Defence experts said the two digits put the LHD on a par with the country’s flagship aircraft carriers, signalling the important role the docks are expected to play in China’s blue-water navy ambitions.

They said the double-digit identifier indicated that the 40,000-tonne Type 075 LHD’s rank and role was more than important than that of other amphibious warships. That is despite not having ship-borne vertical take-off and landing (VTOL) fixed-wing aircraft similar to the Lockheed Martin F-35B Joint Strike Fighter and Bell Boeing MV-22 Osprey multi-role tilt-rotor warplanes on US warships.

The double-digit pennant number of the Hainan ship is consistent with China’s two aircraft carriers, the Liaoning and Shandong – numbered 16 and 17 respectively – according to former PLA instructor Song Zhongping.

“Double-digit hull numbers means they are giant ships on a par with aircraft carriers. That means the Type 075 will be operated like a small aircraft carrier because of their comparable combat abilities,” he said.

In the annual report to the US Congress last year, the Pentagon classified the Type 075 as Landing Helicopter Assault-Replacement (LHA-R) – the amphibious warfare ships that can be used as small aircraft carriers – saying China’s investment in the LHA signalled its intent to continue developing the navy’s expeditionary warfare capabilities.

With an uninterrupted flight deck containing seven deck points, the Type 075 is designed to carry military helicopters such as the Z-8, Z-9 and Z-20, as well as a helicopter drone, according to state media reports.

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But according to experts, all those helicopters are serving in the PLA Air Force and need to be modified into ship-borne aircraft, with some still under development.

A military source who requested anonymity because of the sensitive subject said: “China bought some ship-borne attack helicopters from Russia, including the Kamov-28 and Kamov-31, but they are too big for the navy’s hangars, while some designs and technologies are not as sophisticated as the home-made ones.

“China is developing ship-borne Z-8, Z-9 and Z-20 copters and they will gradually replace those Russian aircraft, which is part of the country’s efforts to have all domestic weapons.”

The Z-8 is a transport helicopter capable of lifting 13 tonnes of weapons, while the Z-9, a version of the French Dolphin SA-365N1, has been turned into ship-borne aircraft for patrol, reconnaissance, anti-submarine, anti-ship and other missions.

Latest pictures posted on the mainland’s military websites showed the naval variant of the Z-20 helicopters equipped with eight KD-10 air-to-ship missiles and anti-submarine warfare (ASW) similar to the US navy’s MH-60R Seahawk multi-mission copter.

China took three years to launch three Type 075 LHDs by 2020. In addition to the Hainan ship, two are undergoing intensive sea trials.

With a maximum speed of 23 knots, the Type 075 can carry about 30 attack aircraft, nearly 1,000 marines and landing craft.

“The Type 075’s lack of an organic fixed-wing aircraft capability would not be felt acutely during a Taiwan contingency given that it would be operating in China’s backyard. This means it could operate under the protective umbrella of aircraft from mainland China,” said Ben Ho, a military studies programme researcher at the S. Rajaratnam School of International Studies in Singapore.

“The PLA is likely to have established at least some form of air superiority in the area of operations before the Type 075 would be deployed. This abates further the platform’s shortfall in air power.”

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Andrei Chang, editor-in-chief of the Canada-based Kanwa Defence Review, said the size of the Type 075 made it too easily detectible and vulnerable to being sunk if sailing in the Taiwan Strait in a combat situation.

“The design of the Type 075 LHD is for sending large groups of troops and weapons, so it doesn’t have independent watertight compartments like other warships, but it’s hollow, making it more vulnerable and easily sunk once bombarded,” he said.

“The huge ship would only be deployed to the battlefield in the late stage of a war, for example, when the PLA believed it was going to win and need to send a large amount of troops and weapons to Taiwan for timely battlefield clear-up works.”

Zhou Chenming, a researcher with the Yuan Wang think tank in Beijing, agreed, saying the Type 075 would not play a key role in conflict.

“Unlike the aircraft carrier platforms that are used for launching fighter jets to achieve air superiority, the Type 075’s speciality is to rapidly send huge numbers of marines and weapons [to where they are needed],” he said.

Earlier reports said military leadership had decided to build a more powerful Type 076 amphibious assault ship with electromagnetic catapult systems to carry helicopters and drones.

An article by the Chinese military magazine Ordnance Industry Science Technology in July said Chengdu Engine Group and other subsidiaries of the state-owned Aviation Industry Corporation of China had started VTOL aircraft research and development for future Type 076 ships.