Saturday, September 13, 2008

China's new Type 071 Landing Platform Docks (LPD)

Spotlight On PLA Navy's New LPD and LHD

By Prasun K. Sengupta

China's PLA Navy (PLAN) on July 6 commissioned its first of six Type 071 Landing Platform Docks (LPD) that will be used for both tri-services operational logistics as well as civilian disaster relief operations. The vessel, with pennant number 998, is now operational with the Navy's South Sea Fleet and has on board four Z-8K heavylift helicopters. The state-owned China State Shipbuilding & Trading Corp (CSTC), a subsidiary of the China State Shipbuilding Corp (CSSC), had on December 21, 2006 launched the first LPD at its Shanghai-based Hudong Zhonghua Shipbuilding facility and this vessel early last September began her sea trials. A modified variant of the Type 071 LPD is also being offered for export to Malaysia by CSTC, which is leading a formidable consortium of Chinese companies that will include China North Industries Corp (NORINCO), China Electronics Trading Corp International (CETC), and guided-missile manufacturer China National Precision Machinery Import-Export Corp (CPMIEC) in its bid to win the Malaysian contract. The Royal Malaysian Navy has projected a requirement for at least two such LPDs, which it calls the multi-role support ship (MRSS).

The Type 071 LPD has an overall length of 150 metres, waterline length of 140 metres, moulded beamwidth of 30 metres, waterline breadth of 24.5 metres, moulded depth of 20 metres, draught of 5.9 metres, full displacement of 14,000 tonnes, cruising speeds of up to 20 Knots, range of 6,000nm at 18 Knots, endurance of 60 days, a crew complement comprising 30 officers and 145 other ranks, a stern-mounted helicopter deck housing four heavylift helicopters, a 4-metre wide 308-lane metre internal vehicle garage, a deck-mounted flight deck measuring 50 metres by 30 metres, 450 square-metre internal hospital deck, a twin-door cantilever hangar measuring 18.5 metres by 23 metres by 8 metres, and a dry dock measuring 40.4 metres by 15.4 metres by 8 metres. The LPD thus incorporates the features of a troop transport ship, amphibious assault support ship, logistics support ship for submarine escape-and-rescue operations, aviation support ship, field hospital ship (with a surgical unit operating for a minimum of 30 days), and a combined forces command-and-control vessel leading a power projection-oriented naval task force. The vessel is also capable of transporting 800 fully equipped troops along with related tracked/wheeled vehicles, six medium-lift assault hovercraft in times of conflict for a period of 14 days, and will also be able to replenish at sea. Alternatively, the vessel will be able to carry 400 troops, a 50-tonne main battle tank, one hovercraft, four LCMs, four LCVPs, and up to four heavylift helicopters. For export customers, CSTC plans to finish construction of the first Type 071 LPD within 45 months of contract signature. CSTC will take three months to complete initial design work, followed by six months of technical design activity, eight months for construction design, seven months for construction preparation, 12 months for hull construction and installation of machinery, a one-month period for launching the vessel, five months for vessel outfitting alongside in the shipyard, two months of harbour and sea trials, and less than a month for finalising the delivery process.

The Type 071 LPD's hull and superstructure are reformed--the hull has flaring sides, while the superstructure has a 10º inclination for the sidewalls and a 15º for the frontal and aft walls. To eliminate cavity reflection, large openings are avoided and the observation windows at the bridge and the aviation command-and-control centre use shielded glass. Helicopters from the cantilever hangars will be transferred into and out of the hangar via an integrated helicopter handling system, with the hangers being able to cater for at least 21 days of continuous helicopter operations. The vessel's maximum persistent pitch and roll are 5º and 15º, respectively. When running at 18 Knots cruising speed with a pair of anti-rolling fins in operation, the residual roll angle at 5-6 sea states will not exceed 4º. The on-board equipment is able to withstand the 45º rolling for 8~10-second periods and persistent ±15º list. The LPD's integrated CODAD propulsion, controlled by an automated propulsion control system, comprises four MTU 20V956TB92 diesel engines each rated at 8,840hp (6.5mW). The engines have single-step vibration isolators, while the generators have double-step vibration dampers. The twin reduction gearboxes with associate clutches and coupling are rigidly mounted and drive twin low-cavitation controllable pitch noise propellers. Twin thrusters are installed at the bow to satisfy the manoeuvrability requirements, while two streamlined and balance spade rudders are fitted to maintain a stable position with respect to 20 Knots wind speed and 3 Knots underwater current. The crew accommodation area is divided into five classes, i.e. Captain, executive officers, engineering officers, department officers, first sergeant and seamen.

Two separate air-conditioning systems independent of one another are installed, with one as a standby unit. Each such system is capable of completely cooling the vessel continuously between 18° and 23° Celsius and 55% relative humidity at maximum ship load (with all machinery and equipment running). The humidity and temperature of the specialised compartments are regulated independently. The vessel's twin fresh water generators are each capable of generating up to 50 tonnes of fresh water per day, with additional fresh water storage being provided for the at-sea replenishment of other ships at a rate of 100 tonnes a day. An integral pumping system comprises pumps at the bilge bay, plus others in the ballast tanks along with fire pumps, with cross-connection and isolation modes of operation being incorporated. For removing oily bilge water from machinery compartments, a bilge water de-oiler compatible with IMO regulations has been installed. The vessel has adopted a three-phase and three-line AC basic power supply system. The main power generating diesel engines are located in the engine and auxiliary propulsion rooms, which are in two separate compartments for damage control reason. All generators feed one switchboard of the dead-front type and are totally enclosed. An integrated switchboard to control all converted power supplies for communications and navigation equipment is fitted.

The on-board weapon systems suite includes four six-barrel 30mm CIWS (with a maximum rate of fire of 5,800 rounds/minute) aft of the funnels and above the helicopter deck facing portside and starboard, and one AK-176 main gun. The vessel's bridge is equipped with an integrated platform management system while the combat information centre (CIC), supplied by the state-owned China Electronics Trading Corp International (CETC), is located behind the bridge in a hardened citadel and is configured to also function as a joint operations command-and-control station, deck and aviation control centre, and a vehicles and troop movements control centre. The bridge also hosts consoles for a low probability of intercept (LPI) marine navigation radar with slave and master display modes, an ECDIS electronic chart display system conforming to IHO S57 standard and operating with CM93 electronic charts, a wind and speed direction instrument with digital display on the bridge, CIC and helicopter hangar. Two ring-laser gyrocompasses with transmission units give azimuth output to various navigational systems, including those for air operations. An electromagnetic log sensor fitted to the hull provides digital speed and distance readings for navigation. A log repeater is housed on the bridge, as is an echo sounder with metric scales with an external digital display, magnetic compass forward and aft of the steering position, an emergency conning station, a differential GPS with a printer, and a single switch to interrupt the supply of all non-essential external lighting in darkened ship's state. The LPD's integrated communications system-comprising HF/VHF/UHF transceivers and SATCOMS-provides for broadband, secure ship-shore, ship-to-ship, ship-to-air and ship-to-submarine communications via voice, image and data through internet, intranet and telephone networks where applicable. An underwater telephone (in accordance with STANAG 1074) has also been installed.

In late 2006, the PLAN's HQ finalised the indigenous design of the Type 081 LHD following conclusion of the third critical design review. Subsequently, the Dalian-based and Wuhan-based shipyards of the state-owned China Shipbuilding Industry Corp (CSIC) were awarded contracts to undertake detailed engineering drawings using TRIBON design software for various bulkheads and compartments of the LHD. Present plans call for Dalian Shipyard to build three LHDs and Wuhan Shipyard to build another three. Smaller work packages will be executed by the state-owned China State Shipbuilding Corp's (CSSC) Hudong-Zhonghua Shipbuilding Group Co Ltd and Jiangnan Shipyard, whose shipbuilding yards are located on both sides of the Huangpu River in Shanghai. On-board sensors and systems identical to those on board the Type 071 LPD will be installed on board the Type 081 LHD, with the principal differences being the top-deck superstructure that will house the island (incorporating the bridge and CIC) as well as a flat-top deck capable of housing eight heavylift helicopters, twin elevators, one Type 730 CIWS, and an internal hangar housing four additional helicopters, a maintenance bay and an armaments stowage area.

The PLAN's Shanghai Research Institute has been spearheading its plans for acquiring a fleet of 64,000-tonne aircraft carriers, LPDs, and helicopter landing decks (LHD) for the past 25 years. In the early 1980s, water-tunnel scale-models of such vessels were constructed and tested in the Institute's 600-metre (656-yard) pool and at Tai Lake in Jiangsu Province. In 1985 the PLAN began a training course for future aircraft carrier/LPD/LHD commanders at its Guangzhou Naval Academy. In January 1993, the PLAN decided to firm up plans for acquiring a 64,000-tonne displacement aircraft carrier under the 9935 Shipbuilding Programme. In parallel, work began on expanding and upgrading the PLAN's naval bases and harbours in Shanghai, Zhejiang, Yulin and Dalian. In 1995-1996 two European countries-France and Spain--approached China for industrial cooperation in LPD/LHD technologies. In February 1995 the Spanish shipbuilder Empresa Nacional Bazan (now Navantia) offered to build for the PLAN a low-cost, lightweight conventional-takeoff-and-landing (CTOL) aircraft carrier-cum-LHD. Navantia proposed two designs: the 23,000-tonne SAC-200 (overall length 728 feet, or 221.8 metres) LPD; and the 25,000-tonne SAC-220 (overall length 787 feet, or 240 metres) LHD. The cost of building either of the two vessels would be US$400 million. The SAC-220 could accommodate up to 21 CTOL combat aircraft or medium-lift helicopters. According to Navantia, the first carrier could be delivered within five years, with the second 42 months later. At the time, Navantia was constructing the 11,500-tonne aircraft carrier 'Chakri Naruebet' for the Royal Thai Navy and was eager to secure further orders in East Asia. China expressed an interest in the proposal, and initial talks between the COSTIND and Navantia were held in January 1996. However, according to Navantia officials, COSTIND officials seemed more interested in obtaining the blueprints of the aircraft carrier than in ordering the actual vessel off-the-shelf. In November 1997, however, Beijing had shelved plans to build fixed-wing aircraft carriers in favour of smaller LHDs and LPDs. In 1999 the Chinese Communist Party's Central Committee and the State Council had earmarked Yuan250 million for the design and construction of one LHD and one LPD.

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