INNOVATIVE CONVERSION
Though all other Great Ships mentioned in this edition are newly constructed, Captain H.A. Downing from Avondale deserves recognition as a unique project and accomplishment. The ship is the first of four AHL tankers being built as double-hulled ships with the addition of a new 510-ft. (155.4-m) long double-hulled forebody constructed by Avondale.
The new forebody is joined to the renovated and modified existing stern section, where the engines, crew quarters and bridge are located — to complete the conversion into a modern, environmentally sound, double-hulled product carrier, and the first commercial, self-propelled double-hulled tanker built in the U.S. to conform with OPA 90 and the Jones Act.
The ship uses a steam-powered central hydraulic system to drive deepwell cargo pumps and deck machinery. It features a new accommodations house and an onboard vapor recovery and inert gas system. Meeting USCG Type II requirements, the design, pumps and coatings systems are capable of transporting a wide range of products from Grade A petroleum to xylene. Overall the ship measures 207 x 27.4-m, with a design deadweight of 39,431 metric tons. A 13,600-hp cross compound steam turbine main engine drives the vessel to a service speed of 15.5 knots. The vessel is outfitted with an array of the latest equipment, which can be reviewed in detail on the accompanying Main Particulars list. One of the more unique aspects of this four-ship project is that it is being run through a yard which has relied completely on Navy business for many years. Subassemblies and modules for an LSD 52 and Fast Sealift Ship moved side-by-side with the 38,000-dwt AHL forebody through the covered factory, through the same blast and paint facility, and along the same path over the Mississippi River levee to their respective erection ways.
"To accomplish this, every department of our shipyard had to adapt to the accelerated schedule, reduced complexity, and highly streamlined requirements of the commercial job," said Ron McAlear, Avondale's vice president of Advanced Programs and Marketing. Avondale and AHL formed a Tiger Team with the U.S. Coast Guard to obtain early approval on a number of design documents that can typically delay a program. According to Mr. McAlear, the Navy understands that commercial programs offer innovation as well as a prudent revenue supplement for the U.S. shipbuilding base. Avondale's 36,074-cu.-m. covered factory for modular construction was designed with the synchronization challenges of Navy and commercial work in mind. Construction is now progressing on the remaining three ships in the AHL program.
The second double-hulled forebody was launched on September 25, and the new ship is to be christened Anasazi. The double-hulled forebody for the third ship, which will be named New River, is also presently under construction at Avondale. A keel laying ceremony was held on October 2, for the fourth ship, which will be named The Monseigneur. The doublehulled product carriers will transport refined products and chemicals.The largest double hull tanker in Germany was built and delivered by Lindenau GmbH in 1996. The 32,250-dwt Sea Devi/(newbuilding No. S 240) was ordered by Partenreederei c/o Carl Buttner, Bremen. The ship is an ecologically beneficial, innovative design from Lindenau, belonging to the shipbuilder's Tanker Class 2000 series.
The newbuilding is the largest ship ever designed and built by Lindenau, and the development, design and construction are touted as proud achievements for the medium-sized shipyard. The newbuilding is equipped with a double bottom with side hull for all cargo and all fuel tanks. The double hull is three times more resistant to collision than a single hull tanker, therefore the ship will receive the class notation COLL 3 for all cargo tanks. Subsequently, insurance companies have rewarded this with a reduction of premiums.
The shipbuilder installed volume bulkheads between each cargo tank. This allows fast unloading and faster washing of cargo tanks. It also provides a double separation of the cargo tanks. The 178.2-m long ship will also receive the Finnish/Swedish Ice Class IB.
Driven by a MAN 6L 58/64 main engine (developing 8,340 kW at 428 rpm) the ship is propelled by a variable pitch, NiAIBr four-blade propeller to 14.7 knots. The vessel also features three Yanmar auxiliary generator sets, one emergency diesel generator, one bowthruster, and one balanced, semi-spade rudder.
Designed for the transport of crude oil and oil products, the ship features seven cargo tanks and two slop tanks. All cargo tanks are coated with Camkote MX, and all cargo pipes, cargo pumps, fittings in the cargo tanks and cargo valves are made of stainless steel. The cargo system aboard Sea Devil is comprised of: seven heat exchangers for cargo heating (at about 900 kW each); two heaters for tank washing (at about 3,000 kW each); one screwpump for tank washing and COW (at about 188 cu. m./hr. 12 bar); seven fixed tank washing machines for cargo tanks (at about 47 cu. m./hr.); two fixed tank washing machines for slop tanks (at about 15 cu. m./hr).; and one oil-fired inert gas generator.
The cargo pump system is remotely controlled and comprised of: nine hydraulically driven deepwell pumps; one portable hydraulic driven deepwell pump; and five electrically driven hydraulic main powerpacks.
The maximum simultaneous discharge capacity is about 3,000-cu.-m./hr. with four cargo pumps running. There is one loading computer, online, connected to cargo tank radar with an overflow alarm system.
Special features aboard Sea Devil include: remote draft indication system with four measuring points; CO2 firefighting system for machinery and ballast pump room; and foam firefighting equipment on deck. Navigation systems are of the latest type and include Atlas ARPA S-band, Atlas ARPA X-band, Atlas DCS ECDIS and Atlas Trackpilot. The electronics package is complemented with a gyro compass and autopilot from Anschutz Standard and wireless equipment according to GMDSS A3 with Satcom C, Satcom B, echosounder, speedlog, weatherfax, DGPS, GPS, Navtex and VHF radio.
