By Greg Torode

HONG KONG, (Reuters) – Military analysts believe that a ship spotted at a Chinese Shipyard in recent satellite images may be a newly developed or improved class of nuclear-powered attack submarine.

The submarine may be a new design, an upgrade to an existing vessel, or something else. Analysts and diplomats have closely been following the Pentagon’s November report that said China was planning to construct a submarine capable of carrying cruise missiles from vertical launch tubes.

Images taken by Reuters using private satellite imagery provider Planet Labs, and other images circulated on social media shows the submarine at a dry dock in Huludao Port of Liaoning.

GRAPHIC: Chinese attack submarine under satellite scrutiny – https://graphics.reuters.com/CHINA-MILITARY/SUBMARINE/myvmnylybpr/China-Submarine.jpg

Greenish hides areas beneath the superstructure and at its stern. Analysts believe these parts could be home to missile launch tubes or a quieter propulsion system. These clear views of submarines at dry dock are rare.

After the dry dock had been flooded, the submarine was seen partly submerged.

Collin Koh, a Singapore security expert said that there is a lot of interest in the possibility of a Type 093 Chinese “hunter-killer”, submarine equipped with vertical launch tubes to carry guided missiles. He said that satellite images have not been able to confirm the identity of the vessel.

Koh of S. Rajaratnam School of International Studies stated that the images were “very interesting, but it is still very difficult to know yet whether we’re looking at some type of refit for test or a whole different class of submarine.”

Koh stated that he was closely watching to determine if new Chinese submersibles will use quieter pumps-jets to propel their propulsion. It is impossible to see what type of propulsion this ship uses because the stern has been shrouded.

China’s sub-sea “hunter killers” would benefit from vertical launch tubes, which could allow them to be more flexible and equip the boats with guided missiles.

The Chinese Defence Ministry didn’t immediately reply to Reuters requests for comment.

China’s attack subs are being developed to address a wide range of possible demands. These include protecting the ballistic missile submarines and tracking down enemy ships.

Jeffrey Lewis is a Professor in Arms Control at the Middlebury Institute of International Studies, Monterey. He said that the new images raise more questions than answers about whether or not they reveal a new type of vessel.

It’s possible, but I have questions. He said that the submarine wasn’t kept in dry dock for very long, and it was not clear how reconfigured they might have done so. According to the Pentagon report there’s a lot of interest.