Chakri Naruebet (OHPC)
The major addition to the Royal Thai Fleet was the vertical/short take off and landing (VSTOL) carrier Chakri Naruebet (which means "The Great of the Chakri Dynasty"), built by Bazan-Ferrol of Spain, and delivered to the RTN in 1997. Although acquisition of its full complement of VSTOL aircraft and helicopters was substantially slowed by the cutbacks imposed on defense purchases, it did come with seven AV-8S and two TAV-8S Matador (Harrier) STOL attack aircraft. Six new-build S-70B-7 Seahawk multi-mission helicopters are also on board.
Because of the ship's capabilities and size it the most auspicious ship of the Royal Thai Navy. But the lack of funding has restricted its operations and as a result, it was not deployed to support the UN mission in East Timor. This Offshore Patrol Helicopter Carrier (OHPC) intends to undertake a wide range of missions such as disaster relief, environment protection, amphibious operations, patrolling of territorial waters and control of local air space, Search And Rescue coordination and Exclusive Economic Zone surveillance. Secondary role is air support for all maritime operations. The 11,400-ton displacement ship was the first air-capable vessel to enter service in Southeast Asia. The RTN designation of offshore patrol helicopter carrier (OPHC) reflects the ship's chief peacetime roles of disaster relief, search and rescue, exclusion zone surveillance and environmental protection. However, the navy also acknowledges that the ship has potential as a regional sea control asset during times of crisis. Due to the costs of operational deployment the carrier is rarely at sea and its harrier jump-jets are almost all non-operational because of a shortage of spare parts (specifically engines). Rivalry between the Royal Thai Marine Corps and the new Air and Coastal Defense Command (ACDC) is of national concern.
HTMS Chakri Naruebet is of a similar design to that of the Spanish carrier Principe de Asturias, it is fitted with a 12 degree ski jump to enable the use of Harrier-style aircraft. The carrier has a full-load displacement of 11486 tons. Its overall length is 182.6m; flight-deck waterline beam 22.5m, and full-load draught 6.2m. U.S. Navy standards of subdivision were followed, with 13 watertight bulkheads and three independent fire zones. Twin rudders provide good maneuverability. The machinery is located in two compartments, and includes two GE LM-2500 gas turbines, two Bazan-MTU 16 1163 TAB83 diesel engines and two twin-reduction gearboxes. Variable-pitch propellers are fitted.
It can accommodate a crew complement of 600 (there are also apartments for the Thai royal family). The ship is equipped with six multi-mission Sikorsky S-70B Seahawk helicopters. These are supplemented with six ex-Spanish Matador AV-8S (Harrier) short take-off/vertical landing (STOVL) aircraft (currently out of service). The Chakri Naruebet's 174.6m x 27.5m flight deck, which terminates in a 12 degree ski-jump, can accommodate five simultaneous helicopter take-off/landings; the hangar provides space for ten medium helicopters or Harrier-sized aircraft. It is estimated that the carrier can carry a maximum of 18 helicopters and aircraft; and 100 tons of ammunition.
The carrier's maximum speed is 26 knots, with a cruise speed of 16 knots. Range is estimated to be 10000 nautical miles at 12 knots. Armament is planed to eventually consist of four Raytheon/General Dynamics Phalanx Close-In Weapon Systems and two 30mm naval guns. Phalanx is a 20mm/53-calibre six-barrel gun capable of firing 3,000 rounds/min to a target range of 1.5km. The ship will be fitted with one eight-cell Mk 41 vertical launch system (VLS) for the Sea Sparrow surface-to-air missile and three Matra BAe Dynamics Sadral six-cell launchers for the Mistral missile. The Sadral launcher is a stabilized turret containing six missiles and launch canisters. The turret is equipped with a television camera which can be fitted with an infra-red channel for target acquisition.
Under the contract signed in July 1992, the Chakrinaruebet is being constructed at Bazan's El Ferrol yard in Spain. The carrier will cost an estimated US$257 million, or US$365 million if fully equipped with combat systems and armament. With a design similar to that of the Spanish carrier Principe de Asturias, it is to be fitted with a 12 degree ski jump to enable the use of Harrier-style aircraft.
The Chakrinaruebet was launched on 20 February 1996. Sea trials are scheduled to commence in October/November 1996, and delivery to take place in March 1997. The carrier will be tasked with warfare/flagship command and control, air support for amphibious operations and the Thai surface fleet, EEZ surveillance and protection, search and rescue, and disaster relief. It will be based in the Gulf of Thailand. The RTN may later consider a second carrier to protect its maritime zones in the Andaman Sea.
The carrier has a full-load displacement of 11,485.5 tons. Its overall length is 182.6m; flight-deck waterline beam 22.5m, and full-load draught 6.12m. It can accommodate a crew complement of 600 (there will also be apartments for the Thai royal family). The structure has altered little from the original plans of 1992, although the sponsons have been changed slightly, the deckhouse for 2D radar has not been installed, and the main deck crane has been moved to the starboard of the forward lift.
The Royal Thai Navy ordered six multi-mission Sikorsky S-70B Seahawk helicopters to be deployed from the Chakrinaruebet in 1997. Costing US$138 million, these helicopters are designed for use in an anti-submarine role. The Thai government was expected to supplement this air group with up to ten short take-off/vertical landing (STOVL) aircraft. These will include nine ex-Spanish Matador AV-8Ss on order for US$90 million. The Chakrinaruebet's 174.6m x 27.5m flight deck, which terminates in a 12 degree ski-jump, can accommodate five simultaneous helicopter take-off/landings; the hanger provides space for ten more medium helicopters or Harrier-sized aircraft. It is estimated that the carrier could carry a maximum of 18 helicopters and aircraft; and 100 tons of ammunition.
The carrier's maximum speed is 26.2 knots, with a cruise speed of 17.2 knots. Range is estimated to be 10,000 nautical miles at 12 knots. Two spade rudders and four hull stabilisers have been fitted.
The twin shaft Combined Diesel or Gas Turbines (CODOG) each rated at 33,600 HP with a power turbine speed of 3,600 rpm are made up of two pairs of GE LM-2500 gas turbines and Bazan-MTU 16V1163 TB83 diesel engines each with an output power of 6437 HP at 1200 rpm which will drive two variable-pitch five-blade propellers. (Thailand's two Naresuan-class frigates, which are expected to escort the carrier, are also fitted with CODOG systems.)
The original plans proposed an electronics fit including 2-D long-range and 3-D medium-range air-surveillance radars, a ten-console command-and-control system, hull-mounted sonar; an electronic-warfare system incorporating electronic support measures, jammers and countermeasures launchers; and armaments including vertical missile launchers, four close-in weapon systems and a pair of 25/30mm cannon mounts. However, the aircraft platform due for delivery in 1997 will only be fitted with basic electronic systems, but not with defensive weaponry, electronic warfare systems, sensors or decoys.
The systems provided include a Hughes AN/SPS-52C 3-D medium range air search radar, a Kelvin Hughes navigation and helicopter control radar, a Kelvin Hughes I-band navigation radar, a MX 1105 Transit/GPS Omega satellite navigation system, as well as an unspecified Tacan system and a simple communications fit. The command and control system is made up of a combat information centre with seven Inisel consoles and an auxiliary console. The centre is based on the Tritan combat data system using Unisys UYK-3 and UYK-20 computers. If upgraded the C2 system will be served by 11 consoles.
Until the carrier is equipped with armor, sensor and combat systems, it will remain heavily dependent on escort vessels for defence. The Thai navy lacks submarines for escort duty (a US$800 million plan to buy three submarines was shelved in May 1995, probably for financial reasons). Consequently, the carrier will have to rely on surface escorts to defend it against surface and submarine attack, although the basic command system will enable it to orchestrate operations involving the air group.
While Bazan says that it does not know of plans to equip the carrier with combat systems and armaments, it is possible that the Thai government intends to install these after delivery. There has been speculation that the US may assist with equipment upgrades, possibly in collaboration with Bazan. Other factors suggest that plans have stalled because the funds are not available.
There is no doubt, however, that the Chakrinaruebet order is a naval procurement landmark that is likely to prompt future carrier owners such as China and Japan to consider their maritime options, and existing carrier-owners such as Brazil, Argentina and India to plan for replacements.
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