Operating efficiently while battling through 50-foot waves is but one challenge for commercial fishing boats that ply the frigid Bering Sea. The Gen-Tech system, a workboat power generation improvement, meets that challenge, saving significant amounts of energy and fuel.
The Gen-Tech system eliminates the need to run the auxiliary engine for generator operation when the main engine is in travel mode. When equipped with an Overhung Load Adaptor (OHLA) from Zero-Max, the two hydraulic pumps connected to the primary engine provide generator power so the auxiliary engine can be left idle. A fuel cost savings of $2,300 or more in an eight-day fishing excursion is typical when using this system.
“The auxiliary engine is not fuel-efficient when in the travel mode,” said Erling Skaar, president of Gen-Tech. “Our system maximizes the operating efficiency of the primary engine with the help of the Overhung Load Adaptor so running a secondary engine is unnecessary. The additional load on the main engine from operating the Gen-Tech system is negligible, and therefore highly efficient and fuel saving.”
The first application for the system was the North American, a 110-ft fishing vessel capable of carrying a full load of Alaskan King Crabs weighing 170,000 lb. The King Crab season is a high-risk business where crews and boats frequently face catastrophic storms, injury and death. The equipment needed to deal with these conditions requires the best and most robust technology.
Commercial fishing vessels like the North American (below) benefit with major energy savings from the Gen-Tech power generation system. It utilizes an overhung load adaptor (left) for increased motor durability and life.
The operators of the North American were intrigued by the system’s fuel saving and pollutant reduction features—that would make for a greener fishing operation, which has a positive global impact.
Gen-Tech’s secret is in the patented controller and software design. The controller learns the power requirement for the input to the hydraulic pumps from the ship’s main engine. Using that information, the controller then adjusts the displacement of the hydraulic pump to maintain stable frequency and voltage through the entire rpm range of the main engine.
The OHLA provides a rock-solid, permanent mounting surface. It transmits rotary motion from the main engine to the hydraulic pumps. Using the OHLA in the system eliminates the need for a secondary gearbox to operate the hydraulic pumps, which would be more costly. The OHLA also adds more stability in the drive train than a gearbox and enhances motor operation by eliminating premature motor or pump failure due to overhung loads (axial or radial) on the pump and motor shaft. In high seas, violent shifting motion multiplies power train stress, so the OHLA’s stability role is even more important than in calm operating conditions. It allows the Gen-Tech system to operate flawlessly in wildly fluctuating conditions.
The OHLA is belt-driven off the main engine via a 2.8 to 1 speed ratio, using a Gates polychain drive. With a SAE-D face mount, the OHLA has a 132 spline input, a 2.25 in. output shaft and a 7-in. pitch diameter on the OHLA’s pulley. For added durability, spherical bearings were selected. The OHLA housing, which weighs 15 lb, is made of 25,000 psi tensile cast iron with shafts of 130,000 psi stress-proof steel.
The overhung load adaptor is mounted between the main engine and the hydraulic pump in the Gen-Tech system. The OHLA eliminates the need for a transition gearbox while providing a rock-solid mounting base connected to the hydraulic pumps.
The OHLA operates at 1,540 idling rpm, 2,500 cruising rpm and 3,360 maximum rpm. It is connected to the two variable displacement hydraulic pumps mounted piggyback; the pumps produce 3000 psi pressure and deliver 120 gpm.
“With Gen-Tech, the North American cruises at 10 knots using only 21 gallons of fuel an hour,” said Skaar. “Without Gen-Tech, the North American cruises at 10 knots using 25 to 26 gallons of fuel an hour. While the dollar savings for an actual 8-day fishing excursion is huge at $2,300, also huge is the reduced carbon emissions and pollutants that help preserve our fishing environment.”
Filed Under: Fluid power, Hydraulic equipment + components, Motion control • motor controls, Pneumatic equipment + components, Pumps