Yards, Suppliers Bring High-Tech To The Table
A high-technology, multi-functional oceanology vessel requires state-of-the-art design and construction, as well as proven electronics and propulsion packages to successfully (and economically) complete its missions. The following is a look at some recent and ongoing projects.
Vessel: R/V Western Flyer Yard: SWATH Ocean Delivery: Summer 1995 The primary mission for the SWATH vessel R/V Western Flyer is to be employed as a stable platform in Monterey Bay and the immediate offshore waters in the prevailing conditions of wind and sea native to these areas for the purpose of deploying, operating and recovering a tethered remotely operated submersible vehicle (ROV), untethered vehicles and/or conducting hydrocasts (CTD) to a depth of 11,000 ft. (3,500 m).
To complete its missions for owner Monterey Bay Aquarium Research Institute, SWATH Ocean has incorporated the latest technology in design and outfitting.
The Western Flyer will be outfitted with a dynamic positioning and tracking system which will enable the vessel to maintain station within 150 ft. (46 m) or less in sea state 5, with a 25-knot wind and a two-knot current. This dual function will allow the vessel to follow a preset navigation track, as in transiting a grid, or to maintain position relative to the moving ROV within predetermined limits. This will be achieved by manual or automated control of the main propeller with individual rudder movement, bowthrusters, canards and stabilizers. As speed control in the zero- to three-knot range is critical to operation, stability is of the essence and the Western Flyer will reportedly perform quite well in rough waters. Vessel & Systems Design The Western Flyer's pontoons provide the major updrift for the vessel as well as provide space for the main engines, bowthrusters, canard and stabilizer equipment, fuel tanks and ballast tanks. The main propulsion consists oftwo Caterpillar3512,850- kW prime movers continuous duty generator sets driving two 1,250-hp main propulsion motors. The propulsion units were the determining factors in sizing the aft pontoons, and the pontoon shape selected allows for direct drive installation of the power train and for normal maintenance/repair access. The wetdeck's main function is to structurally connect the two hulls and provide support for main deck loads, while the main deck is dedicated to oceanographic activities. The cen- terpiece of the main deck is the moon pool area, which is recessed two ft. below the main deck.
Located starboard in the center area is a Hiab 290 crane opposite from the Tether Management System (TMS); located adjacent to the moon pool area are the ROV control room and the scientific labs. A Hiab 290 crane is also located on the port side to support scientific or shipboard activities.
Vessel: Zirfaea Yard: Bodewes Volharding Delivery: 1993 Designed and built for the Dutch Ministry of Transport, Public Works and Water Management, North Sea Directorate, by Bodewes Volharding of Groningen, The Netherlands, the Zirfaea's main task is as a hydrographic surveying and research vessel, working on the North Sea and the Dutch part of the Continental Shelf. Designed by Nevesbu of The Hague, the Zirfaea incorporates a wide range of the latest in hydrographic instrumentation.
Survey and research ships differ in design from other small vessels based on their tasks, layout and, in the Zirfaea's case, special requirements for working in areas like the North Sea. Specifically the vessel features: acoustic standards of high level in machinery, hull and working/ living areas; adequate room for expansion; low operating costs to allow future vessel replacement; a good stability range for all operations, including the handling of relatively heavy equipment over both sides; good course stability at very low speeds; good maneuverability; roll suppression; and large open deck space. The Zirfaea is fitted out with a three-tier superstructure consisting of a bridge deck, a state deck and a forecastle deck which runs continuously from the stem to the working deck amidships aft. The wheelhouse/ survey room on the bridge deck has a 360-degree view; the state deck below the bridge deck features a spacious director's room for meetings; the forecastle deck is used mainly as living quarters. A diesel-electric main propulsion plant — consisting of four generator sets, each of them comprising a Mitsubishi type S6RMPTA marine diesel engine coupled to an Indar generator—power iheZirfaea. Two Indar electromotors are coupled to two Lips steerable Azimuth thrusters (five-blade). A Valmet diesel, type 620D, 90 kW, 1,500 rpm driving an Indar generator, type LCB-250- M/4, serves as the emergency generator. The deck equipment gets its power from a central hydraulic powerpack system via a hydraulic power ring. The powerpack comprises a storage tank, two 22-kW feed pumps and two 160-kW main pump sets. The 220cc open systemtype pumps have a constant hydraulic pressure control system, designed so that one main pump set in conjunction with one feed pump delivers enough power for all normal working conditions.
In order to execute its diversity of operations, the vessel is equipped with a wide range of special instruments, systems and facilities, including: Simrad ADP-701 dynamic positioning system; a 12.5-ft. by 12.5- ft. (3.8-m by 3.8-m) moonpool; Eekels closed-circuit television; Theunissen open-loop intercom; and (two) Datawell Hippy-120C MK II heave compensators.
Vessel: USNS Sumner Yard: Halter Marine, Inc. (Trinity subsidiary) Delivery: May 1995 Trinity Marine Group subsidiary Halter Marine, Inc., located in Moss Point, Miss., recently launched TAGS 61, dubbed USNSSurrcrcer. The vessel is the second of three T-AGS 60 class multi-purpose oceanographic survey ships under construction at Halter Marine for the U.S. Navy.
Sumner was preceded by T-AGS 60, USNS Pathfinder, which will be delivered in October 1994, and will be followed by T-AGS 62, USNS Bowditch, which is scheduled for delivery in November 1995.
Sumner, which measures 329 ft. (100.3 m) long, with a 58-ft. (17.7-m) beam and a 19-ft. (5.8-m) draft at full load, is designed with a a common bus diesel electric propulsion system consisting of twin screw propeller drives through Z-drives. The Z-drives include gear reduction and 360-degree thrust direction control in a compact unit. Elimination of conventional reduction gears and long propeller shafts free space to be used for oceanographic purposes.
Sumner features complete thrust direction control, which provides excellent ship control and maneuverability, enabling precise position keeping and track following. A pair of 2,435-kW and a pair of 1,825-kW diesel generators are integrated to provide power to the propulsion system, ships service and laboratories through a power conditioner. Propulsion power is from two General Electric 4,000-hp DC motors, enabling the vessel to sustain a 16-knot speed.
Incorporating a full array of the latest electronics and oceanographic equipment, theSumner will be able to measure water depth over an area as great as 12 miles wide in the deep ocean; continuously determine its position to within 50 ft. (15.3 m), at any time in any weather condition; and measure oceanic acoustic qualities. A typical mission might include oceanographic sampling and data collection of surface, midwater and ocean floor areas; launch and recovery of scientific packages including ROVs; and shipboard oceanographic data processing and analysis. The Sumner will be operated for the Oceanographer of the Navy by the Military Sealift Com- - mand. Mission scientists and technicians will come from the Naval 3 Oceanographic Office in Bay St. Louis, Mo.
Trinity Marine Group posseses 3 vast experience in the building of oceanographic vessels, having built 3 T-AGOS 13 through 18 (oceanos graphic surveillance ships); T-AGS 1 51 and 52 (hydrographic survey 3 ships); and AGOR-23 and AGOR-24 r (both are oceanographic ships; AGOR-24 is now under construc- ;. tion at Halter Marine).
) The T-AGS 60 class of ships are t designed and built to provide multipurpose oceanographic capabilities i in coastal and deep ocean areas, and are U.S. Coast Guard-certified and e ABS-classed. The class boasts 3,500- i sq.-ft. of working deck, and is 1 equipped with three multi-purpose f cranes (Allied Marine telescoping i boom crane; Hiab foldable boom e crane; Appleton towing crane); one articulated davit, both side and stern t U-Frames (from Fritz Culver); and five winches (from Dynacon).
