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NAVSEA Newswire - October 2009

OCT08-02: Navy Stern Flap Installations Project to Save Millions in Fuel Costs
By Naval Sea Systems Command Office of Corporate Communications

WASHINGTON - The U.S. Navy concluded installation of an energy-saving stern flap on USS Kearsarge (LHD 3) last month. 

This installation is the first on an amphibious assault ship, and is part of an overall effort to make naval ships more fuel efficient.

"A stern flap, located on the aft end of a ship, makes the ship more hydrodynamic, reducing drag and the energy required to propel them through the water," said Fleet Readiness Research and Development Program (FRR&DP) Program Manager Petter Kristiansen.  "Previous installations on other Navy ships generated annual fuel savings of $365,000 to $450,000 per ship." 

Installation of the new stern flap began earlier this summer during a major maintenance overhaul for the amphibious assault ship at Norfolk Naval Shipyard, and is expected to yield fuel savings of more than $540,000 (based on $100 per barrel oil cost) annually.  Kearsarge is scheduled to get underway in November to begin evaluation of the installation.  The dock landing ship USS Whidbey Island (LSD 41) is also expected to return to sea this year after its own stern flap installation.

The first stern flap installations on an LHD and LSD represent a major milestone for Naval Sea Systems Command (NAVSEA) FRR&DP.  Once installed fleet-wide on both LHDs and LSDs, the initiative is expected to yield an annual cost avoidance of approximately $6.3 million, based on fuel oil costing $100 per barrel.

"This is an excellent example of the Navy incorporating a proven fuel-saving technology into our ships," said Kristiansen.  "FRR&DP examines new technologies that offer reduced fuel consumption and significant return-on-investment, but must be tested and validated before fleet-wide implementation.  In these days of lean budgets and volatile fuel prices, we have to identify programs capable of delivering maximum return-on-investment.  Stern flaps deliver immediate and long-term fuel savings."

Stern flaps for LHDs, LSDs and other Navy ships were designed and model-tested by Naval Surface Warfare Center Carderock, a NAVSEA field activity.

Other energy-saving FRR&DP initiatives include underwater hull anti-fouling coatings, solid-state lighting, propeller coating work, steering/stability efforts, Ship Propulsion Condition Monitoring (SPCM), and online water wash for gas turbine ships, and replacing obsolete boiler control system components on LHDs and general-purpose assault ships with new components that allow automated adjustment of boiler inputs for maximum efficiency.

FRR&DP is one of five programs managed or administered by the NAVSEA Fleet Readiness Engineering Office, located at NAVSEA Headquarters, Washington Navy Yard.