Page 18: of Maritime Reporter Magazine (March 1973)

New Flat Tank System

For LNG Containment

Approved By Lloyd's

Lloyd's Register of Shipping has given approval to plans submitted by

Ishikawajima-Harima Heavy Indus- tries. Co., Ltd. of Japan for a pro- posed single - screw 125,000 - cubic - meter LNG ship embodying separate semimembrane IHI flat plate-type tanks.

The ship is of double-skin con- struction with machinery and accom- modation fitted aft, and with six car- go tanks. Dimensions are approxi- mately 892 feet length by 151 feet breadth by 97 feet depth, and the de- sign draft is about 39 feet.

The primary barrier of the IHI tank system employs aluminum alloy plates, 15-25 mm thick, which have sufficient tensile and fatigue strength and ductility at cryogenic tempera- tures down to minus 162° C. Thermal contraction and expansion, and de- flection due to liquid pressure, are catered for by the special sectional form of the curved edges and corners of the tank. The secondary barrier and insulation system consists of a 25 mm thick plywood barrier backed up by a framework of main and sub- joists. The spaces between the joists are filled with phenolic foam arid pol- yurethane foam insulation, and the main joists are connected to the inner hull. By this means, the static and dy- namic pressures on the tank are trans-

Bounce your underwater problems off one of our stainless steel props.

We make our stainless steel propellers to stay down there and take it. Go the long count between costly haulouts. (Often 3 or 4 times longer than ordinary props.)

What's our secret?

Well, there's stainless — and there's

Coolidge stainless.

We use all electric furnaces to get an alloy that's cleaner, stronger. A steel that can really take it under water. Plus a totally modern scientific manufacturing process that turns out the best stainless steel propellers in the business.

In sizes through 14-ft. diameter. And in 3-, 4- and 5-blade models. (Cast steel or bronze also available through 13-ft. diameter.)

If you're tired of prop trouble every time you turn around, get yourself a Coolidge stainless steel propeller.

And you've got yourself a real under- water champ.

Coolidge Propeller Company, 1608 Fair- view Avenue East, Seattle, Wash. 98102. . Telephone 206/325-5100.

Coolidge Propellers

TURNING POWER INTO PROGRESS AROUND THE WORLD mitted through the secondary barrier and insulation system to the main hull of the ship.

Means of heating are provided in the double-skin construction and in the transverse bulkhead cofferdam so that the temperature of the inner deck, sides, bottom and transverse bulkhead plating may be kept above 0° C.

This is the seventh LNG contain- ment system approved by Lloyd's

Register. The others are the Gaz

Transport, Technigaz and Conch

Ocean (membrane-integral types), the Conch (independent type), the

Bridgestone (semimembrane / semi- independent type), and the Moss Ro- senberg (spherical tanks supported on skirts [independent type]).

Lloyd's Register has also approved the Shell system of internal insula- tion developed for the carriage of

LPG, in which the cargo is contained remote from the hull by polyurethane which is sprayed directly onto the inner hull.

The Society is active in research matters affecting the carriage of LNG by sea, and has made considerable progress in the prediction of the forces involved in the movement of liquids in closed tanks—a factor of particular significance to those sys- tems which rely on the transmission of loads to the hull via load-bearing insulation.

On the international level, Lloyd's

Register is collaborating with IMCO on the production of a code of prac- tice for LNG ships, and is simultane- ously engaged in revising and up- dating its own Rules for Liquefied

Gas Ships.

USCG Gives Lockheed $54-Million Contract

For Second Icebreaker

A $54-million contract for the con- struction of a second Coast Guard icebreaker has been awarded Lock- heed Shipbuilding & Construction Co.,

Seattle, Wash. The keel of the new icebreaker, a sister to the Polar Star to be launched the middle of this year, will be laid next fall, with de- livery scheduled for early 1976. These ships, which will be the world's most powerful icebreakers, are powered by three gas turbines developing 60,000 hp and six diesels capable of produc- ing an additional 18,000 hp, and hav- ing a displacement of 11,000 tons.

New Bulk Carrier

Consortium Announced

The formation of a bulk carrier consortium, involving associates of

Rethymnis and Kulukundis, Ltd. of

London, and Star Shipping A-S of

Bergen, Norway, has been announced in New York by Star Shipping, Inc., general agents. Consisting of craned bulk carriers of about 26,000 dead- weight tons, the new consortium will be marketed under the Star name and managed by Star Shipping A-S of

Bergen. The announcement said that the company expects to have at least 14 vessels in operation by mid-1974, with trading principally between the

Pacific basin and the American and

European markets. 26 Maritime Reporter/Engineering News