Advanced Metalworking Solutions for
Naval Systems that Go in Harm's Way

Waterjet Inlet Tunnel Manufacturing Improvement

This project used advanced techniques to cast the Freedom-class LCS waterjet entry edge. The cast component will save significant labor hours, improving the shipyard’s ability to produce multiple ships.


This project developed an improved solution for waterjet inlet manufacturing and provided the necessary development, testing, and evaluation of several promising manufacturing / technology concepts.


The waterjet inlets on the Freedom Class Littoral Combat Ship (LCS) have very specific geometry and smoothness requirements. Legacy shipbuilding practices available to LCS shipyards are not well suited to producing the intake details to the level required. In addition, the intakes are costly to produce in terms of labor and schedule.

Technical Approach

A major focus of the production was the development of a near net-shape cast tunnel entry edge to reduce labor needed for fit-up, with improved accessibility for welding and inspection. The newly designed entry edge, which meets specified geometry and smoothness requirements, was also lighter than the legacy design.


This project developed manufacturing solutions that were approved by the American Bureau of Shipping and have reduced both the production cost and shipyard duration for construction of the Lockheed Martin LCS. (Exact values are proprietary to Lockheed Martin.) This project has provided several major improvements to the LCS Program. It removed 75 percent of the production hours from the legacy design through implementation of the cast entry edge solution. This project also eliminated 40 weld joints per hull. The cast entry edge solution eliminates more than 30% of the weight of the legacy entry edge.


Marinette Marine Corporation and Lockheed Martin have implemented the cast entry edge solution earlier than planned; shipyard implementation was completed in FY10 on LCS-3.




American Bureau of Shipping
Gibbs & Cox
Lockheed Martin Maritime Systems and Sensors