Often a story about marine equipment is as much about the people who create or produce the equipment, as it is about how elegant or effective the equipment is. For the last 15 years, Barbara and Ted Mark, at Next Wave Marine Systems, have been supplying vessel owners throughout North America with their patented SuredriveTM, a drive system coupler that reduces drive line vibration, while increasing the reliability of the driveline. Next Wave Marine has now developed a hydrostatic transmission that improves reliability and safety while reducing fuel consumption and pollution.
The SVS MT has demonstrated savings in fuel and energy efficiency, reduced pollution due to uncombusted fuels, improved maneuvering and handling, and increased reliability. Vessel operators have discovered that they may be able to install smaller main engines, they will consume 20 to 30% less fuel while operating the vessel at its design speed and load characteristics, and they will not see the oily residue in the exhaust water that results from uncombusted fuel. Additional benefits of the system include quieter operation without both the noise of gear clatter, and / or high speed engine generated noise and vibration. In some vessels, the engines can be relocated to the best position for weight and balance of the vessel.
What Ted has done is to literally cut out the inefficient components of the traditional fixed gear ratio transmission and solid drive shaft system. These have been replaced with a continuous variable transmission and the use of hydraulics to transfer the engine power to the propeller. This saves fuel and energy by operating the engine at its peak Torque RPM, or optimum RPM constantly. Power is transferred to the propeller(s) as required for the operation (the propeller can rotate anywhere between 0 and full RPMs as well as switch from forward to reverse with the simple shifting of one lever).
Dave Gerr in his Propeller Handbook notes C5The fixed ratio marine transmission is a LOCKED IN COMPROMISE5. the maximum torque of most engines occurs below maximum RPM. This presents 5(a) conflict for propeller selection. Although the propeller must be chosen so that the engine can approach very close to its top rated RPM, the RPM at maximum torque frequently is as low as 50 percent of top RPM. The only thing to do is compromise, and in so 5compromise5 fuel consumption and engine longevity 5. Specific fuel consumption is usually lowest at around 70 percent of top RPM, and torque at this RPM is at itBs maximum. For this reason, the most economical and efficient speed of operation of many engines is around 70 to 85 percent of the top rated RPM5..D The SVS-MT allows the engine to operate continuously at the RPM that provides the highest power and 70% fuel consumption.
Richard Schoel is a retired US Coast Guard Commander, now working as commercial fisherman in Alaska and owns an SVS-MT. His vessel has now completed four trouble free seasons using the SVS-MT. In his words C5The engine can be installed in a convenient location and is not hooked to the prop shaft. This gives quieter living spaces. There is no shaft vibration which greatly reduces noise 5 variable speed5 is fantastic for manoeuvring, docking, troll fishing, pot pulling, long lining or just cruising. There is no need to deploy stabilizers, buckets and drogues to slow the boat for fishing. Shaft RPM can be from zero to cruise speed by the touch of a lever. There is no more hesitation for a transmission to shift. Forward to reverse is instant and smooth5D
John Main, skipper of the Justin Time III, also using an SVS-MT commented that C The fuel savings alone totalled 1516 liters of fuel5 oil consumption was m compared to last year because with the new system, we were able to run one engine rather than two engines5.The boat packed our prawns and gear better because we were approx. 5000 lbs lighter5I had three times the room in the engine room, because the new engine was mounted sideways in the stern of the boat5 the transmission is about m as big as a twin disc and about l the weight5D
For more information contact Barbara and Ted at Next Wave Marine System.
