History

The Hamilton WHEC was constructed beginning in the 1960s, and they were intended to fulfill both Coast Guard peacetime and wartime requirements, and serve alongside the Navy. During the Vietnam War, several types of vessels supported the “Operation Market Time,” provided patrol duties, boarding and inspection of North Vietnamese vessels and boats, conducted naval gunfire support, missions, and medical assistance to Vietnamese civilians.

From the 1980s to 1992, the entire Hamilton class was modernized through the FRAM (Fleet Rehabilitation and Modernization). The program included weapons, sensors, addition of hangar, engine overhauls and improvement of habitability. Hamilton vessels participated in Military Operations, such as the Operations Urgent Fury, Operations Vigilant Sentinel, Operations Deny Flight, and Operations Iraqi Freedom.

Generations of Hamilton Class

Originally, the HAMILTON Class vessel was built by Avondale Shipyard in the United States from 1966 up to 1971 of which 12 units built for this class of vessel for the U.S. Coast Guard Homeland Security. The vessel designation was Weather High Endurance Cutter (WHEC).

The first three (3) generations of said type vessels were transferred to the Philippine Navy through Foreign Military Sales (FMS) as Excess Defense Articles (EDA) of the U.S., and these are listed in Table 1.

Table 1

Bow Number	Date Keel Laid	Present Designation /Assignment	Date Acquired by the Philippine Navy	Age of Vessel Upon Transferred to the Philippines
WHEC 715 Hamilton	Jan 1965	BRP Gregorio Del Pilar FF-15	13 May 2011	46 years old
WHEC 716 Dallas	Feb 1966	GRP Ramon Alcaraz FF-16	22 May 2012	46 years old
WHEC 719 Bout well	Dec 1966	BRP Andres Bonifacio FF-17	21 July 2016	50 years old

 Table 2

Original Combat Systems Suite Specification and Capabilities As A Naval Surface Combatant Ship

Particulars	Remarks
1. Displacement – 3,050 Tons	1. A displacement of typical destroyer
2. Dimension – 115.20m x 13.1m x 6.1	2. Length Between Perpendicular at the waterlines and wave length at sea state 6; 106 times to happen in the Philippine Seas, has a ratio of 2.12 which means the length of the ship is greater than wavelength of 54m.
3. Flight deck – for heavy type helicopter, 26.80m x 12.2m, for 2 Helos at the Hangar	3. One (1) helicopter can be on repair and maintenance of essential defects, the other one is operational ready for deployment.
4. Propulsion Plant – Combine Diesel and Diesel and Gas Turbine   a) 2x Pratt & Witney FT – 4AG gas turbine, 36,000 brake horsepower     b) 2x Fairbanks Morse 38TBD-1, 7000 Bhp sustained, 2 Shaft, controllable pitch propeller with retractable bow propulsor, 350 Hp	a)   Hot pursuit operation, 2 gas turbines/1 gas turbines operational at interception speed of 29 knots at 2400 nautical miles. b)   Cruising or patrol speed, two diesel engines operational while gas turbine on shut down status.  11 knots at 1400 nautical miles. c)   The Engine CODAG configuration weight of approximately 320-350 tons bottom weight provides greater stability to compensate the top mount weight of helicopter and superstructures with lower center of gravity.
5. Weapons systems
a.  Missiles – 8Mc Donnel Douglas Harpoon with active homing radar, anti-ship missile, sea skimming with range of 130km at the speed of Mach 0.90, 227 kgs warhead.	Sea Skimming anti-ship missile for defense against surface combatant vessels at the horizon during high intensity conflict
b.     Guns – 1xOTO Melara, 76mm, 86 rds per minute rate of fire, 16km range, anti-surface guns,	For surface engagement and provide naval gunfire support to marine landing operation, destruction surface and shore target
2x Aerospace 20mm MK 67, 800 rds per minute 1.5 km range, 1x GE	Protection against fast surface hostile gunboats attacking the ship
20mm Vulcan Phalanx, 6 barreled MK 15, 3000 rds per minute rate of fire and 4×12.7 mm Machine Guns.	Protection and neutralization of incoming missile and surface guns against high valued targets
c.     Torpedoes – 6x324mm MK 32, 2 triple tubes, Honeywell MK anti-submarine active/passive homing to 11km at 40 knots, warhead 45 kgs.	Protection and destruction of hostile submarine and surface ship
6. Countermeasures – Decoy, 2 Lorad Hycor SRBOC 6-barreled fixed MK 36, IR Flames and Chaff	Protection from underwater hostile target, distraction and confusion from incoming hostile anti-ship missiles
7. Electronic Surveillance Measure (ESM) WLR-IC, WLR-3 warning radar	Detect, track, monitor, provide early warning against incoming hostile threat
8. Fire Control – MK 93 MOD 1 GFCS, MK 309 ASW	For hostile submarine destruction
9. Radars – Air Search lockhead SPS 40B, D/E Band, Surface Search: Raytheon SPS 64 (V) 6, I-Band Fire Control: Sperry MK 92, I/J Band Tacan VRN 25	Detect air, surface and control employment of weapons system for precise target engagement with high degree of success
10. SONAR – EDO SQS 38, Hull Mounted active search and attack medium frequency	Hunt, detect, monitor, tract hostile submarine
11. Helicopter – 1HH – 65A or LAMPS-1	Hunt, defect, monitor, tract hostile submarine

 

Hull Structure

The hull structure and scantling are made of strong materials over and above the ship classification rules in accordance with USCG shipbuilding design. It is composed of 11 watertight compartments with two adjacent floodable compartments; the vessel intact stability can still be maintained.

The waterline length of 110.00 meters, and free board of 4 meters can endure the prevailing sea condition 6 with a wavelength of 58 meters, and a waterline length twice the wavelength.

The shape of the underwater hull is V shape which tends to cut through the waves, rather from pushing the waves.  The angle of water entrance at the bow is small and very sharp with less frictional resistance.

Seakeeping and Survivability

Seakeeping behavior of said vessel and survivability with higher degree of seaworthiness was already proven by the USCG in the Pacific, Atlantic and Gulf of Mexico.

Vessel Retrofit

Said class of vessels are mothballed by the USCG after serving more than 30 years. They were retrofitted from cold steel to hotsteel, dismantling all her weapons, sensors, etc., except the primary deck guns, and the OTO Melara Super Rapid Deck Guns. Sensors such as radar, generators, etc., were dismantled before transfer to the Philippine Navy.

Fleet Rehabilitation and Modernization (FRAM) for the Philippine Navy

If a Navy intends to conduct FRAM for said class of vessels for a second time to extend the serviceable life of the vessels in to protect itself in the arena of modern warfare at sea, the following key factors and the prime considerations in the upgrade is to consider the following attributes of a naval surface combatant.

The paramount consideration in the acquisition of warship is survivability – the ability of the warship to prevent or avoid being hit or in case of being hit, the aptitude of the structure to absorb multiple combat hits during engagement at sea, provide protection of the crew under extremely hazardous situation, and be capable of continuous fighting.

Some of the elements of survivability:

• Radar signatures – reduction of attraction of the ship outline profile above waterline that can attract anti-ship sea skimming missile with radar guided homing sensor that can lock-on to the ship.
• Infra-red signature – reduction of heat emission from the engine room that can attract anti-ship missile with heat seeking guidance system that can lock-on to the ship in the terminal homing approach to the target.
• Acoustic signature – reduction of ship hull vibration emanating from the engine machineries and hull resistance due to hull frictional resistance with seawater, reduction of cavitation of propeller, etc. protection from acoustic guidance torpedoes.
• Pressure signature – the pressure signature and the surrounding environment disturbed by the volume of displacement of the hull and that could trigger a bottom laid sea mine with a pressure arming device.
• Magnetic signature – the magnetic properties of the steel hull of the ship is great factor and source of the magnetic properties of the hull that could trigger a bottom or moored sea mine sensitive to the magnetism of an object.

Figure 1

Battle Sphere of Warship in Air, Surface and Sub-Surface

The threat in the Battle Sphere, in the air are the sea-skimming anti- ship missile, attack helicopter and supersonic fighter aircraft attacking in coordination against the warships while at the surface are the naval gunfire from the horizons, fast attack gunboat with short range missile system.  Sub-surface threat are the submarine with acoustic or wire-guided torpedoes, and mines that are either pressure or magnetic mines, etc.

The offensive and defensive capabilities must clearly and specifically identify with the effectiveness within the combat system envelope with high probability of success to defeat the threat.

The two (2) major consideration in the installation of Softkill and Hardkill countermeasures in defeating the threat:

Softkill Methods

• Selection of decoy such as flares intend to distract the homing sensors of attacking hostile anti-ship missiles monitoring with guidance system to deflect away from the real target. The decoy simulated false appearance must be greater than the signature of the real target.

Hardkill Methods

• A physical means to destroy and neutralize immediate and eminent threat in the air and surface by employment of the Closed-in-Weapons System (CIWS) in order to protect its own ship.

Recommendations

The selection of the countermeasures to protect the vessel must be dependent on the appraisal of ship signature threshold, in order to be effective in the employment of the countermeasures.

The hybrid design of Hamilton Class Weather High Endurance Cutter (WHEC) has been proven with long years of performing dual roles in the Coast Guard and the Navy.  Said design can be adopted by both PCG and PN because in time of war the PCG is mandated to join the PN in defense of our maritime territory.

About the Researcher/Editor:

CAPT TOMAS D BAINO PN (Ret) completed his post-graduate studies in Submarine Design at the Department of Naval Architecture, University College of London, United Kingdom of Great Britain under the sponsorship of educational grant of UK Ministry of Defense.  He attended the Ship System Survivability Orientation with Defense Evaluation Research Agency (DERA) of UK Ministry of Defense in London and MEKO Frigate design and construction in Hamburg, Germany.  Capt Baino is an associate editor of the Maritime Review providing series of articles in Naval Ship Design and served as Naval Architect Consultant with the Department of Transportation and Philippine Coast Guard Project Management Office in Ship Acquisition Program from 2017 to 2020

References:

1. Janes Fighting Ship Manual
2. Defense Evaluation Research Agency (DERA) of UK Ministry of Defense Lecture Notes on Ship Survivability.