Tampa Shipyards Delivers Fifth Products Tanker To Ocean Shipholdings
The 30,000-dwt motor vessel Lawrence H. Gianella, fifth of five sophisticated T-5 product carriers designed and constructed by Tampa Shipyards Inc. in Florida, was delivered recently to Ocean Shipholdings, Inc. of Houston. The new ship is now being operated by the owner's subsidiary, Ocean Product Tankers, Inc., under charter to the Navy's Military Sealift Command. The tanker has an overall length of 615 feet, beam of 90 feet, depth of 53 feet 8 inches, and design draft of 34 feet. She is powered by a lowspeed IHI/Sulzer 5RTA76 fuel-efficient diesel engine with a maximum continuous rating of 18,400 bhp at 98 rpm. The engine, derated to prolong its service life, drives a shaft generator through a speed-increasing gearbox to provide electrical power while at sea. The combination of these two characteristics provides the operator with excellent fuel economy.
The propulsion plant is designed for unmanned operation, and is classed + AMS ACCU by the American Bureau of Shipping. The engine is direct drive via a solid shaft to a fixed-blade, nickel-aluminumbronze propeller manufactured by Ferguson. Speed at 75 percent of mcr (15,300 bhp) is 16 knots.
The Gianella is designed to deliver 30,000 long tons of petroleum products worldwide, and is icestrengthened to ABS Ice Class 1C for Arctic and Antarctic operations. Cargo is carried in seven pairs of tanks, each pair being segregated from any other pair to allow seven different liquid cargoes to be carried. Each tank is fitted with a stainless steel, high-pressure hydraulic cargo pump supplied by Framo.
The pumps are sized to discharge the entire cargo within 16 hours, and in service have achieved this easily.
All cargo tanks are fully inerted by a Holec inert gas generating system designed to supply two pairs of tanks through dedicated systems to guard against cargo contamination; the remaining five pairs are served by a common system. Cargo piping and inert gas piping are constructed entirely of stainless steel. Facilities for underway replenishment at sea are provided from two stations; refueling at sea capability over the stern is also incorporated.
The unique construction of the cargo tanks developed by Tampa Shipyards has substantially reduced surface area compared with conventional construction. This results in significant cost reduction in epoxy coating maintenance inside the cargo tanks.
Water ballast is carried in double bottom and wing tanks, completely segregated from the cargo, and is arranged to qualify for "Protectively Located Segregated Ballast" under IMO regulations.
The entire hull, except foundations and superstructure, is constructed of AH36 high-strength steel, realizing a 15-percent saving in total steel weight over Grade A steel, and is designed for a scantling draft of 36 feet.
Extensive vibration analyses were confirmed by instrumenting the ship during sea trials and conducting a comprehensive vibration survey. Noise predictions were also made and confirmed to be acceptable by survey during sea trials.
This survey, combined with the favorable vibration characteristics, results in a comfortable living atmosphere for the crew.
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