HJ403: Hamilton Unveils New Water jet
Hamilton Jet has released a new wateijet model, the 400 mm HJ403 - replacing the popular HJ391 model. According to the manufacturer, the new unit will offer many benefits over other propulsion systems for high speed work and patrol boats with power inputs up to 900 kW. As with all Hamilton wateijets, the HJ403 is designed to provide excellent high speed and cruising performance and superior cavitation resistance at low speeds and when under loaded conditions. The wide range of impeller options available ensure its compatibility with a variety of engine models, either direct driven or via a gearbox, and the flexibility of the jet unit makes it suitable for many different types of vessel in single or multiple installations.
While the basic specifications of the HJ403 are similar to its predecessor, the new model includes several new design features to improve the installation and operation of the jet. It is available in either zero or five degree shaft angle options to suit different engine alignments and vessel trim, and the jet features a more compact balanced reverse duct with the same superior zero-speed and reverse maneuvering performance and lower actuating loads. The latter allows the unit to utilize a single reverse cylinder with faster response times. The HJ403 is more compact than the previous model, with the intake block positioned further aft against the transom, reduced length between coupling flange and transom, and reduced height from base to fully raised reverse duct. This unit is also lighter than the HJ391. The jet incorporates Hamilton's JT steering system, which minimizes thrust loss when steering. The HJ403 is the first new model to feature stainless steel leading edge inserts in the stator to reduce wear when operated in abrasive conditions. The HJ403 may be configured for manual hydraulic or power assisted steering, while the standard reverse function uses Hamilton's new HFRC Reverse Control System. This servo hydraulic system "decouples" the reverse control levers from the reverse duct movement while providing full follow up control. It also allows quadruple jets to be controlled in pairs using only two reverse controllers.