By Jeff Jordan
IntelliJet Marine, Inc.
Why can't a boat be more like a plane… a car…a refrigerator… or even a washing machine? All of them are more energy efficient through the use of electronically controlled, variable-speed drives.
Boats had a head start. They had single-speed propeller drives in the 1860s (remember the Monitor and the Merrimac). The Wright brothers didn't bring them to planes until the 1900s. This was about the time the single-speed automobile (remember the Stanley Steamer) was being displaced by the multi speed transmission (the Ford Model T had two speeds; the Model A had three speeds; the modern car had many more).
There are millions of recreational boats in use in the U.S., which still have single-speed propeller drives. Most new boats in the U.S. have single-speed propeller drives. Almost all boats that don’t have single-speed propeller drives have single-speed water-jet drives.
Most new commercial, military and police boats around the world now incorporate water-jet drives…er…of course, that's single-speed water-jet drives. Single-speed jet airplanes (the F-86 Sabre and the MIG 17) had their day in the 1950s. The super-secret SR-71 Blackbird was operational in the 1960s and still holds the records for speed, time around the world, etc., because it incorporated variable inlets, variable turbine bypasses and variable jet nozzles. All modern jet fighters incorporate these features, and they are electronically controlled.
Not surprisingly, boats are notorious for excessive fuel consumption, carbon emissions, propeller-related injuries, damage to marine life, poor reliability and high maintenance costs. All of these are directly related to the single-speed propeller drive and to its exposure to the environment: it injures soft things and gets broken by hard ones.
So are boats the low-hanging fruit in the quest for greater sustainability, or what?!! Where else can you find a propulsion technology that's fundamentally unchanged in 150 years?
Imagine a recreational boat with a propeller drive. Keep the boat and the motor, but discard the propeller drive and replace it with a big, comfortable swim platform. The new IntelliJet drive is under the swim platform, out of sight and out of mind, like the motor under the hood of a car. It substantially reduces fuel consumption and carbon emissions, eliminates propeller-related injuries and damage to marine life, enhances reliability and reduces maintenance costs.
The technical details are more thoroughly discussed in "Feature 3: Waterjets: Utilising computational design for better efficiency" in the current issue of Ship and Boat International, a publication of the Royal Institution of Naval Architects in London, UK.
Engineers may also enjoy peer-reviewed papers and related presentations at American Society of Naval Engineers (ASNE) functions, including at the Advanced Naval Propulsion Symposium and at ASNE Day 2015 last March. We also have four issued U.S. patents and several international patents issued and pending.
Videos showing the prototypes in action and other info are available at www.power.iijet.com.