Marine Research Vessel Gets Structural Overhaul

Western Flyer (shown on cover) is nearing completion of a year-long structural aluminum reinforcement project at Bay Ship & Yacht Co., Alameda, Calif. The 117 x 53 ft. twin-hulled SWATH is undergoing a major overhaul to correct structural cracking that had been discovered and monitored prior to haulout in July, 1998. Built for the Monterey Bay Aquarium Research Institute (MBARI) by SWATH Ocean Systems, Western Flyer, displacing 419 long tons, is home-ported at Moss Landing, Calif., where its primary mission is as support ship and deployment platform for unmanned submarine Tiburon. The ROV is deployed through a "moon pool" opening in the center of the wet deck under the main cabin and has depth capability to more than 13,000 ft. The overhaul in process includes doubling the quantity of frames in the upper hulls, reconstruction of the attachment point between structs and upper hulls to redistribute high stress areas, and construction of new lower hull sections. The computer-modeled redesign was engineered by the naval architecture firm The Glosten Associates. Major internal reconstruction on multi-hulled vessels presents unique logistical problems, not the least of which is the necessity of removing almost all the heavy machinery in the upper hulls in order to have room to do the required structural work.