The largest of the Navy's coastal patrol craft, the patrol gunboat was conceived in the early 1960's in response to the volatile Cuban Missile Crisis, intended primarily for coastal patrol and blockade operations as well providing task force protection against possible patrol boat missile threat. Because of their high speed and maneuverability, the gunboats were valuable in support of inshore raiding and reconnaissance operations. Their speed also enabled them to shadow enemy vessels for the purpose of collecting special intelligence.
The patrol gunboat could spend 2 weeks at sea, if necessary, without any replenishment. For the most part, at-sea time was limited to a few days between port calls. Food and fuel could be re-supplied by UNREP (underway replenishment) but a major limiting factor was in the quantity of freshwater that could be made from seawater. Even though the gunboat crew was small -- only 28 to 32 sailors -- the ship's evaporators wouldn't keep the crew adequately supplied. All seagoing vessels can experience water shortages, but this was a particularly troubling problem for the crews of these ships.
With only 10 feet from waterline to the tips of the propellers, these shallow draft vessels had excellent in-shore capability for they could maneuver into places that larger ships couldn't possibly travel. On the open seas, even in calm weather, this shallow navigational draft sometimes made the gunboat an uncomfortable ship to ride. Heavy seas would cause these boats to roll, pitch and yaw relentlessly. It was not unusual for a patrol gunboat to experience 45 to 55 degree rolls for days on end. In a harbor without a breakwater, rolls of 10 to 15 degrees was not uncommon. During one particular storm, the crew of one gunboat saw their ship heel over to the point that the inclinometer bubble reached 65 degrees. It was during this storm the ship lost one of the radio whip antennas, all the stanchions and lifelines on one side, and the ship's boat --all torn off by waves and heavy weather. If the constant side-to-side rolling wasn't bad enough, the pounding fore-to-aft motion of the ship's bow in up and down angles of 15 to 25 degrees, followed by the inevitable slam against the uncompressible ocean surface would seem to rattle the brains, bones and teeth of the gunboat sailors. Resting, sleeping and eating were all but impossible under these conditions, and fatigue overwhelmed even the most durable sailors. It was at times like this that the gunboat sailor understood why the first question asked of him upon his arrival onboard was "Ever been seasick?"!
Ounce-for-ounce, the PG was the most lethal weapons platform in the US Navy arsenal during their lifetime. Not to say that they could match the fire-power of the big boys for they couldn't, but, for the job the gunboat was designed to do, there was no ship that could out-gun them. The close-in fire-power of the PG was devastating to anything that these boats challenged. The weapons systems include a Mk 63 Gun Fire Control System that controlled a 40 millimeter gun mount aft and one 3"/50 caliber rapid fire gun mount forward. Additional armament consisted of two twin .50 caliber machine guns mounted port and starboard behind the pilot house and numerous M16's, M60 machine guns, and M79 grenade launchers. Over time, the US Navy perceived a need for a fast, missile-equipped ship. Consequently, some of the gunboats had the 40mm gun removed and replaced by 2 missile launchers. The missile system consisted of port and starboard launchers and magazines on the fantail with the capacity of four surface-to-surface missiles.
A unique feature of the patrol gunboat is the engineering plant, with a combination diesel and gas turbine (CODOG) propulsion system, twin Cummins / Caterpillar V-12 diesel engines for cruising and a General Electric LM-1500 marine gas turbine for high speed operations. The two diesels engines give the PG a cruising speed of 15 - 17 knots while the gas turbine (which is essentially the same as the J-79 aircraft engine used in the F-4 Phantom) propels the ship at speeds in excess of 35 knots. From a full stop a PG can attain a speed in excess of about 35 knots in less than one minute, and from maximum speed, can stop in less than the ships length. This high maneuverability is due to twin variable pitch propellers. Speed and pitch can be controlled from either the pilot house or from an enclosed operating station located in the engineering spaces. The PG has the ability to switch from diesel to gas turbine operations at short notice and without stopping.
The Asheville Class Patrol Gunboats remained in commission throughout the Viet Nam War, participating in numerous coastal and riverine operations. They were also utilized for Counter Drug Operations following the war. Construction of these ships took approximately 18 months from keel laying to completion at a cost of about $5 million. Thirteen of the ships still exist, some with other government agencies, some transferred to foreign navies. According to Mr. Ed McLean of the Environmental Protection Agency, READY, MARATHON, ASHVILLE and CROCKETT have been scrapped. The ships were 164.5 feet long, 23.8 feet wide with a draft of 9.5 feet, displacement was 226 tons, ships complement was 4 officers, 4 chiefs and 20 enlisted men.
Cut-away of a Patrol Gunboat
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Last updated on 24 July, 2006 by Terry W. McManuels[theboats/page_footer.htm]