Saving thousands of gallons of fuel while battling through thunderous 50-ft waves are challenges for today's commercial fishing boats operating in the frigid Bearing Sea. Those challenges are met by the Gen-Tech system, a patented workboat power-generation improvement that is a major energy and fuel saver.
The Gen-Tech system eliminates running a separate auxiliary engine for generator operation when the main engine is in travel mode. When equipped with the overhung load adaptor (OHLA) from Zero-Max, the two hydraulic pumps connected to the primary engine work effortlessly providing generator power so auxiliary engine operation is unnecessary. A fuel cost savings of $2,300 or more in an eight-day fishing excursion is typical using this system, according to Gen-Tech.
"The auxiliary engine is not fuel efficient when in the travel mode," says 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. There is no added wear to the engine or connecting components. Thanks to the OHLA's rugged design, we're assured of smooth and reliable pump and generator operation. That's extremely important in the adverse and hostile environments that these fishing vessels are subjected to." Workboat of the future includes innovative power system
The first application for the Gen-Tech system was a state-of-the-art workboat called the North American, a 35-year-old 110-ft house-forward fishing vessel capable of carrying a full load of king crab weighing 170,000 lb. The North American is a crab boat that ventures forth for the Alaskan king crab fishing season. As movies and TV shows have accurately depicted, 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, exactly the way the North American was designed and outfitted. What makes the North American's power system so unique is the Gen-Tech system aboard. According to Skaar, that system is a product of over nine years of innovative research, rigorous testing, the development of new technology, and a dedicated mission statement.
"When the fishing vessel isn't risking it all for a quick fortune and the continuation of an epic lineage, it's being put to use as a working model for the environmentally conscious vessels of the future," says the North American's website (http://www.fvnorthamerican.com/)
. Its fuel-saving and pollutant-reduction features make for a greener fishing operation, which has a positive global impact. How the Gen-Tech system works
Gen-Tech's secret is in the patented controller and software design. The controller actually "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.
In the Gen-Tech system, the overhung load adaptor from Zero-Max 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 that can be more costly. Also, the OHLA adds much more stability in the drive train than a gearbox. Most importantly, the OHLA 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 (Model 1036S) is belt driven off the main engine (Caterpillar Model 399-1125 hp) via a 2.8 to 1 speed ratio using a Gates polychain drive. With a SAE-D face mount, the OHLA has a 13-tooth 8/16 spline input, a 2 1/4-in. output shaft, and a 7-in. pitch diameter on the OHLA's pulley. For added durability, spherical bearings were selected for this application. Extra rugged to meet all operating conditions, the OHLA housing is made of 25,000-psi tensile cast iron with shafts of 130,000-psi stress-proof steel. Weight is 195 lb.
The OHLA operates at 1,540 idling rpm, 2,500 cruising rpm, and 3,360 maximum rpm. Connected to the two variable displacement hydraulic pumps mounted "piggyback," the pumps produce 3,000 psi pressure and deliver 120 gal per min.
"With Gen-Tech, the North American cruises at 10 knots using only 21 gallons of fuel an hour," says 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 eight-day fishing excursion is huge at $2,300, also huge is the reduced carbon emissions and pollutants that help preserve our fishing environment. We're pleased to have discovered the Zero-Max OHLA and having it integrate so effectively in the Gen-Tech system."
Source: Zero-Max http://www.zero-max.com/overhung-loa...c-11-l-en.html http://www.designfax.net/enews/20110412/feature4.php