PRODUCT SPOTLIGHT
WATERJETS
HamiltonJet Debuts its Largest Waterjet
HamiltonJet's newest and largest waterjet propulsion units have completed trials and entered service in a 55m Korean Coast Guard patrol vessel. The first pair of HT1000 waterjets, each with an impeller diameter of 1.2m, were delivered to Korea early in 2008, with the boat launched and sea trials conducted in November. Each of the Korean Coast Guard (KCG) 300-ton class vessels is fitted with a pair of fully controllable HT1000 waterjets, as well as a pair of slightly smaller HamiltonJet HM811 boost jets (no steering or reverse control). All four waterjets are driven by 3700hp MTU engines and provide a maximum boat speed of over 36 knots. At full speed each HT1000 waterjet pumps 11 cu. m. of water per second. "Currently the KCG have over 120 vessels fitted with HamiltonJet waterjet units," said Mike Shearer, Global Sales & Marketing Manager for HamiltonJet. "For this project a much larger waterjet than those in the existing product range was required to allow the vessel to patrol at over 20 knots on the outer jet units alone." The central boost jets are only used for high speed operations. The HT1000 was designed specifically for this, and is a
HamiltonJet Technical Manager Phil Rae discusses aspects of the HT1000 design with Technical Director Mike Hamilton.
HamiltonJet fitter Neil Harrison tightens the Astern Deflector bracket on the HT1000 waterjet.
different hydrodynamic design from HamiltonJet's other waterjet models. HamiltonJet Technical Manager Phil Rae said the pump design for the HT1000 was developed using HamiltonJet's in-house computational fluid dynamics (CFD) software, and a complete scaled prototype unit was tested in the company's high speed test boat
and hydrodynamic test facility. "For the full scale unit, the design, structural analysis, simulation and production tooling development was almost exclusively computer based," says Mr Rae. "This allowed for 'virtual' trial assem- Twin HamiltonJet HM811 boost waterbly and seamless manufacturing integra- jets are flanked by HT1000 waterjets on the transom of the KCG 300T vestion."
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W�rtsil� Waterjets for JHSV
Rolls-Royce Targets Navy with New Waterjet
Rolls-Royce launched a new waterjet for naval markets (although the company contends it will be suited too for commercial and offshore markets), the Kamewa FF67 aluminum waterjet, available from late 2009, will also be suitable for commercial marine and offshore markets. Rolls-Royce said the FF67, which will be the most powerful of the FF series, is an entirely new design incorporating built-in hydraulics for the first time. Rolls-Royce has provided Kamewa FF550 waterjets for 12 Fast Patrol Boats and four Fast Supply Vessels built by ADSB for the UAE Navy and UAE Coast Guard. Kamewa waterjets also help power the six 72m Baynunah Class corvettes that Abu Dhabi Ship Building (ADSB) is building for the UAE Navy. In addition, Kamewa FF375S waterjets also power the ADSB Sea Keeper high-speed landing craft. The FF67 will weigh approximately 1650kg, including the hydraulic valve block and the redesigned axial flow pump provides more thrust over the whole speed range, designed to offer higher bollard pull and improved acceleration. In addition, a completely new steering nozzle, developed from the Kamewa A3 series, allows turning at high speed. An improved reversing "bucket" system provides reversing efficiency of up to 65 percent of forward thrust.
The first 103-m JHSV will be equipped with four W�rtsil� WLD1400SR Axial waterjets, with options for nine additional shipsets expected to be exercised between 2009 and 2013. Prior to their selection by Austal, several W�rtsil� WLD-axial waterjet units underwent a number of sea trials and tests by the U.S. Navy. Standard development tests in a hydrodynamic research laboratory were made, and a design evaluation by the Navy in
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the 36-in. water tunnel at the Naval Surface Warfare Center in Carderock, Md., was also performed. All tests have confirmed the design parameters and the gains in cavitation margins with associated benefits, such as improvement of acceleration, and increase of the available thrust. Noise and vibration tests performed during sea trials by an independent test institute, confirmed the extremely low noise levels compared to ships equipped with a previous generation of
Maritime Reporter & Engineering News