Page 10: of Marine News Magazine (October 2010)

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10 MN October 2010

Posted on MaritimeProfessional.com

By federal law, the Naval Militia consists of the

Naval Militia of the various states. Property of the Department of the Navy, including vessels and armament, may be issued to the various state Naval Militia if at least 95% of the members of the unit receiv- ing the property are members of the

U.S. Navy Reserve or the U.S. Marine

Corps Reserve and the organization, administration, and training of the Naval

Militia conform to U.S. Navy standards.

The Naval Militia traces its history back to the

Revolutionary War, when various colonies formed their own Navies. The Commonwealth of Massachusetts reacti- vated its Naval Militia during the War of 1812. When the

Spanish-American War started in 1898, fifteen States established Naval Militia. These were used to keep order on the waterfront and to defend coastal areas. In Cuban waters, the Naval Militia performed various scouting and blockading missions in support of the U.S. Navy. During

World War I, though, the U.S. Navy uti- lized the Naval Militia more as a source of trained manpower than as independent units to be mobilized. Naval Militia person- nel were disbursed throughout the Fleet, losing their unique identity. Currently, seven states have active Naval Militia: Alaska, New Jersey, New York, Ohio,

South Carolina, Texas, and Virginia. Five states have Naval

Militia that are inactive: California, Connecticut, Georgia,

Illinois, and Maryland. Personnel in the various Naval

Militia may be enlisted or commissioned into the U.S.

Navy, Marine Corps, or Coast Guard at the rate or rank for which they are qualified.

Posted on MaritimeProfessional.com by Dennis Bryant

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Naval Militia

Maritime Version of National Guard

New York Naval Militia member Bharath Bhola, an

Aviation Boatswain Mate, pilots Patrol Boat 230 during a joint operation with the New York

State Department of Environmental

Conservation in the Hudson River. (Photo by Master Sgt. Corine Lombardo)

Reducing Engine Noise

At this year's CIMAC conference Wärtsilä presented a paper on noise reduction of medium speed engines. Changes made to the crankcase covers and camshaft covers brought the emitted sound level down by approximately 6dB(A).

A multi-layer sandwich solution applied to the turbocharger casing and charge air cooler reduced noise levels 5dB(A).

Engine noise was reduced by placing an additional covering on top of the existing cylinder head valve covers. It is pro- posed that these optional parts will be available for current and future Wärtsilä medium speed engines providing a noise reduction of approximately 5dB(A). At this year's CIMAC conference Wärtsilä presented a paper following a five year research program on noise reduction of medium speed engines. The test engine used was a seven cylinder 32 series engine of 3.5MW at 750 rpm with 320 mm bore and stroke of 400 mm. Changes made to the crankcase cov- ers and camshaft covers included replacing the one piece cast aluminum covers by a two piece cast aluminum frame with bonded and bolted 2mm steel cover plate, giving greater rigidity and reducing noise radiation that brought the emitted sound level down by approximately 6dB(A). A multi-layer sandwich solution of fireproof fabric, mineral wool, aluminum plate and finally more fireproof fabric applied to the turbocharger casing and charge air cooler reduced emitted noise levels from these parts by 5dB(A). Tests showed that 27% of engine noise emanates from the top of the engine. Noise level from this area was reduced by placing an additional covering comprising a 2 mm vibro- acoustically treated steel plate with a 1mm corrugated micro-perforated plate on top of the existing cylinder head valve covers. Posted on MaritimeProfessional.com by Keith Henderson on 9/19/2010