Stern Flaps - A Chronicle of Success at Sea (1989-2002)

The U.S. Navy has been a leader in the application of stern flaps for performance improvement on large surface vessels. As of this writing, there are 53 ships with stern flaps active in the combined U.S. Navy and Coast Guard. Current commitments bring the total number of scheduled stern flap installations in the fleet to 175 units, with a potential fuel cost savings of $20 million/year. In 1989, the first at-sea prototype stern flap was retrofit to the frigate USS COPELAND (FFG 25), which at trials, exhibited a reduction in power throughout the speed range, resulting in substantial annual fuel savings, and increased top speed. Throughout the 1990s, full-scale stern flaps were retrofit on U.S. Navy patrol craft, destroyers, and cruisers, all of which have exhibited significant powering reductions, fuel savings, and top-end speed increases during at-sea trials. Ship trials on the destroyer USS OSCAR AUSTIN (DDG 79), the first ship of the new DDG 51 Flight IIA sub-class, built with a stern flap as a new construction item, showed improved performance over the parent hull. The first prototype integrated wedge-flap design was evaluated on the destroyer USS RAMAGE (DDG 61) in 2000. The retrofit stern flap portion reduced power in the range of 5 to 15%, increased top speed by nearly 1 knot, and produced annual fuel savings of $195,000. The RAMAGE stern flap installation was also the first performed using a cofferdam, on a waterborne ship, at pier-side. Sea trials have now been conducted on prototype stern flaps for U.S. Coast Guard vessels. Trials of limited scope were conducted on the ISLAND Class patrol boats, which represented not only the smallest craft to which this technology has been applied, but also the initial use of a greatly reduced span flap, and the initial design for a fully-planing craft. Trials were recently conducted on a HAMILTON Class high endurance cutter, which evaluated the first “contour” flap design.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/9780939773879
• Corporate Authors:

  Society of Naval Architects and Marine Engineers

  601 Pavonia Avenue
  Jersey City, NJ  United States  07306-2907
• Authors:
  • Cusanelli, Dominic S
• Publication Date: 2011

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 16p
• Monograph Title: Sustainabilty in the Maritime Industry: A collection of relevant papers

Subject/Index Terms

• TRT Terms: Design; Fuel consumption; Power; Propulsion; Ships; Speed
• Uncontrolled Terms: Stern flaps
• Subject Areas: Marine Transportation; Vehicles and Equipment; I91: Vehicle Design and Safety;

Filing Info

• Accession Number: 01372516
• Record Type: Publication
• ISBN: 9780939773879
• Files: TRIS
• Created Date: Jun 14 2012 10:55AM