US Navy divers recently completed a first-time full underwater waterjet seal on the Littoral Combat Ship (LCS) USS Fort Worth which enabled them to inspect and replace the cathodic protection system anodes mounted in the intakes. On this waterjet propelled ship it’s a job that needs to be done every four months, and so NAVSEA’s Supervisor of Salvage and Diving (SUPSALV) was tasked to develop a procedure that would enable the anodes to be replaced at sea in order to avoid dry-docking.
A3 Series Waterjet: Rendering courtesy of Rolls-RoyceIn early course Navy engineers developed a plate to seal the waterjet inlet, as well as external patches to isolate the waterjet, so as to create a dry working environment for the inspection (a fairly common procedure in smaller waterjet propelled vessels for this kind of inspection, but less so for a large warship of this type). Joe Theodorou, SUPSALV program manager pointed out: “Having this capability saves the Navy $100... [More]
A unique new propulsion system for boats was shown off for the first time at the recent Auckland On Water Boat Show. The Contrapel Hybrid Drive, the fruit of some eight years R&D, is claimed to be so advanced that it carries out all the functions of both propellors and water jets with none of the drawbacks of either. Notably it can continue operating in brown and black waters.Founder of the New Zealand company, Barry Davies, explains the technology succinctly: “ The Contrapel technology is a propeller system working above the waterline. Externally it resembles a traditional water-jet, however, internally the method for developing thrust has much more in common with conventional propeller systems.”
Contrapel Propulsion System Units: Photo credit Contrapel
Key to the system is a pair of contra-rotating, fully enclosed hybrid propellors (‘hybrid’ in the sense that they are composed of different things) that operate above the water line. Their purpose is... [More]
Abu Dhabi Ship Building (ADSB), UAE, recently launched their third Baynunah Class corvette, hull number four of a fleet of six. The Baynunah program is due for completion for the UAE Navy by 2014. The hull of LOA 234 ft (71.3 m) displaces 915 t and is constructed of steel with an aluminum superstructure. There is an unusual CODAD propulsion system comprising four diesel engines driving three waterjets The four engines are MTU 16V595 TE90 rated at 4.2 MW. Maximum speed with all four engines running is 32+ kn: at the cruising speed of 15 kn the range is 2,400 nm. The Baynunah class corvettes have a design endurance of 14 days. [More]
Tags: Abu Dhabi Ship Building (ADSB), UAE, Baynunah, corvette, CMN, BR70, MTU, 16V595 TE90, Kamewa, 112S11, 125B11, waterjet, Renk, AUSL, ASL 2 x 115, TISO
The goal of veteran adventurer Alan Priddy as he sets out in his 90 ft (27.4 m) wave-piercing powerboat Good Heart later this year is to try one more time to better the 61-day record for a world circumnavigation set almost a decade ago by the trimaran Earthrace. The record-breaking attempt, comprising five separate legs, will start and finish in Gibraltar, and in accordance with rules set by the Union Internationale Motonautique both the Suez and Panama canals are to be transited en route. How is the boat being constructed and with what propulsion for this epic 24,000 mile race against time?
Not a traditional boat builder, but metal-working fabricators, Micklewright Structures, situated at Dudley in the U.K. were chosen to build the uniquely designed powerboat and fashion the aluminium plates of its futuristically shaped hull on to steel structural members: "I particularly wanted their engineering skills and welding capability" explains Priddy.The ‘dread... [More]
Swedish corvette is engineered for stealth
By Edward Lundquist
The Swedish corvette Visby is stealthily to the core, right down to the all-composite shaft.
From the carbon fiber hull and radar absorbent coating to the enclosed gun mount, flush antennas and telescoping mast, this ship has extremely low signatures. The camouflaged appearance is hard to see, and the engine exhaust being ducted into the water jets reduces the infrared signature (the engine exhaust mixed with the water does create a visible vapor “exhaust”). The machinery sits on vibration isolation mounts, and non-magnetic materials are used throughout.
Despite this unique approach to warship design, Lt. Cmdr. Bjorn Spangberg of the Royal Swedish Navy’s Third Naval Warfare Flotilla doesn’t see a downside.
Spangberg is head of Trials Unit Visby technical division with the Third Naval Warfare Flotilla, and before that was aboard the Visby class as chief engineer.
HamiltonJet HT1000 waterjet [More]
Waterjet manufacturer HamiltonJet has had considerable commercial success with its new HT series since the first model was introduced less than two years ago with 60 units being sold to date. [More]