The recent award from the Japanese Defense Agency for its two newest Coastal Mine Sweepers secures Omnithruster’s position as one of the leading designers and manufacturers of advanced, low noise, shock hardened thrusters.
The Omnithruster JT575AM, designed from the ground up for the Japanese Defense Agency, incorporates the patented Omniphaser noise masking system. This device uses some of the thruster’s own output to reintroduce a water/air mixture into the thruster inlet. The air bubbles compress and expand while traveling through the impeller absorbing
incipient cavitation energy that normally emanates a noise. This reduction in noise is dramatic; enough in fact, for the U.S. Navy to begin the retrofit of the system to the Omnithruster JT1700-1AM’s installed on the Mine Countermeasure Class (MCM) ships. The JT575AM is manufactured out of centrifugally cast Nickel-Aluminum Bronze and is completely non-magnetic. Custom hydraulic cylinders and stainless steel mechanical components are also utilized to minimize the magnetic content of the overall package, critical for use on a minesweeper.
The thruster design has been evaluated by DDAM (Dynamic Design Analysis Method) to insure that it meets the shock requirements of the U.S. Navy (NAVSEA 0908-LP-000-3010) and the Japanese Defense Agency. Figure 6-11 depicts the stress concentration of the steering valve and nozzles as the unit is subjected to a shock level specified in Design Data Sheet 072-01, “Shock Design Values” (U.S. Navy Confidential). The flanged connections are strengthened by using high strength fasteners. Metric fasteners were utilized throughout the design for ease of integration aboard the Japanese ship.
It is obvious that the JT575AM is a very specialized unit, but it goes to show just how adaptable the JT Series can be to a specific installation. Omnithruster’s ability to offer a customizable commercial product that has been fully tested in the military environment puts it in a unique position amongst its competitors. The JT Series, and its smaller sibling the HT Series, continue to “lead the way” in waterjet thruster technology.