Exhaust Silencer Development


The Independence-class of US Navy Littoral Combat Ship (LCS) is a high speed, small crew vessel intended for operation in the littoral zone. The ship is a trimaran design with a wide beam above the waterline that supports a larger flight deck than those of the Navy’s much larger destroyers and cruisers, as well as a large hangar and a similarly large mission bay below. The ship propulsion system is powered by diesel and gas turbine engines. The Independence-class vessel is produced by Austal USA.


GLSV developed a new exhaust silencer to meet the acoustic, flow, and shock qualification requirements.

The new silencer was engineered to be a fully shock-hardened design, meeting Grade A shock in accordance with MIL-S-901D.

Problem / request

GLSV was awarded a contract to design, qualify, and manufacture diesel exhaust silencers on the Independence-class LCS ship. Although in the late stages of the LCS shipbuilding program, our customer sought alternate sources of supply, and GLSV was awarded this contract.


GLSV worked with Austal to develop a new exhaust silencer, taking it from initial concept to delivery of a fully-qualified silencer, executed under an aggressive schedule.

Technical Approach

GLSV executed this turnkey project utilizing our broad technical engineering and production manufacturing skills. Our engineering team designed and optimized the silencer to meet acoustic and flow requirements, while meeting the unique durability requirements imposed by MIL-S-901D, which is the military specification for high impact mechanical shock which applies to equipment mounted on Navy ships. The image below is from a GLSV simulation model of a shipboard exhaust silencer:

Our design met the requirements of Grade A shock, which applies to items which are essential to the safety and continued combat capability of the ship. The silencer was qualified through a heavyweight shock test.

GLSV manufactured the silencers with welding and fabrication processes in accordance with NAVSEA S9074-AR-GIB-010-278, and nondestructive testing in accordance with MIL-STD-271.