Professional Boatbuilder

The Electric Propeller Company is a subsidiary of Above the Waterline working under the trade name of Electroprop.    This article appeared in Professional BoatBuilder on November 15, 2018   

The Electric Propeller CompanyIn 2002 James Lambden purchased a 1977 Catalina 30, Kapowai, with an Atomic Four engine that “would habitually quit at the most needed of times.” He removed the engine and repowered with an electric outboard motor that proved completely inadequate. And so began a 16-year odyssey to perfect electric-propulsion systems for yachts. His second system also came off the shelf, but the third and subsequent systems he developed himself using Kapowai as a test bed for the components that make up a fully integrated electric-propulsion system.Over the years, Lambden’s The Electric Propeller Company, or Electroprop, in Santa Barbara, California, has experimented with a variety of electric motors, motor controllers, gearboxes, throttles, and batteries, and developed increasingly sophisticated electronic control systems and software. Lambden: “You can choose from 10 different motors, a variety of motor controllers, and numerous fans, relays, and other components, resulting in millions of possible permutations. It takes time to work through all the possibilities and to develop an optimized system.”

Electroprop now has a range of prepackaged electric- and hybrid-propulsion systems from 6 kW continuous to 21 kW, operating on 48V and 96V. Boatbuilders can supply a fiberglass engineroom, and Electroprop will ship it back complete with a fully functioning propulsion system ready to drop in and requiring minimal electrical installation.The company focuses on reliability and ease of use. All the systems’ electrical/electronic components are housed inside an anodized-aluminum case that acts as a Faraday cage to protect the drives from lightning. A cable-operated (mechanical) throttle connected to the side of the box is in contrast to the more common digital (electronic) throttle controls. Lambden says it’s “more reliable and easier to install.” The CAN bus–connected system display is fastened into the case, but it is removable for remote installation.The aluminum case is designed as a base unit with two large hinged-out sections that provide excellent access to all components, terminals, etc. If any part fails, it is easy to replace. Access covers provide a variety of fan-cooled air-inlet options for different physical installations. All drives have waterproof wiring harnesses. It is obviously a well-thought-out physical setup.“We have installation-proofed the system. We have lightning-proofed it. We have gear drives, which are more efficient and more reliable than belts, eliminate side loads, and reduce the cost of ownership over time. The systems are designed for first scheduled maintenance to be in eight to 10 years, when batteries are replaced,” Lambden says.

The opened-out case of an Electro­prop unit shows the various sections and the considerable thought and engineering that went into making all components readily accessible.
“The secret to arriving at technological superiority is an unlikely one. It is done by proceeding with a very limited number of custom orders, and avoiding volume production until all research and development is completed, and volume production capability is fully developed. This reserves funds for development while limiting the risk of exposure to the marketplace.”His current target is to build and install one system a month, ramping up to 100 a year. Concurrently, he’s organizing a dealership network and distributors.Lambden has invested hundreds of thousands of dollars into Electroprop, which he still owns. He says, “Encouragement from friends, customers, and like-minded individuals who want to see sustainable, high-efficiency, low-carbon-footprint technologies has been essential to the development of these systems.” He has postponed raising equity in the belief that “the further along the development, the less the risk borne by the eventual stockholders, and the more the equity is valued.” He summarizes: “After 16 years of doing this, the company is in a strong position technologically, with scalable manufacturing. Rollout and OEM adoption of the technology will become the focus of the next chapter.”


The picture below of a fully assembled Electroprop Sailor Drive did not appear in the original article.    I have included it here so the reader can see how the system goes together in a compact drive system.