One of the most-discussed missing pieces to the puzzle for planners in Beijing is amphibious lift capability — the ability to transport equipment and personnel across the Taiwan Strait and unload off of Taiwan’s rugged coast.

The April 23 commissioning of China’s first Yushen-class landing helicopter assault ship is a big step in that direction — the small-scale aircraft carrier can transport helicopters, hovercraft and armoured amphibious assault vehicles.

Another Yushen-class ship was launched in January and is currently undergoing sea trials, while new vessels are being constructed around the rate of one every six months. But the ongoing expansion of China’s amphibious lift capability is not limited solely to naval vessels.

Large ferries recruited from China’s civilian fleet were used in naval exercises held both last summer and in July, suggesting that Beijing could use non-military vessels to leapfrog its current amphibious transport bottleneck.

In a Jamestown Foundation report published last month, Conor Kennedy, an instructor at the China Maritime Studies Institute of the US Naval War College, used open-source research to highlight the movements last summer of a Chinese ferry, the Bang Chui Dao.

Kennedy’s research highlighted what may be the first attempt by China to convert a commercial ferry into an amphibious vessel for military purposes.

Ferries typically can only load and unload vehicles at ports, but the Bang Chui Dao had been retrofitted with a ramp that enables vehicles to roll on and off at sea — an ability that Chinese state television highlighted in multiple news reports on an amphibious exercise in southern China’s Guangdong province.

“A surge in PLA landing ship construction would be expected before serious preparations for a cross-Strait invasion,” Kennedy wrote, referring to China’s People’s Liberation Army.

“This would be exposed to ship spotters and overhead imagery over the course of many months and has not yet been observed. Nevertheless, the testing of new ramp systems as seen on the Bang Chui Dao could offer the PLA a potentially fast and cheap method of surging amphibious lift capabilities without raising concerns.”

The Allied invasion of Normandy in World War II was the biggest amphibious invasion ever, with more than 24,000 soldiers crossing the English Channel to France.

For China to overrun Taiwan’s military, which could potentially be aided by the US and Japan, and take control of the democracy of 24 million, even more troops would be needed.

Given that the Taiwan Strait is roughly five times wider than the English Channel, delivering as much equipment and personnel in the first wave would be crucial to Chinese success.

The Bang Chui Dao ferry collects an amphibious assault vessel in this screenshot from the Jamestown Foundation report, which was taken from CCTV’s military channel.

Just days after Kennedy’s report was published, Thomas Shugart, an adjunct senior fellow at the Centre for a New American Security, tweeted a thread using information from the website Marine Traffic showing two large Chinese ferries that normally operate in China’s north anchored off the same amphibious training site where the Bang Chui Dao had operated with PLA naval vessels the summer before.

One of the ferries, the Bo Hai Ma Zhu, is more than 2.5 times larger than the biggest civilian ferries used in the US — the Jumbo Mark II ferries used by the Washington State Ferries system.

The other ferry, the Huadong Pearl VIII, is even larger. Shugart estimates that China’s civilian vehicle carriers represent more than 1.1 million tonnes of potential vehicle and troop transport ships.

For perspective, Shugart notes that is more than three times the roughly 370,000 tonnes of China’s entire fleet of amphibious assault ships. Furthermore, Hong Kong has an additional 370,000 tonnes of civilian vehicle carriers, which could potentially be enlisted under the new National Security Law.

The same day, China’s nationalist English-language news outlet, Global Times, confirmed the PLA Navy had held “cross-sea exercises” aimed at Taiwan.

“Large groups of different types of amphibious armored vehicles and military trucks were loaded onto civilian ships as part of the transport mission,” it said, citing state broadcaster CCTV.

A brigade affiliated with the PLA 72nd Group Army had also “conducted an equipment loading and unloading exercise with civilian ships involving multiple types of military vehicles”, it reported.

“The revelation that China appears to be modifying at least some of its large ferries to be able to send amphibious assault forces directly onto the beach casts China’s large fleet of roll-on/roll-off ferries in a very different light,” Shugart told Nikkei Asia.

“What looked before like mostly civilian vessels that, at best, might be used to transport PLA forces to captured or temporary ports, now could have the ability to send first-echelon forces directly ashore in the first wave of an invasion.”

Using modified ramps on ferries to test the ability of civilian ships to deliver large numbers of amphibious tanks serves two purposes for Beijing, said Shen Ming-shih, a research fellow at the Institute for National Defense and Security Research (INDSR) in Taipei.

“This makes up for the shortcoming China has in large amphibious ships,” Shen said, “but it also sends a message that China is ready to attack now if Taiwan were to declare formal independence”.