The short video is shot from a public beach in China’s Guangdong province, the unidentified filmer standing quietly by some fishing boats and a few tourists out for a walk.

Just to their right, a line of strange looking ships loom in the mist. The enormous ships are unmoving, raised above the waves by thick pylons. Drop-down bridges connect them to each other, the front one extending down to the sand.

The original video reportedly disappeared from WeChat shortly after it was uploaded, but copies circulated widely among watchers of China-Taiwan hostilities. The 19-second clip was their first clear look at what many believe are China’s newest tool for its Taiwan invasion plans.

The barge-like Shuqiao ships were first seen during the construction phase in January, and reported by Naval News. The Zhanjiang beach test showed how together they can create a loading dock from almost a kilometre out to sea – exactly what China needs to overcome one of the key challenges of any land invasion of Taiwan.

They also provide crucial insight into China’s advancing integration of its military, paramilitary and civilian operations.

Under the rule of Xi Jinping, China’s military is pursuing the capability to forcibly annex Taiwan if it fails to convince or coerce the island’s government to submit peacefully. Most annexation scenarios involve a full ground invasion of Taiwan’s main island, but there are fewer than 20 beaches on which an amphibious assault could land, and in wartime those can be defended, filled with anti-landing equipment.

Analysts say these barges can negate that key defence and, potentially, give the People’s Liberation Army (PLA) direct access to any road within about 150 clear metres of the shore. Taiwan has more than 1,500km (930 miles) of coastline which several major roads and highways closely skirt, including as close as 30km to central Taipei.

“These bridge-barges are purpose-built for a Taiwan invasion scenario,” said Andrew Erickson, a professor of strategy at the China Maritime Studies Institute. “They embody the seriousness with which China under Xi is pursuing absorption of Taiwan by any means possible.

“The Shuqiao barges are not a panacea that can overcome all difficult landing conditions, but they definitely provide PLA planners with more options along far greater stretches of Taiwan’s coastline.”

Many have noted the barges’ vulnerabilities. Yu Pei-chen, a former army major general turned city councillor, told local media that Taiwan’s military could use its newly acquired Himars rocket systems to quite easily take them out.

“China should build more barges of the same kind and send them to Taiwan. That would save the ammo for our armed forces,” Yu said.

But Lu Li-Shih, a retired navy major and now political commentator, urged careful evaluation, telling a political talkshow he expected the barges wouldn’t be deployed until Taiwan’s armed forces “lose their control of the air and sea”.

Jason Wang, chief executive of Ingenispace, a geospatial analysis company, said the ships were a clear sign of China’s “creativity”.

“They can produce the ships really fast – four to six months – and get them into theatre,” Wang said. ‘They can also iterate improvements faster than everybody else.”

Several analysts said it was highly unlikely the barges would be used in a first wave of attack. Instead they’d be part of a follow on landing, servings as a causeway to help deliver large numbers of troops, vehicles and artillery transferred from accompanying vessels. High-resolution satellite imagery seen by the Guardian shows the barges at Zhenjiang were also carrying amphibious vehicles on their decks.

The Zhanjiang beach where the vessels were filmed is near a PLA Navy facility, the headquarters for the PLA’s Southern Theatre Command, which runs operations targeting Taiwan.

US intelligence has said Xi has ordered the PLA to be capable of invasion by 2027, although military experts have noted that a number of variables – including ongoing corruption issues in the PLA and the unpredictability of US support for Taiwan under Trump – could push that in either direction.

Regardless, the PLA is now undergoing one of the biggest military buildups since the second world war. Xi has overhauled the command structure, boosted missile and nuclear stocks, and strengthened paramilitary arms including the coastguard and the paramilitary fleet of fishing boats known as the maritime militia. The different groups are cooperating more than ever on joint operations.

Satellite images show the barges were escorted by at least two civilian ships from a nearby civilian dock, and that several other boats – including some marked as fishing vessels on their tracking ID – were sailing laps behind them, appearing to practise running interference.

At least three more barges are under construction or in early testing. The barge design suggests they have been built to work with the roll-on, roll-off ferries that China has been repurposing or building to bring tanks and another heavy armoured vehicles across the Taiwan Strait.

Shipbuilding is a key part of the expansion of the PLA, which has the world’s largest navy. In a recent report on China’s growing “dual use” shipbuilding industry, the Centre For Strategic and International Studies said China’s largest single state-owned shipbuilder had built “more commercial vessels by tonnage in 2024 than the entire US shipbuilding industry has built since the end of world war two”.

Additional research by Jason Tzu Kuan Lu