T
he Freedom-variant Littoral Combat Ship (LCS) is designed to thwart and vanquish threats along the
coasts and shores of oceans and seas. Tese dangers can include pirates on small, speedy craft, submarine attacks and underwater mines planted to close shipping lanes or deny access to ports. Te first LCS, the USS Freedom (LCS-1), was commissioned in 2008. Te next Freedom-variant LCS, USS Fort Worth (LCS-3), was commis- sioned in 2012. Five more either have been launched or are in various stages of construction, and three more are planned for construction in the coming years. “Our industry team appreciates the
U.S. Navy’s confidence in the LCS program as we continue down the learning curve to make these ships more capable and more affordable,” said Joe North, vice president of Litto- ral Ship Systems at Lockheed Martin’s Mission Systems and Training busi- ness. “We’ll continue to build best-in- class, cost effective ships for the Navy, supporting its need to defeat littoral threats and provide maritime access in critical waterways.” According to Lockheed Martin, the shipbuilding team has incorporated best practices and lessons learned from USS Freedom and USS Fort Worth in as early as the second ship in the line, which is unprecedented in shipbuild- ing. Te Navy Metalworking Center has played its own role in achieving improvements through projects that have redesigned fabricated parts and assemblies into cast components that reduce weight and cost and improve speed and ease to manufacture. Te Navy Metalworking Center was established in 1988 as one of the Centers of Excellence of the Office of Naval Research’s Manufacturing Technology (ManTech) program. It supports the Navy’s need to reduce acquisition and total ownership costs by developing and transitioning innovative metalworking and manu- facturing solutions and is operated by Concurrent Technologies Corp., a nonprofit applied scientific R&D
professional services organization. Since the launch of the first LCS
in 2008, the ManTech program has invested millions of dollars in projects to improve the capability and cost effi- ciency of the ships. Following are three casting conversion examples that have saved considerable time and money in building the Navy vessels. “Candidate projects for ManTech funding are generally proposed by the shipyard, although they can be identi- fied by the Navy Program Offices and/or technical codes,” said Robert E. Akans, senior technical director, Navy Metalworking Center. “In the case of these three projects, the issues were brought forward by the shipyard (Marinette Marine Corp.) and the
ship design prime contractor (Lock- heed Martin).”
Waterjet Inlet Tunnel Entry Edge Littoral Combat Ships are driven
by waterjet systems instead of propel- lers for higher speed. According to the Naval Sea Systems Command, each waterjet draws seawater in through a duct, increases the water’s pressure and then ejects it, causing the ship to move. During production of the first
LCS, the waterjet inlet tunnel’s leading edge was made by welding 13 formed steel plates to the ship’s hull. Due to the production challenges of correctly positioning each plate while account- ing for welding distortion, installation
The cast waterjet inlet tunnel, shown here prior to the removal of gates and risers has saved many production labor hours since the second Freedom variant littoral combat ship was made.
August 2014 MODERN CASTING | 49
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