Page 109: of Maritime Reporter Magazine (September 1993)

r modified propeller is at a disad- antage when required to absorb ery high powers. They are already 1 service handling engine and gas lrbine outputs, which would have een unthinkable a few years ago.

Many of the leading propeller lanufacturers are now active in this eld, KaMeWa and Riva-Lips hav- ig achieved significant references, litsubishi's foil-borne "Rainbow" as their own design of MWJ-5000A fater jets with an interesting de- ign of two-stage impeller. They are uilt at the company's Takasago urbo-machinery factory, where a ersion for 25,000 hp is being devel- ped.

Contra-Rotating Propellers

Several months' sea experience is low available from the 258,000-dwt anker Cosmo Delphinus, which has he first installation of high-pow- sred machinery driving contra-ro- ating propellers. A Mitsubishi rUEC75LSII engine with a maxi- num power of 20,600 kW (28,000 }hp) at 84 rpm drives a three-bladed 29-foot diameter after propeller di- rectly. The five-bladed 32.5-foot di- ameter forward propeller is driven at 50.4 rpm through a transmission consisting of a large-diameter hol- low Geislinger flexible coupling, a

Renk Tacke planetary gear having seven planet wheels and a concen- tric outer shaft. The otherwise lost wake energy from the forward pro- peller is recovered by the after one and converted to additional thrust.

The plant is mechanically-compli- cated, but the components ~ damper, gear, bearings and glands — have been rig-tested for long periods. Ex- tensive loaded trials and sea service have confirmed the anticipated 15 percent reduction in engine power needed to attain the same speed in a conventionally-powered sister ship.

This represents a substantial sav- ing in fuel cost to be set, over the life of the ship, against the increased capital expense. An economic fore- cast is awaited with interest.

Argentina Lures Owners

With Relaxed Crew,

Insurance, Tax Regulations

Argentina is encouraging ship- owners from around the world to register their ships under the Ar- gentine flag, and relaxing restric- tions on such things as crew levels, insurance, taxes, and paperwork.

Officials reportedly expect these measures to place Argentina on a level with Norway's registry laws, saying the new law resembles

Norway's international ship regis- ter by requiring shipowners to fol- low international staffing levels to ensure vessel security and safety.

Other staffing levels are left to the discretion of the shipowner, who may use crewmembers from any coun- try. Other provisions include the elimination of bureaucratic delays in the registration and deregis- tration process.

September, 1993

Local maritime sources report- edly said roughly 80% of Argentine vessels now operate under foreign flags to avoid high costs and bureau- cratic delays. It is hoped the new measures will immediately lure Ar- gentine shipowners and their South- ern Cone neighbors in Brazil and

Uruguay.

First Cyclone-Class Ship

Commissioned

The Cyclone, lead ship of the new

Cyclone class of ships, was commis- sioned in early August at the U.S.

Naval Academy. The new ship has a crew of four officers and 24 en- listed personnel. Its primary mis- sion, and that of the 12 Cyclone- class ships slated to follow, will be coastal patrol and surveillance.

With a top speed of 30 knots, it is armed with Stinger missiles, 40 mm grenade launchers, machine guns and chain guns. The Cyclone was the first ship ever to be commis- sioned at the U.S. Naval Academy.

Oil Pollution Declines As

Shipping Measures Take Effect

Oil pollution of the oceans as a result of human activity has de- creased in recent years, largely be- cause of the success of measures designed to prevent marine pollu- tion from ships, reports a new study from the Joint Group of Experts on the Scientific Aspects of Marine Pol- lution (GESAMP).

The study, "Impact of Oil and

Other Related Chemical Wastes on the Marine Environment," is the 50th to be produced by the group, which is made up of experts nomi- nated by eight United Nations bod- ies, including the International

Maritime Organization, the agency concerned with maritime safety and the prevention of pollution from ships. The report finds that oil pollution resulting from shipping operations has decreased during the past three decades. The entry into force in 1983 of the International

Convention for the Prevention of

Pollution from Ships, 1973, as modi- fied by the Protocol of 1978 relating thereto (MARPOL 73/78) had what the report calls "a substantial posi- tive impact." It is calculated that the input from shipping activities de- clined from 1.47 million tons in 1981 to 0.54 million tons in 1989.

Tanker accidents contribute about five percent of total oil input, based on the 1990 estimate, but the actual total can vary considerably from year to year. However, the reduced adhe- sion to surfaces and the reduced bio- logical impact in some situations, such as mangroves, make dispersed oil a generally less harmful pollut- ant than untreated oil. The most effective strategy for protecting sen- sitive coastlines is to disperse the oil offshore. The report concludes that if properly applied, dispersants can help remove oil from the water sur- face and dilute it to non-toxic con- centrations.

BRUNVOLL ARE PRODUCERS OF • Controllable and fixed pitch:

Bow and Stern Thrusters - Azimuthing (Rotatable) Thrusters for manoeuvering and main propulsion • Complete Drive System Packages, Diesel, Electric or Hydraulic • Thruster control systems for normal duty or to suit dynamic positioning systems of various manufacturers

BRUNVOLL

BRUNVOLL A.S. 6401 MOLDE NORWAY

TELEPHONE +47 72 51 966

FAX +47 72 53 424

TELEX 42572 BRUMO

Circle 189 on Reader Service Card 103

Circle 347 on Reader Service Card

Proven Performance » Reversing and Reduction m Power to 40,000 HP m Horizontal or Vertical Offset m Single or Multiple Prime Mover

Los Angeles, California Houston, Texas Somerville, New Jersey 2600 E. Imperial Highway 117 N. Palmer Street 20 West End Avenue

Lynwood, CA 90262 Houston, TX 77003 Somerville, NJ 08876

BEAR CORPORATION Tel: (310) 605-2600 Tel: (713) 224-8911 Tel: (908) 725-4200

Fax:(310)635-6080 Fax:(713)224-8584 Fax:(908)725-4955

PROVIDING ADVANCED MMARINE PROPULSION mUMrECHNOLOGY

Competitive Pricing

WesTech's Marine Propulsion Gears are known for efficiency, reliable performance, smooth operation, ease of maintenance and long service life. WesTech's Marine Gears are available in an extensive range of designs for both diesel and gas turbine power applications.

On-Time Delivery