX with a seminar on “Advanced Topics in Stepped-Hull Design.” More builders are offering stepped hulls, hoping to provide boats with higher speeds and efficiency. Kaidy wanted to separate fact from marketing hyperbole.
“The idea that the hull is operating a gigantic bubble and is supported by compressed air can only be described as complete baloney,” he says. “Drag is low at these speeds all on its own. The idea that drag is lowered further by introducing air has not been demonstrated at all, so the whole idea of a stepped hull having ‘air bearings’ or ‘air lubrications’ is unsupported.”
Some stepped hulls lack the proper engineering and naval architecture. “A lot of the plugs out there were designed by a plug builder who used a rule of thumb that didn’t necessarily apply,” he told me in a follow-up interview. “The reality is the market is filled with a lot of stepped-hull boats that don’t actually work. Stepped hulls, when applied properly, are effective, however.”
How? They “lock the boat, regardless of speed, into its optimal running trim angle,” says Kaidy, whose company is working on seven stepped hulls. “Every planing hull has an optimal trim angle that is typically between 3.5 and 4.2 degrees — that is where the lift is greatest and the drag is lowest. It’s called the drag bucket.”
Kaidy’s Ocean5 developed an analytical tool to determine this optimal trim angle. Its Virtual Seatrial computer software analyzes hull designs through a “digital sea trial.”
Kaidy predicts that in the next few years a “whole new stable of boats with stepped hulls will come to the market.”
I plan on putting together an article about this design technique’s rise in popularity; its pros and cons; the characteristics of an effective — and non-effective — stepped hull; and which types of boats benefit most from the design.
This article originally appeared in the November 2013 issue.
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