The Island-class patrol boat is a class of cutters of the United States Coast Guard. Forty-nine of these boats were launched between 1985 and 1992, and while all have been retired from American service, several continue to serve in a number of foreign coast guards and navies.
The Island class was initiated during the Reagan administration, which regarded it as an important tool in the war on drugs. The early ships in the class were deployed to Florida, Puerto Rico and other ports in the Southeast United States and were somewhat successful in drug interdiction efforts. As more ships were built, the class was deployed throughout the United States and replaced obsolete cutters. They undertook the full range of Coast Guard missions, including search and rescue, fisheries enforcement, migrant and drug interdiction, and military operations.
The ships were deployed around the world. In 2003, eight of the Island-class boats were transferred to the Mediterranean and Persian Gulf to assist the United States Navy's 5th and 6th Fleets in Operation Iraqi Freedom, and six were permanently assigned to Bahrain after the war.
The Island-class boats served well past their original 15-year design life and were replaced in the U.S. Coast Guard fleet by Sentinel-class cutters. Over a dozen decommissioned ships have been transferred to allied navies and coast guards and continue on active duty.
Origins and contracting The Coast Guard began a process to replace its aging Point-class and Cape-class cutters in late 1982. It determined that there was an urgent need for replacement ships in order to police drug smuggling and illegal immigration, particularly in the Caribbean and Southeastern United States. In order to speed procurement and lower risks and costs, the Coast Guard required bids for its new Island-class cutters to be based on existing patrol boats, rather than brand new designs.
In choosing a military patrol boat design for the class, the Coast Guard explicitly prioritized performance over longevity. The drug smugglers of the 1980s were using high-performance motorboats to speed past law-enforcement vessels meant to interdict them. The 30-knot performance of the Island class vessels was achieved by powering a light hull with large engines. The hull was made light, in part, by using relatively thin steel. This thinner steel had less reserve to accommodate the inevitable corrosion, and had consequences throughout the class's life. The Coast Guard expected the service life of these vessels to be 15 years.
On 11 May 1984 the Coast Guard awarded a $76 million contract to Marine Power Equipment Company of Seattle, Washington for the first 16 patrol boats. Its bid was based on an existing Korean patrol boat produced by the Dae Woo Shipbuilding. Bollinger Machine Shop and Shipyard, Inc. of Lockport, Louisiana, the losing bidder, sued in Federal court to have the award overturned. Bollinger argued that Marine Power had violated the contracting rules by substituting 12-cylinder engines for the 20-cylinder engines in the "Parent Craft" that it based its submission on. The court agreed, and set aside Marine Power's contract.
In August 1984 the Coast Guard awarded a $76.8 million contract to Bollinger for the first 16 cutters. These became the A-series ships. Bollinger's design was based on the Vosper Thornycroft Ltd. patrol boat. Farallon was the first of these vessels produced. Her keel was laid on 26 December 1984.
Bollinger owned the exclusive license to build the Vosper Thornycroft design, which precluded other American shipyards from bidding on subsequent contracts for Island-class ships. In order to allow for competition, the government purchased the license from Bollinger for $5.5 million and then solicited bids for an additional 16 ships with options for 17 more. Bollinger was awarded this second contract, which had a face value of $99.3 million for the 16 firm orders, in February 1987. Shortly thereafter, options on five additional boats were exercised with $31 million of funding provided by the Anti-Drug Abuse Act of 1986. The final twelve cutters were funded in the FY 1990 Department of Defense budget.
Construction and characteristics All of the ships in the Island class were built at Bollinger's Lockport, Louisiana shipyard. The hulls were built of welded steel plates, while the main deck and superstructure was built of aluminum to save weight. The hull form was a round-bottomed, semi-displacement design. The ships are long overall, with a beam of , and a full-load draft of . The full-load displacement of the A-series boats was 163 tons.
Propulsion is provided by two fixed-pitch, five-bladed propellers which are diameter. In the A and B-series boats, these were driven by two 16-cylinder Paxman Valenta 16-CM RP200M Diesel engines, each of which could generate 2,880 continuous horsepower. In the C-series boats, the main engines installed were Caterpillar 3516 Diesel engines rated at 2,730 horsepower. One of the challenges with the propulsion package on A and B-series boats was that their minimum speed was 9 knots, which was too fast to safely tow some small boats. The Caterpillar engines in the C-series boats lowered the minimum speed to 4 knots, solving this search and rescue limitation. All configurations had ZF gearboxes installed between the engines and the 4-inch diameter propeller shafts, and twin rudders were located aft of the twin propellers.
Electrical power aboard was produced by two Caterpillar 3304T Diesel generators, each capable of producing 99 Kw.
Total capacity of the ships' fuel tanks was which gave them an unrefeuled range of 1,882 miles running at 26 knots. The potable water tanks aboard held . Water makers were installed which could produce of potable water per day. There were also tanks for sewage, gray water, lubrication oil, dirty oil, and oily water.
All Island-class boats were equipped with an active fin stabilization system to reduce rolling while underway. Each of the two fins were tall and had of wetted surface.
The A and B-series were originally armed with a Mark 16 20mm cannon on the foredeck and two M60 machine guns. As originally designed, the cutters had 10 tons of weight reservations for additional weapons. Some of this was used when the Mk 38 25mm cannon was installed on the C-series boats instead of the 20mm weapon. The rest of the class was upgraded to the larger gun beginning in FY 1990. Similarly, the M60 machine guns were upgraded to M2 machine guns on all ships.
An Avon Searider boarding boat was stowed on a raised section above the engine room. In the late 1990's these were replaced by a cutter boat - medium built by Zodiac of North America. This boat was a rigid inflatable long with a beam of . It was propelled by a 90 horsepower Yamaha outboard engine and could achieve a maximum speed of 33 knots. The boats could be launched on either side of the ship using an Appleton Marine crane which had a working capacity of .
As originally built, the ships had accommodations for two officers, two petty officers, and twelve enlisted men, with two extra bunks for visitors. There was a galley and mess. The boats which served in Bahrain as part of Patrol Forces Southwest were equipped with additional berths to accommodate the embarked law enforcement detachments which boarded suspect boats.
Variants and modifications A-series (WPB 13011316) Coast Guard requirements resulted in a larger bow fuel tank than in the original Thorneycraft design. Bollinger moved a bulkhead aft by two feet to accommodate the larger tank. When the tank was full and a ship was running at higher speeds into a head sea, A-series cutters experienced cracking in their steel bow plating. The affected steel was specified at 4 pounds per square foot, which meant that it was less than thick. This issue was resolved by reinforcing the original bow plating and by avoiding the operating conditions that produced the cracking. Nationally-syndicated columnist Jack Anderson criticized this problem and other aspects of Island-class procurement.
B-series (WPB 13171337) B-series cutters were built with heavier bow plating to avoid the hull cracking experienced in the A-series.
C-series (WPB 13381349) Bollinger submitted a Value Engineering Change Proposal to the U.S. Navy, which administered the Island-class construction contract on behalf of the Coast Guard, to change the Paxman Valenta main engines for Caterpillar engines on the last twelve ships. The Navy accepted this proposal. The Caterpillar engines were cheaper to buy and maintain, were 3.3 tons lighter, and more fuel efficient. The greater fuel efficiency increased the range of the C-series vessels. An additional operational benefit was that the Caterpillar engines were equipped with a trolling clutch, reducing the minimum speed to 4 knots, allowing the C-series to safely tow small boats. The Caterpillar engines were also made in America, unlike the Paxman engines. +Comparison of Island-class patrol boat seriesA-seriesB-seriesC-seriesFull-load displacement163 tons157 tons153 tonsMain enginesPaxman Valenta 16-CM RP200MPaxman Valenta 16-CM RP200MCaterpillar 3516Maximum speed29.7 knots29.7 knots28 knotsUnrefueled range900 nm at 29.7 knots 2,700 nm at 12 knots900 nm at 29.7 knots 2,700 nm at 12 knots840 nm at 28 knots 2,400 nm at 12 knotsMain armament20-mm gun mk 67, converted to 25-mm Bushmaster cannon Mk 3820-mm mk 67 gun, converted to 25-mm Bushmaster cannon Mk 3825-mm Bushmaster cannon Mk 38
110/123 conversion program In the early 1990s, the Coast Guard faced the obsolescence of several ship and aircraft types which worked in offshore waters. Replacement of these assets would take decades and billions of dollars. It developed the Integrated Deepwater System Program to recapitalize its fleet over 25 years. The prime contract for the Deepwater program was awarded on 25 June 2002 to Integrated Coast Guard Systems, a joint venture of Northrup Grumman and Lockheed Martin.
The Deepwater program was constrained to a maximum expenditure of $500 million per year. Given the other priorities of the program, replacement of the Island-class patrol boats was not possible within the budgetary constraints of the early years. As an interim measure, Integrated Coast Guard Systems proposed to substantially modify Island-class cutters to upgrade their capabilities and extend their lives until the mid-2010s when fast response cutters were planned to replace them. The conversions were to be executed under subcontract by a joint venture between Bollinger and Halter Marine.
Major conversion work included replacing rusted hull plates, adding to the stern to make room for a high-speed stern launching ramp, replacing the superstructure to give the bridge better visibility and to accommodate mixed-gender crews, and updated electronics. The refit added about 15 tons to the vessel's displacement, and reduced its maximum speed by approximately one knot. The eight cutters modified were;
The specification for the converted patrol boats included unrestricted speed up through sea state 3, or seas averaging less than . In September 2004, Matagorda made a high-speed transit to avoid Hurricane Ivan, in seas which may have exceeded the design specification. Her hull buckled during the trip. After extensive study, the hulls of the converted patrol boats were reinforced. In 2006, Nunivak experienced hull deformation while underway aft of the area which had been reinforced. The reason for this failure could not be determined.