Orders & Innovation Drive Propulsion Gear Manufacturers
Using recent orders—recieved and fulfilled—and technical innovation as a barometer, MR/EN has found that propulsion gear manufacturers, in general, have been busy in efforts to tweak product and service performance.
Drawing definitive conclusions or defining trends encompassing the broad universe of propulsion gear manufacturers would be presumptuous at best; inaccurate at worst. Instead, please read on to discover the moves manufacturers have made lately to optimize product performance.
For additional technical information on a particular manufacturer's product line, please circle the appropriate number on the Reader Service Card bound in this issue. For a complete listing of manufacturers and corresponding circle numbers, refer to the box on page 37.
Thrusters & Water Jets Lips Jets, 100 percent owned by Lips BV of The Netherlands, engineers, markets and produces high quality water jet systems. Lips Jets' range covers the complete market demand, with units designed and built to match a shipyard's or operator's specifications. This level of customization is possible, thanks to a few special features on the units, including the location in-board of the thrust bearings, the proven cavitation characteristics of the adopted pump and the reportedly easy-to-use control system.
Lips waterjets are fabricated by welding in AISI 316 L stainless steel plates, a process which allows a light and resistant construction. Lips Jets is focused on fast passenger and car ferries on the commercial side, as well as naval ships and the leisure market.
MJP Waterjets' J500S-DD double drive propulsion system was shown by the Swedish Coast Guard to power 10 new vessels, which are being built by Karlskronavarvet in Sweden. MJP has previous experience supplying waterjet propulsion systems to the British Navy, the U.S. Army and Danish Farvandsvaesendet. The units were reportedly chosen for their efficiency in both forward and reverse, and the unit's patented flexible shaft coupling, which allows the drive shaft to flex without disturbing the tip clearance of the impeller blades. This arrangement allows the drive shaft to be directly mounted to the engine-mounted gearbox without the need of cardan shafts or support bearings.
MJP will deliver 10 complete shipsets of J500S-DD jet propulsion systems, including intakes, hydraulics and remote control system RMC-DD. The order is reportedly the largest placed for jet propulsion systems from a Swedish yard during the decade, and the order includes an option for three more shipsets during 1996.
Hamilton water jets are available to match most gasoline, highspeed diesel and gas turbine engines up to 3,000 kW. The Hamilton Jet series of water jets is available in the HJ, HS and HM series models, for vessels of all different hull structures and sizes. The HJ series is a range of high efficiency, single-stage axial flow units.
Offering a large number of models and impeller rating combinations allows these jets to be directly driven by all common gasoline and marine diesel engines up to 1,200 kW in high speed craft, eliminating the need of a gearbox. The HS series is a range optimized specifically for very high speed craft operating in the 45- to 60-knot speed range. The series features a multi-stage axial flow pump design. The HM series is an extension to the HJ series, is suitable for power inputs up to 3,000- kW, and designed for the propulsion of fast ferries, workboats and patrol boats in the 66- to 164-foot range.
Norway's Brunvoll Thruster has delivered more than 2,500 thruster systems throughout the world since 1965. Brunvoll was the supplier for the Finnyards-built Icebreaker Fennica, a vessel honored as an Outstanding Oceangoing Vessel of 1993 by Maritime Reporter & Engineering News (December, 1993). The company focuses on controllable and fixed-pitch bow and stern thrusters, azimuthing thrusters, complete drive system packages (both diesel electric and hydraulic) and related control systems.
Also featured on the Fennica were Aquamaster-Rauma propulsion units. Known worldwide for its Z-drive and winch systems, Aquamaster-Rauma recently formed a new company on the Gulf Coast to exclusively handle the marketing and distribution of its Aquamaster propulsion and Rauma deck equip- ment in the U.S. Headquartered in Metairie, La., Aquamaster-Rauma will be responsible for the distribution of Z-drives, ice-strengthened Zdrives and contra-rotating propeller drives.
In addition, the Louisiana-based company will offer Aquamaster- Rauma's experience in vessel design concepts which optimize the propulsion system. Within the last year in the U.S., Aquamaster-Rauma has sold Z-drive systems for a multipurpose tug under construction at Nashville Bridge and the $60-million overnight passenger ship American Queen being built at McDermott Shipyard.
The Nashville Bridge project, the twin screw 6,000-hp tug Kinsman Hawk, will be the most powerful Aquamaster tug delivered to date. Shipwrights Inc. recently unveiled a new Twin Prop bow thruster, a system the manufacturer claims can exceed the effective use of 10-hp in an eight-inch tunnel, and in fact effectively use up to 50-hp in an eight-inch tunnel.
Shipwrights claims that since the system is only about one-fourth the size of that required by systems of comparable power, the openings can be located lower and further forward in most hulls, resulting in greater leverage, while maintaining hull integrity and hydrodynamic efficiency. The tunnels are constructed of GRP composite, aluminum or steel. A special Stator Screen is available with the eight-inch system to keep debris out of the tunnel. The thruster system, which feature twin NiBrAl propellers, is available in 25- to 50-hp models for boats in the 40- to 100-foot range, while boats in the 100- to 200-foot range can be accommodated using multiple tunnels, the manufacturer claims. For corrosion protection, each Twin Prop unit is constructed using 316 L stainless steel housings and propeller shafts.
SchottelPump-Jets and propulsion units have proven ideal for use in a variety of vessels. Recently, the Mare Azul of the Sines port authority in Portugal was equipped with two Schottel Pump-Jets, type SPJ22. One pump-jet was installed in the bow and one in the stern. The Schottel Pump-Jets reportedly give the Mare Azul exceptionally high maneuverability, while allowing the boat to operate in extremely shallow water. Schottel propulsion units have also proven effective for use in a minesweeper and a research vessel. The types of propulsion used in the vessels, SRP 300 E in the minesweeper and SRP 3030 LS in the research vessel, are new designs by Schottel.
Schottel designed the SRP 300 E with the goal of minimizing noise emission. The actual generation of sound is reportedly minimized by using hypoid gear trains in the underwater gearbox.
Development of the SRP 3030 LS was prompted by the demand for a rudder propeller rated at 3,000 kW and optimized from the point of view of sound emission.
The use of high-performance materials such as GRP and polyamide for the hydrodynamic optimization of the underwater part of the unit, and the tractor-type propeller, all play a major role in reducing flow-induced noise generation. KaMeWa offers an extensive product range, including thrusters, water jets (tunnel and rotatable) and controllable- and fixed-pitch propellers. The company designs and manufactures cp and fp propellers of all types from conventional propellers to highly-skewed propellers for low vibration/pressure pulse levels and quiet running. A technical leader in the water jet field, the company has supplied water jet units rated as high as 27,880-bhp, and by the end of 1993, the aggregated power of KaMeWa's water jets amounted to 1.4 million bhp. Thrustmaster of Texas, Inc.
has found a hot market in supplying Z-drives and tunnel thrusters to the casino boats currently being built in Louisiana. To date, ten 600- hp Z-drives (two per vessel) have been supplied, along with four 450- hp tunnel thrusters. Controls include full follow up controls for the Z-drives. The company is currently negotiating to supply thrusters for a second series of vessels, the specifi- (To the left): A technical diagram of the MJP Water Jet J500S.
cations of which call for 700-hp Zdrives with automatic hydraulic kick up of the outdrive leg.
Another company which supplies both thrusters and water jets is North American Marine Jet, Inc. The company builds two different types of marine jet propulsion systems. Nomera 12-14-20 units cover gasoline or diesel engines from 140- to 800-hp and are designed for ves- sels from 16- to 90-feet, attaining speeds of 20 to 50 knots.
The Traktor jet units from North American Marine Jet operate at 100- to 600-hp and are for vessels from 17- to 150-feet, attaining speeds from five to 20 knots.
Propellers Known worldwide for its propeller production, Bird-Johnson Co.
now offers water jets from 400 to 9,000 kW, built under license from MJP Marine Jet power.
The units reportedly offer high efficiency, low vibration and feature advanced reversing/steering & control systems.
Bird-Johnson also offers intermediate controllable pitch propeller systems from 500 to 5,000 hp, systems which were designed for affordability and ease of installation and servicing. On the inland front, Bird-Johnson offers the "New Generation" Workwheel Series, a five-blade propeller designed to optimize the performance of workboat wheels. The New Generation series—which incorporates technology routinely used in the design of large commercial and military propellers, the company announced—features: .60 blade area ratio, approximately; optimized variable pitch distribution; and nonlinear blade skew.
The bottom line benefits according to the manufacturer: a two to five percent increase in propeller efficiency; approximately 50 percent reduction in ship vibration levels due to propeller-induced unsteady hull pressure; and an approximately 50 percent reduction in ship vibration levels due to propeller-induced unsteady shaft forces.
Another propeller manufacturer with a well-established reputation is Rolla SP Propellers.
The company is presently involved in a number of fast propulsion and propeller system projects, custom designing and manufacturing surface piercing propellers for military projects such as: the Trinity Marine- built "XFPB" for the U.S. Navy and Mexico; Peterson Builders' "US Navy Mk V" Cougar Cat; McDonnell Douglas' "Magnum 40;" and Swede Ships' "Swedish Customs." Voith Schneider America, Inc. touts not only its vast array of products, but also its pre- and after-sales service.
The company offers engineering, production, R&D, testing, consulting, supervision, sales and after sales service of the Voith Schneider Cycloidal propulsion system.
Suitable for a wide range of vessels— oil skimming tugs, shuttle ferries and oceanographic vessels to name a few—the Voith Schneider cycloidal system is known for many positive traits.
Named manufacturer of the year in 1992 by Hatteras Yacht for its work on N/C machined propellers, Michigan Wheel utilizes fully-integrated CAD/CAM to all ISO propeller tolerances. Aside from its line of thrusters and propellers, Michigan Wheel also offers the Towmaster Rudder System and nozzles.
Sound Propeller features a product line complete with shafting, nozzles, bearings and shaft accessories. Sound Propeller also uses computer technology to analyze and design propellers for optimum efficiency. The company offers its own standard configurations, and can manufacture its own or supplied custom designs to meet the needs of a specific vessel.
The company also offers field repairs. Gears The Cincinnati Gear Company, well-known for its marine reduction gears for military and commercial applications, has drawn upon its extensive gas turbine experience to develop the "MA" series of gearboxes. These include a variety of parallel shaft and epicyclic gearbox designs for gas turbine applications of 1,000-hp and up. The gearboxes feature modular construction which permits them to be configured .in a variety of turbine- only or turbine diesel (CODOG and CODAG) arrangments.
Chosen for a 19,720-kW Ro/Ro ferry project were MAAG type MG- 150 W/P gearboxes. Two of the gearboxes transmit the total 20 MW power developed by the Wartsila Diesel engines to two variable pitch KaMeWa propellers, to give the 538- foot ship a speed of about 22 knots. Each main gear train consists of two pinions that engage with an eightfoot diameter bull gear. Each gearbox weighs 25 tons complete with lubrications system.
All rotating parts run in MAAG plain bearings. Additional PTO layshafts drive on-board generators with an output of 1.6 MW. Integral tilting pad thrust bearings with a thrust collar on each side of the bull gear take up the propeller thrust.
The axial thrust is therefore transmitted directly from shaft to casting, and hence to the foundations, resulting in a minimum of friction losses. MAAG gearboxes were chosen recently for another high-profile project, the building of the largest catamaran ferry ever for Stena.
For the project, MAAG will supply a split power PROPJET Gearbox System Type HPG-185/C system.