China unveiled new dragon-themed drillers that it hopes will build the world's 'longest undersea high-speed railway tunnel'

• China just showed off its second dragon-themed tunneller, which it said will drill an undersea railway.
• It's touted by China as the world's longest undersea high-speed railway tunnel.
• But that's likely a matter for debate. A high-speed tunnel in Japan has a longer underwater section.

China's state-run railway giant on Monday revealed the second of its dragon-themed tunnel-boring machines for what it says is the longest undersea rail channel in the world.

The Yongzhou machine, unveiled at China Railway Construction's Changsha facility, was given a "Dragon of Fortune" paint coat to commemorate the Year of the Dragon, per state media The People's Daily.

Another grand tunneling machine, the Dinghai, was also painted to resemble a dragon and was unveiled at the same facility in January.

State media said both machines would be used to drill the Jintang undersea tunnel, a railway channel about 10 miles long that runs as deep as 255 feet below the seabed.

The Jintang undersea tunnel has been lauded by Chinese media as "the world's longest undersea high-speed railway tunnel," but that title might be up for debate.

Japan's Seikan high-speed railway tunnel includes a longer underwater stretch, which is 14.5 miles and passes under the Tsugaru Strait. It is limited to speeds of 100 miles per hour.

The Channel Tunnel, which connects England and France, boasts an even longer underwater section of about 23.5 miles, and its railway operates at a maximum speed of around 100 miles per hour.

But the Jintang tunnel is part of the larger Ningbo-Zhou railway, which is 47 miles long in total and designed for speeds of up to 155 miles per hour. That would make the Ningbo-Zhou the world's longest high-speed railway tunnel with an underwater section.

It would enable rail travel between Zhoushan Island, China's third-largest island, and the country's east coast.