China has launched the first of several semi-submersible ships for commercial, not military uses. The new, 211 meter long 90,000 DWT (deadweight ton) ships are aimed at firms that build and maintain offshore oil facilities. But these semi-submersible ships are increasingly in demand for military use and the Chinese have made arrangements to draft such vessels into service if needed.
China already has smaller versions of these ships for military use. In 2014 satellite photos revealed that China had built a smaller version of new U.S. Navy T-MLP (Mobile Landing Platform) logistical support ships. The Chinese MLP was 25 percent shorter and over a third lighter that the very similar (in design and purpose) to the larger American version. It was only in early 2013 that the U.S. Navy received the first (USNS Montford Point) of three T-MLP ships. Montford Point successfully completed its sea trials and entered service in 2015 with the other two to follow 2018. The navy wants two more so they can use two of these five new ships to serve as floating bases to support commando type operations ashore.
The American MLPs are 75,300 DWT vessels that, in effect, serve as seagoing piers for situations where there is no friendly port handy. Each is 239 meters (785 feet) long and has up to 2,322 square meters (25,000 square feet) of space for storage of vehicles and aircraft. The second two MLPs will be the AFSB (Afloat Forward Staging Base) variant that has command and control equipment (electronics and communications gear) added as well as distinct flight deck area.
The MLP looks like a container ship with the main deck lowered to approximately the height of a dock. On the side of the MLP are mooring fenders (so cargo ships can, literally, tie up like at a dock). The MLP also has ramps for getting cargo from ships or a dock. Cargo would be transferred to landing craft or LCAC (air-cushion high speed landing craft which can carry 60 tons of cargo). The MLP can also partially submerge itself so that its deck is underwater. Landing craft can then move over the deck and the MLP can bring its deck back out of the water so the landing craft can be loaded. Currently MLPs are to each carry three LCACs. The AFSB variants can also carry helicopters and MV-22 tilt rotor aircraft. The navy plans to increase the fire resistance of part of the deck so that the AFSBs can also handle vertical takeoff version of the F-35.
Each American T-MLP costs $500 million and is built to commercial (not military) ship standards and uses a civilian crew (as is the case with all USNS ships). Each can carry over 1.5 million liters of fuel. The T-MLP is highly automated and only needs a crew of 34.
China has long studied American naval logistics, as the U.S. was a pioneer in this area. This has resulted in China copying the designs of American naval supply ships as well as the resupply techniques used by the U.S. Navy. China is one of the largest ship builders in the world and many of its own commercial ships belong to a naval reserve and regularly train with the navy.